Empirical Literature on Asthma Care

Published Date: 13 Sep 2016 Last Modified: 15 Jan 2018

This brief critically considers the empirical literature on asthma care. Emphasis is on UK studies although research from the USA (and other countries) is also considered. It is argued that both environmental and genetic factors are implicated in asthma onset, based on epidemiological evidence. Deficits in care provision persist: these gaps in care may be attributable to a wide range of modifiable factors, including unsatisfactory health professional (GP, nurses) input, limited use of care plans, and patient unawareness. Overall, however, conclusive inferences about asthma care provision are hampered by:

1. A preponderance of retrospective/correlational studies, and a paucity of randomised control trials, which demonstrate causality;

2. A paucity of research on particular gaps in asthma care;

3. Failure to account for third-variable moderator effects.

The Office for National Statistics (2004) publishes comprehensive statistics on asthma-related mortality, morbidity, treatment, and care, collapsed by demographic categories. Data is collected from the General Practice Research Database (GPRD). Issues addressed include mortality, prevalence, time trends, patients consulting general practice, incidence of acute asthma, and hospital inpatient admissions.

Research suggests that health care providers often fail to agree on the precise criteria for diagnosing asthma, whether mild or severe (e.g. Buford, 2005). Severe asthma is often defined based on pulmonary function measurements, such as forced expiratory volume in 1 second, and hospitalisation. However, neither of these indicators reliably predicts asthma severity (Eisner et al, 2005).

Eisner et al (2005) evaluated the efficacy of a method for identifying a cohort of adults with severe asthma based on recent admissions to an intensive care unit (ICU) for asthma. Four hundred adults with severe asthma enrolled at seventeen Northern Carolina hospitals were surveyed. A control group of patients hospitalised without ICU unit admission was also recruited. The study examined whether admission to an ICU unit is in itself a reliable indicator of asthma severity.

Asthma patients with a recent ICU admission generated higher asthma scores (based on the frequency of current asthma symptoms, use of steroids and other medications, and history of hospitalisations/intubations), and poorer quality of life, were more likely to have been hospitalised, visited an asthma specialist in the previous twelve months, been in an asthma-related emergency department, and received inhaled corticosteroids in the past year. Data analysis controlled key background variables (e.g. demographic factors), increasing confidence in the reliability of the findings. However, this study was based on quasi-experimental design and hence may be confounded by sampling bias.

Trends in annual rates of primary care consultations, mortality, and hospital visits/admissions were monitored for children under 5 years and 5-14 year olds. For children aged <5, weekly general practice consultations rose during the early 1990s, peaked around 1993 (circa 150/100,000 children), then began to decline. This decrease persisted through the 1990s, falling to about 70/100,000 by 2000. Annual hospital admissions have also declined through the 1990s, falling from circa 100/10,000 in 1990 to approximately 50/10,000 by 2000. By contrast the number of patients treated for asthma has increased marginally albeit year-to-year change may be insignificant. Mortality rates decreased steadily, from around 10 million in the 1960s to approximately 2 million the year 2000.

For 5-14 year olds, weekly general practice visits rose in the early 1990s (circa 70/100,000 in 1990), showed a fluctuating pattern through the mid 1990s, but has declined steadily since 1997 (about 50/100,000 by 2000). The number of patients treated annually for asthma has risen slowly but steadily, although this increase seemed to level out by the mid/late1990s. Both mortality rates have dropped steadily since the early 1990s, from about 14 million in 1990 to circa 2 million by 2000. Annual hospital admissions has also fallen steadily, from just under 30/10,000 in 1990 to about 15/10,000 by 2000. These patterns suggest an increase in self-management (e.g. action plans) that obviates the need to visit a general practice, and that asthma care overall is having the desired effect on mortality.

The prevalence of wheezing and asthma in children has generally increased during the last 40 years. Although there is a paucity of reliable national statistics, data is available from specific parts of the UK, notably Leicester, Sheffield, and Aberdeen (see Figure 1).

 

The prevalence of wheezing increased from 12% (1990) to 26% (1998) in Leicester, and from 17% (1991) to 19% (1999) in Sheffield. The prevalence of asthma showed a similar pattern in both cities, rising from 11% (1990) to 18% (1998) in Leicester, and from 18% (1991) to 30% (1999) in Sheffield. Wheezing incidence rates for Aberdeen increased from 10% (1964), to 20% (1989), 25% (1994), and 28% (1991).

Data from national birth cohorts suggests a sharp increase in the average weekly GP consultations for hay fever/allergic rhinitis from 1991 to 1992. The rates rose from circa 13/100,000 (0-4 year olds) and 40/100,000 (5-14 years olds) in 1991 to about 25/100,000 (0-4 year olds) and 76/100,000 (5-14 year olds) as 1992 approached. Trends subsequently dropped off slightly but then started to show an increase again around 1998. By the year 2000 the figures were roughly 20/100,000 (0-4 year olds), and 56/100,000 (5-14 year olds).

Data from a nationally representative sample of schools across the country suggests that the prevalence of asthma was fairly even across different regions. However, Data for England suggests a higher prevalence outside big cities. The greatest proportions of wheezing was found in the South West, while the highest proportion of asthma cases was found in East Anglia and Oxford (see Figure 2).

 

In a recent Annual Report, Asthma UK (2003/2004) noted that one child in 10 has asthma and a child is admitted to hospital every 18 minutes due to an asthma attack. Over 600 copies of Asthma in the Under Fives are downloaded from the UK Asthma website monthly and on average every classroom in the UK has at least 3 children with asthma.

The impact of acute asthma can be debilitating. Around 5.2 million people in Britain are presently being treated for asthma, and asthma prevention/care costs the NHS on average almost £900 (i.e. £889) million per year. GPs across the country treat over 14,000 new episodes of asthma each week, and UK Asthma met almost 25,000 requests for health promotion documents and other materials.

About 40% of workers who have asthma find that working actually exacerbates their asthma, and 1 in 5 asthmatic people feel excluded from areas of the workplace in which people smoke. Over 12.7 million working days in the UK are lost as a result of asthma, and it is estimated that the annual cost of asthma to the economy is £2.3 billion.

Asthma UK also states that 82% of people who are asthmatic find that passive smoking triggers their asthma, and 19% of people with asthma indicate that their medical condition makes it difficult for them to play with children in their family. One in 3 children has had their routine daily activities disrupted due to asthma and 39% of asthmatic people are badly affected by traffic fumes (which stop them exercising). About 500,000 people have asthma that is very difficult to control.

In 2003/2004 over 90 researchers worked on Asthma UK-funded projects and, Asthma UK spent £2.5 million on asthma-related research. The group funded/is funding 63 research projects.

These statistics paint a rather bleak picture of asthma prevalence, incidence, and the effects on people’s lives.

Numerous epidemiological studies have been published that address the etiology of asthma in population groups (International Archives of Allergy & Immunology, 2000; Kitch et al, 2000; Schweigert et al, 2000; Tan, 2001; Court et al, 2002; Smyth, 2002; Weissman, 2002; Tan et al, 2003; Wenzel, 2003; Gibson & Powell, 2004; Barnes, 2005; Pinto & Almeida, 2005).

Barnes (2005) considered evidence on the role of genetic factors in resistance to atopic asthma, Studies which focus on the role of genetic factors in resistance to tropical/parasitic diseases (e.g. malaria) overlap with genetic associations found for asthma. It was concluded that genetic factors might be implicated in the development of allergic illnesses.

Pregnancy is thought to increase the probability of asthma attacks in about 4% of all pregnant women. Beckmann (2006) assessed eighteen pregnant women with asthma. The study was based on a longitudinal design. Participants were recruited from local prenatal clinics and private enterprises, and enrolled during the first trimester. Patients kept a daily log recording peak expiratory flow data until delivery. Three peak-flow assessments were recorded after which the best value was entered into the log. Asthma was diagnosed by a health professional. Participants were also required to record asthma symptoms, exacerbations, medications, and cigarette use. To increase participation, subjects were reminded by telephone to complete their log.

Data analysis showed that peak expiratory flow (PEF) was variable as a function of particular trimesters. Peak air flow was highest during the second trimester, with a statistically reliable difference between the second and third trimester. Unfortunately, the small sample size limits the generalisability of the findings. However, the study was based on a longitudinal design, allowing tentative causal inferences.

Schweigert et al (2000) reviewed the literature on the role of industrial enzymes in occupational asthma and allergy. Enzymes used by detergent manufacturing companies (e.g. amylases, cellulases) are toxicologically benign, with mild irritation effects on the body. However, these enzymes do affected asthma and allergy. Thus, the industry is required to adhere to exposure guidelines for these enzymes.

Kitch et al (2000) considered literature on the histopathology of late onset of asthma (i.e. onset in adulthood), and whether allergic exposure and sensitivity have the same impact on asthma development in adulthood as they do in children. Epidemiological studies suggest that the prevalence of asthma in older adults aged 65years or more is between 4% and 8%. The illness appears to be more common in women, especially those with a long history of smoking, and with respiratory symptoms (e.g. cough, wheeze, shortness of breath). Asthma in adulthood often developed before the age of 40, with maximum incidence occurring around early childhood.

Beyond the age of 20 years the incidence of asthma tends to remain stable through young, middle-aged, and older adulthood. Death rates in adults are generally lower than figures for children; “Mortality rates attributable to asthma among those aged between 55 and 59 years of age and 60 and 64 years of age were 2.8 and 4.2 respectively, per 100,000 people, the highest rates among all age groups” (p.387). However, as adults get older asthma is less and less likely to be identified as the main cause of death due to the increased incidence of other pathology.

Epidemiological research in Japan highlights a link with air pollution (International Archives of Allergy & Immunology, 2000). The prevalence of asthma among kindergarten and elementary school children has increased steadily since the early 1960s, rising from 0.5-1.2% between 1960 and 1969, to 1.2-4.5% (1970-1979), 1.7%-6.8% (1980-1989), and 3.9-8.2% (1990 onwards). By contrast, data indicates little or no change in asthma prevalence amongst adults. Figures range from 1.2% in 1950-1959 to 1.2-4.0% (1960-1969), 0.9-5.0% (1970-1979), 0.5-3.1% (1980-1989) the 1960s to 1.6-2.9% (1990 onwards) (see Figure 3).

Asthma in Japanese children is more common amongst boys than girls although this gender difference has diminished noticeably since the 1960s. Asthma usually appears in infancy or early in childhood but has been known to begin across all age groups. Inherited (genetic) dispositions to allergies have been implicated in the onset of asthma. There is normally a strong correlation between asthma onset and a family history of asthma.

Overall, asthma-related mortality in Japan has decreased since the mid 1990s. Delays in seeking treatment and rapid exacerbation of symptoms have been strongly implicated in asthma mortality. Unfortunately, this article offers little information about the designs of studies reviewed. Inferences regarding the possible causes of asthma morbidity and mortality may be inconclusive if much of the evidence is derived from cohort studies, rather than case control studies that more effectively eliminate alternative causes.

The premenstrual period in women has been implicated in asthma exacerbation. Tan (2001) reviews epidemiological literature suggesting that female sex-steroid hormones may be significant in understanding the premenstrual-asthma link, albeit the available evidence is tenuous. The luteal phase of the menstrual cycle is associated with airway inflammation and hyper-responsiveness, and hence may explain asthma exacerbation during the premenstrual phase. However, this increase in asthma severity can still be treated effectively using the normal drugs.

Studies suggest that premenstrual asthma affects the rate of hospital admissions – the majority of adults admitted are women, indicating that hormonal factors play an important role. Other evidence suggested that emergency presentations increased before ovulation. It is suggested that oral contraceptive pills or gonadotrophin releasing hormone analogues may be especially effective treatments. However, premenstrual asthma was rarely associated with serious mortality. Unfortunately, most of the studies reviewed were retrospective and questionnaire based, and hence subject to response bias. There was a paucity of randomised control trials, or pseudo experiments that may permit causal inferences.

Court et al (2002) considered the distinction between atopic (extrinsic) asthma, common in younger people, and non-atopic (intrinsic) asthma, found mostly in older groups. Additionally, they also considered whether identification of asthma cases in epidemiological research should be based on a doctor’s diagnosis or self-reported asthma symptoms. Nearly 25,000 people in England were surveyed. Data was collected regarding whether participants had experienced wheezing in the past 12 months and/or had been diagnosed as asthmatic by a doctor.

People with atopic asthma were more likely to have experienced wheeze and been diagnosed as asthmatic in the past, compared with the non-atopic group.

Logistic regression analysis showed that gender, social class, smoking status, living in an urban/rural area, and house dust mice (HDM), were all risk factors for the presence of wheeze both with (age not significant) and without (urban/rural area not significant) a diagnosis of asthma. Wheeze/asthma was more prevalent in women, younger people, lower social classes, previous/current smoking, living in an urban area, and greater HDM IgE levels. Smoking status, social class, and age were all risk factors for wheeze in both atopic and non-atopic cases. Gender was also a risk factor for atopic subjects, and urban living for non-atopics.

Other research has considered the epidemiology of severe or ‘refractory’ asthma, which is rather less well understood compared with milder forms of asthma. Wenzel (2003) reviews evidence indicating that severe asthma (defined as asthmatics requiring continuous high-dose inhaled corticosteroids or oral corticosteroids for over half of the preceding year) may account for circa ≤ 5% of asthma cases. Data from a large Australian-based study, which has followed a large cohort of asthmatics for over three decades, implicates childhood pulmonary problems with reduced lung function in adulthood.

Data suggests that over two-thirds of severe asthmatics were afflicted with asthma in childhood. Other risk factors implicated include genetic mutations (in the IL-4 gene and IL-4 receptor), and environmental factors (e.g. allergen, tobacco exposure, house dust mite, cockroach and alternaria exposures), respiratory infections (e.g. pathogens like chlamydia), obesity, gastroesophageal reflux disease, increased body mass index, lack of adherence to corticosteroid regimes, and poor physiological response to medication. Physiological factors are also implicated, notably structural changes in airway reactivity, inflammation of the peripheral regions of the lungs. Steroids are the main form of treatment.

Tan et al (2003) demonstrated the role of respiratory infection in patients with severe (i.e. near fatal) asthma, acute exacerbations, or chronic obstructive pulmonary illness (COPD). Participants had all been diagnosed as asthmatic by a physician and were undergoing treatment. All showed evidence of forced expiratory volume in 1 second (FEV₁) increase of 200mL. COPD patients were suffering from chronic cough and dyspnea, with a predicted FEV₁% 50%, with no β-agonist reversibility. Near fatal cases were patients undergoing ventilatory support in the intensive care unit of a hospital (National University Hospital and Alexandria Hospital, Singapore) as a result of a severe exacerbation.

Acute asthma subjects were characterised by non-improvement following administration of β-agonists, and/or severe exacerbation judging from clinical/blood data. Analysis showed that near-fatal cases were the least likely to have the influenza A + influenza B virus, but the most prone to have adenovirus and picornavirus, compared with the other two groups (see Figure 4). This suggests that viral infection may be a risk factor for severe asthma. However, due to sampling size/bias (n= 68), and failure to control for key background variables (e.g. asthma history, smoking history, prior medication use, and outpatient spirometry), the findings can be considered tentative.

Smyth (2002) reviewed epidemiological studies on asthma in the UK, and worldwide. The number of new asthma cases seen by GPs has increased noticeably since the mid 1970s. Nevertheless, asthma incidence has tended to decrease since the early 1990s, consistent with data from the Office for National Statistics (2004). By the year 2000 circa 60-70, 40-50, 20-25 new cases (per 100,000 of a given age group) were reported amongst, respectively, preschool children, 5-14 year olds, and people older than 15 years. Significant ethnic differences have been reported, with high asthma prevalence in Afro-Caribbean children. Since 1962, the number of preschool children hospitalised for asthma rose steadily, then peaked in the late 80s and early 90s, and has begun to decline since. The hospitalisation rates in 1989 were 90/10,000 (preschool children), 30/10,000 (5-14 year olds), and 10/10,000 (15 years or older). By comparison the rates for 1999 were 60/10,000, 20/10,000, and 10/10,000 respectively (see Figure 5).

The British Thoracic Society identifies specific benchmarks or ‘best practice’ which health professionals are required to meet when caring for asthma patients (BTS, 2004). These recommendations are mostly based on scientific evidence from RCTs, epidemiological studies (cohort and case-control), meta-analytic reviews, and other good quality research. The recommendations related specifically to the following topics:

1. Diagnosis and assessment in children and adults (e.g. key symptoms, recording criteria which justified diagnosis of asthma);
2. Pharmacological management (e.g. use of drugs [inhaled steroids, β₂ agonist] to control symptoms, prevent exacerbation, eliminating side effects, employing a ‘stepwise’ protocol for treatment);
3. Use of inhaler devices (technique and training for patients, agonist delivery, inhaled steroids, CFC vs. HFA propellant inhalers, suggestions on prescribing devices);
4. Non-pharmacological management (e.g. breast feeding and modified milk formulae for primary prevention, and allergen avoidance for secondary prevention, alternative medicines);
5. Management of acute asthma (initial assessment, clinical features, chest x-rays, oxygen, steroid treatment, referral to intensive care)
6. Asthma in pregnancy (drug therapy, management during labour, drug treatment in breastfeeding mothers);
7. Organisation and delivery of care (e.g. access to primary care delivered by trained clinicians, regular reviews of people with asthma, audit tools for monitoring patient care after diagnosis);
8. Patient education (e.g. action plans, self-management, compliance with treatment regimes).

Overall, despite these guidelines, recent research suggests that patients’ treatment needs are not being met. For example, Hyland and Elisabeth (2004) report data on the unmet needs of patients. Focus groups were organised between parents, patients, and clinicians. Patients and parents reported various needs that weren’t been met including frequent exacerbations, and a preference for less complex drug regimens (i.e. with fewer drugs). Many individuals had worries regarding treatment and experienced asthma symptoms 3 or more days per week. As Levy (2004) suggests, there is a need for health professionals to address these concerns, especially in relation to the BTS guidelines.

Levy, a GP and Research Fellow in Community Health, identified current deficiencies in the care of asthma victims. These comprised:

1. Higher than expected exacerbations (42/1000 patients per year);
2. Under-diagnosis: more patients presenting for treatment with uncontrollable asthma, who had not been diagnosed previously;
3. Deficiencies in treatment uptake: many patients fail to collect their prescriptions;
4. Many patients with symptoms delay presenting for treatment, until their medical situation becomes critical;
5. Health care professionals are failing to assess patients objectively (PEF, oximetry), both pre- and post-treatment;
6. Failure to adhere to national guidelines for the care of acute asthma (e.g. not enough oral steroids and β-agonists are prescribed for patients presenting with asthma attacks.
7. Considerable variations across GPs, NHS Trusts, clinics, and other sources of care provision: patient follow-up appointments range from a few days to six months, in direct violation of standards set by the British Thoracic Society (BTS, 2004).

Levy suggests various strategies for improving asthma care including diagnosis criteria (e.g. “any patient with recurring or respiratory symptoms [cough, wheeze, or shortness of breath], or who has been prescribed anti-asthma treatment should be considered to have asthma” (p.44)), use of computerised templates, having systems or triggers in place for recalling patients (e.g. patients requesting more medication, or who have been seen out of hours), introducing more effective protocols for monitoring and informing asthma patients (e.g. using a checklist to ascertain various key information on patients status, such as effects of asthma on patients life, recent exacerbations), providing written self-management plans (e.g. how to detect uncontrolled asthma, using PFM charts), and having an agreed procedure for managing acute asthma attacks (e.g. selecting a low threshold for using oral steroids).

Currently there is a lack of research testing the value of these recommendations on asthma health outcomes. However various strategies are continually being implemented in various parts of the country to improve the quality of asthma care. For example,

Holt (2004) describes the effects of implementing the RAISE initiative, launched by the National Respiratory Training Centre, in a primary care setting. This scheme is designed to raise awareness of existing variations in standards of care, improve standards of care through education, support, and feedback, increase awareness and understanding of respiratory disease, use asthma as platform to demonstrate the value of shared experiences across different agencies/professionals, and augment the profile of primary care settings as the main source of asthma care and innovation. The RAISE led to various improvements, such as:

1. The use of ‘active’ and ‘inactive’ asthma registers, to distinguish patients who currently have asthma symptoms from those who don’t.

2. Introduction of computerised templates to improve accuracy and reliability of data recording during consultations (e.g. progressing sequentially from assessment of symptoms, to peak flow, inhaler, and advice stages).

3. Use of symptom questionnaires (e.g. handed out with repeat prescriptions) that help patients with well-managed asthma decide whether they can opt for a telephone consultation, rather than taking the trouble to visit the practice for a face-to-face consultation.

Haggerty (2005) identifies several factors paramount to effective care and management of asthma in UK patients. These comprise adequate patient education about the nature of asthma (e.g. number of asthma episodes, use of quick relief medicines, long term symptoms, restrictions on daily activities, and emergency visits), use of asthma action plans, and customised treatment plans (to achieve early control), and addressing patients own concerns and perception.

Treatment for asthma is usually in the form of regular inhaled corticosteroids (ICS), oral corticosteroids (OCS), and β agonists. These treatments are usually administered by a health professional when symptoms manifest and/or become severe. However, since asthma can often exacerbate rapidly, before an individual can seek medical help, it is vital that asthma patients receive the necessary care from health professionals, and also self-management skills. GPs and nurses play a critical role.

Griffiths et al (2004) conducted a randomised control trial to assess the effect of a specialist nurse intervention on the frequency of unscheduled asthma care in an inner city multiethnic clinic in London. The role of specialist nurses in asthma care has been uncertain. Interventions in which specialist nurses educate patients about asthma, after hospital attendance with acute asthma, were shown to have inconsistent effects on unscheduled care. However, outreach initiatives to educate medical staff had shown no effect. Thus, an intervention was designed that combined patient education with educational outreach for doctors and practice nurses. It was suspected that such an integrated approach would benefit ethnic minority groups, especially given their higher hospital admission rates and reduced access to care during asthma exacerbation. The key research question was whether specialist nurses could improve health outcomes in ethnic minority groups.

Outcome variables were the percentage of patients receiving unscheduled treatment for acute asthma during a 12 month period, and time to first unscheduled attendance with acute asthma. The study was based on 44 practices in two east London boroughs. Participants comprised over 300 patients (aged 6 to 60) who were admitted to or attending the hospital, or the out of hours GP service with acute asthma. Half the sample were classified as South Asians, 34% were Caucasian, while 16% were Caucasian. The intervention was based on a liaison model. Practices were assigned to either a treatment or control condition.

Practices randomised to the treatment condition ran a nurse led clinic involving liaison with GPs and practice nurses, incorporating education, raising the profile of guidelines for the management of acute asthma, and providing on-going clinical support. In practice these practices received two one-hour visits from a specialist nurse who discussed guidelines for managing patients with acute asthma. Discussions were based on relevant empirical evidence. A computer template was provided to elicit patient information on various treatment issues, such as inhaler technique and peak expiratory flow, and offer self-management advice. By contrast, control practices received a visit promoting standard asthma care guidelines.

Data analysis showed that the intervention lengthened the time to first attendance (median 194 days for intervention practices, and 126 days for control practices), and also reduced the proportion of patients presenting with acute asthma (58% treatment practices versus 68% in control practices (see Figure 6). These effects were not moderated by individual differences in ethnicity, albeit Caucasians seemed to benefit more from the intervention compared with minority ethnic groups.

 

O’Connor (2006) noted that asthma care in the UK remains below the required standards. The majority of the 69,000 hospital admissions and circa 1400 deaths annually are attributable to poor patient adherence to treatment regimens. Nurses, it is argued, play an important role in promoting adherence. Additionally, use of a new inhaled corticosteroids – circlesonide – may also help increase adherence. Circlesonide is much easier to use than more established asthma drugs (e.g. it has a once-daily dosing). Evidence is reviewed suggesting that peak expiratory flow remains stable when patients are given circlesonide compared with a placebo.

Tsuyuki et al (2005) assessed the quality of asthma care delivered by community-based GPs in Alberta, Canada. They reviewed clinical charts for over 3000 patients from 45 primary care GPs. Of this number 20% had ever visited an emergency department or hospital, 25% had evidence that a spirometry had been performed, 55% showed no evidence of having received any asthma education, 68% were prescribed an inhaled corticosteroid within the past 6 months, while a very small minority (2%) had received a written action plan. Figure 6 shows percentage of participants receiving medication.

Sixty-eight percent were prescribed an inhaled corticosteroid, 11% were given an oral corticosteroid, and 80% received a short acting β-agonist, while 8% were prescribed a long acting β-agonist. Participants with an emergency room/hospital event were (marginally) more likely to be prescribed medication (no group differences in use of short acting β-agonists). Regarding pulmonary testing, 25% had evidence of a pulmonary function test (not peak flow), 46% had peak flow monitored, 34% showed no evidence of pulmonary function tests, while 26% had an x-ray. Again individuals with an emergency room/hospital event were more likely to be tested (see Figure 7).

Data about education received by patients was also evaluated. Twenty-two percent received information about environmental triggers, 20% on inhaler use, 10% on how to perform a home PEF test, 2% on written action plans, while 55% received no education at all. Those with an emergency room/hospital event were more likely to receive education. Receiving asthma education, use of spirometry, and prescription of inhaled corticosteroids, were all predicted by number of asthma-related clinic visits (4 or more) and having an emergency room/hospital event. Additionally, asthma education was predicted by cormorbidities, and absence of documentation regarding asthma triggers, while use of spirometry was predicted by being a non-smoker, and symptoms or triggers. Finally, use of inhaled steroids was predicted by symptoms.

Overall, this study highlights numerous gaps in the care provided by GPs, partly echoing criticisms of GPs in the UK (Levy, 2004). For example, Levy (2004) cited ‘under-treatment’ as one of several gaps in asthma care. Nevertheless, Tsuyuki et al’s (2005) study is limited by its retrospective design and possible physician bias. Since GPs particularly interested in asthma may have been more likely to participate (e.g. necessary records etc), it is possible that the level of care was somewhat overestimated.

Patterson et al (2005) tested the effectiveness of a programme of asthma clubs on clinical outcomes (e.g. inhaler use) and quality of life in 173 asthmatic children. Participants attended asthma clubs at school on a weekly basis over a 2-month period. Outcome measures comprised spirometry and inhaler method, and scores on the Paediatric Quality of Life Questionnaire. The programme produced marginal but insignificant changes in quality of life scores, and inhaler technique (at 16 weeks). However, there was no effect on spirometry.

Action/Care Plans

Research suggests that the use of written action plans “facilitates the early detection and treatment of an exacerbation and is therefore an essential aspect of the self-management of exacerbations” (Gibson & Powell, 2004). An action plan is a written protocol prescribed to an asthma patient for use in managing an asthma attack or escalating symptomatology. The plan is written specifically to meet the needs of an individual patient, so in effect, no two action plans will be exactly the same. The plan provides guidance on when and how to self-administer medications, how to access medical services in the event of exacerbation. Gibson and Powell (2004) identify the following components of a ‘complete’ action plan:

1. When to increase treatment (i.e. the action point - what level of symptoms or peak expiratory flow (PEF) are required to trigger the action plan);
2. How to increase treatment (e.g. corticosteroid inhalers, combined with oral ingestion);
3. For how long (e.g., until symptoms subside);
4. When to seek help from health professionals.

Gibson and Powell (2004) define an action plan as incomplete if the use of ICS is not prescribed. A plan was considered non-specific if it provided general rather than tailored information about asthma management. They reviewed twenty-six randomised control trials which assessed the effects of action plan components on asthma health outcomes. Action plans were generally based on PEF values, and treatment instructions specified increases in both OCS and ICS.

Compared with usual asthma care complete action plans reduced hospital admissions (46% variance predicted), although only ‘personal best’ plans based on PEF reduced emergency room visits and improved airway capacity. Action plans were recommended as ‘traffic light’ systems in some studies. Evidence also suggested that symptom based action plans were generally similar to PEF based plans. Regarding treatment instructions, increases in ICS and OCS doses significantly improved health outcomes. Finally, the health value of incomplete or non-specific action plans was uncertain due to limited research evidence.

The following key points were highlighted (see Figure 8);

1. Action plans improve health outcomes when based on personal best (rather than predicted) PEF;
2. Action plans with multiple (e.g. four) action points are not significantly better than plans with fewer points;
3. Action plans based on symptoms (rather than PEF values) are no less effective;
4. Complete action plans using ICS and OCS are highly effective in managing severe exacerbations.

Burns (2005) reviewed the UK literature on the value of action plans in asthma management. Studies confirm that action plans may reduce exacerbations and oral corticorsteroids, improve control of asthma symptoms, and reduce consultation times. However, uptake of plans has been limited – only 6% of asthma patients are issued with an action plan, partly due to poor commitment by health professionals. Critiques argue that action plans may discourage hospital/clinic visits, even when such attendance is paramount to ensure patient survival. Furthermore, patients often view action plans as something for ‘other’ people and some GPs suspect that patients may have trouble comprehending action plans. However, much of the evidence reviewed is inconclusive due to the lack of a placebo group in some studies. Thus, it is not clear whether group differences observed were induced by action plans specifically, or patients’ perception of being ‘treated’.

Carroll (2005) discusses the value of care plans (or ‘integrated care pathways’, ‘anticipated recovery pathways’, or ‘care maps’), which describe essential treatment and management protocols for asthma (and other conditions). Currently, there remains a paucity of UK research on the effectiveness of care maps on health outcomes for asthma patients. Nevertheless, available evidence suggests that care plans can have several benefits, for example by increasing adherence to medication, reducing admission times, improving communication across disciplines, and facilitating the implementation of national standards for asthma care. Thus, care maps are currently recognised by the Department of Health (1998). However, it is noted that care maps can hamper personal initiative.

An asthma care pathway was developed and implemented at the emergency department of the Southport and Ormskirk Hospital NHS Trust. This development was based on a comprehensive literature review, which highlighted considerable variations in asthma care across physicians, clinics, and hospitals. The care plan was designed to improve compliance with standards set out by the British Thoracic Society, and incorporated several stages: initial assessment (e.g. PEF values, and guidance on identifying mild, moderate, and severe asthma); drug therapy (e.g. inhaler corticosteroids), on-going clinical assessments (e.g. monitoring vital signs, PEFs); and discharge planning (e.g. specific criteria for discharging patients, ensuring inhaler method is correct etc).

Hospital management approved the care pathway in November 2004. Both nurses and physicians were trained accordingly. An audit process assessed whether the care plan was properly documented and easy to read. Findings highlighted several problems including: duplication of activities/documentation; failure to conform to BTS guidelines (e.g. prescribing nebulised ipratropium as the first stage of treatment for patients with moderate asthma); and failure to check and correct inhaler technique before patients are discharged. Implementation of the care plan continues to be audited and improved accordingly. Unfortunately, given the limitations of audits, it is not clear the extent to which issues arising here would generalise to other NHS trusts.

Dinakar et al (2004) assessed the effectiveness of an asthma action plan in managing exacerbations. Participants were caretakers of asthmatic children who were attending a general practice clinic in an inner-city hospital. They completed a questionnaire assessing various asthma-related factors including asthma severity, frequency of exacerbations, and possession/utility of an asthma action plan (e.g. ‘if your child has an asthma action plan, do you feel it helps in the yellow and red zones?’). The yellow zone refers to symptoms that require albuterol ≥ three times a day, > two nights in succession, while the red zone was defined by symptoms that necessitate oral steroids/urgent visit. The majority of participants had an asthma action plan, and most of these found the plan useful in managing exacerbations. However, these findings are constrained by the small sample size and lack of statistical analysis. Thus, it is not clear whether the observed patterns are reliable.

Chen et al (2004) developed and evaluated a care plan for children with asthma in a randomised control trial. The care plan was developed on the basis of in-depth interviews with the parents of children with asthma. Parents were randomly assigned to either an experimental or control group in an allergic clinic of a children’s hospital in China. The experimental group received a care plan in addition to the usual care. The care map incorporated an algorithm addressing assessment and treatment issues (e.g. recognition of asthma symptoms, daily medication regimes, interpretation of peak flow meter rates, dietary requirements, the need for follow-up, and emergency action plans for acute asthma attacks).

Findings showed that those in the experimental group were less likely to attend the emergency room (over a 6 month period), and had more positive attitudes towards asthma. By contrast, those in the control group had irregular follow-ups by a doctor and inconsistent use of medication. It was concluded that a care plan could improve the quality of life for asthma children and their parents. Unfortunately, this study did not incorporate a placebo group. Thus, it is not clear whether the observed group differences resulted from the action plan, or merely the perception of ‘receiving a treatment’, which in turn could lead to a self-fulfilling prophesy. The findings would have been more conclusive given a group administered with a ‘fake’ treatment (e.g. similar care plan, but on something else).

Some evidence suggests that lack of education amongst asthma patients can impede their satisfaction with and involvement in asthma care. Mancuso et al (2006) considered this issue, by assessing the relationship between patient literacy and their evaluations of health care provision and willingness to be involved in making decisions about their care. Patients from a primary care practice in New York completed the Test of Functional Health Literacy in Adults (TOFHLA), a well-established index of basic numeric and literacy skills as related to health care. Patients also provided information about asthma characteristics, such as severity (whether patients needed to be hospitalised), asthma control (how often patients had exacerbations), and their perception of asthma and health care experiences, access to care, and the quality of care received.

Data from 175 patients who came for follow-up visits was analysed. Multivariate analysis showed that marginal/inadequate health literacy was associated with lower satisfaction with asthma status, poorer health outcomes from asthma care, more difficult access to care, and an unwillingness to partake in making decisions about treatment. These findings highlighted the need for physicians to educate patients more effectively regarding asthma and asthma care. However, since this was a cross-sectional survey, the direction of potential causality is questionable. For example, it is possible that an unwillingness to be involved in treatment decisions may foster ignorance of various aspects of care. A similar argument can be made about the impact of reduced access to care and lack of knowledge about health issues.

Some evidence suggests children rely heavily on their parents for information about their condition. Parents in turn often look to health care providers for related information. Finally, health care providers are expected to be knowledgeable about various aspects of asthma care, so that they can communicate effectively and productively with parents and children.

Buford (2005) interviewed parents and children regarding their perceptions of health care providers and their involvement in helping children cope with asthma. Parents “voiced the need for ongoing education about asthma by their health care providers” (p.159), and felt it was essential that health providers communicate directly with the children. Parents also felt that health providers themselves may hamper asthma care, notably through delays in diagnosing asthma, and inconsistencies in the advice given by different providers.

Overall, this study highlighted the importance of educating health providers about asthma care and parent expectations. It is also pertinent to educate parents on asthma and how best to convey this information to their children. Nevertheless, this study utilised a small ad-hoc sample, so the generality of the findings to the wider population may be questionable. Research suggests that these guidelines are not always implemented by clinicians, despite the benefits for the quality of patient care.

Health Resource Utilisation

Asthma patients often delay seeking treatment, especially individuals with mild/moderate asthma symptoms. Thus identifying the correlates of care utilisation has been the focus of research (e.g. Buetow et al, 2004; Davies et al, 2004; Silver et al, 2005).

Diagnosis of allergic rhinitis morbidity may be implicated in UK health care utilisation. Price et al (2005) noted that allergic rhinitis and asthma tend to coexist, and although rhinitis does not add significantly to treatment costs, it has epidemiological, pathological, and therapeutic links with asthma. Both conditions are probably different symptoms of the same underlying pathology - airway inflammation, although rhinitis tends to develop before asthma symptoms manifest. An epidemiological cohort study was conducted to assess incremental impact of rhinitis on health resource utilisation of asthma patients.

Data for 27,303 adults (mean age 34 years) was collected from the UK MediPlus® database, which contains information for over one million patients from a representative pool of ≥500 GPs. Patients were considered eligible for the study if they had one or more asthma-related visits to their GP during a 12 month follow-up phase. Patients were considered to have rhinitis if there was a record that rhinitis was diagnosed and/ or relevant drugs prescribed. Measures of age, gender, oral/inhaled corticosteroid, and short-acting b-agonist prescriptions, were treated as covariates. Overall, 83.1% of patients had asthma, while 16.6% had both conditions. Figure 9 shows that patients with rhinitis visited their GP for asthma more often than patients who had asthma alone, even after adjusting for covariates. Furthermore rhinitis patients were significantly more prone to be hospitalised for asthma.

Logistic regression analysis revealed that the probability of asthma related hospitalisation was predicted by allergic rhinitis, as well as being female, currently smoking, number of short-acting β-agonists, and oral/inhaled corticosteroid use. Overall, this study confirms that added respiratory symptomatology increases health service utilisation. However, findings should be interpreted with caution. Due to the large sample size even unreliable and fragile associations between variables may be significant. It may be appropriate to consider only findings significant at very stringent significance level (e.g. p<.0001).

Other evidence suggests that patient’s treatment needs and preferences are not always adequately addressed. Hyland and hl (2004) argued that “the practice of medicine is often most successful when the physician understands the patient’s perceptions not only of illness but also of treatment” (p.2142). Doctors may focus too much on the clinical management of asthma, and hence fail to appreciate patients real needs. They conducted focus groups with patients, parents, and clinicians. Additionally, questionnaire surveys were conducted in the UK, Germany, and Spain. The aim was to identify unmet patient needs. The focus groups highlighted differences in perceptions of treatment between clinicians and patients/parents. Patients reported good asthma management but also frequent exacerbations.

The majority of patients preferred simpler drug regimens (i.e. fewer drugs) and were worried about their treatment. Furthermore most patients tended to rely on reliever medications, and some patients who reported their asthma as being under control also experienced asthma symptoms more than three days a week, visited the emergency department, or contacting a GP for home a home visit during the last few months.

It was concluded that patients and GPs might interpret asthma and related terminology (e.g. ‘well-controlled’) differently. Furthermore, it is suggested that patient anxiety about their treatment may undermine adherence to treatment regimes. However, the study does not actually demonstrate a link between patient-clinician perceptual discrepancies and treatment adherence. Indeed, such an association may be tenuous especially in the context of key covariates such as the presence of other pathology (e.g. rhinitis) and having a care plan.

Ethnic differences may be implicated in disparities in children’s access to/utilisation of care. Greek et al (2006) assessed ethnic differences in family perceptions of the usual source of care (USC) for children with asthma. Of particular interest were (a) family reports of the presence and nature of the USC for children, and (b) differences in the USC for children from different ethnic groups. Data from the 1996-2000 Medical Expenditure Panel Survey (MEPS) Household Component was analysed. The MEPS is a national survey of the US households that provides information on health resource utilisation and other factors.

Adults with knowledge of a family’s health care use provided information about whether a child was asthmatic and the family’s utilisation of health care. For example “whether there is a particular doctor’s office, clinic, health centre, or other place that the individual usually goes if he/she is sick or needs advice about his/her health” and whether the USC “was a specific medical person or a facility” (p.62).

Logistic regression highlighted significant ethnic differences in USC. For example, among asthmatic children aged 10-17 years, Spanish-speaking Hispanics and blacks were less likely than Caucasians to have a USC. Minority groups were also more likely to specify their USC as a hospital or outpatient department, and experience access barriers related to appointments.

Davies et al (2004) assessed the value of asthma controller therapy (montelukast) on health resource utilisation in children with asthma. Participants were children who had participated in randomised clinical trials comparing montelukast and placebo groups. They were asked to partake in an additional study comparing montelukast and usual treatment groups. Use of oral corticorsteroids, number of visits to the doctor and emergency departments, and number of hospitalisations, were treated as outcome measures. Level of utilisation was the same in patients who had received montelukast and those administered cromolyn or inhaled corticosteroids. However, this study focused on children with mild to moderate asthma, thus it is not clear whether the findings would generalise to patients with severe asthma, who have more to loose by not visiting a physician, emergency department or hospital, or taking steroids.

Buetow et al (2004) investigated barriers to attendance for GP asthma care. Participants were over 400 children with suspected breathing difficulties from twenty-six schools in Auckland New Zealand. Data was collected via questionnaires, which was administered to parents/guardians. Multivariate analysis revealed that expected visits to the GP were heightened by perceived need, health problems, severity of asthma symptoms, and ethnicity (Maori and Pacific, as opposed to Caucasian).

Silver et al (2005) assessed the impact of anxiety in caretakers for inner city children with asthma on asthma severity (based on day and night symptomatology) and utilisation of acute care services (the number of primary care visits [GP], emergency department visits, and asthma-related hospitalisation during the preceding 6 months). Care utilisation was positively related to asthma severity but not caretaker anxiety. However, the analysis failed to control for important covariates, such as parental input and existing treatment regime.

Some evidence suggests that having allergic rhinitis may affect utilisation of care resources. Thomas et al (2005) investigated this relationship in a retrospective cohort study using data (collected between 1998 to 2001) from a UK MediPlus general practice database. The database contains records for circa 2 million patient visits to over 500 GPs. Records of diagnosed allergic rhinitis (or prescriptions suggesting rhinitis) covering the period from October 1998 to April 2001 were extracted. Outcome data was established for the period October 2000 to September 2001.

Data was recovered for 9522 asthma-related GP visits (1879 and 7643 with and without allergic rhinitis, respectively) out of more than 14,000 asthma patients. Analysis showed that rhinitis independently predicted greater hospital utilisation, number of asthma-related GP visits, and costs of prescriptions. These findings indicate that children with asthma and rhinitis may require more medical care (both emergency and nonemergency). However, the correlational results negate conclusive inferences about cause and effect.

Follow-up

Sin et al (2004) assessed the efficacy of an intervention on the rate of follow-up visits with a primary care physician. Asthma patients (n=125) from the emergency department of a community hospital were assigned to a usual care or enhanced care condition. Both groups received the usual care. However, the enhanced care group had a coordinator health professional who made follow-up appointments with the patients GP, together with one or more reminder phone calls to the patient.

Outcome data was assessed at 6 months of follow-up: the enhanced care group had higher quality of life scores, more follow-up visits to the GP, were more likely to utilise written action plans, and reported fewer asthma symptoms. This study suggests that minimal inputs from a health professional can engender follow-up visits in asthmatic patients. However, this effect was short-lived, and the absence of a placebo group renders the findings inconclusive.

CHAPTER FOUR - CONCLUSION

It became clear early in this literature review that there are gaps in asthma care provision, certainly in the UK (Levy, 2004). Thus, unsurprisingly, numerous studies have sort to identify significant correlates of various care deficiencies, such as poor following, limited use of care plans, and the frequency of hospital/emergency room visits.

Factors implicated in the quality of asthma care provision are more often than not moderated by various background variables, including ethnicity, gender, and age. Thus, for example, attempting to understand the role that nurse can play in encouraging follow-up appointments requires an understanding of the possible interactions between nurse input and key background factors, such as gender or parent/patient literacy levels. In essence, the determinants of the quality of asthma care are multiple and interdependent.

However, conclusive inferences about the effects of GPs, nurses, and other factors on asthma care provision are not possible based on the existing literature.

One reason for this is that there is a paucity of randomised control trials, which are the gold standard for establishing cause and effect relationships in health care. Most of the studies found were based on questionnaire surveys, or relied on retrospective designs involving the use of pre-existing data archives. Some studies employed longitudinal designs, but these rely primarily on temporal sequence to demonstrate causality. Thus, A preceded B, so therefore B could not have caused A. Although A could have caused B longitudinal evidence does not demonstrate this causal link. Nevertheless, in view of the ethical constraints that limit the scope of randomised control trials, it is essential to fully consider the implications of existing retrospective and cross-sectional studies.

Another reason is the limited research on certain gaps in asthma care identified by Levy (2000). Firstly, the issue of under-diagnosis: why are patients with milder symptoms not diagnosed as asthmatic, until they present with an acute exacerbation? Weissman (2002) notes, “Unfortunately, physicians’ diagnosis of asthma and BHR [bronchial hyper-reactivity] are not particularly good “gold standards” for identification of asthma. It is likely that a physician’s diagnosis of asthma under-detects sub-clinical mild asthma” (p.6). Concerns have also been expressed about under-treatment (patients not collecting prescriptions) and health professionals failing to assess patients objectively, using peak expiratory flow and oximetry. Little is known about GP, nurse, and patient characteristics that predict these failings.

Finally, existing research often fails to account for the moderating effects of various background, clinical, and other variables that may qualify reported relationships. Significant associations reported in the literature (e.g. between developing rhinitis symptoms and hospitalisation) may be moderated by other variables, such as age, gender, and even actions of the primary care provider^[1]. Even randomised control trials generally fail to test for interactions, for example, using a multi-factorial analysis of variance design (Field, 2000).

Nevertheless, one salient feature that has emerged from the present review is the value of care/action plans for facilitating the management of asthma attacks. Randomised clinical trials have shown that care plans significantly improve health outcomes, across multiple criteria (e.g. PEF, improving compliance with BTS standards, reducing hospital admissions). Furthermore, care/action plans appear to be attracting considerable interest amongst health professionals, especially those working with asthma patients. Despite all this, uptake amongst patients remains extremely low, as little as 6% by some estimates (Burns, 2005; Haggerty, 2005).

Evidence suggests that GPs are reluctant to provide plans to patients partly because of doubts about the ability of some patients to fully understand a care plan. Indeed, it is possible that patient misunderstanding/confusion can lead to avoidable mortality following an acute asthma exacerbation. However, there appears to be no evidence substantiating this view of patients. While children may be too young to comprehend a care plan, no evidence was found that parents are unable to grasp care plan protocols, especially given adequate and regular support from their health provider. Moreover, there is a more essential point to be made. Given the emphasis on evidence-based practice in health care provision (Thompson et al, 2004), it is essential that care plans are implemented given the evidence verifying their effectiveness.

Overall, asthma care is a multifaceted provision that requires close collaborations between different health care staff (Holt, 2004), working to support patients through appropriate care, while simultaneously accounting for individual differences between patient groups (e.g. pregnant women, ethnic minorities, children) that may moderate the efforts of health professionals.

There is room for improvement.

There is a need for further (mostly randomised control) research designed to address specific gaps in care (Holt, 2004; Levy, 2004; Wilkinson & Finch, 2004; Finch, 2005), especially those areas that do not appear to have attracted sufficient research activity. For example, under-diagnosis of patients, under-treatment, health professionals failing to evaluate patients objectively before and after treatment. Randomised control trials can be used to establish causality once key correlates have been identified.

The present review permits some tentative recommendations:

1. Retrospective and correlational designs have been the main approach to studying aspects of asthma care, in both the UK and the USA. Thus, there is a need for more randomised control trials, to establish cause-effect relationships;

2. More research is needed that identifies correlates of under-diagnosis (GPs failing to diagnose milder asthma cases), under-treatment (patients not collecting prescriptions), and health professionals failing to evaluate patients objectively. This list is not exhaustive. Future studies should attempt to verify existing literature on the value of care plans, correlates of successful follow-up, frequency of hospitalisation/emergency events, and other parameters of care;

3. Research needs to account for the moderating effects of individual differences amongst patients, such as genetic predispositions, literacy levels, age, gender, ethnicity, previous and current pathology (e.g. rhinitis).

Without appropriate experimental evidence demonstrating causality it would be difficult to develop effective interventions designed to improve asthma care provision. Nevertheless, there is a sufficient evidence base to justify at least limited efforts designed to implement certain aspects of asthma care, such as care plans. Asthma patients require a lot of support and GPs in particular need to base asthma management on