G. van den Boom

Underdiagnosis of asthma: is the doctor or the patient to blame? The DIMCA project

BACKGROUND It is important to diagnose asthma at an early stage as early treatment may improve the prognosis in the long term. However, many patients do not present at an early stage of the condition so the physician may have difficulty with the diagnosis. A study was therefore undertaken to compare the proportion of patients who underpresented their respiratory symptoms with the proportion of underdiagnosed cases of asthma by the general practitioner (GP). A secondary aim was to investigate whether bad perception of dyspnoea by the patient was a determining factor in the underpresentation of asthma symptoms to the GP. METHODS A random sample of 1155 adult subjects from the general population in the eastern part of the Netherlands was screened for respiratory symptoms and lung function and the results were compared with the numbers of asthma related consultations registered in the medical files of the GP. In subjects with reduced lung function the ability to perceive dyspnoea was investigated during a histamine provocation test in subjects who did and did not report their symptoms to their GP. RESULTS Of the random sample of 1155 subjects 86 (7%) had objective airflow obstruction (forced expiratory volume in one second (FEV1) below the reference value corrected for age, length, and sex minus 1.64SD on two occasions) and had symptoms suggestive of asthma. Of these 86 subjects only 29 (34%) consulted the GP, which indicates underpresentation by 66% of patients. Of all subjects with objective airflow obstruction who presented to their GP with respiratory symptoms, 23 (79%) were recorded in the medical files as having asthma, indicating underdiagnosis by the GP in 21% of cases. Of the subjects with objective airflow obstruction who visited the GP with respiratory symptoms 6% had bad perception of dyspnoea compared with 26% of those who did not present to the GP in spite of airflow obstruction (χ2 = 3.02, p = 0.08). CONCLUSIONS Underpresentation to GPs of respiratory symptoms by asthmatic patients contributes significantly to the problem of underdiagnosis of asthma. Underdiagnosis by the GP seems to play a smaller role. Furthermore, there are indications that underpresentation of symptoms by the patient is at least partly explained by a worse perception of dyspnoea.

Self-management of asthma in general practice, asthma control and quality of life: a randomised controlled trial

Background: A study was undertaken to determine the effectiveness of asthma self-management in general practice. Methods: Nineteen general practices were randomly allocated to usual care (UC) or self-management (SM). Asthma patients were included after confirmation of the GP diagnosis. Follow up was 2 years. Patients kept diary cards and visited the lung function laboratory every 6 months. Outcomes were number of successfully treated weeks, limited activity days, asthma specific quality of life, forced expiratory volume in 1 second (FEV1), FEV1 reversibility, concentration of histamine provoking a fall in FEV1 of 20% or more (PC20 histamine), and amount of inhaled steroids. Results: A total of 214 patients were included in the study (104 UC/110 SM; one third of the total asthma population in general practice); 62% were female. The mean percentage of successfully treated weeks per patient in the UC group was 72% (74/103 weeks) compared with 78% (81/105 weeks) in the SM group (p=0.003). The mean number of limited activity days was 1.2 (95% CI 0.5 to 1.9) in the SM group and 3.9 (95% CI 2.5 to 5.4) in the UC group. The estimated increase in asthma quality of life score was 0.10 points per visit in the UC group and 0.21 points per visit in the SM group (p=0.055). FEV1, FEV1 reversibility, and PC20 histamine did not change. There was a saving of 217 puffs of inhaled steroid per patient in favour of the SM group (p<0.05). Conclusion: Self-management lowers the burden of illness as perceived by patients with asthma and is at least as effective as the treatment usually provided in Dutch primary care. Self-management is a safe basis for intermittent treatment with inhaled corticosteroids.

Association between health-related quality of life and consultation for respiratory symptoms: results from the DIMCA programme

In general practice, diagnosis of chronic obstructive pulmonary disease (COPD) is hampered by underpresentation. A substantial proportion of subjects experiencing respiratory complaints do not consult their general practitioner (GP). In this study, the relationship between disease-specific quality of life and presentation of respiratory symptoms to a GP is investigated. A random sample from the general population (undiagnosed subjects) was screened for symptoms and objective signs of COPD (n=1,155). The lung function of subjects with symptoms of COPD was monitored for 6 months. During this period, 48 new COPD patients with a persistently reduced lung function (forced expiratory volume in one second (FEV1) less than or equal to the predicted value minus 2 SD) were detected. A disease-specific quality-of-life questionnaire (chronic respiratory questionnaire (CRQ)) was administered and clinical and GP consultation data were collected. Multivariate analysis showed that quality-of-life impairments due to dyspnoea and fatigue and variability in lung function (bronchial hyperresponsiveness, reversibility and peak expiratory flow rate variability) were related to medical consultation. Only 31% of the newly detected patients reported that they had ever visited their GP for respiratory complaints. A similarly low percentage was found in the rest of the sample (26%). It is concluded that the mere presence of respiratory symptoms or a (gradually) reduced lung function is insufficient reason for patients to seek medical help. Subjects are more likely to consult their general practitioner once their quality of everyday life is affected or they experience variability in lung function.

Epidemiological aspects and early detection of chronic obstructive airway diseases in the elderly.

The burdens of chronic obstructive airway diseases among the elderly in Europe, and worldwide, are increasing. Although asthma is common in all ages, the main airway disease affecting the elderly is chronic obstructive pulmonary disease (COPD). The aim of this paper is to review the prevalence and incidence of COPD on the basis of population studies. As the prevalence estimates of asthma are probably well known, only the incidence and remission of asthma will be discussed. The underdiagnosis of obstructive airway diseases is huge. A Dutch programme for early detection of obstructive airway disease among the elderly has, thus, been included in the presentation. A prerequisite for fighting COPD is to acquire data on illnesses and death. COPD has only recently been defined by cut-off points of spirometric outcomes, which is why measures of the prevalence of COPD have been distorted by use of a large number of different diagnostic terms and lung function criteria. The prevalence of clinically-relevant COPD has been estimated in several community studies to 4–6% in adult population samples, with a considerable increase by age, particularly among smokers. The incidence of COPD not only increases heavily with age and smoking, but also occupational exposure to dust, gas and damp. Precise estimates of the incidence of COPD or spirometric airflow limitation are not available. Demographic changes will result in a further substantial increase of chronic obstructive airway disorders, mainly chronic obstructive pulmonary disease, among the elderly. The increasing burden of chronic obstructive pulmonary disease has to come to the awareness of the public, governments, health authorities, and industry.

Early intervention with inhaled corticosteroids in subjects with rapid decline in lung function and signs of bronchial hyperresponsiveness: Results from the DIMCA programme

Background: Asthma is generally accepted as an inflammatory disease that needs steroid treatment. However, when to start with inhaled steroids remains unclear. A study was undertaken to determine when inhaled corticosteroids should be introduced as the first treatment step. Objective: To investigate the effectiveness of early introduction of inhaled steroids on decline in lung function in steroid-naïve subjects with a rapid decline in lung function in general practice. Subjects: Patients with signs/symptoms suspect of asthma (i.e., persistent and/or recurrent respiratory symptoms) and a decline in forced expiratory volume in 1 s (FEV1) during 1-year monitoring of 0.080 l or more and reversible obstruction (≥10% predicted) or bronchial hyperresponsiveness (PC20≤8 mg/ml) were studied. They had been identified in a population screening aiming to detect subjects at risk for chronic obstructive pulmonary disease (COPD) or asthma. Design: A placebo-controlled, randomized, double-blind study. Methods: 75 subjects out of a random population of 1155 were found eligible, and 45 were willingly to participate. Subjects were randomly treated with placebo or fluticasone propionate 250 µg b.i.d., and FEV1 and PC20 were monitored over a 2-year period. Outcome variables: The primary outcome measure was decline in FEV1; the secondary outcome measure was bronchial hyperresponsiveness (PC20). Results: 22 subjects were randomly allocated to the active group with inhaled corticosteroids and 23 to placebo. Change of FEV1 in the active treated group was +43 ml in post-bronchodilator FEV1 (p =0.341) and +62 ml/year (p =0.237) in pre-bronchodilator FEV1 after 1 year, and −22 ml (p =0.304) for post-bronchodilator FEV1 and −9.4 ml (p =0.691) for pre-bronchodilator FEV1 after 2 years, compared to placebo. The effect on PC20 was almost one dose-step (p =0.627) after 1 year and one dose-step (p =0.989) after 2 years. Conclusion: In this study, the early introduction of inhaled corticosteroids in newly diagnosed asthmatic subjects with rapid decline in lung function did not prove to be either clinically relevant or statistically significant in reversing the decline in FEV1. For PC20, no significant changes were detected.