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 diYculty 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 (FEV 1 ) 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 ( 2 = 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. (Thorax 2000;55:562-565)

The aim of this prospective study was to detect subjects in the general population with objective signs of chronic obstructive pulmonary disease (COPD) or asthma at an early stage. This was done by means of a two-stage protocol involving screening and a subsequent 2-yr monitoring of all subjects with positive results of screening. The study was done in 10 general practices located in the eastern part of the Netherlands. A random sample was taken from the general population aged 25 to 70 yr. All known COPD and asthma patients were excluded. A total of 1,749 subjects met the inclusion criteria: 1,155 subjects (66%) agreed to participate in the screening stage of the study. A total of 604 subjects (52.3%) showed symptoms or objective signs of COPD or asthma during the screening and were considered "positive." Of those with positive screening results, 384 subjects (64%) agreed to participate in the second, 2-yr monitoring stage of the study. The costs involved in detection were calculated for three different scenarios, as follows: (1) The detection of subjects with persistently decreased lung function or an increased level of bronchial hyperresponsiveness (BHR) during 6 mo of monitoring; (2) Scenario 1 plus the detection of subjects with a rapid decline in lung function with signs of BHR during 12 mo of monitoring; (3) Scenario 2 plus the detection of subjects with a moderate increase in the decline in lung function or signs of BHR during 24 mo of monitoring. The costs of lung function assessments, organization, transportation, and patient time were included. The costs were converted to United States dollars on the basis of purchasing power (1 United States dollar = 2.08 Netherlands guilders). During the second stage, 252 subjects were detected with objective signs of COPD or asthma at an early stage. Smoking status as a screening criterion was neither sensitive nor specific. Because there was no evidence of biased recruitment or selection during the program, the proportions of subjects found to have objective signs of COPD or asthma at an early stage could be extrapolated to the general population. Of the general population, 7.7% showed persistently reduced lung function or increased BHR. Another 12.5 % of the general population showed a rapid decline in lung function (> 80 ml/yr) in combination with signs of BHR, and a further 19.4% of the general population showed mild objective signs of COPD or asthma. The average costs per detected case varied from US$953 (Scenario 1) to US$469 (Scenario 3). In conclusion, detection of COPD or asthma at an early stage by means of a two-stage protocol was feasible at relatively little expense in comparison with other mass screening programs. Persistently decreased lung function or a rapid decline in lung function (Scenario 2) was observed in approximately 20% of the general adult population.

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.

In a two-stage detection program, subjects with signs of obstructive airway disease were selected from a random sample of the general population. Subjects (n = 82) were randomly assigned to either fluticasone propionate 250 microg twice a day or placebo twice a day via pMDI in a 1-yr, double-blind trial if they met criteria for persistent airway obstruction, increased bronchial hyperresponsiveness, or a rapid decline in FEV(1). Main outcome measures were postbronchodilator FEV(1), quality-adjusted life years (QALYs), and direct medical cost. Secondary measures were prebronchodilator FEV(1), PC(20), health-related quality of life (CRQ), symptom-free weeks, episode-free weeks, exacerbations, and indirect cost. Subgroup analysis was based on reversibility of obstruction. Analysis revealed a significant gain in postbronchodilator FEV(1) (98 ml/yr; p = 0.01) in favor of fluticasone. Only subjects with reversible obstruction showed an improvement in PC(20) (1.4 doubling dose; p = 0.03). Early treatment resulted in 2.7 QALYs gained per 100 treated subjects (p = 0.17) and in a clinically relevant improvement in dyspnea (CRQ; p < 0.03). The incremental cost effectiveness ratios were US$13,016/QALY for early treatment and US$33,921/QALY for the combination of detection and treatment. The incremental cost for one additional subject with a clinically relevant difference in dyspnea was US$1,674. In conclusion, early intervention with fluticasone resulted in significant health gains at relatively low financial cost.

Recently, we published data of a 2 year randomized controlled study in which the effects of continuous versus symptomatic bronchodilator treatment in patients with moderate asthma or chronic bronchitis were investigated. The results showed that FEV1 decline in the continuously treated group was significantly larger than in the symptomatically treated group (72 versus 20 ml/year, P < 0.05). We reanalysed these data in order to investigate the hypothesis that the continuous use of bronchodilators may mask a rapid decline in lung function. Lung function decline was assessed by regression analysis of seven FEV1 measurements. Respiratory symptoms were assessed by means of the MRC questionnaire every 12 months, and they were also recorded by the patients in a weekly report. Of the participating patients 144 completed the study. Increased lung function decline in the continuously treated group was not reflected in a significant deterioration of the symptoms. Moreover, the decline in FEV1 showed no correlation at all with changes in respiratory symptoms in continuously treated patients (r = -0.03, P = 0.80), whereas in the symptomatically treated group, there was a better relation (r = -0.32, P = 0.003) to changes in respiratory symptoms. These results show that continuous bronchodilation may indeed mask the worsening of the disease. This lack of awareness of deterioration of the disease is probably caused by the continuous symptom relief of bronchodilators. It may be misleading to both patients and physicians.

Objectives: To investigate the extent of underpresentation of shortness of breath to general practitioners (GPs) in a random sample of the general population without a confirmed diagnosis of obstructive airways disease (OAD). A second objective was to assess the influence of a person's perception of symptoms and psychological factors as possible causes for underpresentation. Design: A random sample of the general population (n = 1155) was screened for respiratory symptoms. Of those who experienced shortness of breath at some stage during the preceding year, the ability to perceive dyspnoea was assessed in 134 patients, by means of a Borg score and a visual analogue scale (VAS) during each step of a histamine provocation test. A psychological profile was assessed in 130 subjects using five validated questionnaires. Patients: Two random sample groups (n = 134 and n = 130) of adults reporting dyspnoea without a diagnosis of OAD. Results: Of the initial sample, 285 (25%) had experienced shortness of breath in the year preceding the screening: only 93/285 (33%) had ever consulted their GP for this. Multivariate analysis showed that neither a person's perception of dyspnoea nor psychological factors could explain underpresentation. Conclusions: Underpresentation of symptoms is a major factor contributing to underdiagnosis of OAD, but this is not related to the patient's perception of symptoms nor to their psychological profile.