House dust mite avoidance measures improve peak flow and symptoms in patients with allergy but without asthma: a possible delay in the manifestation of clinical asthma?

Background: Asthma caused by allergy to house dust mite is a growing problem. Patients with allergy who do not have asthma (yet) might develop asthma depending on exposure to precipitating factors.

Objective: We sought to determine whether house dust mite avoidance measures have an effect on the development of asthma.

Testing bronchial hyper-responsiveness: provocation or peak expiratory flow variability?

Background: Assessing bronchial hyper-responsiveness (BHR) is a main diagnostic criterion of asthma. Provocation testing is not readily available in general practice, but peak expiratory flow (PEF) is. Several guidelines promote the use of PEF variability as a diagnostic tool for BHR.

Risks and benefits of periodic treatment of asthma with inhaled corticosteroids.

It is important to determine whether inhaled corticosteroids can be discontinued during a stable phase of asthma. So far, most studies have shown that it is not possible to discontinue medication. We studied 14 patients with corticosteroid-dependent asthma who had shown a decline in forced expiratory volume in 1 second (FEV(1)) of at least 80 ml/year and at least 1 exacerbation per year during 2 years of bronchodilator treatment.

Bronchial hyperresponsiveness and exposure in pig farmers.

Objective: To study the effect of exposure on bronchial responsiveness in pig farmers.

Method: A group of 196 pig farmers were tested for lung function and bronchial responsiveness to histamine in the summer of 1992. To achieve sufficient contrast in respiratory morbidity and exposure, 96 of the farmers were selected because they had chronic respiratory symptoms and the remaining 100 because they were free from any respiratory symptoms.

Spirometry in general practice: the performance of practice assistants scored by lung function technicians.

Recently, spirometers have become available for use within general practice as an alternative to peak flow meters. This study investigates whether practice assistants, after comprehensive training, can effectively carry out spirometry with patients suffering from asthma and other chronic obstructive pulmonary diseases. A scoring system, consisting of 20 items, was devised to determine the effectiveness of the assistants' instructions and to assess the patient's subsequent use of the spirometer.

Measurement of quality of life in patients with chronic obstructive pulmonary disease.

In measuring quality of life in chronic obstructive pulmonary disease (COPD) we have to make a distinction between using quality-of-life (QOL) instruments for research or for patient care purposes. For research purposes, these instruments have proven their value. However, for healthcare, the value of these instruments has not yet been established.

Respiratory morbidity in relationship to farm characteristics in swine confinement work: possible preventive measures.

Swine confinement farming is associated with an increased risk of respiratory morbidity. Adverse health effects have been shown in association with levels of dust, endotoxins, and ammonia. This study was conducted to evaluate characteristics of confinement farms associated with respiratory morbidity in order to establish priorities for preventive measures.

Prevalence of asthma and COPD in general practice in 1992: has it changed since 1977?

Background: Asthma and COPD are common diseases of the airways which are mainly diagnosed and treated in general practice.

Aim: Various studies have reported an increase in the morbidity of asthma and COPD. There are two possible reasons for such an increase.

Diagnosis of asthma and chronic obstructive pulmonary disease in general practice.

There may be an overlap between the clinical pictures of asthma and chronic obstructive pulmonary disease which hampers a clear distinction between the two diseases. Most symptoms presented by patients do not clearly belong exclusively to either asthma or chronic obstructive pulmonary disease. By the nature of their discipline and training, general practitioners focus mainly on symptoms presented, which do not give a decisive answer in the differential diagnosis between the two diseases.

Evaluation of the suitability of weekly peak expiratory flow rate measurements in monitoring annual decline in lung function among patients with asthma and chronic bronchitis.

Background: Early detection and treatment of patients with asthma or chronic bronchitis who have a rapid annual decline in lung function is essential in order to improve their long-term prognosis. This annual rate of decline can be assessed accurately by monitoring the forced expiratory volume in one second (FEV1) which is a routine procedure in hospital respiratory laboratories but not in general practice. General practitioners usually measure patients' peak expiratory flow rate (peak flow) to evaluate lung function.

Treatment of mild asthma with inhaled corticosteroids: is discontinuation of therapy possible?

Background: This study investigated if long-term therapy with inhaled corticosteroids could be discontinued in mild asthma when patients are in a clinically stable phase of the disease. Data were derived from a 2-year randomized, controlled, bronchodilator intervention study in family practice.

Methods: The experimental (stop-steroid) group consisted of 19 asthmatic patients who had used inhaled corticosteroids daily during at least the year preceding this study and who stopped using these drugs because of participation in the bronchodilator intervention study.

Asthma and chronic bronchitis. Can family physicians predict rates of progression?

Objective: To investigate whether the progression rate of asthma or chronic bronchitis can be predicted from a cross-sectional assessment of features that can be measured by family physicians.

Design: Secondary analysis of data from a 2-year randomized, controlled bronchodilator intervention study in family practice.

Setting: Twenty-nine general practices in the eastern part of The Netherlands.

Periodic treatment regimens with inhaled steroids in asthma or chronic obstructive pulmonary disease. Is it possible?

Objective: To determine whether inhaled corticosteroids can be discontinued in the stable phase of asthma or chronic obstructive pulmonary disease (COPD) or if this therapy should be continued.

Design: Nonrandomized open uncontrolled 5-year trial.

Setting: Prospective study in general practice.

The influence of an inhaled steroid on quality of life in patients with asthma or COPD.

Relatively little is known about the influence of inhaled corticosteroids on general well-being (quality of life) in patients with asthma or COPD. In a 4-year prospective controlled study, we examined the influence of beclomethasone dipropionate (BDP), 400 micrograms, two times daily, on quality of life in 56 patients with asthma or COPD in comparison with the effects of BDP on symptoms and lung function. During the first 2 years, patients received only bronchodilator therapy with salbutamol or ipratropium bromide.

Continuous and on demand use of bronchodilators in patients with non-steroid dependent asthma and chronic bronchitis: four-year follow-up randomized controlled study.

Background: A previous two-year study of continuous and on demand bronchodilator therapy in patients with moderate asthma and chronic bronchitis showed a deterioration in lung function in those on continuous therapy.

Aim: A two-year follow-up study was undertaken of patients who had been shown in the previous study to have non-steroid dependent (mild) asthma and chronic bronchitis, in order to investigate the effect of continuous and on-demand treatment with bronchodilator therapy.

Method: Patients for the study were drawn from 29 general practices in the catchment area of the University of Nijmegen, the Netherlands.

Does bronchial hyperresponsiveness precede or follow airway obstruction in asthma or COPD?

Objective: The following hypothesis was tested: The degree of bronchial hyperresponsiveness (BHR) is a risk factor for the progression of airway obstruction in asthma, while in chronic obstructive pulmonary disease (COPD) it reflects the existing airway obstruction.

Methods: The relationships between the (annual change in) PC20 histamine and the (annual change in) FEV1 were investigated in a 2-year prospective controlled study. The FEV1 and the PC20 histamine were assessed at 6-month intervals.