The prevalence of chronic obstructive pulmonary disease (COPD) and its subsequent burden on health care differ from country to country but is extensive in most populations.1 COPD exacerbations contribute substantially to the burden by generating the majority of costs due to the use of healthcare services2 and by provoking significant impact on patients' health status.3 In the Netherlands, the burden of COPD mainly affects GPs as most patients with COPD are managed in primary care; as such, there is a growing need to identify changes in the burden and to redirect care to those demographic subgroups that are at highest risk of COPD and its exacerbations. In this context, trend studies may be very useful. So far, most COPD trend studies have used data from national health surveys to estimate trends in the general population,4,5 and so their results may not reflect the burden in general practice.
A recent trend study using data from a general practice network demonstrated a constant rise of physician-diagnosed COPD in women.6 This could be caused by the increase of tobacco use in women relative to men in the past few decades. The risk of developing COPD in smokers is related to the lifetime cumulative dose, which explains the finding that it is mostly diagnosed in people aged ≥65 years and is highly unlikely in those aged <40 years.5 Independent from smoking, socioeconomic status is an important risk factor for COPD.7 In addition, factors linked to socioeconomic status, such as respiratory tract infections, housing conditions, air pollution, and diet each contribute to the risk of having exacerbations.8–10 Obviously, sex, age, and socioeconomic differences are important factors that can influence trend changes of COPD and exacerbations. Although these factors are well registered in general practice registration networks, their roles have not been well studied in COPD trend studies in primary care.
How this fits in
Changes in the burden of chronic obstructive pulmonary disease (COPD) on primary care are not well studied. This long-term trend study demonstrated a decrease in the overall prevalence of physician-diagnosed COPD and in exacerbation rates in Dutch general practices. However, the prevalence of COPD has increased in women, in particular those aged ≥65 years with low socioeconomic status. These results indicate the need to focus more on this subgroup in COPD diagnosing, management and research.
In this article, long-term trends in physician-diagnosed COPD prevalence and COPD exacerbations in the period 1980–2006 are reported by prospectively studying a dynamic cohort from the Continuous Morbidity Registration Nijmegen. The aim was to identify trend changes in COPD prevalences and COPD exacerbation occurrence rates in different subgroups of the general practice population.