Seasonality and determinants of moderate and severe COPD exacerbations in the TORCH study

Abstract

We investigated the impact of season relative to other determinants of chronic obstructive pulmonary disease (COPD) exacerbation frequency in a long-term international study of patients with forced expiratory volume in 1 s (FEV1) ,60% predicted. COPD exacerbations were defined by worsening symptoms requiring systemic corticosteroids and/or antibiotics (moderate) or hospital admission (severe). Seasonality effect was calculated as the proportion of patients experiencing an exacerbation each month.Exacerbations in the northern and southern regions showed an almost two-fold increase in the winter months. No seasonal pattern occurred in the tropics. Overall, 38% of exacerbations were treated with antibiotics only, 19% with systemic corticosteroids only and 43% with both, while 20% required hospital admission irrespective of the season. Exacerbation frequency was associated with older age, lower body mass index, lower FEV1 % pred and history of prior exacerbations. Females and patients with worse baseline breathlessness, assessed using the Medical Research Council (MRC) dyspnoea scale, exacerbated more often (rate ratio (RR) for male versus female 0.7, 95% CI 0.7-0.8 (p,0.001); RR for MRC dyspnoea score 3 versus 1 and 2 combined 1.1, 95% CI 1.1-1.2 (p,0.001)). The effect of season was independent of these risk factors.COPD exacerbations and hospitalisations were more frequent in winter.

A trial of beclomethasone/formoterol in COPD using EXACT-PRO to measure exacerbations

“…The recruitment approach employed in the study was specifically designed to enrich the patient population by ensuring the recruitment of patients prone to exacerbations. The frequency and severity of COPD exacerbations is worse during the winter season [4,5] and the study design is optimised to capture such seasonal events by randomising patients immediately before the winter peak of exacerbations. Furthermore, the use of EXACT scores transmitted digitally on a daily basis may provide a sensitive way to detect and monitor exacerbation events, and thus enable differences between the study treatments to be accurately determined.…”

“…COPD patients often experience exacerbations, which are an acute worsening of symptoms beyond the normal dayto-day variation [1]. Exacerbations of COPD, which are associated with a worse quality of life [2] and increased mortality [3], are more frequent during the winter season [4,5], being associated with an increased prevalence of infections with respiratory viruses [6]. These winter exacerbations have a greater impact on patients in terms of hospitalisations and recovery [5].…”

Global Associations between Air Pollutants and Chronic Obstructive Pulmonary Disease Hospitalizations: A Systematic Review

“…The confounding effects of temperature and humidity add further challenges. Although we know that there are seasonal effects on COPD exacerbations in northern and southern regions (49), the relationships between temperature and humidity and COPD admissions are not clear.…”

Acute exacerbation of chronic obstructive pulmonary disease: predictors of outcome: single center prospective study from India

“…This was in accordance to other studies by Husebo et al and others. [32][33][34][35] There was no difference in the number of exacerbations between the smokers and ex-smokers. This could conclude that the stoppage of the smoking was too late.…”