Independent effect of prior exacerbation frequency and disease severity on the risk of future exacerbations of COPD: a retrospective cohort study

Abstract

Few studies have researched the independent effect of COPD severity on the risk of future exacerbations adjusted by previous exacerbation frequency. We aimed to analyse the independent effect of COPD severity on the risk of exacerbations in the following year, and whether this effect was stronger or not than the effect of a previous history of exacerbations. We conducted a retrospective population-based cohort study including 900 patients with confirmed COPD. Exacerbation frequency was observed for the previous year and for the following year. Patients were defined as ‘Frequent Exacerbator’ (FE) phenotype if they suffered ⩾2 exacerbations in a year, and were categorised according to the severity of COPD (GOLD Grades 1–4). Odds ratios (ORs) were estimated by logistic regression adjusting for age, gender, smoking status, severity of COPD and being FE in the previous year. The main predictor of being FE among all grades of COPD severity was a history of frequent exacerbations in the previous year: adjusted OR 4.97; 95% confidence interval (CI) (3.54–6.97). COPD severity was associated with a higher risk of being FE: Crude OR GOLD Grade 4 3.86; 95% CI (1.50–9.93). However, this association diminished after adjusting for being FE in the previous year: adjusted OR 2.08; 95% CI (0.75–5.82). Our results support that a history of frequent exacerbations in the previous year is the most important independent predictor of exacerbations in the following year, also among the most severe COPD patients. Severity of COPD would be associated with a higher risk of exacerbations, but this effect would be partly determined by the exacerbations suffered in the previous year.

Risk factors of chronic obstructive pulmonary disease exacerbations

“…Prior exacerbations had a sensitivity of 51.9% and a specificity of 85.8% for the frequency of the exacerbation in the following year. The frequency of AECOPD in the previous year was the most important independent predictor of severity of “frequent exacerbations” in the following year …”

“…According to both older and newer published research, the most consistent predictor of COPD exacerbations is a previous history of exacerbations …”

“…According to both older and newer published research, the most consistent predictor of COPD exacerbations is a previous history of exacerbations. 37,[58][59][60][61][62] A recent Portuguese study 59 analysing the 5-year prediction of the combination of exacerbations, hospital admissions and mortality in stable COPD patients, previous year exacerbation represented the best predictor of the future risk of exacerbations, independent of severity. During the 5-year follow-up, almost 70% of GOLD C patients and almost 90% of GOLD D patients suffered exacerbations.…”

“…The frequency of AECOPD in the previous year was the most important independent predictor of severity of "frequent exacerbations" in the following year. 60 The exacerbation history is one of the most important risk factors for hospitalisation, death and future exacerbations. The risk for AECOPD is also directly correlated with age and with lung function impairment.…”

<p>Modelling the Cost-Effectiveness of Indacaterol/Glycopyrronium versus Salmeterol/Fluticasone Using a Novel Markov Exacerbation-Based Approach</p>

“…Exacerbations formed the basis of the health states given their importance as drivers of future events [25][26][27][28][29][30] and COPD-related economic costs. [31][32][33][34][35] The model was developed using R programming language (RStudio version 1.1.383, R version 3.4.2).…”