Project

Comorbidities and burden of COPD: a population based case-control study

Completed · 2011 until 2013

Type
Fundamental Research
Range
Monocentric project at KSSG
Units
Status
Completed
Start Date
2011
End Date
2013
Financing
Industry
Brief description/objective

COPD is associated with a relevant burden of disease and a high mortality worldwide. Only recently, the importance of comorbidities of COPD has been recognized. Studies postulated an association with
inflammatory conditions potentially sharing pathogenic pathways and worsening overall prognosis. More evidence is required to estimate the role of comorbidities of COPD. Our aim was to investigate the
prevalence and clustering of comorbidities associated with COPD, and to estimate their impact on clinically relevant outcomes. In this population-based case-control study, a nation-wide database provided
by the Swiss Federal Office for Statistics enclosing every hospital entry covering the years 2002-2010 (n = 12’888’075) was analyzed using MySQL and R statistical software. Statistical methods included
non-parametric hypothesis testing by means of Fisher’s exact test and Wilcoxon rank sum test, as well as linear models with generalized estimating equation to account for intra-patient variability. Exploratory multivariate approaches were also used for the identification of clusters of comorbidities in COPD patients. In 2.6% (6.3% in patients aged > 70 years) of all hospitalization cases an active diagnosis of COPD was recorded. In 21% of these cases, COPD was the main reason for hospitalization. Patients with a diagnosis of COPD had more comorbidities (7 [IQR 4-9] vs. 3 [IQR 1-6]; p < 0.001), were more frequently rehospitalized (annual hospitalization rate 0.33 [IQR 0.20-0.67] vs. 0.25 [IQR 0.14 - 0.43]/year; p < 0.001), had a longer hospital stay (9 [IQR 4-15] vs. 5 [IQR 2-11] days; p < 0.001), and had higher in-hospital mortality (5.9% [95% CI 5.8%-5.9%] vs. 3.4% [95% CI 3.3%-3.5%]; p < 0.001) compared to matched controls. A set of comorbidities was associated with worse outcome. We could identify COPD-related clusters of COPD-comorbidities.