TY - JOUR
T1 - Risk of community-acquired pneumonia in chronic obstructive pulmonary disease stratified by smoking status
T2 - a population-based cohort study in the United Kingdom
AU - Braeken, Dionne C. W.
AU - Rohde, Gernot G. U.
AU - Franssen, Frits M. E.
AU - Driessen, Johanna H. M.
AU - van Staa, Tjeerd P.
AU - Souverein, Patrick C.
AU - Wouters, Emiel F. M.
AU - de Vries, Frank
PY - 2017
Y1 - 2017
N2 - Background: Smoking increases the risk of community-acquired pneumonia (CAP) and is associated with the development of COPD. Until now, it is unclear whether CAP in COPD is due to smoking-related effects, or due to COPD pathophysiology itself.Objective: To evaluate the association between COPD and CAP by smoking status.Methods: In total, 62,621 COPD and 191,654 control subjects, matched by year of birth, gender and primary care practice, were extracted from the Clinical Practice Research Datalink (2005-2014). Incidence rates (IRs) were estimated by dividing the total number of CAP cases by the cumulative person-time at risk. Time-varying Cox proportional hazard models were used to estimate the hazard ratios (HRs) for CAP in COPD patients versus controls. HRs of CAP by smoking status were calculated by stratified analyses in COPD patients versus controls and within both subgroups with never smoking as reference.Results: IRs of CAP in COPD patients (32.00/1,000 person-years) and controls (6.75/1,000 person-years) increased with age and female gender. The risk of CAP in COPD patients was higher than in controls (HR 4.51, 95% CI: 4.27-4.77). Current smoking COPD patients had comparable CAP risk (HR 0.92, 95% CI: 0.82-1.02) as never smoking COPD patients (reference), whereas current smoking controls had a higher risk (HR 1.23, 95% CI: 1.13-1.34) compared to never smoking controls.Conclusion: COPD patients have a fourfold increased risk to develop CAP, independent of smoking status. Identification of factors related with the increased risk of CAP in COPD is warranted, in order to improve the management of patients at risk.
AB - Background: Smoking increases the risk of community-acquired pneumonia (CAP) and is associated with the development of COPD. Until now, it is unclear whether CAP in COPD is due to smoking-related effects, or due to COPD pathophysiology itself.Objective: To evaluate the association between COPD and CAP by smoking status.Methods: In total, 62,621 COPD and 191,654 control subjects, matched by year of birth, gender and primary care practice, were extracted from the Clinical Practice Research Datalink (2005-2014). Incidence rates (IRs) were estimated by dividing the total number of CAP cases by the cumulative person-time at risk. Time-varying Cox proportional hazard models were used to estimate the hazard ratios (HRs) for CAP in COPD patients versus controls. HRs of CAP by smoking status were calculated by stratified analyses in COPD patients versus controls and within both subgroups with never smoking as reference.Results: IRs of CAP in COPD patients (32.00/1,000 person-years) and controls (6.75/1,000 person-years) increased with age and female gender. The risk of CAP in COPD patients was higher than in controls (HR 4.51, 95% CI: 4.27-4.77). Current smoking COPD patients had comparable CAP risk (HR 0.92, 95% CI: 0.82-1.02) as never smoking COPD patients (reference), whereas current smoking controls had a higher risk (HR 1.23, 95% CI: 1.13-1.34) compared to never smoking controls.Conclusion: COPD patients have a fourfold increased risk to develop CAP, independent of smoking status. Identification of factors related with the increased risk of CAP in COPD is warranted, in order to improve the management of patients at risk.
KW - COPD
KW - respiratory infections
KW - incidence
KW - smoking risk
KW - PRACTICE RESEARCH DATABASE
KW - INHALED CORTICOSTEROIDS
KW - CESSATION INTERVENTIONS
KW - CIGARETTE-SMOKING
KW - TOBACCO SMOKING
KW - COPD PATIENTS
KW - OUTCOMES
KW - ADULTS
KW - CARE
KW - HOSPITALIZATION
U2 - 10.2147/COPD.S138435
DO - 10.2147/COPD.S138435
M3 - Article
C2 - 28860737
SN - 1178-2005
VL - 12
SP - 2425
EP - 2432
JO - International journal of chronic obstructive pulmonary disease
JF - International journal of chronic obstructive pulmonary disease
ER -