RT Journal Article
SR Electronic
T1 Effects of Smoking, Depression, and Anxiety on Mortality in COPD Patients: A Prospective Study
JF Respiratory Care
FD American Association for Respiratory Care
SP 54
OP 61
DO 10.4187/respcare.02487
VO 59
IS 1
A1 Peian Lou
A1 Peipei Chen
A1 Pan Zhang
A1 Jiaxi Yu
A1 Yong Wang
A1 Na Chen
A1 Lei Zhang
A1 Hongmin Wu
A1 Jing Zhao
YR 2014
UL http://rc.rcjournal.com/content/59/1/54.abstract
AB BACKGROUND: Smoking, depression, and anxiety increase the risk of death in patients with COPD, but the combined effect of these factors is unknown. We assessed the interactive effects of smoking, depression, and anxiety on mortality in patients with COPD. METHODS: We collected and analyzed data from 7,787 subjects with COPD, in 14 rural communities, from May 2008 to May 2012, and used logistic regression to evaluate the interactions and relative excess risk due to interaction (RERI). We applied the attributable proportion of interaction and the synergy index to evaluate the additive interactions of the factors. RESULTS: In our COPD subjects the interaction of current smoking and depression symptoms increased the death risk by 3.8-fold (odds ratio 3.78, 95% CI 2.51–5.05), with significant biological interactions (RERI 1.74, 95% CI 0.51−2.99, attributable proportion 0.48, 95% CI 0.13–0.85, synergy index 2.98, 95% CI 1.44–4.56). The biological interactions increased with increasing years or pack-years of smoking: for subjects with ≥ 30 years of smoking: RERI 1.80, 95% CI 1.05–2.75, attributable proportion 0.48, 95% CI 0.15–0.82, synergy index 2.85, 95% CI 1.75–3.96; for subjects with ≥ 40 pack-years of smoking: RERI 3.11, 95% CI 1.54–4.71, attributable proportion 0.60, 95% CI 0.31–0.91, synergy index 4.00, 95% CI 2.84–5.26. Similarly, the combined effect of current smoking and anxiety symptoms increased the death risk by 4.3-fold (odds ratio 4.27, 95% CI 95% CI 2.96–5.59), with significant biological interactions (RERI 1.51, 95% CI 0.31–2.74, attributable proportion 0.46, 95% CI 0.11–0.87, synergy index 2.89, 95% CI 1.31–4.51). The biological interactions also increased with increasing years or pack-years of smoking: for subjects with ≥ 30 years of smoking: RERI 1.41, 95% CI 0.45–2.43, attributable proportion 0.45, 95% CI 0.12–0.81, synergy index 2.88, 95% CI 1.24–5.98; for subjects with ≥ 40 pack-years of smoking: RERI 3.15, 95% CI 2.07–4.61, attributable proportion 0.55, 95% CI 0.21–0.94, synergy index 3.00, 95% CI 1.45–4.75. CONCLUSIONS: Smoking, depression, and anxiety are associated with higher risk of death in patients with COPD. The risk of death, depression, and anxiety increases with increasing duration of smoking (years) and cigarette pack-years. Chinese Clinical Trials Registration ChiCTR-TRC-12001958.