Co-morbid psychological dysfunction is associated with a higher risk of asthma exacerbations: a systematic review and meta-analysis

Background: The longitudinal associations between psychological dysfunction (PD) and asthma exacerbations (AE) have not been adequately addressed. This study aimed to systematically assess the influence of PD on AE, and to determine whether different PD affects AE differentially. Methods: Electronic databases (PubMed, Cochrane library, Web of Science, Embase, and Ovid) were searched for prospective cohort studies on the influence of PD on AE in individuals with asthma. Relative risk (RR) and adjusted RR (RRadj) were pooled across studies. Subgroup analyses assessed the effects of different types of PD and the time-dependent response to the duration of PD exposure. Results: Ten articles that involved 31,432 adults with asthma with follow-up of 6.0-86.4 months were included. PD significantly increased the risk of AE [RRadj = 1.06, 95% confidence interval (95% CI): 1.04-1.09, P< 0.001], presenting as hospitalizations (RRadj = 1.22, 95% CI: 1.12-1.34, P< 0.001), unscheduled doctor visits (RR = 4.26, 95% CI: 2.52-7.19), and emergency department (ED) visits (RRadj = 1.06, 95% CI: 1.01-1.10, P= 0.009) because of asthma. Depression significantly increased the risk of AE (RRadj = 1.07, 95% CI: 1.04-1.11, P< 0.001), presenting as hospitalizations (RRadj = 1.26, 95% CI: 1.07-1.49, P= 0.007) and ED visits (RRadj = 1.06, 95% CI: 1.02-1.11, P= 0.007) because of asthma. Anxiety was only associated with an increased risk of AE in pregnant women (RR = 1.05, 95% CI: 1.01-1.08), possibly due to the small amount of data available on anxiety. The influence of PD on AE was only significant when the PD exposure time exceeded one year. Conclusions: Co-morbid PD adversely affects AE, and there are differential effects of depression and anxiety. Asthmatic subjects with PD may benefit from more attention when establishing a treatment regimen in clinical practice.