SEASONALITY OF HOSPITALIZATION FOR ALCOHOL USE DISORDERS: A CROSS-SECTIONAL STUDY IN CHINA

Abstract Background Seasonal patterns have been observed in several psychiatric disorders such as depression and schizophrenia, but there is no consensus on the seasonality of alcohol use disorders. Objectives We thus retrospectively analyzed a large-scale database to explore whether seasonality affects hospitalization for alcohol use disorders. Method In this study, a total of 14,357 inpatients with alcohol use disorders were recruited over a 7- year time span, and after applying rigorous data criteria, 2,176 inpatients were ultimately included in the statistical analysis. Results Patients with alcohol use disorders admitted in various seasons had significant differences in length of stay (H=13.592, df=3, P=0.004), and corrected Bonferroni post hoc tests suggested that patients admitted in spring had a shorter length of stay than in the other three seasons (P=0.009, P=0.013, P=0.048 for summer, autumn and winter, respectively). In addition, seasonality may have influenced the relapse of the disease. We found that disease recurrence was unevenly distributed across various seasons (X2=10.486, df=3, P=0.015), with corrected Bonferroni post hoc tests suggested a higher proportion of recurrent admissions in summer(P<0.05). We then performed a Binary logistic regression, and the effect of seasonality on disease recurrence remained significant after controlling for gender, occupation, and marital status. Taking winter as a reference, the risk of relapse was higher in spring and summer (OR=1.284, 95CI%=1.00-1.65, P=0.048; OR=1.393, 95CI%=1.08-1.80, P=0.011, respectively). Conclusion This is the first large sample size study to explore the seasonality of hospitalization for alcohol use disorders in a Chinese population. Our study found that patients with alcohol use disorders admitted in the spring had shorter hospital stays, but also had more relapses in the spring and summer. These findings will contribute to the exploration of risk factors for alcohol use disorders as well as provide preliminary evidence for clinical development of prevention strategies.