Does the 'Chinese New Year effect' exist? Hospital mortality in patients admitted to internal medicine departments during official consecutive holidays: a nationwide population-based cohort study

Abstract

Objective: Our study aimed to compare the mortality risk among patients admitted to internal medicine departments during official consecutive holidays (using Chinese New Year holidays as an indicator) with that of weekend and weekday admissions.

Design: Nationwide population-based cohort study.

Setting: Taiwan's National Health Insurance Research Database.

Patients: Patients admitted to internal medicine departments in acute care hospitals during January and February each year between 2001 and 2013 were identified. Admissions were categorised as: Chinese New Year holiday (n=10 779), weekend (n=35 870) or weekday admissions (n=143 529).

Outcome measures: ORs for in-hospital mortality and 30-day mortality were calculated using multivariate logistic regression with adjustment for confounders.

Results: Both in-hospital and 30-day mortality were significantly higher for patients admitted during the Chinese New Year holidays and on weekends compared with those admitted on weekdays. Chinese New Year holiday admissions had a 38% and 40% increased risk of in-hospital (OR=1.38, 95% CI 1.27 to 1.50, p<0.001) and 30-day (OR=1.40, 95% CI 1.31 to 1.50, p<0.001) mortality, respectively, compared with weekday admissions. Weekend admissions had a 17% and 19% increased risk of in-hospital (OR=1.17, 95% CI 1.10 to 1.23, p<0.001) and 30-day (OR=1.19, 95% CI 1.14 to 1.24, p<0.001) mortality, respectively, compared with weekday admissions. Analyses stratified by principal diagnosis revealed that the increase in in-hospital mortality risk was highest for patients admitted on Chinese New Year holidays with a diagnosis of ischaemic heart disease (OR=3.43, 95% CI 2.46 to 4.80, p<0.001).

Conclusions: The mortality risk was highest for patients admitted during Chinese New Year holidays, followed by weekend admissions, and then weekday admissions. Further studies are necessary to identify the underlying causes and develop strategies to improve outcomes for patients admitted during official consecutive holidays.

Keywords: Chinese New Year; cohort study; holiday; internal medicine; mortality; weekend effect.