Stock volatility and hospital admissions for cardiovascular disease: results from the National Insurance Claims for Epidemiological Research (NICER) study

BACKGROUND: The association between stock volatility and cardiovascular diseases (CVD) was described during the 2008 Global Stock Market Crash; however, whether the finding in an occasional stock market crash is spurious remains unclear. METHODS: A time-series design was used to evaluate the association between short-term exposure to daily returns of two major indices and daily hospital admissions for CVD and its subtypes based on claims data from the National Insurance Claims for Epidemiological Research (NICER) study covering 174 major cities in China. The average percentage change in daily hospital admissions for cause-specific CVD per 1% change in daily index returns was calculated because the Chinese stock market policy limits its change by 10% of the previous day's closing price. A Poisson regression in a generalised additive model was used to assess the city-specific association; then, overall national estimations were pooled by random-effects meta-analysis. FINDINGS: Totally 8,234,164 hospital admissions for CVD were recorded during 2014–2017. Points of the Shanghai closing indices ranged from 1991·3 to 5166·4. A U-shaped association was observed between daily index returns and CVD admissions. Changes of 1% in daily returns of the Shanghai index corresponded to 1·28%(95%CI: 1·04%–1·53%), 1·25%(0·99%–1·51%), 1·42%(1·13%–1·72%), and 1·14%(0·39%–1·89%) increases in hospital admissions for total CVD, ischaemic heart disease, stroke, or heart failure on the same day, respectively. Similar results were observed for the Shenzhen index. INTERPRETATION: Stock market volatility is associated with an increased CVD admission. FUNDING: Chinese Ministry of Science and Technology (2020YFC2003503) and National Natural Science Foundation of China (81973132, 81961128006).