We thank Dr. Cookson and Dr. Salloum for their interest in our study and possible suggestions for the results we obtained. They suggest that cardiovascular deaths increased in relation to a stock market crash in China but not in Los Angeles because the health care system in Los Angeles was better able to manage acute cardiovascular disease. However, Ma et al observed increases in total and out-of-hospital cardiac deaths in China, but not in in-hospital cardiac deaths, indicating that most deaths were sudden out-of-hospital cardiac deaths. Also, Dr. Cookson and Dr. Salloum suggest that investors may have taken up “short positions” and profited from a stock market crash. However, this is likely to represent only a minority of investors. Most investors (and the public) had financial losses during the stock market crash.

Dr. Cookson and Dr. Salloum suggest the possibility that our study ended too soon. We were looking for signals that were acute or subacute, similar to previously studied events such as the Northridge earthquake, missile attacks, and sporting events. In each of these instances, cardiovascular deaths increased within days or a few weeks. Furthermore, Ma et al investigated different lag structures and observed the largest effect with a 1-day lag after stock market volatility in China. The major portion of the Dow Jones Industrial Average crash occurred in early October 2008 (although it continued into 2009); thus, October, November, and December 2008 should be sufficient to observe an acute or subacute increase in cardiovascular deaths. Nonetheless, we cannot rule out a long-term persistent change.