In Reply Our study of religious service attendance and suicide controlled for numerous common causes of this relationship; the association was robust after such control, with a 5-fold reduction in suicide for those attending at least weekly.1 The study was observational so it is possible that there are unmeasured common causes. While it would have been good to control for childhood abuse, we used Nurses’ Health Study (NHS) I data. Data on childhood abuse is available in the NHS II, not in the NHS I. The NHS II began to measure attendance in 2008, so the follow-up through 2012 would have been insufficiently short. We did carry out sensitivity analysis for unmeasured confounding, which suggested substantial confounding would be required to explain away the estimate (a confounder would have to be associated with both suicide and attendance by a risk ratio of 12-fold each to explain away the effect estimate, and by 3.7-fold each to shift the confidence interval to include 1). Moreover, control was made for past attendance, so child abuse would have to substantially affect current attendance through pathways independent of past attendance. One cannot be certain about causality with observational data, but the evidence here is relatively strong.
VanderWeele TJ, Li S, Kawachi I. Religious Service Attendance and Suicide Rates—Reply. JAMA Psychiatry. Published online November 30, 2016. doi:10.1001/jamapsychiatry.2016.2780