Laxative use after cardiac arrest: exposure timing, treatment selection, and outcome interpretation

Abstract

We commend Duan et al. for examining laxative use after cardiac arrest. However, because follow-up began at return of spontaneous circulation, whereas exposure timing was not reported, the observed association may reflect both immortal time and treatment selection: patients who survived and recovered sufficiently may have been more likely to receive laxatives. A time-varying exposure defined by first administration, with landmark analysis as a sensitivity analysis, would better align treatment and risk time. The reported time-varying-effect model does not estimate the effect of initiating treatment on a particular day and, therefore, cannot support a 15-day treatment window. The findings should be framed as observational associations rather than evidence that laxatives improve survival.

The authors' abstract, as published at the source. Journal of Intensive Care, 2026 · DOI ↗