The review searched seven databases to July 2026 for adult surgical cohorts in which social connection was measured before operation, identifying 445 studies of which 72 yielded poolable estimates, mostly based on marital status. Weaker connection was associated with early postoperative mortality (OR 1.50, 95% CI 1.12-2.01) and non-home discharge (OR 1.95, 1.35-2.81); the primary outcome, all-cause postoperative survival, gave a hazard ratio of 1.37 with a confidence interval spanning 1. Certainty was graded low or very low throughout and every estimable prediction interval included the null.
Why it is interesting: The largest attempt yet to treat social connection as a surgical prognostic exposure finds the signal concentrated in discharge destination and early death, and shows how thin the underlying measurement is — mostly a marital status tick-box.