ABSTRACT Background There is a critical gap between the need for eating disorder (ED) treatment and provider availability. Single‐Session Interventions (SSIs) are structured programs intentionally designed for a single client encounter and show promise for filling ED‐treatment and prevention gaps by enhancing accessibility of evidence‐based intervention. Recent studies have started to examine the efficacy of SSIs for various ED concerns, ranging from prevention to symptom reduction. A robust examination of the efficacy of SSIs in addressing ED concerns is thus needed. Objective This review assessed whether, and to what degree, ED SSIs are efficacious. Further, this study examined whether the efficacy of SSIs was moderated by SSI function (i.e., treatment versus prevention), SSI implementation format (i.e., self‐guided versus provider delivered), SSI administration method (i.e., remote versus in‐person), and follow‐up duration after SSI completion. Method Systematic review and meta‐analysis were conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta‐Analysis guidelines. A multi‐level random effects meta‐analysis using a restricted maximum likelihood estimator was conducted to synthesize effect sizes from 22 primary studies ( k = 331 effect sizes). Multi‐level meta‐regression was conducted to test moderators of ED SSI efficacy. Findings from non‐randomized trial design studies were qualitatively synthesized. Results Overall Hedge's g effect size for efficacy of ED SSIs from 22 studies was significant with a small effect ( g = −0.23, 95% CI = −0.40 to −0.05, p < 0.01). There was no heterogeneity between studies (between‐study σ 2 = 0.00), but there was high heterogeneity in effect sizes within studies (within‐study σ 2 = 2.65). Moderator analyses demonstrated that ED SSIs were significantly efficacious for reducing ED‐related symptoms, reducing other mental health concerns, and enhancing quality of life. ED SSI efficacy was significantly different from zero for self‐guided SSIs and remotely delivered SSIs. Finally, ED SSIs demonstrated efficacy immediately following intervention completion, and the efficacy did not strengthen or weaken at follow up. Discussion Findings supported that SSIs reduced ED concerns, which suggests that SSIs have the potential to reduce the public‐health burden of EDs by improving scalability of prevention and treatment.
Negi et al. (Sun,) studied this question.