Systematic Review and Meta-Analysis of Mortality in Patients With Anorexia Nervosa

Objective: Anorexia nervosa (AN) has one of the highest mortality rates among psychiatric disorders. This systematic review and meta-analysis examined the all-cause mortality of AN patients compared to the general population using the standardized mortality ratio (SMR). Method: MEDLINE, PsycINFO, EMBASE, WOS, Dissertations and Theses A&I, and Google Scholar were searched from inception to May 2025 for longitudinal studies reporting all-cause SMR for AN patients. Risk of bias was assessed using the Newcastle-Ottawa Scale. Random-effects meta-analysis was conducted and presented as a forest plot. Subgroup and meta-regression analyses were done. SMRs for male- and female-specific samples were compared. Results: Thirty studies involving 33,176 patients were identified. The pooled SMR from 22 studies was 5.06 (95% CI [3.47–7.38]). Suicide and cardiac deaths accounted for 21% and 19% of deaths, respectively. Studies with lower mean BMI were associated with higher SMRs before correction for multiple testing (p = 0.018, adjusted p = 0.252). The pooled SMR of male-specific samples was 3.47, 95% CI (1.60–7.52), similar to female-specific samples (3.86, 95% CI [1.82–8.20]). Discussions: Our findings confirm that AN remains a severe psychiatric disorder, underscoring the clinical importance of suicide prevention and monitoring cardiac complications. A low BMI is a crucial clinical indicator for high-risk groups and allocating resources. Limitations include excluding studies with zero deaths, substantial heterogeneity among included studies, the underrepresentation of male and non-Western populations, and most studies originating from specialist clinics.