Posttraumatic stress in adult civilians exposed to violent conflict, war and associated human rights abuses in the Eastern Mediterranean Region: A systematic review and meta-analysis.

Background: The Eastern Mediterranean Region (EMR) is the stage of the world's most violent conflicts and the origin of the largest refugee population worldwide. These conflicts can result in symptoms of posttraumatic stress (PTS). To date, no comprehensive meta-analysis on proportions of PTS in civilians from the EMR has been conducted. Sample characteristics, methodological, conflict-related and displacement-related factors might affect rates of PTS.

Methods: A systematic literature search for studies investigating PTS in adult civilians from the EMR was conducted until March 2020 and resulted in 118 individual study samples that were suitable for inclusion. A quality assessment was conducted. A random effects meta-analysis on proportions and sensitivity analyses were performed, and a 95% prediction interval was calculated. Subgroup analyses to identify moderators (e.g. diagnostic instruments, displacement) were conducted.

Results: The quality of the included study samples varied. The pooled estimate of proportions from all 118 study samples was 0.31 (95% CI: 0.27 - 0.35). Heterogeneity was considerable (Q = 10151.58, p < .0001; I = 98.64%). The prediction interval was 0.01 to 0.76. The results remained unchanged after excluding nine outlier study samples. Heterogeneity remained high in all subgroups (range of I: 87.91 to 99.62).

Limitations: Due to heterogeneity the pooled estimate cannot be interpreted. Moderators contributing to heterogeneity could not be detected.

Conclusions: The proportion of symptoms of PTS in civilians from the EMR varies considerably. The prediction interval indicates that the true rate falls between 1% and 76%. Future studies need to identify variables that affect heterogeneity.