The prevalence of prolonged grief disorder in bereaved individuals following unnatural losses: Systematic review and meta regression analysis

Background: Previous research has indicated that one out of ten naturally bereaved individuals develops prolonged grief disorder (PGD). Less is known about the prevalence of PGD following unnatural deaths, such as accidents, disasters, suicides, or homicides. The aim of this study was to compute the pooled prevalence of PGD and to determine possible causes of its varied estimates. Methods: A literature search was conducted in PsycINFO, Ovid Medline, PILOTS, Embase, Web of Science, and CINAHL. A meta-analysis using random effects models was performed to calculate the pooled prevalence rate of PGD. Multivariate meta-regression was used to explore heterogeneity among the studies. Results: Twenty-five articles met eligibility criteria. The random-effects pooled prevalence was 49%, 95% CI [33.6, 65.4]. Death of only child, violent killings and non-western study location were associated with a higher PGD prevalence. A longer time since loss and a loss in a natural disaster were associated with a lower PGD prevalence. Limitations: These findings should be interpreted with caution, because of the heterogeneity in study methodology. Conclusions: This first meta-analysis of PGD following unnatural losses indicated that nearly half of the bereaved adults experienced PGD. This illustrates the importance of assessing PGD in individuals affected by loss and trauma.