Introduction: Poor psychological health has been documented in the bereaved, with approximately 10% to 20% experiencing PGD. Early identification of caregivers with sub-clinical PGD is required to ameliorate the associated distress and potentially prevent difficult to treat PGD. Utilising a large population-based cohort of bereaved caregivers, the aim of this study is to report the prevalence of, and explore the predictors of, clinical and sub-clinical levels of PGD.

Method: Participants were caregivers of cancer patients admitted to three Victorian palliative care (PC) services who were subsequently bereaved. Baseline data were collected upon patient admission (T1), then six (T2), 13 (T3) and 37 (T4) months post-bereavement. Validated self-report measures, including the Prolonged Grief Disorder Scale (PG-13), were administered at each time point. Caregivers were identified as having sub-threshold PGD if they met three of the four criteria required for a PGD diagnosis.

Results: Of 301 caregivers completing the PG-13 at T1, 15% met criteria for PGD, 7% at T2, 11% at T3, and 5% at T4. Sub-threshold PGD was more common, 29% at T2, 20% at T3, and 14% at T4. Using the PG-13 summary score, multiple linear regression analysis including family functioning, social support, dependency, death circumstances, pre-loss anticipatory grief, and self-rated coping at T2, found that pre-loss anticipatory grief (p<.0001) and self-rated coping at T2 (p=.0004) significantly predicted PGD at T4.

Conclusions: The prevalence of PGD was low, however the number of caregivers with sub-threshold PGD was high. Caregiver pre-loss PG at T1 and caregiver self-assessment at T2 were predictive of PGD in the longer-term, suggesting value to screening at these times. Simply asking caregivers how they are coping at six months post-bereavement may be effective in identifying those at high risk of PGD. PC bereavement services are potentially well placed to conduct such screening and institute early intervention.