Cross-national analysis of the prevalence of prolonged grief disorder

Background
Prolonged grief disorder (PGD) is now included as a diagnosis in international classification systems. Most research on PGD is based on Western populations, but first data from non-Western countries have recently become available. Little is still known about country-related effects on PGD's prevalence.

Objective
Determining possible causes of variations in the prevalence of PGD as defined by DSM-5-TR and ICD-11 within and between countries.

Methods
We retrieved data from 24 prevalence studies, the World Bank and the 2022 World Risk Report. Negative binomial regressions were used to explore methodological, loss-related and country context characteristics as predictors of PGD. The average rate of PGD was calculated using random effects models.

Results
The included studies comprised 34 samples from 16 countries (20,347 participants). Non-probability sampling and older mean age of the sample as well as lower country vulnerability were associated with higher PGD rates. The average PGD prevalence was 13 % (95 % CI [11, 22]), varying from 5 % (95 % CI [3, 11]) in probability to 16 % (95 % CI [13, 25]) in non-probability samples.

Limitations
Samples from Europe and North America were overrepresented. For about half of the countries, data were available from only one sample.

Conclusions
While confirming the importance of studies' methodological quality, the results show that PGD is of public health relevance around the world, but especially common in less vulnerabled countries with better access to daily necessities and healthcare services, highlighting sociocultural impacts on grief processing. Further investigations of cross-national differences are needed.

Highlights

•  This is the first investigation cross-country variations in prevalence rates of prolonged grief disorder (PGD)
•  On the basis of 34 samples from 16 countries, we found that PGD rates could be predicted by age, sampling approach, and country vulnerability
•  This shows that PGD is of relevance around the world, but seems to be more common in less vulnerable countries with good access to daily necessities and healthcare services