Testing the latent structure of ICD-11 prolonged grief disorder symptoms in the U.K. adult population: An exploratory structural equation modeling approach

Testing the distinctiveness of prolonged grief disorder from posttraumatic stress disorder and depression in large bereaved community samples

BACKGROUND

This study sought to test the distinctiveness of symptoms of prolonged grief disorder (PGD) from posttraumatic stress disorder (PTSD) and depression.

METHODS

Confirmatory factor analysis (CFA) and target exploratory factor analysis (EFA), were used to test the distinctiveness of PGD from PTSD and depression symptoms in a large sample of adults bereaved for at least six months (N = 1917). Identified factors were explored in relation to demographic (i.e., age, gender) and loss-related (i.e., time since bereavement, nature of death, relationship to deceased, age of deceased, and frequency of contact with deceased) correlates.

RESULTS

The CFA model provided a good fit to the data, while the target EFA provided a slightly improved fit. All items loading strongly and significantly onto their respectively factors, and the IGQ items had few significant cross-factor loadings. All demographic and loss-related variables (except for death of a sibling and death from other causes) were associated with each of the factors, however, these associations were strongest for the PGD factor.

LIMITATIONS

Participants were recruited using a non-probability sampling method and were from a relatively affluent Western nation.

CONCLUSION

Findings from the current study demonstrate that PGD reflects an empirically distinguishable albeit related disorder to PTSD and depression in a sample of bereaved adults. The identification of correlates common to PGD, PTSD, and depression, as well as those unique to PGD, affords a comprehensive understanding of the risk factors associated with bereavement-related psychopathology.

Differential correlates of prolonged grief and depression after bereavement in a population-based sample

Bereavement can lead to prolonged grief disorder (PGD) as well as episodes of major depression. Studies on the prevalence of PGD and its differences from postbereavement depression have not been conclusive. This study compared the correlates of depression and prolonged grief (PG) symptoms in a population-based random sample (N = 535) using the Beck Depression Inventory, Inventory of Complicated Grief-Revised, Anxiety Sensitivity Index (ASI), and Adult Separation Anxiety Questionnaire (ASAQ). Correlates of PG and depressive symptoms were examined using linear regression in 328 bereaved respondents. The prevalence of probable PGD based on PGD-2009 criteria was 3.0% among bereaved respondents and 1.9% in the total sample. PG was related to bereavement-related features including sex of the deceased, β = - .110, p = .026; time since loss, β = - .179, p = .001; the number of lifetime losses experienced, β = .157, p = .016; and perceived closeness with the deceased, β = .214, p < .001. Only lower income of the bereaved predicted depression, β = - .139, p = .018. In women, but not in men, the loss of a male family member (i.e., brother or son) was a significant predictor of PG symptoms, β = - .180, p = .006. The results confirm the qualitative distinction between depression and PG in a nonclinical sample and show that PG is mainly related to the intrinsic and extrinsic characteristics of the deceased or of death, whereas depression relates only to the characteristics of the bereaved person.

The International Grief Questionnaire (IGQ): A new measure of ICD-11 prolonged grief disorder

Prolonged grief disorder (PGD) is included in the 11th version of the International Statistical Classification of Diseases and Related Health Problems (ICD-11). This study sought to test the validity and reliability of a new brief measure to screen for ICD-11 PGD-the International Grief Questionnaire (IGQ). The psychometric properties of the IGQ were tested using data collected from two bereaved samples of adults from the United Kingdom (n = 1,012) and Ireland (n = 1,011). Confirmatory factor analysis demonstrated that a correlated two-factor model best captured the latent dimensionality of the IGQ in both samples. Estimates of internal reliability were high, whereas the convergent and concurrent validity of the scale were supported through strong associations with external measures. Measurement invariance and differential item functioning testing showed no statistically significant difference in the latent structure of the IGQ nor the functioning of the IGQ items by age, sex, and nationality. For participants who were bereaved for more than 6 months, the rates of probable PGD derived from the IGQ were 10.9% and 15.3% for the Irish and U.K. samples, respectively. The IGQ is a brief, easy-to-use, self-report screening measure that captures all diagnostic criteria of PGD set forth in the ICD-11. Findings from this study provide initial support for the validity, measurement invariance, and reliability of the IGQ among two national samples.