High score on the Relative Stress Scale, a marker of possible psychiatric disorder in family carers of patients with dementia

Objective To compare the scores on the Relative Stress Scale (RSS) with those on the General Health Questionnaire (GHQ) and the Geriatric Depression Scale (GDS), and to establish a cut-off score for RSS in order to distinguish carers with symptoms of psychiatric disorders from those without. Methods One hundred and ninety-four carers of 194 patients suffering from dementia according to ICD-10 were included in the study. Burden of care was assessed by the 15-items RSS, and psychiatric symptoms by means of the GHQ-30 and the 30-items GDS. A case score above 5 on GHQ and above 13 on GDS were used to define carers with probable psychiatric morbidity. Sensitivity (SS), specificity (SP), accuracy and likelihood ratio for a positive test (LR+) were calculated for different cut-points of the RSS. Results Fifty-six percent of the carers had a GHQ score above 5, and 22% had a GDS score above 13. A two-step cluster analysis using 192 of the 194 carers, identified three groups of carers; a low risk group for psychiatric morbidity (LRG), 82 carers with GHQ <= 5 and GDS <= 13; a medium risk group (MRG), 69 carers with GHQ > 5 and GDS <= 13; and a high-risk group (HRG), 40 carers with GHQ > 5 and GDS > 13. The optimal RSS cut-off to distinguish between the LRG and the others was > 23 (SS 0.72, SP 0.82, accuracy 0.76, LR + 4.0), whereas the optimal cut-off to separate the HRG from the others was > 30 (SS 0.74, SP 0.87, accuracy 0.84, LR + 5.7). Conclusion The RSS is a useful instrument to stratify carers according to their risk of psychiatric morbidity. Copyright (c) 2006 John Wiley & Sons, Ltd.