Background: The objectives of this study were to characterize the psychiatric comorbidity of a group of older subacute inpatients and then determine whether their psychiatric comorbidity affected measures of rehabilitation outcomes.

Methods: Eighty-eight older subacute inpatients were recruited for this prospective study. Psychiatric comorbidity was defined according to a participants' performance on four inventory scales: the Geriatric Depression Scale (GDS), Geriatric Anxiety Inventory (GAI), Brief Psychiatric Rating Scale and Health of the Nation Outcome Scale 65+. Rehabilitation outcome referred to the participants' length of stay and their performance at discharge on the EuroQol-5D health-related quality of life questionnaire and Barthel index.

Results: 68% of the participants scored in the clinical range on at least one of the four scales assessing psychiatric comorbidity at admission, with 51% in the clinical range for GDS and 32% for the GAI. The decrease in scores by the time of discharge was significant for all four scales. Linear regression analyses pointed to a trend for depressive symptoms at admission to be an influential but nonsignificant predictor of rehabilitation outcome. An interesting association was found between the length of the previous acute admission and the GDS score on admission to the subacute unit.

Conclusion: A high prevalence of psychological symptoms was identified upon admission, with a significant decrease by the time of discharge. These factors did not significantly predict the selected measures of rehabilitation outcome. Opportunities for future longitudinal research on the prevalence and impact of psychiatric comorbidities on patient outcomes are considered.