Measuring functional outcomes in a Medical Psychiatric Unit: a validation study

Abstract

Objective At least 25% of patients admitted in a general hospital because of a somatic problem, have psychiatric comorbidity. Psychiatric comorbidity is associated with a longer hospital stay, more severe somatic and social problems and a higher number of discharges to inpatient care settings. A Medical Psychiatric Unit (MPU) provides specialized care for these patients. Little is known about the effect of MPU-care on functional outcomes. A valid instrument to measure this is missing. The aim of the study was to examine if changes in functional outcomes can be measured in patients admitted to a MPU using the Care Dependency Scale (CDS) and Health of the Nation Outcome Scales (HoNOS).

Method In a single centre observational prospective design, construct validity of the CDS and HoNOS was investigated in a medical psychiatric unit population. Measurements were conducted at admission and discharge. The Spearman's correlation with the Clinical Global Impression (CGI) and the widely used Camberwell Assessment of Needs Short Appraisal Schedule (CANSAS) was determined on difference scores.

Results 50 patients were included, whereby an admission and discharge measurement was carried out. The CDS and HoNOS showed moderate to good correlations with the CGI and CANSAS. The correlations did not have a significant difference, with one exception: the CDS correlates significantly stronger with the residents' CGI than the HoNOS.

Conclusion The CDS and HoNOS are both consistent with clinical observations and show construct validity. This study shows that the instruments are complementary and partly measuring different domains. For a complete outcome measurement of functional status both the CDS and HoNOS are needed.