A generic health status instrument in the assessment of rheumatoid arthritis.

Seventy-three patients with RA were assessed by means of the Nottingham Health Profile (NHP), the Arthritis Impact Measurement Scales (AIMS) and a number of clinical measures. Patients with RA scored higher than controls on the NHP scales for energy, pain, mobility and sleep. Energy, pain, mobility and emotions scales of the NHP correlate significantly with other measures such as clinical assessments, matching scales of the AIMS and the Beck Depression Inventory, indicating satisfactory validity for the instrument with RA. Five of the six scales of the NHP are stable on retesting. The social scale of the NHP on the other hand does not correlate with the matching instrument of the AIMS and is relatively unstable over time. Measurement properties of generic health status instruments such as the NHP will require serious attention as they are increasingly used in evaluation studies.