Objectives: To investigate the course of hand osteoarthritis (OA) over two years by currently available outcome measures.
Methods: 189 participants of the GARP (Genetics, ARthrosis and Progression) study with hand OA were followed for two years. Self-reported hand pain and functional limitations were assessed with the Australian / Canadian Osteoarthritis Hand Index (AUSCAN LK 3.0). Pain intensity upon lateral pressure in the interphalangeal and thumb base joints was graded on a four-point scale. Osteophytes (0-3) and joint space narrowing (JSN) (0-3) was scored at baseline and after two years in interphalangeal and thumb base joints. Standardised response means (SRM) were calculated.
Results: 172 (91%) patients completed the two-year follow-up (mean age 60.5 years, 78.5 % women). Statistically significant increases in self-reported pain and function scores, in pain intensity scores as well as in osteophyte and JSN total scores were seen over two years. SRMs were 0.25, 0.23, 0.67, 0.34 and 0.35 respectively for self-reported pain and function scores, pain intensity scores, osteophyte and JSN total scores. Radiological progression was not associated with changes in self-reported pain and function. Women in an early post-menopausal stage were especially at risk to progress radiologically.
Conclusions Currently available outcome measures were able to assess progression over the relatively short time period of two years. Radiographic outcomes were more responsive than self-reported outcomes. Pain intensity upon lateral pressure seems to be a responsive measure but need validation.