Clinicians' and patients' assessment of activity overuse and underuse and its relation to physical capacity.

To explore clinicians' and patients' (self)-assessment of activity overuse and underuse, and its relationship with physical capacity in patients with chronic musculoskeletal pain (CMP). Study design was cross-sectional. Participants included patients with CMP, admitted to a multidisciplinary outpatient pain rehabilitation program. The main measures used were as follows: a five-point scale to rate overuse and underuse, filled out by clinicians and patients; a five-point scale to rate physical capacity, filled out by clinicians and patients; and lifting and aerobic capacity. Cohen's κ were calculated to test the agreement between assessments. Depending on the normality, a t-test or a Mann-Whitney U-test was used to test differences between the results of a capacity test and patients' and clinicians' assessments of capacity. A total of 141 patients were included: 42% were men, and 60% had back pain, 21% had neck pain, 19% had pain in a different location. Six percent of the patients rated themselves as underusers; clinicians rated 23% of the patients as underusers. Clinicians and patients fairly agreed (61%; κ=0.23) in their assessments of overuse and underuse. Differences in the physical capacity of overuse and underusers, as assessed by clinicians and patients, were all nonsignificant (P>0.05). The physical capacity of overusers did not differ from that of underusers (P<0.05). In conclusion, although clinicians and patients with CMP fairly agree on their assessment of activity overuse and underuse, the physical capacity of overusers was not different from that of underusers.