Responsiveness of observational and self-report methods for assessing disability in mobility in patients with osteoarthritis.
OBJECTIVE
To establish the responsiveness of observational and self-report methods for the assessment of disability in mobility in patients with osteoarthritis (OA).


METHODS
Data from 186 patients with hip OA or knee OA were used. Data from 1 observational method and 4 self-report methods for the assessment of disability in mobility were collected at week 0 and again 12 weeks later. Using correlations and factor analysis, the relationships among changes in these 5 methods were established.


RESULTS
Intercorrelations between change scores of the self-report methods ranged from 0.12 to 0.34. Correlations between the observational method and the self-report methods ranged from 0.14 to 0.26. In the factor analysis, both the self-report methods and the observational method loaded on the same factor.


CONCLUSIONS
In a longitudinal design, no evidence for differential responsiveness of observational and self-report methods was obtained. Because of the advantages of questionnaires (they are easier to use, less time-consuming, and less of a burden to subjects), this implies that the use of self-report methods is to be preferred over observational methods.
Steultjens
M P
MP
Netherlands Institute of Health Services Research, NITEL, Utrecht.
Roorda
L D
LD
Dekker
J
J
Bijlsma
J W
JW
D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009068:Movement / Q000502:physiology*; D015207:Osteoarthritis, Hip / Q000503:physiopathology* / Q000523:psychology*; D020370:Osteoarthritis, Knee / Q000503:physiopathology* / Q000523:psychology*; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011594:Psychometrics; D012650:Self Disclosure; D011795:Surveys and Questionnaires