[Reproducibility study of the "400 Points assessment", a measurement of the hand's functional ability].

Objectives: Evaluate the inter-rater and test-retest reproducibility of the "400 Points assessment", a measurement of the functional ability of the hand. The scale included four tests: function of the hand, prehension strengths, handling and displacement of things, and function with both hands.

Methods: Thirty patients with hand injuries were participated. The inter-rate agreements were examinated between three occupational therapists. The First rater was an experienced user of this instrument (observer 1), the second one was a novice user (observer 2), the last rater is a student who had never used it before (observer 3). Subjects were tested twice by the same raters independently, with 30 minutes intervals between tests. Statistical analysis was done by calculating average differences and intraclass correlation coefficient.

Results: (i) The difference between the three raters agreements was small for the two measurements, except for function with both hands in the second period. Every intraclass correlation coefficient was higher than 0.95. (ii) Difference between the two measurements was small for every observer. These differences are not significant except for function with both hands. Intraclass correlation coefficients are all higher than 0.82 even than 0.90 for the total score. The difference between the two periods for the overall test is small, from 5% to 10% for seven patients and from 10 to 15% for two patients. Differences at two times had the same agreement for the three observers.

Conclusion: "400 Points assessment" is reproducible (inter-rater and test-retest reproductibility). The test "function with both hands" requires more experience of the assessment.