Psychometric properties of the Assessment of Motor and Process Skills in patients undergoing rehabilitation following hand-related disorders

Introduction Assessment of Motor and Process Skills (AMPS) has been proven to be a suitable measurement tool for assessing performance-based ADL ability; however, its reliability and validity have not been tested on patients with hand-related disorders. Methods Patients referred for outpatient hand rehabilitation were assessed with AMPS, The Canadian Occupational Performance Measure (COPM), dynamometer and goniometer at baseline and after eight weeks of hand therapy. Construct validity and responsiveness of AMPS were assessed by hypothesis testing. Construct validity was assessed by correlating the baseline score of AMPS with the baseline score of the other measurement tools. Responsiveness was assessed by correlating the change scores of each measurement tool with a Global Rating Scale. Results Fifty-one patients were recruited. The construct validity of AMPS indicated that the various measurement tools captured different aspects to functioning from the AMPS, as the correlations between AMPS and the other measurement tools were generally weak to low (r < 0.25 to 0.49). AMPS was less responsive than COPM when correlated with the GRS. The correlation between COPM and GRS was r = 0.62 compared with the AMPS motor, r = 0.45 and AMPS process, r = 0.33. Relative responsiveness of AMPS is similar to that of the dynamometer (r = 0.39) and goniometer (r = –0.34). Discussion In a sample of 51 patients, this study found that the construct validity of AMPS seemed to be moderate, while the responsiveness of AMPS seemed to be poor. However, due to the small sample size no conclusions can be made, and should be further assessed in larger studies.