The simple shoulder test is responsive in assessing change following shoulder arthroplasty.
METHODS
Prospective cohort study with repeated measures.


OBJECTIVE
To establish the responsiveness of the Simple Shoulder Test (SST) in comparison to other commonly used clinical outcomes in patients undergoing shoulder arthroplasty.


BACKGROUND
Responsiveness statistics are a useful means to compare different outcomes in terms of their ability to detect clinical change. While the responsiveness of the SST has been established for rotator cuff repair, it has not been determined for patients undergoing arthroplasty.


METHODS
Patients undergoing shoulder arthroplasty (n=120) were evaluated prior to surgery and 6 months after. The evaluation included the SST, Disabilities of the Arm, Shoulder and Hand questionnaire, range of motion, and isometric strength. Responsiveness to change was assessed using standardized response mean (SRM), while longitudinal construct validity was evaluated using Pearson correlation. Receiver operating characteristics curves were plotted to determine clinically important difference of SST.


RESULTS
The SST and Disabilities of the Arm, Shoulder and Hand questionnaire were highly responsive (SRM, >1.70) for this population. For the assessment of impairment, range of motion (SRM, 0.64-1.03) was moderately to highly responsive, while isometric strength was minimally to moderately responsive (SRM, 0.32-0.69). The clinically important difference of the SST was established at 3.0 SST points. Pearson correlations indicated moderate associations between the change scores of the SST and the Disabilities of the Arm, Shoulder and Hand questionnaire (r=0.49).


CONCLUSIONS
The SST has been previously shown to be valid and highly reliable. The present results show that the SST is also responsive following shoulder arthroplasty and that it has a clinically important difference of 3.0 SST points. This should provide confidence to clinicians who wish to use a brief shoulder-specific measure in their practice.
Roy
Jean-Sébastien
JS
School of Rehabilitation Science, McMaster University, Hamilton, Ontario, Canada. jean-sebastien.roy.1@ulaval.ca
Macdermid
Joy C
JC
Faber
Kenneth J
KJ
Drosdowech
Darren S
DS
Athwal
George S
GS
D000368:Aged; D019643:Arthroplasty, Replacement / Q000534:rehabilitation*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D016059:Range of Motion, Articular; D012785:Shoulder Joint / Q000601:surgery*