Between-session changes predict overall perception of improvement but not functional improvement in patients with shoulder impingement syndrome seen for physical therapy: An observational study

Do between-session changes in global rating of change (GRoC) predict change in GRoC and self-report of function at discharge in patients with shoulder impingement that initially improve in early sessions of treatment (GRoC>5)? Is there a difference between individuals who initially respond to treatment (GRoC>5) compared to those that do not (GRoC<5) for self-report of function? This longitudinal, observational study had 55 patients seen for a formal physical therapy program after a medical diagnosis of shoulder impingement. Physical therapy used a standardized protocol. The American Shoulder and Elbow Surgeons Subjective Shoulder Scale (ASES) and self-report of improvement of condition using the GRoC were measured. We found no significant correlation between the first visits between-sessions changes of the GRoC and the change score of the ASES (r=0.13; p=0.39) in patients with shoulder impingement that initially improve in early sessions of treatment (GRoC>5). There was a moderate correlation between the first visits between-session changes of the GRoC and the final reported GRoC (r=0.48; p<0.01) for the patients who responded to treatment. There was no difference in ASES change scores between those who initially respond to treatment (N=10) and those who do not (N=34). ASES mean change scores were 21.5 for the responders and 14.3 for the non-responders. These findings suggest that a GRoC of 5 or greater is related to a perceived change in one's condition upon termination of formal physical therapy but is not related to actual improvement in one's self-report of function. This finding suggests that the construct of the GRoC may not be related to the constructs of the ASES, or between-session changes are not prognostic in patients with shoulder impingement and should not solely dictate treatment decision making.