Table III.

Mixed model–based mean differences in SPADI score between patients who participated in physical therapy within first 3 months and patients who did not by period in ROW cohort

Period	Estimate	Lower 95% CI	Upper 95% CI	P value
3 mo	−13.03	−25.72	−0.34	.04
6 mo	−1.26	−17.80	15.28	>.99
12 mo	−4.34	−20.33	11.66	.89
18 mo	−11.59	−24.80	1.61	.10

SPADI, Shoulder Pain and Disability Index; ROW, Rotator Cuff Outcomes Workgroup; CI, confidence interval.

P values were adjusted using the multivariate t distribution. The mixed model included baseline SPADI score, time, categorical physical therapy (yes vs no), and interaction between physical therapy and time.