Table 4.

Baseline and follow-up means and effect sizes for pain and functioning outcomes, intervention and control groups

	Intervention Group (N = 28)		Control Group (N = 23)		Treatment Effect Size, Partial Eta Squared*	P Value for Treatment Effect*
	M ± SD		M ± SD
	Baseline	Follow-up	Baseline	Follow-up
PROMIS 4-item Pain Interference, t score†	58.7 ± 6.1	57.9 ± 6.4	57.0 ± 8.4	57.0 ± 8.0	0.003	0.726
PROMIS 4-item Physical Function difficulty, t score†	33.2 ± 4.3	31.9 ± 4.2	32.7 ± 6.2	32.0 ± 4.7	0.006	0.600
PROMIS 4-item Social Participation, t score†	38.1 ± 7.3	38.4 ± 7.3	37.0 ± 6.4	38.0 ± 8.0	0.001	0.810

^*Based on repeated-measures analysis of variance.

^† T scores are normed such that a score of 50 represents the mean or average for the reference population and 1 standard deviation = 10 t-score points. For Pain Interference, a higher score means worse symptomatology (possible range = 42–76). For Physical Function (range = 23–57) and Social Participation (range = 29–64), lower scores represent worse functioning.