. Author manuscript; available in PMC: 2022 Jul 1.

Published in final edited form as: Arch Phys Med Rehabil. 2021 Mar 5;102(7):1317–1323. doi: 10.1016/j.apmr.2021.02.014

Table 6.

Model equation, R², and NMAE for regressions predicting Roland-Morris Disability Questionnaire from PROMIS Physical Function, Pain Interference and Average Pain Intensity for PROMIS I W2 and ACT samples individually and combined.

Sample	Equation	R²	NMAE
PROMIS I W2 (n=179)	6.433 – 0.357 x PF + 0.289 x PI + 0.234 x Avg Pain	0.46	0.63
ACT (n=384)	5.451 – 0.356 x PF + 0.316 x PI + 0.140 x Avg Pain	0.58	0.56
ACT + PROMIS I W2 (n=563)	5.689 – 0.352 x PF + 0.307 x PI + 0.157 x Avg Pain	0.58	0.55

NOTE: NMAE = Normalized Mean Absolute Error; PROMIS I W2 = PROMIS 1 Wave 2 Pain and Depression study; ACT= Assessment of Chiropractic Treatment for Low Back Pain and Smoking Cessation in Military Active Duty Personnel. PF = PROMIS Physical Function T score; PI = PROMIS Pain Interference T score; Avg Pain = PROMIS Pain Intensity score. R² and NMAE are adjusted using linear equating to address regression to the mean.