Table 3.

Secondary Outcomes Over Time^a

Treatment Group	n	Outcome
		MIC in Low Back Pain Intensity			MIC in Back-Related Disability			MIC in Pain Impact
		HR	95% CI	P	HR	95% CI	P	HR	95% CI	P
Overall Analysis
Control	201	Reference			Reference			Reference
LTOT	201	0.95	0.75-1.21	0.69	0.97	0.74-1.27	0.84	0.70	0.46-1.05	0.08
Analysis for Continuous Duration of LTOT
Control	201	Reference			Reference			Reference
LTOT (months)
3	43	1.10	0.73-1.66	0.66	1.09	0.68-1.73	0.73	0.70	0.32-1.53	0.37
6	23	0.61	0.32-1.16	0.13	0.98	0.54-1.78	0.96	0.85	0.34-2.12	0.73
9	16	1.23	0.70-2.17	0.48	0.82	0.40-1.68	0.59	0.67	0.21-2.14	0.50
12	119	0.94	0.72-1.24	0.67	0.96	0.71-1.30	0.79	0.68	0.42-1.08	0.10
Analysis for Opioid Dose Response Based on Number of Quarters Used
Control	201	Reference			Reference			Reference
LTOT (quarters)
1	25	1.37	0.81 −2.31	0.24	1.16	0.62-2.17	0.63	0.97	0.35-2.68	0.95
2	23	0.81	0.45-1.46	0.48	1.02	0.56-1.85	0.95	1.19	0.54-2.61	0.67
3	34	0.88	0.56-1.38	0.58	0.90	0.55-1.48	0.67	0.39	0.14-1.06	0.07
4	119	0.94	0.72-1.24	0.67	0.96	0.71-1.30	0.79	0.68	0.42-1.08	0.10
Analysis for Opioid Dose Response Based on Baseline MME Dosage
Control	201	Reference			Reference			Reference
LTOT (MMEs)
≤30	100	1.17	0.89-1.55	0.27	1.02	0.74-1.42	0.88	0.70	0.42-1.17	0.18
>30 to <50	66	0.71	0.50-1.03	0.07	0.95	0.65-1.39	0.80	0.67	0.36-1.22	0.19
≥50	35	0.86	0.54-1.37	0.52	0.86	0.51-1.45	0.57	0.74	0.34-1.63	0.46
Analysis for Continuous Opioid Use or Abstinence for 12 Months
Control	132	Reference			Reference			Reference
LTOT	119	0.82	0.61-1.09	0.18	0.92	0.66-1.27	0.61	0.60	0.37-0.98	0.04

Abbreviations: LTOT, long-term opioid therapy; MME, morphine milligram equivalent; HR, hazard ratio; CI, confidence interval.
^aMinimally important changes were defined as a 1-point decrease on the numerical rating scale for low back pain intensity, a 2-point decrease on the Roland-Morris Disability Questionnaire for back-related disability, and a 7.5-point decrease on pain impact based on the numerical rating scale for low back pain intensity and the physical function and pain interference scales of the Patient-Reported Outcomes Measurement Information System. In all analyses, 271 (67.4%), 217 (54.0%), and 96 (23.9%) participants achieved a MIC in each of these outcome measures, respectively, except for the analysis for continuous opioid use or abstinence for 12 months. Therein, 187 (74.5%), 144 (57.4%), and 69 (27.5%) participants achieved a MIC in each of these outcome measures, respectively. Hazard ratios and P values were computed using the Cox proportional hazards model for time to achievement of a minimally important change.