Table 3.

Mixed logistic regression models measuring the association (Odds Ratio (95%CI)) between change in morphine equivalent opioid dose (MED) and change in depression over time before and after adjusting for covariates.

	Model 1 OR (95% CI)	Model 2 OR (95% CI)	Model 3 OR (95% CI)	Model 4 OR (95% CI)	Model 5 OR (95% CI)	Model 6 OR (95% CI)	Model 7 OR (95% CI)
Opioid use
No use	1.00	1.00	1.00	1.00	1.00	1.00	1.00
≤ 50 mg	1.99 (1.19–3.31)	1.45 (0.87–2.41)	1.12 (0.67–1.85)	2.00 (1.24–3.22)	1.84 (1.11–3.06)	1.71 (1.03–2.82)	1.08 (0.65–1.79)
> 50 mg	3.32 (1.43–7.69)	2.95 (1.30–6.68)	1.81 (0.81–4.04)	3.25 (1.47–7.20)	3.09 (1.35–7.10)	2.96 (1.30–6.78)	2.65 (1.17–5.98)
Pain Characteristics
Pain Severity		1.40 (1.25–1.56)					1.05 (0.93–1.19)
Pain Duration (yrs)		1.01 (0.99–1.03)					1.02 (0.99–1.04)
Health Related Quality of Life
SF-Pain Interfere			0.97 (0.96–0.99)				0.98 (0.96–0.99)
SF-Physical Func			0.99 (0.98–1.00)				0.99 (0.98–1.01)
SF-Physical Role			1.00 (0.99–1.01)				1.00 (0.99–1.01)
SF-Gen Health			0.97 (0.96–0.98)				0.99 (0.98–1.00)
Comorbidities
# comorbidities				1.11 (0.99–1.26)			1.04 (0.92–1.19)
Anxiety:				12.13 (6.50–22.64)			8.33 (4.39–15.81)
Obese/over weight				1.29 (0.68–2.42)			0.87 (0.45–1.69)
Psychosocial characteristics
# stressful people					1.50 (1.17–1.93)		1.32 (1.05–1.65)
# support people					0.78 (0.67–0.92)		0.92 (0.81–1.06)
Demographic characteristics
Age:
≥ 60						0.80 (0.38–1.70)	0.72 (0.34–1.53)
46–59						1.46 (0.73–2.90)	1.10 (0.59–2.05)
18–45						1.00	1.00
Race: Non-white						1.73 (0.97–3.10)	1.75 (1.03–2.98)
Education: < high school						3.03 (1.46–6.27)	1.57 (0.83–2.98)
Gender: female						0.82 (0.44–1.52)	0.61 (0.35–1.05)
Disability Status: On/apply						3.28 (1.82–5.92)	1.00 (0.59–1.70)
Model Information
Pseudo R-square	19.25%	25.42%	36.82%	30.60%	21.44%	24.92%	48.28%
AIC	914.40	873.70	781.10	759.56	899.55	879.32	667.30

^aAll models adjusted for years since baseline assessment.