. Author manuscript; available in PMC: 2021 Oct 1.

Published in final edited form as: Arthritis Care Res (Hoboken). 2020 Oct;72(10):1440–1448. doi: 10.1002/acr.24052

Table 2.

Results of cross-sectional and longitudinal multiple regression analyses

		Longitudinal
	Cross-sectional^*	Model 1^†	Model 2^§	Model 3^¶	Model 4**
T1 depressive symptoms (CESD)	0.70 (0.54, 0.86)	0.17 (0.02, 0.31)	−0.01 (−0.19, 0.16)	−0.10 (−0.27, 0.07)	−0.08 (−0.25, 0.09)
	p < 0.0001	p = 0.02	p = 0.87	p = 0.24	p = 0.38
T1 perceived stress	0.84 (0.32, 1.36)	----	0.91 (0.35, 1.46)	1.73 (1.17, 2.29)	1.73 (1.17, 2.29)
	p = 0.002		p = 0.001	p < 0.0001	p < 0.0001
T1-T2 decrease in perceived stress	----	----	----	−10.77 (−13.28, −8.27)	----
				p < 0.0001
T1-T2 decrease in perceived stress, ≥2 points	----	----	----	----	−12.06 (−14.93, −9.20)
					p = <0.0001
Model R²	0.64	0.56	0.57	0.62	0.61

Tabled values are beta (95% confidence interval) and p-value from multiple regression analyses, with change in SF-36 Vitality score (fatigue) as the dependent variable.

Cross-sectional analysis controlled for T1 age, sex, race, education (high school or less vs. greater than high school), income (below federal poverty vs. not), disease duration, self-reported disease activity and damage, pain, self-reported fibromyalgia, and obesity.

^†

Model 1 controlled for T1 age, sex, race, education, income, disease duration, self-reported disease activity and damage, pain, self-reported fibromyalgia, and obesity, plus T1 CESD and T1fatigue.

^§

Model 2 added T1 perceived stress.

^¶

Model 3 added any T1 – T2 decrease in perceived stress

^••

Model 4 added T1 – T2 decrease (≥2 points) in perceived stress score