Table 3.

Regression analyses to show univariable linear and multivariable GAM models

Predictors	Univariable association		Multivariable model
	β (95% CI)	P	β (95% CI)	P
Age, years	− 0.008 (− 0.03–0.01)	0.50	− 0.008 (− 0.03–0.01)	0.40
Sex	0.46 (− 0.23–1.16)	0.20	0.54 (− 0.29–1.26)	0.10
Disease duration, years	0.01 (− 0.02–0.04)	0.50	0.02 (− 0.01–0.03)	0.15
Mood status score	− 0.05 (− 0.08–− 0.02)	0.001	− 0.04 (− 0.07–− 0.02)	0.01
Night sleep duration on weekdays	0.03 (− 0.15–0.21)	0.70	0.21 (− 0.04–0.50)	0.20
Night sleep duration on weekends	− 0.06 (− 0.21–0.10)	0.50	− 0.20 (− 0.41–− 0.02)	0.03
Time to fall asleep, Minutes	− 0.01 (− 0.03–− 0.001)	0.03	− 0.007 (− 0.01–0.01)	0.20
Sleep quality score	EDF* = 2.10	0.0006	EDF* = 2.10	0.01
Time to go to bed on weekdays	EDF* = 2.40	0.20	EDF* = 2.45	0.08
Wake-up time on weekdays	EDF* = 1.32	0.80	EDF* = 1.72	0.25
Nap duration on weekdays, Minutes	EDF* = 1.13	0.20	EDF* = 1.96	0.03
Nap duration on weekends, Minutes	− 0.003 (− 0.01–0.006)	0.50	Removed by backward elimination
Time to go to bed on weekends	EDF = 3.51	0.04
Wake-up time on weekends	0.05 (− 0.08–0.19)	0.40
Snoring	− 0.027 (− 0.11–0.057)	0.55
diet score	0.006 (− 0.03–0.05)	0.80
Smoking, Pack-Years	0.01 (− 0.02–0.04)	0.60
Physical activity	− 0.03 (− 0.24–0.18)	0.80
Social activity	0.06(− 0.14–0.26)	0.80
Body mass index	− 0.003 (− 0.01–0.009)	0.60
Number of tender joints	− 0.001 (− 0.06–0.06)	0.97
Number of swollen joints	0.01 (− 0.05–0.07)	0.70
Extra-articular manifestations	− 0.02 (− 0.14–0.09)	0.70
Hemoglobin level	− 0.005 (− 0.13–0.12)	0.90
C-reactive protein	− 0.008 (− 0.03–0.01)	0.40
Triglyceride level	− 0.001 (− 0.005–0.004)	0.80
Fasting blood sugar	− 0.002 (− 0.11–0.006)	0.50

The univariable outcomes presented as EDF are the products of non-linear regression models whereas β represents the linear associations. Self-rated wellness/health score was the dependent variable. p values < 0.05 are signified in bold

^*EDF effective degree of freedom