Table 2.

Prospective association of baseline CRP with fatigue at follow-up (N=2921)

Adjustment*	β	P	R2	ΔR2 due to CRP	% ΔR2 due to CRP
Unadjusted model	0.126	<0.001	0.016	0.016	100%
Model 1: Sociodemographic variables	0.113	<0.001	0.038	0.012	32.1%
Model 2: Model 1 + Biomedical factors	0.060	0.006	0.047	0.002	5.3%
Model 3: Model 2 + Fatigue-related symptoms	0.055	0.008	0.137	0.002	1.5%
Model 4: Model 3 + Health-related behaviors	0.044§	0.033	0.153	0.001	0.9%

β = standardized regression coefficient expressing the change in standardized fatigue score per one standard deviation in CRP concentration; CRP = C-reactive protein; R² = R-square of the model; ΔR² = change in R-square; % ΔR²= percentage change in R-square

^*Sociodemographic variables include age, sex, ethnicity, and education. Biomedical factors include body-mass index, systolic blood pressure, and regular aspirin use. Fatigue-related symptoms include depressive symptoms, sleep quality, and pain. Health-related behaviors include smoking, alcohol consumption, and physical activity.

^§No effect modification was observed for age (P = 0.259), sex (P = 0.542), ethnicity (P = 0.779), or education (P = 0.987).