Table 3.

Attributable Fraction of Fitness to CKD^a by Race and Total Sample

Variable	Prevalence of low fitness in full population (%)		Prevalence of low fitness in people eventually developing CKD (Pd)		Adjusted HR for low vs mod/high fit	Population attributable fraction (PAF)c
	Low fitd / Total	%	Low fit events / Total events	%	HRb (95% CI)	%
Blacks	553/1,941	28.5	38/82	46.3	1.94 (1.20,3.16)	22.5
Whites	183/1,901	9.6	9/43	20.9	2.07 (0.89, 4.83)	10.8
Overall	736/3,842	19.2	47/125	37.6	2.00 (1.31,3.04)	18.9

^aChronic kidney disease (CKD) defined as eGFR <60 mL/min/1.73m².

^bHR adjusted for baseline gender, age, field center, maximal education throughout study, time varying healthy diet index, smoking status, alcohol intake, BMI, systolic BP, and fasting glucose, and baseline eGFR.

^cPAF=(P_d (HR_adj −1))/HR_adj × 100%, Where P_d is the proportion of inactive people among cases, and HR_adj is the HR of CKD, comparing low to mod/high fitness, adjusted for confounding factors.

^dLow fit: bottom lowest gender-specific quintile (bottom 20%).

eGFR, estimated Glomerular Filtration Rate; HR, hazard ratio.