Table 4.

Association between hospitalization and decline in ADLs by age group

	BADLs		IADLs
	< 65 years (n = 401)	≥65 years (n = 448)	< 65 years (n = 401)	≥65 years (n = 448)
	Adjusted RRa [95% CI]
Cumulative length of hospital stay (per day)	1.013 [1.001 to 1.025]	1.014 [1.003 to 1.026]	1.017 [1.006 to 1.028]	1.007 [0.999 to 1.015]
	P for interactionb = 0.52		P for interactionb = 0.43
	BADLs		IADLs
	< 65 years (n = 401)	≥65 years (n = 448)	< 65 years (n = 401)	≥65 years (n = 448)
Number of hospitalizations
0	ref	ref	ref	ref
1	1.83 [1.00 to 3.35]	1.56 [1.00 to 2.43]	1.53 [0.96 to 2.42]	1.30 [0.96 to 1.77]
≥ 2	2.65 [1.49 to 4.70]	2.04 [1.35 to 3.07]	1.38 [0.82 to 2.32]	1.32 [0.85 to 2.06]
	P for interactionc = 0.82		P for interactionc = 0.87

BADL, basic activities of daily living; IADL, instrumental activities of daily living; RR, risk ratio; CI, confidence interval; ref., reference

^aAdjusted for age, sex, dialysis vintage, body mass index (< 18.5, ≥18.5 to < 25, ≥25), functional status score, comorbidities (diabetes, cerebrovascular diseases, coronary heart disease, other cardiovascular diseases, congestive heart disease, cancer other than skin cancer, neurologic disease, peripheral vascular disease, dementia, and psychiatric disorder), albumin, phosphorus, creatinine and single-pool Kt/V

^bTesting the statistical significance of the product terms in the cumulative length of hospitalization and age group using a Wald test

^cTesting the statistical significance of product terms in the number of hospitalizations and age group using a Wald test