. Author manuscript; available in PMC: 2012 May 1.

Published in final edited form as: J Urol. 2011 Mar 21;185(5):1775–1780. doi: 10.1016/j.juro.2011.01.003

Table 2.

Multivariable relative risks for incident urinary incontinence, by incontinence frequency, according to caffeine intake

	Caffeine intake (mg/day)				P
Case definition	0–149	150–299	300–449	≥ 450	trend
Person-years	122,501	49,105	40,086	13,500
Any UI^*
Cases	8,364	3,117	3,174	1,028
Adjusted RR (95% CI)^†	1.00 (reference)	0.98 (0.94 – 1.02)	1.03 (0.99 – 1.07)	1.00 (0.93 – 1.06)
Multivariable RR (95% CI)^‡	1.00 (reference)	0.97 (0.93 – 1.01)	1.02 (0.98 – 1.07)	0.98 (0.91 – 1.05)	0.98
Frequent UI^*
Cases	2,280	795	990	359
Adjusted RR (95% CI)^†	1.00 (reference)	0.99 (0.91 – 1.07)	1.07 (0.98 – 1.15)	1.21 (1.08 – 1.36)
Multivariable RR (95% CI)^‡	1.00 (reference)	0.98 (0.90 – 1.06)	1.06 (0.98 – 1.15)	1.19 (1.06 – 1.34)	0.01

Any UI is defined as incontinence at least once per month; Frequent UI is defined as incontinence at least once per week.

^†

Adjusted for age (in months) and cohort.

^‡

Adjusted for age (in months), cohort, parity (0, 1–2, 3 or more births), BMI (kg/m², continuous), cigarette smoking (never, past, current: 1–14, 15–24, 25–34, 35 or more cigarettes per day), race (white, black, Asian-American, other/missing), diabetes, total fluid intake (liters/day, continuous), and physical activity (metabolic equivalent-hours per week, continuous).