TABLE 3.

Partial and full population attributable risk percentage (PAR%) of different lifestyle factors on gallstone disease for women in the Nurses’ Health Study (NHS)¹

Lifestyle factor	Healthy definition	Person-years with healthy factor, %	Incidence, no. per 100,000 person-years: nonhealthy/healthy	PAR% (95% CI): individual factor	PAR% (95% CI): combined
Smoking	Never smoking	45	595/607	1 (−1, 4)	62 (37, 79)
AHEI-2010	Upper 2 quintiles	41	639/547	8 (5, 11)
BMI, kg/m2	18.5–24.9	51	820/394	33 (30, 36)
Physical activity	≥15 METs/wk	42	662/518	9 (6, 12)
Coffee consumption	≥2 cups/d	39	645/530	10 (7, 13)
Moderate alcohol intake	0.5–1.5 drinks/d	22	634/483	13 (8, 17)

¹The PAR% is dependent on the magnitude of the association and the prevalence of exposure and describes the proportion of symptomatic gallstone disease that could be prevented if 1 or all of the mentioned exposures were to be eliminated from the population. Briefly, the PAR% was calculated by combining the observed prevalence rates of each healthy lifestyle factor with the estimated HR from the multivariable Cox proportional hazards model, which was adjusted for age, questionnaire cycle, regular use of statins and thiazide diuretics (yes/no), regular use of NSAIDs (≥2 times/wk; yes/no), postmenopausal hormone use (pre-/missing menopause, never used, current user, past user), history of hypercholesterolemia and hypertension (yes/no), and mutually adjusted for each of the healthy lifestyle factors. AHEI-2010, Alternate Healthy Eating Index 2010; MET, metabolic equivalent; NSAID, nonsteroidal anti-inflammatory drug; PAR%, population attributable risk percentage.