TABLE 2.

Combined results of subgroup analysis for HEI-2015 and risk of mortality (highest HEI-2015 vs. the lowest category)

Outcome	Stratification criterion	Number of included studies (n)	Pooled HR (95% CI)	Heterogeneity
				I2 (%)	P value∗
All-cause mortality	Gender
	Male	5	0.84 (0.78, 0.89)	83.8	<0.001
	Female	8	0.78 (0.76,0.80)	20.4	0.268
	Region
	United States	13	0.80 (0.79, 0.81)	24.4	0.197
	Non-United States	3	0.90 (0.82, 0.98)	0	0.613
	Sample size
	<15,000	8	0.82 (0.77, 0.87)	0	0.959
	>15,000	9	0.81 (0.79, 0.83)	62.6	0.006
	Follow-up period
	<15 y	10	0.83 (0.81, 0.86)	27.9	0.188
	≥15 y	7	0.8 (0.79, 0.81)	0	0.476
Cancer-cause mortality	Gender
	Male	2	0.79 (0.75, 0.82)	0	0.587
	Female	5	0.82 (0.78, 0.85)	0	0.798
	Region
	United States	9	0.8 (0.78, 0.83)	0	0.792
	Non-United States	2	0.83 (0.69, 0.97)	0	0.364
	Sample size
	<15,000	3	0.89 (0.71, 1.07)	0	0.793
	>15,000	9	0.8 (0.78, 0.83)	0	0.772
	Follow-up period
	<15 y	6	0.85 (0.79, 0.90)	0	0.954
	≥15 y	6	0.8 (0.77, 0.82)	0	0.701
CVD-cause mortality
	Gender
	Male	3	0.82 (0.72, 0.94)	81.3	0.005
	Female	4	0.80 (0.73, 0.87)	57.5	0.07

Abbreviations: CI, confidence interval; CVD, cardiovascular disease; HEI, Healthy Eating Index; HR, hazard ratio.

^∗P value for heterogeneity within each subgroup.