TABLE 4.

Subgroup analysis of depression for the highest vs. lowest category of dietary beta-carotene intake.

Stratification	Number of studies	Pooled RR	95% CI	P-value	Heterogeneity
All studies	8	0.63	0.55, 0.72	P < 0.001	P = 0.31; I2 = 15%
Geographical region
Asia	6	0.64	0.54, 0.76	P < 0.001	P = 0.22; I2 = 27%
Non-Asia	2	0.62	0.50, 0.76	P < 0.001	P = 0.28; I2 = 16%
Exposure assessment
FFQ	6	0.64	0.54, 0.76	P < 0.001	P = 0.22; I2 = 27%
Recall method	2	0.62	0.50, 0.76	P < 0.001	P = 0.28; I2 = 16%
Sex
Male	1	0.36	0.13, 1.00	/	/
Female	6	0.65	0.54, 0.78	P < 0.001	P = 0.23; I2 = 28%
Population
Adolescent	3	0.46	0.33, 0.64	P < 0.001	P = 0.82; I2 = 0%
Middle aged and elderly	4	0.67	0.58, 0.78	P < 0.001	P = 0.42; I2 = 0%
Sample size
< 1,000	4	0.46	0.34, 0.62	P < 0.001	P = 0.95; I2 = 0%
> 1,000	4	0.68	0.59, 0.80	P < 0.001	P = 0.37; I2 = 5%
Adjustment of BMI
Adjusted	6	0.62	0.54, 0.72	P < 0.001	P = 0.22; I2 = 28%
Unadjusted	2	0.68	0.46, 1.02	P = 0.06	P = 0.33; I2 = 0%
Adjustment of energy intake
Adjusted	5	0.61	0.52, 0.71	P < 0.001	P = 0.27; I2 = 22%
Unadjusted	3	0.69	0.54, 0.89	P = 0.003	P = 0.34; I2 = 8%