Table 2.

Pooled risks of type 2 diabetes mellitus (T2DM; and 95 % confidence intervals) in association with ‘healthy’ dietary patterns in different subgroup analyses

				Meta-analysis		Heterogeneity
Subgroup	Category	No. of studies	No. of participants	OR	95 % CI	I 2 (%)	P value	P value for between-subgroup heterogenity
Sex	Female	2	76 145	0·86	0·77, 0·95	0·0	0·69	0·96
	Male	3	106 576	0·86	0·80, 0·94	0·0	0·77
	Both	8	184 882	0·86	0·79, 0·93	36·0	0·14
Region	Western	8	254 057	0·86	0·82, 0·91	0·0	0·81	0·68
	Eastern	5	113 546	0·87	0·76, 1·00	48·5	0·10
Overall quality score of study	High	5	159 107	0·85	0·79, 0·90	0·0	0·87	0·60
	Low	8	208 496	0·88	0·81, 0·94	31·3	0·17
Follow-up years	≥10 years	9	261 100	0·86	0·80, 0·91	27·1	0·20	0·76
	<10 years	4	106 503	0·87	0·79, 0·95	0·0	0·89
Person-years	≥100 000	3	116 362	0·85	0·77, 0·94	0·0	0·44	0·96
	<100 000	5	74 237	0·87	0·77, 0·99	57·1	0·05
Adjustment for physical activity	Yes	11	326 512	0·86	0·82, 0·90	3·4	0·41	0·31
	No	2	41 091	0·76	0·60, 0·96	0·0	0·57
Publication year	After 2010	8	208 496	0·87	0·81, 0·93	29·9	0·18	0·81
	Before 2010	5	159 107	0·85	0·79, 0·92	0·0	0·80
Adjustment for family history of T2DM	Yes	7	223 519	0·86	0·79, 0·93	0·0	0·81	0·96
	No	6	144 084	0·87	0·80, 0·93	42·5	0·12
Ethnic difference	Western	5	173 534	0·88	0·80, 0·96	0·0	0·47	0·82
	Western-Japanese/Chinese	3	80 523	0·85	0·80, 0·91	0·0	0·98
	Japanese/Chinese	5	113 546	0·87	0·76, 1·00	48·5	0·10
Adjustment for educational status	Yes	3	95 897	0·87	0·81, 0·94	0·0	0·38	0·55
	No	10	271 706	0·85	0·80, 0·90	4·6	0·39
T2DM incidence	≥1000 cases	6	230 746	0·86	0·80, 0·92	2·8	0·23	0·82
	<1000 cases	7	136 857	0·86	0·80, 0·93	0·0	0·58
Health-care system employee participants	Yes	6	219 215	0·87	0·80, 0·94	0·0	0·89	0·74
	No	7	148 388	0·86	0·80, 0·92	39·6	0·12