Table 2.

Stratified and meta-regression analysis to explore the effects of study characteristics

	Number of cohorts	Pooled RRs (95% CI)*	P value of meta-regression†
Study design
Historical cohort	10	1.22 (1.10–1.36)	0.55
Prospective cohort	4	1.10 (1.01–1.20)
Indicators of participant characteristics
Country
Asia	8	1.09 (1.04–1.21)	0.10
Western	6	1.27 (1.12–1.44)
Mean age (years)
≤50	8	1.12 (1.04–1.19)	0.14
>50	6	1.26 (1.11–1.44)
Sex
Men only	7	1.09 (1.02–1.16)	0.09
Women only	4	1.28 (1.08–1.51)	0.31
Both men and women	3	1.40 (0.98–2.00)
Mean SUA level (mg/dl)
≤5.5	6	1.18 (1.15–1.32)	0.98
>5.5	8	1.16 (1.05–1.28)
Indicators of study quality
Study adjustment for
alcohol intake
No	9	1.27 (1.13–1.43)	0.02
Yes	5	1.07 (1.02–1.12)
Metabolic confounders‡
Insufficient	8	1.21 (1.09–1.34)	0.46
Sufficient	6	1.11 (1.02–1.21)
Follow-up duration (years)
≤8	6	1.25 (1.03–1.51)	0.37
>8	8	1.13 (1.05–1.20)
Diabetes ascertainment
Blood measurements only	4	1.18 (1.02–1.37)	0.81
Report only	3	1.24 (0.96–1.59)	0.64
Both	7	1.14 (1.06–1.23)

*Pooled RRs of type 2 diabetes for each 1 mg/dl increase in SUA within the strata of each study characteristic are indicated.

†Represents the test for significance of the effect across strata.

‡If the RRs were adjusted for more than three confounders (among BMI, fasting plasma glucose, hypertension [or systolic blood pressure], HDL cholesterol, and triglycerides), they were regarded as sufficient; otherwise, they were regarded as insufficient.