Impact of diabetes mellitus on mortality in pulmonary hypertension: A systematic review and meta-analysis

Table 2 Subgroup analysis of studies based on country, sample size, follow-up period, mean age, or study quality

Group	Included studies	Odds ratio (95%CI)	P value	P-within subgroups heterogeneity	I2%	P-meta-regression
Overall risk of mortality	14	1.40 (1.15-1.70)	< 0.001	0.002	60	NA
Subgroup analysis
Country United States vs non-United States
United States	6	1.17 [0.89-1.53]	0.26	0.27	22	< 0.001
Non-United States	8	1.55 [1.25-1.92]	< 0.001	0.14	36
Sample size < 200 vs ≥ 200
Sample size < 200	7	1.22 [0.71-2.12]	0.47	0.06	50	0.340
Sample size ≥ 200	7	1.46 [1.19-1.80]	< 0.001	0.003	70
Follow up < 5 years vs ≥ 5 years
Follow up < 5 years	5	1.52 [0.78-2.98]	0.22	0.06	56	0.640
Follow up ≥ 5 years	9	1.37 [1.13-1.67]	0.001	0.006	63
Overall mean age < 60 years vs ≥ 60 years
Mean age < 60 years	7	1.61 [1.27-2.05]	< 0.001	0.40	3	0.138
Mean age ≥ 60 years	7	1.26 [0.99-1.61]	0.06	0.004	68
Study quality score based on NIH risk of bias
High	3	2.52 [1.47-4.32]	0.0008	0.90	0	0.807
Moderate	10	1.23 [1.05-1.43]	0.010	0.20	26
Unclear	1	1.78 [1.40-2.25]	Not applicable	Not applicable	Not applicable

NIH: National Institutes of Health.