. 2019 Mar 12;11:25. doi: 10.1186/s13098-019-0420-3

Table 2.

Subgroup analysis of the relation between MPV and DR patients

Subgroup	Study	No. of studies	SMD	95% CI	Heterogeneity
Subgroup	Study	No. of studies	SMD	95% CI	P value	I² (%)
DR vs control
Location	Turkey	7	0.66	0.42–0.90	= 0.003	70
	China	3	0.94	0.49–1.40	= 0.005	81
	India	2	1.82	1.09–2.56	= 0.003	70
Study quality	High	11	0.79	0.57–1.01	< 0.0001	76
Study quality	Low	2	4.53	− 0.14 to 9.21	< 0.00001	99
DR vs T2DM without DR
Location	Turkey	7	0.24	0.09–0.40	= 0.11	42
	China	2	0.33	0.09–0.56	= 0.68	0
	India	2	0.87	0.49–1.25	= 0.23	30
Study design	Case–control	10	0.76	0.17–1.35	< 0.00001	97
Study design	Cross-sectional	2	0.37	0.11–0.62	= 0.95	0
Study quality	High	10	0.30	0.15–0.45	= 0.03	51
Study quality	Low	2	2.36	− 0.79 to 5.51	< 0.00001	99
DR sub-type	NPDR vs control	4	0.41	0.16–0.65	= 0.182	38.3
	PDR vs control	4	0.81	0.48–1.14	= 0.031	66.1
	NPDR vs T2DM without DR	3	0.04	− 0.16 to 0.24	= 0.642	0
	PDR vs T2DM without DR	3	0.48	0.28–0.68	= 0.349	5.1
	PDR vs NPDR	4	0.41	0.17–0.64	= 0.193	36.6
Intervals^a
≤ 60 min	DR vs control	3	0.39	0.20–0.58	= 0.60	0
≤ 60 min	DR vs T2DM without DR	2	0.02	− 0.25 to 0.30	= 0.18	43
> 60 min	DR vs control	2	0.99	0.67–1.31	= 0.19	41
> 60 min	DR vs T2DM without DR	2	0.37	0.15–0.58	= 0.53	0

MPV mean platelet volume, DR diabetic retinopathy, T2DM without DR type 2 diabetic mellitus without diabetic retinopathy, NPDR non-proliferative diabetic retinopathy, PDR proliferative diabetic retinopathy, SMD standard mean difference, CI confidence interval

^aIntervals of MPV collection and measurement