Interferon-associated retinopathy risk in patients with diabetes and hypertensive hepatitis C

Table 1 Main characteristics of the studies included in the meta-analysis

Ref.	Year	Country	Study design	Type of IFN	No. of HCV (+) IAR (+) cases/HCV (+) IAR (-) controls	Reported end-points	Follow-up	Study quality
Kawano et al[11]	1996	Japan	Prospective cohort	Natural IFN α, recombinant IFN α-2a/2b	17/49	Retinopathy	48 wk	5
Okuse et al[19]	2006	Japan	Prospective cohort	Recombinant IFN α-2b	18/56	Retinopathy	24 wk	6
d'Alteroche et al[25]	2006	France	Prospective cohort	IFN α, PIFN α	11/133	Retinopathy	72 wk	6
Panetta et al[21]	2009	United States	Retrospective cohort	Consensus IFN, PIFN α-2a/2b	114/48	Retinopathy	48 wk	5
Mehta et al[20]	2010	United States	Retrospective cohort	PIFN	26/39	Retinopathy	48 wk	4
Kim et al[18]	2010	South Korea	Prospective cohort	PIFN, conventional IFN	13/22	Retinopathy	36 wk	8
Vujosevic et al[26]	2012	Canada	Prospective cohort	PIFNα-2a/2b	22/66	Retinopathy	36/60 wk	8
Mousa et al[22]	2013	Egypt	Prospective cohort	PIFN α-2a/2b	40/42	Retinopathy	48 wk	6

IFN: Interferon; PIFN: Pegylated interferon.

Table 2 Summary relative risks for the association of hypertension and interferon-associated retinopathy risk by study design, ethnicity

	Subgroup	Ref.	RR (95%CI)	Z (P value)	Heterogeneity of study design
					χ2	Df (P value)	I2
HTN	Study design
	Prospective	[11,18-20,25,26]	2.38 (1.46-3.87)	3.49 (0.000)	13.62	5 (0.018)	63.30%
	Retrospective	[20,21]	0.74 (0.16-3.33)	0.40 (0.690)	2.99	1 (0.084)	66.50%
	Ethnicity
	Asian	[11,18,19]	1.56 (1.07-2.27)	2.31 (0.021)	1.33	2 (0.514)	0.00%
	Caucasian	[20,21,25,26]	1.96 (0.78-4.92)	1.43 (0.154)	18.69	3 (0.000)	84.00%
	African	[22]	2.21 (0.15-33.50)	0.57 (0.567)	-	-	-
	Treatment duration
	24 wk	[11,18,19]	1.56 (1.07-2.27)	2.31 (0.021)	1.33	2 (0.514)	0.00%
	48 wk	[20-22,25,26]	2.00 (0.85-4.68)	1.59 (0.112)	18.67	4 (0.001)	78.60%
	Overall	[11,18-22,25,26]	1.90 (1.15-3.15)	2.50 (0.013)	23.82	7 (0.001)	70.60%

HTN: Hypertension; -: Could not be calculated.