Impacts of age and gender at the risk of underlying medical conditions and death in patients with avian influenza A (H7N9): a meta-analysis study

Figures & data

Figure 1 Flow chart of selection of publications for inclusion in meta-analysis.

Note: ^aFive authors were contacted for additional data to determine eligibility.
Abbreviation: UMCs, underlying medical conditions.

Table 1 Characteristics and extracted details of included studies in the meta-analysis (N=15)

Author (reference)	Publication year	Study design	Type of publication	Diagnostic methods	Study period	Sample size (cases, UMCs/non-UMCs)	Fatal cases/nonfatal cases (UMCs; non- UMCs)	Covariate adjustment (stratification)	Quality appraisal scores
Feng et al (4)	2014	RCC	EPR	RT-PCR	March–May 2013	22 (15/7)	5/10; 2/5	None	6
Ma et al (5)	2017	RCC	EPR	RT-PCR	March 2013– May 2016	102 (57/45)	28/29; 19/26	Gender	7
Lu et al (6)	2013	RCC	EPR	RT-PCR	March 20– April 7, 2013	4 (3/1)	2/1; 0/1	Age	5
Ji et al (7)	2014	RCC	EPR	RT-PCR	March 20– May 10, 2013	28 (17/11)	6/11; 3/8	None	6
Virlogeux et al (11)	2016	RCC	EPR	RT-PCR	March 2013– August 2014	395 (189/206)	93/96; 80/126	None	6
Liu et al (12)	2013	RCC	EPR	RT-PCR	March 2– April 25, 2013	40 (26/14)	9/17; 1/13	None	6
Liu et al (13)	2015	CS	EPR	RT-PCR	March 22– April 30, 2013	16 (15/1)	6/9; 0/1	Age and gender	7
Zhang et al (14)	2013	RCC	EPR	RT-PCR	March– April 2013	18 (12/6)	4/8; 2/4	Age and gender	6
Cheng et al (15)	2015	RCC	EPR	RT-PCR	March 1, 2013– June 30, 2014	85 (55/30)	24/31; 6/24	Age and gender	7
Xie et al (16)	2014	RCC	EPR	RT-PCR	March 1, 2013– March 2, 2014	61 (37/24)	16/21; 4/20	Age and gender	6
Chai et al (17)	2013	RCC	EPR	RT-PCR	March– April 10, 2013	6 (5/1)	2/3; 0/1	Age and gender	6
Wu et al (18)	2017	RCC	EPR	RT-PCR	March 2013– November 30, 2016	656 (291/365)	156/135; 109/256	None	6
Wang et al (19)	2016	RCC	EPR	RT-PCR	January 11– April 10, 2014	25 (21/4)	12/9; 2/2	None	7
Chen et al (20)	2014	RCC	EPR	RT-PCR	Not available	53 (28/25)	9/19; 5/20	None	6
Yang et al (21)	2017	RCC	EPR	RT-PCR	August 2013– March 2017	256 (123/133)	50/73; 50/83	Age and gender	7

Abbreviations: CS, cohort study; EPR, externally peer-reviewed; RCC, retrospective case–control study; RT-PCR, real-time reverse transcription polymerase chain reaction; UMCs, underlying medical conditions.

Figure 2 Forest plots on effect sizes of underlying medical conditions associated with fatalities of H7N9-infected cases.

Notes: (A) The pooled estimate. (B) Subgroup analyses of certain UMC types, age, and gender.
Abbreviations: CCD, chronic cardiovascular diseases; CHD, coronary heart disease; CLD, chronic liver disease; CMD, chronic metabolic diseases; CRD, chronic respiratory diseases; RD, rheumatic diseases; UMC, underlying medical condition.

Figure 3 Forest plot on estimates of combined effects of UMCs with age or gender in H7N9 patients.

Abbreviation: UMC, underlying medical condition.

Table 2 Summary of heterogeneity and publication bias on each meta-analysis of UMCs associated with fatalities of H7N9-infected cases

Study	Numbers of studies	Heterogeneity			Publication bias
		Q	P-value	I^2 (%)	Egger’s test [t(P)]	Begg’s test [z(P)]
The pooled estimate certain UMC types	15	7.61	0.909	0.0	0.20 (0.848)	0.74 (0.488)
Having two or more UMCs	4	0.52	0.915	0.0	1.26 (0.333)	0.34 (0.734)
CRD	7	9.35	0.155	35.8	1.32 (0.245)	0.00 (1.000)
CHD	5	1.01	0.909	0.0	0.09 (0.937)	0.24 (0.836)
CMD	7	1.81	0.936	0.0	1.43 (0.213)	0.60 (0.548)
CLD	7	2.39	0.881	0.0	0.38 (0.720)	0.60 (0.548)
CCD	8	1.58	0.979	0.0	0.35 (0.741)	0.12 (0.902)
RD	4	0.11	0.991	0.0	−1.32 (0.317)	−0.34 (1.000)
Estimates by adjusting for the effects of age and gender
Age
60 years of age and older	7	0.59	0.997	0.0	0.22 (0.507)	0.00 (1.000)
0–59 years old	7	3.42	0.490	10.5	0.42 (0.730)	0.24 (0.806)
Gender
Male	7	0.74	0.994	0.0	−0.49 (0.132)	0.60 (0.548)
Female	7	1.96	0.926	0.0	−0.21 (0.753)	0.15 (0.881)
The estimate of combined effects of UMCs with age or gender
60 years of age and older vs 0–59 years old	7	6.07	0.414	1.1	−2.04 (0.097)	1.80 (0.072)
Male vs female	7	2.79	0.835	0.0	−0.22 (0.750)	0.30 (0.764)

Abbreviations: CCD, chronic cardiovascular diseases; CHD, coronary heart disease; CLD, chronic liver disease; CMD, chronic metabolic diseases; CRD, chronic respiratory diseases; RD, rheumatic diseases; UMCs, underlying medical conditions.

Figure 4 Funnel plots on meta-analyses of underlying medical conditions associated with fatalities of H7N9-infected cases.

Notes: ^aEstimates by adjusting for the effects of age and gender. ^bThe estimate of combined effects of UMCs with age or gender.
Abbreviation: UMC, underlying medical condition.

Figure 5 Sensitivity analysis plots on meta-analyses of underlying medical conditions associated with fatalities of H7N9-infected cases.

Notes: (A) The pooled estimate. (B) The estimate of combined effects of underlying medical conditions with age or gender. (C) The estimates by adjusting for the effects of age and gender.