Table 2

Results of univariable metregression analyses for the prevalence of NG infection in infertile populations

	Predictors		Studies/strata	Samples	Univariable analyses		Variance explained
	Predictors		Total N	Total N	OR (95% CI)	P value*	R² (%)
Population characteristics	WHO region	AMRO	33	7960	1.00		5.1
		AFRO	24	2281	3.95 (1.54 to 10.09)	0.004
		EMRO	14	1550	1.37 (0.45 to 4.19)	0.576
		EURO	73	8987	1.32 (0.64 to 2.76)	0.452
		SEARO	15	1207	1.24 (0.42 to 3.70)	0.692
		WPRO	19	4905	1.23 (0.45 to 3.37)	0.686
		Multicenter	6	374	8.96 (1.90 to 42.29)	0.006
	Sex	Men	43	16 560	1.00		2.0
		Women	141	10 704	1.98 (1.06 to 3.67)	0.031
	Infertility type	Primary/majority primary	52	9330	1.00		0.7
	Infertility type	Secondary/majority secondary	24	1756	2.14 (0.88 to 5.17)	0.091
		Not specified/not applicable	108	16 178	1.06 (0.58 to 1.95)	0.840
	Infertility diagnosis	General infertility/not specified	64	12 441	1.00		4.7
	Infertility diagnosis	Tubal factor infertility	50	3238	2.39 (1.23 to 4.63)	0.010
		Male factor infertility	24	8263	0.72 (0.31 to 1.67)	0.442
		Ovarian and non-tubal infertility	26	2255	0.80 (0.36 to 1.81)	0.595
		Mixed and unexplained infertility	20	1067	2.03 (0.83 to 4.98)	0.122
	Presence of urogenital signs and symptoms	Asymptomatic	64	16 484	1.00		8.2
		Symptomatic	24	1408	5.94 (2.61 to 13.54)	<0.001
		Not specified	96	9372	1.67 (0.96 to 2.91)	0.070
Study methodology characteristics	Assay type	NAAT (current infection)	33	12 594	1.00		22.0
		Culture (current infection)	94	9682	2.54 (1.34 to 4.83)	0.005
		Other† (current infection)	7	458	4.08 (1.09 to 15.27)	0.037
		IgG (ever infection)	25	1470	22.10 (9.53 to 51.20)	<0.001
		IgA/unclear	25	3060	3.74 (1.61 to 8.67)	0.002
	Year of data collection‡		184	27 264	0.97 (0.95 to 0.99)	0.001	5.5
	Sample size	<100 participants	81	3803	1.00		3.0
		≥100 participants	103	23 461	0.51 (0.30 to 0.86)	0.011
Risk of bias domains	Infertility definition	Follows WHO definition	70	11 293	1.00		0
	Infertility definition	Otherwise/unclear	114	15 971	0.85 (0.49 to 1.46)	0.549
	Exposure to antimicrobials	Lack of exposure last week	25	2037	1.00		2.2
		Exposure in last week	9	1503	0.91 (0.23 to 3.61)	0.890
		Unclear	150	23 724	2.27 (1.06 to 4.90)	0.036
	Infection ascertainment	Consistency in assay used	179	26 612	1.00		0
	Infection ascertainment	Otherwise/Unclear	5	652	1.30 (0.25 to 6.66)	0.750
	Response rate	≥80%	2	70	1.00		0
	Response rate	<80%/unclear	182	27 194	0.78 (0.06 to 10.10)	0.849

*Strength of evidence for an association with prevalence was deemed ‘good’ at 0.05<p value≤0.10, and ‘strong’ at p value≤0.05.
†Includes Gram stain, gonozyme and fluorescent antibody assays.
‡Missing values for year of data collection were imputed using data for year of publication adjusted by the median difference between year of publication and year of data collection (for studies with complete information).
AFRO, African Region; AMRO, Region of the Americas; EMRO, Eastern Mediterranean Region; EURO, European Region; NAAT, nucleic acid amplification test; NG, Neisseria gonorrhoeae; SEARO, South-East Asia Region; WPRO, Western Pacific Region.