Table 4.

Meta-regression analysis of the effect of key variables on the risk of sequelae

	Participants (number of studies)	Bivariate meta-regression*		Multivariate meta-regression†
		OR (95% CI)	p value	OR (95% CI)	p value
WHO region
Americas	13 951 (68)	1·00	..	1·00	..
European	6716 (59)	1·03 (0·92–1·16)	0·58	0·93 (0·67–1·30)	0·68
Western Pacific	1187 (15)	0·97 (0·85–1·12)	0·72	0·86 (0·61–1·21)	0·38
Southeast Asia	158 (5)	0·90 (0·71–1·14)	0·36	0·78 (0·52–1·18)	0·24
Africa	115 (3)	1·06 (0·80–1·39)	0·70	0·93 (0·61–1·41)	0·71
East Mediterranean	34 (1)	0·85 (0·53–1·35)	0·49	0·74 (0·42–1·29)	0·28
Data collection period (year)
<1980	7452 (38)	1·00	..	1·00	..
1980–89	6559 (48)	0·94 (0·86–1·03)	0·18	0·87 (0·54–1·42)	0·59
1990–99	6108 (47)	1·09 (1·00–1·19)	0·06	0·97 (0·59–1·57)	0·89
≥2000	2042 (19)	0·94 (0·82–1·08)	0·37	0·86 (0·52–1·41)	0·55
Follow-up (months)
<12	1631 (29)	0·96 (0·86–1·06)	0·40	1·06 (0·90–1·24)	0·49
12–35	8184 (52)	1·01 (0·89–1·08)	0·85	1·07 (0·93–1·24)	0·33
36–60	1315 (18)	0·92 (0·88–1·06)	0·21	1·01 (0·87–1·18)	0·88
>60	10 002 (39)	1·00	..	1·00	..
Mixed (across the age ranges)	1029 (15)	1·12 (1·01–1·33)	0·03	1·15 (0·96–1·38)	0·13
Study design
Prospective	20 095 (124)	1·00	..	1·00	..
Retrospective	2066 (29)	1·06 (1·00–1·17)	0·28	1·05 (0·94–1·18)	0·39

^*Estimates compared to most prevalent group within the subgroup.

^†Multivariate regression approach (WHO region with the Americas as the baseline, data collection period with <1980 as the baseline, follow-up with >60 months as the baseline).