Table 4 Pooled proportion of under-estimated maternal deaths, disaggregated by study covariates

Total proportion of underestimated maternal deaths (exc high risk of bias studies)

18

39% (31–48)

I^2 = 93.1

H^2 = 14.3

p < 0.001

Type of system

Heterogeneity between groups p = 0.44

 CRVS

16

39% (27–51)

I^2 = 93.2

H^2 = 14.8

%; p < 0.001

 Health and Demographic surveillance system

2

32% (16–50)

I^2 = 93.4

H^2 = 15.2

P < 0.001

 District Health Information System or Health Management information system)

4

49% (42–75)

I^2 = 92.65

H^2 =  = 13.6

p < 0.001

Country income level

Heterogeneity between income groups: p = 0.36

 High or upper middle-income country

16

36% (25–48)

I^2 = 92.2%

H^2 = 12.8%

(P < 0.001)

 Low or lower-middle-income

9

45% (31–58)

I^2 = 94.1%

H^2 = 16.8%

(P < 0.001)

 Mid-year of data collection

Heterogeneity between groups: p = 0.38

 Before 2000

4

42% (26–58)

I^2 = 93.1

H^2 = 14.5

(P =  < 0.001)

 2000–2010

6

47% (37–57)

I^2 = 76.7

H^2 = 4.3

(P =  < 0.001)

 After 2010

8

29% (14–48)

I^2 = 96.1

H^2 = 25.5

(P =  < 0.001)