Table 2.
Characteristics of included studies
| First author, year | Country, period of data collection | Sample type (national/subnational) | Sample size | UIC median [IQR] or [mean ± sd] | Risk of bias: 0–3 low 4–6 intermediate 7–9 high |
|---|---|---|---|---|---|
| Before 1995 | |||||
| Chaouki, 1994 [23] | Algeria (1994) | Sub-national | 982 | [17.9 ± 0.1] | 2 – low |
| Ngo, 1997 [24] | DRC (1991–1992) | National | 306 | 39.3 [31.1, 52.9] | 0 – low |
| 1995–2005 | |||||
| Hess, 1999 [25] | Cote de'Ivore | Sub-national | 72 | 351 [74 - 2241] | 2 – low |
| Hess, 1999 [25] | Cote de'Ivore | Sub-national | 66 | 136 [12 - 915] | 1 – low |
| Ojule 1998 [26] | Nigeria, 1998 | Sub-national | 90 | [213.4 ± 9.9] | 3 – low |
| Ojule 1998 [26] | Nigeria, 1998 | Sub-national | 105 | [149 ± 14.7] | 3 – low |
| Dillon, 2000 [27] | Senegal 1996–1997 | Sub-national | 462 | [60 ± 39] | 1 – low |
| Eltom, 2000 [28] | Sudan 1998–1999 | Sub-national | 47 | 38 [12.7, 50.8] | 3 – low |
| Lwenje, 2000 [29] | Swaziland | National | 165 | 295 [95% CI 265.5–425.6] | 1 – low |
| 2006–2020 | |||||
| Akdader-Oudahmane, 2020 [30] | Algeria 2016–2017 | Sub-national | 173 | 233 [157, 326] | 4 – intermediate |
| Garnier et al., 2016 [31] | Burkina Faso | National | 946 | 74 [NA, NA] | 1 – low |
| Kavishe et al., 2020 [32] | Burundi 2018 | National | 87 | 86.7 [NA, NA] | 1 – low |
| Habimana et al., 2013 [33] | DRC, 2009–2011 | Sub-national | 225 | 138 [105, 172] | 1– low |
| IGN, 2017 [14, 34] | Djibouti, 2015 (NS) | National | 230 | 265 [170, 445] | 0 – low |
| MOHP, 2017 [35] | Egypt, 2014–2015 | National | 1498 | 135 [NA, NA] | 0 – low |
| Hamza, 2007 [36] | Egypt, 2006 | Sub-national | 113 | [102.9 ± 31.1] | 2 – low |
| Elsayed, 2016 [37] | Egypt,2016 | Sub-national | 400 | 170 [NA, NA] | 1 – low |
| Mohammed, 2020 [38] | Ethiopia, 2013–2014 | Sub-national | 562 | 120.6 [68.9, 216.4] | 1 – low |
| Fereja, 2018 [39] | Ethiopia | Sub-national | 354 | 85.7 [45.7, 136] | 1 – low |
| Kedir, 2014 [40] | Ethiopia, 2012 | Sub-national | 435 | 58.1[21.4, 111.1] | 1 – low |
| Ersino, 2013 [41] | Ethiopia, 2009 | Sub-national | 172 | 15 [2.5, 33] | 2 – low |
| Takele, 2017 [42] | Ethiopia, 2017 | Sub-national | 403 | 137 [97, 177] | 1 – low |
| Keno, 2017 [43] | Ethiopia, 2014 | Sub-national | 40 | 88.6 [66.9, 133.5] | 3 – low |
| Negeri, 2014 [44] | Ethiopia, 2011 | Sub-national | 423 | 48 [NA, NA] | 2 – low |
| NaNA, 2019 [45] | Gambia 2018 | National | 118 | 113.5 [50.1, 205.9] | 0 – low |
| GHS, 2017 [46] | Ghana, 2015 | National | 102 | 183.5 [NA, NA] | 0 – low |
| Gyamfi, 2018 [47] | Ghana, 2016 (ss) | Sub-national | 239 | 159 [NA, NA] | 3 – low |
| Adu-Afarwuah, 2018 [48] | Ghana, 2009–2011 | Sub-national | 295 | 137 [78, 221] | 2 – low |
| Farebrother et al., 2018 [49] | Kenya | Sub-national | 162 | 337 [198, 505] | 4 – intermediate |
| Randremanana, 2019 [50] | Madagascar, 2014 | National | 170 | 53 [9, 89] | 0 – low |
| Stinca, 2017 [51, 52] | Morocco 2013–2014 | Sub-national | 245 | 32 [17, 58] | 3 – low |
| Sadou 2013 [53] | Niger 2012 | Sub-national | 240 | 119 [NA, NA] | 2 – low |
| Hess, 2016 [54] | Niger, 2014–2015 | Sub-national | 662 | 69 [38.1, 114.3] | 1 – low |
| Jibril, 2016 [55] | Nigeria, 2014 | Sub-national | 300 | 193 [NA, NA] | 2 – low |
| Kayode, 2019 [56] | Nigeria, 2012 | Sub-national | 133 | 135 [NA, NA] | 1 – low |
| Ujowundu, 2010 [57] | Nigeria, 2009 | Sub-national | 302 | [152.09 ± 41.65 ] | 2 – low |
| Rohner, 2016 [58] | Sierra Leone, 2013 | National | 154 | 175.8 [NA, NA] | 0 – low |
| MOH-FGS, 2020 [34] | Somalia, 2018–2019 | National | 236 | 369 [142.9, 752] | 0 – low |
| Mabasa, 2019 [59] | South Africa, 2012–2013 | Sub-national | 565 | 164 [92, 291] | 3 – low |
| Stinca, 2017 [51, 52] | South Africa | Sub-national | 207 | 174 [95.3, 297.6] | 3 – low |
| Mtumwa, 2017 [60] | Tanzania, 2009–2010 | National | 947 | 136.8 [58.8, 258] | 1 – low |
| Ba, 2020 [61] | Tanzania, 2015–2016 | National | 266 | 156.1 [64.6, 260.4] | 0 – low |
| Stinca, 2017 [51, 52] | Tanzania, 2016 | Sub-national | 330 | 422 [270, 609] | 3 – low |
| Chinyanga, 2006 [62] | Zimbabwe, 2006 | Sub-national | 94 | 115.5 [43, 225] | 4 – intermediate |