Table 2 Characteristics of studies included in the systematic review (n = 78) (B)
 Study | Year | Country | Type of study | N(total) | Mean Age (years) | Male | Female |
|---|---|---|---|---|---|---|---|
 Adamu [12] | 2010 | Nigeria | Prospective | 488 | 32 | 301 | 187 |
 Ademe [13] | 2022 | Ethiopia | Retrospective | 267 | 36 | 160 | 107 |
 Agboola [14] | 2014 | Nigeria | Prospective | 276 | NA | 197 | 79 |
 Ahmed [15] | 2010 | Nigeria | Prospective | 3717 | 32.5 | NA | NA |
 Ajao [16] | 1981 | Nigeria | NA | 360 | NA | 240 | 120 |
 Almeimoune [17] | 2021 | Mali | Prospective | 631 | 36.13 | NA | NA |
 Assouto [18] | 2009 | Benin | Retrospective | 613 | 30 | 377 | 236 |
 Attipou [19] | 2005 | Togo | Retrospective | 932 | 32 | 600 | 332 |
 Awori [20] | 2005 | Kenya | Prospective | 398 | NA | NA | NA |
 Ayenew [21] | 2016 | Ethiopia | Retrospective | 295 | 33.7 | 230 | 65 |
 Ba [22] | 2021 | Senegal | Prospective | 601 | 30.2 | 428 | 173 |
 Bang [23] | 2021 | Cameroon | Prospective | 120 | 37.6 | 80 | 40 |
 Camara [24] | 2021 | Guinea Conakry | Retrospective | 460 | 41.5 | 297 | 163 |
 Coulibaly [25] | 2019 | Mali | Prospective | 100 | 34.4 | 70 | 30 |
 Daddy [26] | 2020 | Niger | Prospective | 262 | 26.57 | 190 | 72 |
 Debrah [27] | 2012 | Ghana | Retrospective | 122 | 31.3 | 63 | 59 |
 Dembélé [28] | 2021 | Mali | Prospective | 101 | 33.6 | 89 | 12 |
 Dewulf [29] | 1986 | Rwanda | NA | 204 | NA | NA | NA |
 Diallo [30] | 2020 | Gabon | Retrospective | 311 | 29.5 | 177 | 34 |
 Diaw [31] | 2018 | Senegal | Retrospective | 90 | 34 | 64 | 26 |
 Didier [32] | 2020 | Niger | Prospective | 151 | 25.2 | 106 | 45 |
 Diop [33] | 2011 | Senegal | Retrospective | 504 | 39.6 | 343 | 161 |
 Dossouvi [34] | 2021 | Togo | Retrospective | 204 | 29 | 125 | 79 |
 Doui [35] | 2009 | Central Africa | Prospective | 160 | 35.6 | 108 | 52 |
 Doumi [36] | 2009 | Sudan | Prospective | 421 | NA | 242 | 179 |
 Ehlers [9] | 2021 | South Africa | Retrospective | 3609 | NA | NA | NA |
 Engbang [66] | 2021 | Cameroon | Prospective | 218 | 36.32 | 112 | 91 |
 Gaye [38] | 2016 | Senegal | Retrospective | 161 | 41 | 120 | 41 |
 Gbessi [39] | 2015 | Benin | Retrospective | 169 | NA | 96 | 73 |
 Gebre [40] | 2016 | Ethiopia | Retrospective | 166 | 27.2 | 94 | 72 |
 Gebrie [41] | 2019 | Ethiopia | Prospective | 192 | 31.46 | 107 | 64 |
 Hagos [42] | 2015 | Ethiopia | Retrospective | 299 | 31.5 | 240 | 59 |
 Hanks [43] | 2014 | Ethiopia | Retrospective | 328 | 35.6 | NA | NA |
 Harissou [44] | 2015 | Niger | Prospective | 302 | 23 | 227 | 75 |
 Harouna [45] | 2001 | Niger | Retrospective | 742 | NA | NA | NA |
 Ibrahim [46] | 2015 | Nigeria | Prospective | 612 | 44.9 | NA | NA |
 Kambire [47] | 2017 | Burkina | Retrospective | 343 | 29 | 265 | 78 |
 Kambire [48] | 2018 | Burkina | Retrospective | 394 | 33 | 290 | 104 |
 Karuhanga [49] | 2020 | Tanzania | Retrospective | 284 | 39 | 185 | 99 |
 Kassegne [50] | 2015 | Togo | Retrospective | 303 | 24 | 242 | 61 |
 Katswere [51] | 2018 | Benin | Prospective | 128 | 30 | 81 | 47 |
 Korsé [52] | 2021 | Guinea Conakry | Prospective | 135 | 34 | 93 | 42 |
 Kotiso [53] | 2007 | Ethiopia | Retrospective | 587 | 30.7 | 391 | 196 |
 Madubogwu [54] | 2020 | Niger | Retrospective | 177 | 33.98 | 92 | 85 |
 Magagi [2] | 2016 | Niger | Prospective | 622 | 22.9 | 467 | 155 |
 Mbah [55] | 2006 | Nigeria | Prospective | 136 | 25 | 95 | 41 |
 Mcconkey [56] | 2022 | Sierra Leone | Retrospective | 173 | NA | NA | NA |
 Melkie [57] | 2016 | Ethiopia | Retrospective | 304 | NA | 188 | 183 |
 Mjema [58] | 2020 | Tanzania | Prospective | 199 | 47 | 73 | 126 |
 Motto [59] | 2021 | Cameroon | Prospective | 63 | 41.06 | NA | NA |
 Mpirimbanyi [60] | 2020 | Rwanda | Retrospective | 563 | 28 | 377 | 186 |
 Mpirimbanyi [61] | 2017 | Rwanda | Retrospective | 51 | NA | NA | NA |
 Nega [62] | 2009 | Ethiopia | NA | 143 | 26.6 | 79 | 64 |
 Negash [63] | 2017 | Ethiopia | Retrospective | 238 | 26.5 | 196 | 74 |
 Ngakani [64] | 2020 | Gabon | Retrospective | 451 | 35.3 | 282 | 169 |
 Nyundo [65] | 2013 | Rwanda | Prospective | 229 | 28.8 | 144 | 85 |
 Obonna [66] | 2014 | Nigeria | Retrospective | 2408 | 35 | 1605 | 803 |
 Ogbuanya [67] | 2021 | Nigeria | Retrospective | 879 | NA | NA | NA |
 Ogbuanya [67] | 2016 | Nigeria | Prospective | 684 | 38.89 | 398 | 286 |
 Ohene-yeboah [68] | 2006 | Ghana | Prospective | 3114 | 32.8 | 2040 | 1074 |
 Paluku [69] | 2018 | Benin | Prospective | 128 | NA | 81 | 47 |
 Paluku [70] | 2020 | Benin | Prospective | 76 | 28 | 43 | 33 |
 Rahman [71] | 2018 | Ghana | Retrospective | 411 | 36.3 | 287 | 124 |
 Sanogo [72] | 2020 | Mali | Retrospective | 334 | 24 | 114 | 220 |
 Smith [73] | 2021 | South Africa | Retrospective | 1464 | 34 | 861 | 603 |
 Songne [74] | 2008 | Togo | Retrospective | 943 | 42 | 697 | 246 |
 Soumah [75] | 2011 | Senegal | Retrospective | 88 | 23.19 | 58 | 30 |
 Spence [76] | 2016 | South Africa | Prospective | 169 | 34.9 | 116 | 53 |
 Tamegnon [77] | 2021 | Togo | Retrospective | 219 | 29 | 140 | 79 |
 Tassew [78] | 2017 | Ethiopia | Retrospective | 299 | 33.9 | 211 | 98 |
 Tendeng [79] | 2018 | Senegal | Prospective | 118 | 35.9 | 94 | 24 |
 Tounkara [80] | 2018 | Mali | Prospective | 120 | 30 | 77 | 43 |
 Tsegaye [81] | 2006 | Ethiopia | Retrospective | 511 | 32 | 389 | 122 |
 Valimungighe [82] | 2015 | Congo | Prospective | 203 | 30.2 | 82 | 121 |
 Wossen [83] | 2019 | Ethiopia | Retrospective | 439 | 28.4 | 332 | 107 |
 Yawo [84] | 2021 | Guinea Conakry | Retrospective | 412 | 31.36 | 218 | 194 |
 Zare [85] | 2020 | Burkina | Retrospective | 675 | 36 | 498 | 177 |
 Zare [86] | 2018 | Burkina | Retrospective | 426 | 30 | 314 | 112 |