Table 1 presents the socio demographic, economic and health characteristics of 38,966 adolescent girls sampled from various regions in Africa. The majority of the adolescents (60.1%) reside in rural areas. Regarding marital status, about (79.9%) adolescents were single/never married and 21.6% were been married. Among those who have been married, a larger proportion (76.8%) of adolescents married between the ages of 15–19, while 23.2% married before the age of 15.
Nearly half of the adolescents (48.9%) had attained secondary education, while 35.7% had completed primary education. Around 14.4% has no education, and a smaller fraction had higher education (1.0%). In terms of wealth distribution, about 45.6% were classified as rich, 34.1% as poor, and 20.3% as middle-income. About 67.9% of the adolescents were not working, while 32.1% were engaged in some form of employment (Table 1).
About 6.1% adolescents were pregnant during the data collection period. A large proportion of the adolescents (89.6%) do not use contraceptives. About 15.3% adolescents had one child, and 2.7% have two or more children.
Most adolescents (88.5%) do not have health insurance. The majority of adolescents had a normal weight (72.0%), while 17.6% were underweight, 8.4% were overweight, and 2.1% were obese. Most adolescents (65.7%) do not use mosquito nets, while 34.0% used treated nets, and 1.8% use untreated nets.
Table 1
Sampled adolescents characteristics in Africa (N = 38,966)
Predictors/factors | Frequency | Proportion |
Residence | | |
| Urban | 15544 | 39.9 |
| Rural | 23422 | 60.1 |
Marital status | | |
| Never married/Single | 30668 | 79.9 |
| Ever Married | 8298 | 21.62 |
Age at first Marriage (n = 8,174) | | |
| < 15 | 1927 | 23.2 |
| 15–19 | 6371 | 76.8 |
Education status | | |
| No education | 5610 | 14.4 |
| Primary | 13924 | 35.7 |
| Secondary | 19047 | 48.9 |
| Higher | 385 | 1.0 |
Wealth status | | |
| Poor | 13300 | 34.1 |
| Middle | 7910 | 20.3 |
| Rich | 17756 | 45.6 |
Currently pregnant | | |
| No | 36602 | 93.9 |
| Yes | 2364 | 6.1 |
Use of contraceptive | | |
| No | 34922 | 89.6 |
| Yes | 4044 | 10.4 |
Health insurance | | |
| No | 34497 | 88.5 |
| Yes | 4468 | 11.5 |
Currently working | | |
| No | 26448 | 67.9 |
| Yes | 12500 | 32.1 |
Parity | | |
| No | 31939 | 82.0 |
| 1 | 5977 | 15.3 |
| 2+ | 1050 | 2.7 |
Body mass index | | |
| Underweight | 6315 | 17.6 |
| Normal weight | 25845 | 72.0 |
| Overweight | 3009 | 8.4 |
| Obese | 746 | 2.1 |
Type of mosquito net | | |
| No net | 25222 | 65.7 |
| treated net | 13058 | 34.03 |
| Untreated net | 686 | 1.78 |
Anemia status | | |
| Not anemic | 21980 | 56.4 |
| Anemic | 16986 | 43.6 |
Table 2 presents the percentage of anemia among adolescent girls in various African countries. Several countries show alarmingly high rates of anemia among adolescent girls. For instance, Gabon has the highest prevalence at 72.0%, followed by Mali with 65.4%, Ivory Coast with 62.2%, Nigeria with 60.5%, Burkina Faso with 57.6%, Liberia with 55.1%, Mozambique with 54.9%, and Togo with 54.7%.
The total data aggregated from all countries show that out of 38,966 adolescent girls 16, 986 (43.6% 95% CI:42.97_, 44.21) adolescent girls were anemic. The prevalence of anemia ranged from 14.7% in Rwanda to 72% in Gabon (Table 2).
Table 2
Magnitude of Anemia among Adolescent Girls in Africa
Country | Not Anemic n(%) | Anemic n(%) |
Burkina Faso | 835 (42.4) | 1136 (57.6) |
Burundi | 1235 (64.1) | 692 (35.9) |
Democratic Republic of the Congo | 1239 (59.9) | 830 (40.1) |
Ivory Coast | 586 (37.8) | 966 (62.2) |
Cameroon | 966 (58.3) | 692 (41.7) |
Ethiopia | 2574 (80.1) | 641 (19.9) |
Gabon | 287 (28.0) | 738 (72.0) |
Ghana | 778 (56.2) | 608 (43.8) |
Gambia | 739 (56.5) | 568 (43.5) |
Equatorial Guinea | 683 (52.9) | 609 (47.1) |
Liberia | 398 (44.9) | 488 (55.1) |
Lesotho | 564 (75.9) | 179 (24.1) |
Mali | 341 (34.6) | 645 (65.4) |
Malawi | 1126 (64.7) | 616 (35.3) |
Mozambique | 1386 (45.1) | 1688 (54.9) |
Nigeria | 1088 (39.5) | 1665 (60.5) |
Niger | 461 (54.0) | 393 (46.0) |
Rwanda | 1403 (85.3) | 242 (14.7) |
Sierra Leone | 805 (50.6) | 787 (49.4) |
Togo | 400 (45.3) | 484 (54.7) |
Tanzania | 877 (55.0) | 718 (45.0) |
Uganda | 932 (67.1) | 457 (32.9) |
South Africa | 312 (66.1) | 160 (33.9) |
Zambia | 1963 (66.6) | 986 (33.4) |
Total | 21980 (56.4) | 16986 (43.6) |
Figure 1 illustrates the prevalence of anemia among adolescent girls across various African countries. Countries with a prevalence higher than the overall average (43.6%) are marked in red, while those below the average are marked in green. The highest prevalence was observed in Central and West African countries, including Gabon, Mali, Ivory Coast, and Nigeria. In contrast, lower prevalence was found in East and East-Central African countries, as well as in Southern African countries, including Rwanda, Ethiopia, Lesotho, and South Africa (Fig. 1).
Table 3 presents a chi-square analysis of the distribution of anemia among African adolescent girls by various predictor variables. The prevalence of anemia is slightly higher among urban residents, with 44.4% being anemic compared to 43.2% of rural residents. Adolescents who had ever been married show a higher prevalence of anemia (48.7%) compared to their never married/single counterparts (42.3%). The prevalence of anemia is higher among girls who married before the age of 15 (50.7%) compared to those who married between 15–19 years (48.2%).
Educational attainment shows a strong inverse relationship with anemia prevalence. Adolescents with no education had the highest prevalence of anemia (54.2%), followed by those with primary education (40.2%), secondary education (43.2%), and higher education (37.3%). This indicates that higher education levels are protective against anemia. Wealthier adolescents had a lower prevalence of anemia. The prevalence was highest among poor girls (46.4%), followed by those from middle-income households (44.7%), and was lowest among rich girls (41.0%). Employment status does not significantly affect anemia prevalence, with both working (43.7%) and non-working (43.7%) girls showing the same prevalence rates (Table 3).
Pregnant adolescents had a significantly higher prevalence of anemia (54.9%) compared to non-pregnant girls (43.0%). Adolescents who used contraceptives have a lower prevalence of anemia (38.3%) compared to those who do not use contraceptives (44.3%). The number of children a girl has given birth to is associated with increased prevalence of anemia. Adolescent girls with no children have a prevalence of 42.8%, those with one child have a prevalence of 47.3%, and those with two or more children have the highest prevalence at 49.0%.
The prevalence of anemia was lower among girls with health insurance (39.1%) compared to those without it (44.3%). The prevalence of anemia was highest among adolescents using untreated mosquito nets (49.0%), followed by those using treated nets (45.1%), and those not using any net (42.8%). Higher BMI was associated with a lower prevalence of anemia. Underweight girls have an anemia prevalence of 45.2%, normal weight girls have 45.0%, overweight girls have 41.5%, and obese girls have the lowest prevalence at 40.9%.
Table 3
A chi-square analysis of magnitude of anemia by predictor variables among African adolescent girls
Factors | Not anemic frequency (%) | Anemic frequency (%) |
Residence | | |
| Urban | 8581(55.6) | 6852(44.4) |
| Rural | 13359(56.8) | 10174(43.2) |
Marital status | | |
| Never married/Single | 17687 (57.7) | 12981(42.3) |
| Ever Married | 4253 (51.3) | 4045 (48.7) |
Age at first Marriage (n = 8,298) | | |
| < 15 | 959 (49.3) | 985 (50.7) |
| 15–19 | 3294 (51.8) | 3060 (48.2) |
Education status | | |
| No education | 2587(45.8) | 3059(54.2) |
| Primary | 8252(59.8) | 5556(40.2) |
| Secondary | 10891(56.8) | 8286(43.2 ) |
| Higher | 210(62.7) | 125(37.3) |
Wealth status | | |
| Poor | 7632 (53.6) | 6601(46.4) |
| Middle | 4336 (55.3) | 3498 (44.7) |
| Rich | 9972 (59.0) | 6927 (41.0) |
Currently pregnant | | |
| No | 20864 (57.0) | 15714 (43.0) |
| Yes | 1076 (45.1 ) | 1312 (54.9) |
Use of contraceptive | | |
| No | 19427 (55.7) | 15467 (44.3) |
| Yes | 2513 (61.7) | 1559 (38.3) |
Health insurance | | |
| No | 19165 (55.7) | 15240 (44.3) |
| Yes | 2775 (60.9) | 1785 (39.1) |
Currently working/Occupation | | |
| No | 14938 (56.3) | 11591 (43.7) |
| Yes | 6991 (56.3) | 5428 (43.7) |
Parity | | |
| No | 18199 (57.2) | 13637 (42.8) |
| 1 | 3180 (57.2) | 2851 (47.3) |
| 2+ | 561 (51.0) | 538 (49.0) |
Body Mass Index (BMI) | | |
| Underweight | 3499 (54.8) | 2889 (45.2) |
| Normal weight | 14190 (55.0) | 11592 (45.0) |
| Overweight | 1780 (58.5)) | 1263 (41.5) |
| Obese | 414 (59.1) | 287 (40.9) |
Type of mosquito net | | |
| No net | 14418 (57.2) | 10804 (42.8) |
| Treated net | 7172 (54.9) | 5886 (45.1) |
| Not treated net | 350 (51.0) | 336 (49.0) |
Note: all predictor variables except employment status were statistically significant with anemia.
Table 4 presents the binary logistic regression analysis of various factors associated with anemia among adolescent girls in Africa. The results are shown in terms of Crude Odds Ratios (COR) and Adjusted Odds Ratios (AOR), along with their 95% Confidence Intervals (CI).
Adolescent girls living in rural areas had a slightly lower odds of anemia compared to those in urban areas (COR: 0.950, 95% CI: 0.91–0.99). However, this association is not significant after adjusting for other factors (AOR: 0.88, 95% CI: 0.78–1.01). Adolescent girls who had ever married showed higher odds of anemia compared to their never-married/single counterparts (COR: 1.298, 95% CI: 1.34–1.36). However, this variable was not included in the multivariable analysis due to convergence issues. Adolescents who married at ages 15–19 show slightly lower odds of anemia compared to those married before age 15 (COR: 0.90, 95% CI: 0.81-1.00), but this difference is not significant after adjustment of other factors (AOR: 0.99, 95% CI: 0.88–1.11).
Education appears protective against anemia. Compared to adolescents with no education, those with primary (AOR: 0.72, 95% CI: 0.5–0.80), secondary (AOR: 0.76, 95% CI: 0.66–0.86), and higher education (AOR: 0.61, 95% CI: 0.21–1.75) had lower odds of anemia. Adolescents from rich households have significantly lower odds of anemia compared to those from poor households (AOR: 0.86, 95% CI: 0.76–0.98).
Pregnancy was associated with higher odds of anemia (AOR: 1.13, 95% CI: 1.01–1.27) compared to those who were not pregnant. Using contraceptives linked to significantly lower odds of anemia (AOR: 0.46, 95% CI: 0.40–0.53). Adolescents who had given birth to one child have higher odds of anemia compared to those with no children (COR: 1.20, 95% CI: 1.13–1.26). Similarly, adolescents with two or more children also have higher odds of anemia (COR: 1.28, 95% CI: 1.13–1.44). However, when adjusted for other factors, these associations are no longer statistically significant.
Having health insurance shows no significant association with anemia (AOR: 1.03, 95% CI: 0.81–1.30). Regarding to nutritional status, adolescents who were obese had significantly lower odds of anemia compared to those who were underweight (AOR: 0.57, 95% CI: 0.38–0.86). Using a treated mosquito net was associated with higher odds of anemia (AOR: 1.26, 95% CI: 1.15–1.39).
The multivariable analysis revealed that 1.14% of the variation in anemia among adolescent girls was due to differences at the cluster/community level (ICC = 0.014, p < 0.05). This suggests that about 1.14% of anemia cases may be attributable to other unobserved community-level determinants.
Table 4
Bivariate and multivariable analysis to determine anemia among adolescent girls in Africa.
Factors | COR (95% CI) | AOR (95% CI) |
Residence | | |
| Urban | 1 | |
| Rural | 0.950 (0.91–0.99)** | 0.88(0.78–1.01) |
Marital status | | |
| Never married/Single | 1 | |
| Ever Married | 1.298(1.34–1.36)** | |
Age at first Marriage (n = 8,298) | | |
| < 15 | 1 | 1 |
| 15–19 | 0.90(0.81–0.99)* | 0.99(0.88–1.11) |
Education status | | |
| No education | 1 | 1 |
| Primary | 0.57(0.53–0.60)** | 0.72(0.5–0.80)* |
| Secondary | 0.64(0.60–0.68)** | 0.76(0.66–0.86)* |
| Higher | 0.50(0.40–0.64)** | 0.61(0.21–1.75) |
Wealth status | | |
| Poor | 1 | 1 |
| Middle | 0.93(0.88–0.99)** | 0.95(0.85–1.08) |
| Rich | 0.80(0.77–0.84)** | 0.86(0.76–0.98) |
Currently pregnant | | |
| No | 1 | 1 |
| Yes | 1.617(1.49–1.76)** | 1.13(1.00-1.27)* |
Use of contraceptive | | |
| No | 1 | 1 |
| Yes | 0.78(0.72–0.83)** | 0.46(0.40–0.53)* |
Health insurance | | |
| No | 1 | 1 |
| Yes | 0.81(0.76–0.86)** | 1.03(0.81–1.30) |
Currently working/Occupation | | |
| No | 1 | 1 |
| Yes | 0.99(0.96–1.04) | |
Parity | | |
| No | 1 | 1 |
| 1 | 1.20(1.13–1.26)** | 1.01(0.91–1.12) |
| 2+ | 1.28(1.13–1.44)** | 1.05(0.89–1.21) |
Body mass index | | |
| Underweight | 1 | 1 |
| Normal weight | 0.99(0.93–1.04) | 1.04(0.91–1.21) |
| Overweight | 0.85(0.78–0.94)** | 0.91(0.75–1.12) |
| Obese | 0.84(0.71–0.98)** | 0.57(0.38–0.86)* |
Type of mosquito net | | |
| No net | 1 | 1 |
| Treated net | 1.09(1.05–1.14)** | 1.26(1.15–1.39)* |
| Not treated net | 1.28(1.10–1.50)** | 1.31(0.9–1.76) |
| ICC | - | 0.011 |
Note: **: P < 0.05. *: P < 0.2, boldface with *: P < 0.05