Comparisons between respondent and confidante sociodemographic characteristics are displayed in Table 1. Across all country contexts, respondents did not appear to select confidantes with homophily; there were statistically significant differences in age and education level in all the studies, except for age in Cote D’Ivoire. Generally, the confidante sample was older and more educated than respondents. (See Technical Appendix for distributions of respondent and confidante characteristics.)
Table 1
Comparison between respondent and confidante socio-demographic characteristics, by study context
| Cote d'Ivoire | Ethiopia | Ghana | Java | Nigeria | Rajasthan | Uganda |
Number of respondents | 2,738 | 3,668 | 4,596 | 8,969 | 11,106 | 5,832 | 2,063 |
Number of confidantes | 2,024 | 4,062 | 3,731 | 6,680 | 7,836 | 6,030 | 2,727 |
Sociodemographic information | | | | | | | |
Age at last birthday | p = 0.12 | p < 0.001 | p = 0.026 | p < 0.001 | p < 0.001 | p < 0.001 | p < 0.001 |
R younger than CF | 21.4% | 16.2% | 20.9% | 14.7% | 13.3% | 10.4% | 27.6% |
Same age | 65.8% | 67.8% | 63.7% | 70.3% | 72.7% | 72.7% | 55.8% |
R older than CF | 12.8% | 16.0% | 15.4% | 15.0% | 14.0% | 16.8% | 16.6% |
Level of education | p < 0.001 | p < 0.001 | p < 0.001 | p < 0.001 | p < 0.001 | p < 0.001 | p < 0.001 |
R less educated than CF | 21.9% | 19.8% | 19.1% | 12.7% | 14.9% | 21.2% | 22.4% |
Same education | 59.4% | 62.4% | 64.7% | 78.1% | 73.6% | 64.9% | 61.0% |
R more educated than CF | 18.7% | 17.9% | 16.1% | 9.2% | 11.5% | 13.9% | 16.7% |
Place of residence | NA | p < 0.001 | p < 0.001 | p < 0.001 | NA | NA | p = 0.097 |
Same location | . | 93.9% | 88.8% | 91.0% | . | . | 94.4% |
Different location | . | 6.1% | 11.2% | 9.0% | . | . | 5.6% |
Marital status | NA | NA | p = 0.51 | p < 0.001 | NA | NA | NA |
Both married/cohabiting | . | . | 51.7% | 65.5% | . | . | . |
Neither married/cohabiting | . | . | 21.6% | 17.0% | . | . | . |
R yes, CF no | . | . | 12.5% | 10.6% | . | . | . |
R no, CF yes | . | . | 14.3% | 6.9% | . | . | . |
Number of children | NA | NA | p < 0.001 | NA | NA | NA | NA |
R has less children | . | . | 22.1% | . | . | . | . |
Same number of children | . | . | 53.6% | . | . | . | . |
More children | . | . | 24.3% | . | . | . | . |
Notes: P-values presented here come from Pearson's chi-square test for independence between the analytic sample of respondents and sample of confidantes in each country. All tests were done using weighted data. The proportions presented in this table represent the distribution of respondent-confidante pairs for each socio-demographic and behavioral indicator.
The average number of reported confidantes was less than 1 in four of the seven studies, ranging from 0.79 in Cote D’Ivoire to 1.69 in Uganda (Table 2). Reporting zero confidantes was most common in Java (4374, 48.8%) and Nigeria (5315, 47.0%), and least common in Uganda (404, 19.3%) and Rajasthan (932, 15.8%). Across all studies, there were significant differences in sociodemographic characteristics between respondents who reported any confidantes and respondents who reported none (Table 2). Women with no confidantes were more likely to be older in all contexts, less educated (except Uganda), live in rural areas (except in Cote d’Ivoire, Ghana and Uganda), be married (except in Ghana and Rajasthan) use family planning (except in Java and Rajasthan) and have more children (except in Uganda).
After comparing the unadjusted 2017 and annualized 2018 abortion incidence rates, we found that the annualized 2018 rate was higher for almost all countries. Due to a concern that more recent reports may be subject to reporting bias,10,11 we utilize 2017 as the year of reference for annual estimates. (See Technical Appendix, Section C for details and 2018 annualized rates.)
Figure 1 displays four different confidante abortion rates for each country: one-year estimates that are not adjusted for transmission bias, two transmission bias adjusted rates, and the published abortion rates from the original studies. (More details available in the Technical Appendix). In the first transmission bias adjustment approach (adjustment 1a), we included all uncertain abortions in the incidence estimate. In Ethiopia, Java, and Uganda, this slightly changes the resulting rates, as few respondents reported they were “uncertain” about their confidantes’ abortions (Technical Appendix, Table D). Using approach 1b, we included only less certain abortions with additional information on the method used, which was only possible in Cote D’Ivoire, Nigeria and Rajasthan. Across the three countries, there was little to no difference in estimates between the two approaches. As such, we did not include these results in Fig. 1.
In approach 2, we estimated transmission bias using data from respondents who self-reported an induced abortion. This proportion ranged from 0.5% of respondents in Java to 20.1% in Cote D’Ivoire (Technical Appendix, Table E). Among these respondents, we estimated the proportion who shared this information with their confidantes (Fig. 2). Across pooled confidantes, this ranged from 41% in Nigeria to 57% in Rajasthan. In all contexts except Java, respondents reported their abortions to a higher proportion of confidante 1 compared with confidante 2.
Approach 2 resulted in the highest transmission bias-adjusted estimates; adjusted abortion incidence rates were at least double the non-adjusted rates in all contexts, increasing to an implausibly high rate in Ghana of 99.8 abortions per 1,000 women of reproductive age (95% CI: 82–121) and very high rates in Nigeria (63.2 per 1000, 95% CI:52–75) and Uganda (72.1 per 1000, 95% CI: 56–92).
There is variation between the estimates produced from this analysis and previously published rates (Fig. 1). In Cote D’Ivoire and Nigeria, our adjustment approach 1a rates are comparable to published rates, which is expected given the similarities in the methodologies. However, the transmission bias adjusted rates from this study’s approach 2 are much larger than the previously published estimates in Cote D’Ivoire (48 per 1,000 vs. 32 per 1,000) and Nigeria (63 per 1,000 vs, 35 per 1,000). This is likely because the original study only used uncertain abortions to adjust for transmission bias, which does not account for abortions that are completely invisible to respondents. Differences between the rates for Ghana are likely due to this study’s reliance on 2017 reports; the original study noted that the confidante abortion rate from the past 12 months appeared unreasonably high. As such, the one-year confidante abortion rate was annualized using reports of confidante abortions that occurred in the past three years.
Table 3 shows that majority of the foundational assumptions of confidante method were violated in all seven contexts based on previous publications analyzing this data. Assumptions related to study design and recall bias, which can be assessed by checking for implausibly low confidante abortion rates, were most likely to be met in all contexts except Java and Rajasthan. None of the published papers had attempted to quantify popularity bias. Selection bias, transmission bias, and barrier effects were most assessed and attempted to be adjusted for in published analyses.
Table 3
Risk of bias assessment for studies included in this analysis
| Study design bias | Transmission bias | Social desirability/recall bias | Selection bias | Barrier effects | Popularity bias |
Cote D'Ivoire | Assessed: Low risk of bias | Assessed: High risk of bias | Assessed: Low risk of bias | Assessed: High risk of bias | Assessed: High risk of bias | Not assessed |
Ethiopia | Assessed: Low risk of bias | Assessed: High risk of bias | Assessed: Moderate risk of bias | Assessed: High risk of bias | Assessed: High risk of bias | Not assessed |
Ghana | Assessed: Low risk of bias | Assessed: High risk of bias | Assessed: Low risk of bias | Not reported | Assessed: High risk of bias | Not assessed |
Java, Indonesia | Assessed: Moderate to high risk of bias | Assessed: High risk of bias | Assessed: Moderate risk of bias | Assessed: High risk of bias | Assessed: High risk of bias | Not assessed |
Nigeria | Assessed: Low risk of bias | Assessed: High risk of bias | Assessed: Low risk of bias | Assessed: High risk of bias | Assessed: High risk of bias | Not assessed |
Rajasthan, India | Assessed: Moderate to high risk of bias | Assessed: High risk of bias | Assessed: Moderate risk of bias | Assessed: High risk of bias | Assessed: High risk of bias | Not assessed |
Uganda | Assessed: Low risk of bias | Assessed: High risk of bias | Assessed: Low risk of bias | Assessed: High risk of bias | Assessed: High risk of bias | Not assessed |