Page 17 - IJPS-8-2

International Journal of
Population Studies Accuracy of mother’s reporting on child immunization in Yemen

Table 1. Measures of agreement between vaccination card (“gold standard”) and mother’s report and vaccination coverage
according to both sources of information – Yemen, 2013.
Agreement of instruments/sources of information Children aged 12 – 23 months
Vaccinated children based on Card info at R3?
Yes No Total
BCG
Vaccinated children based on mother’s report at R1?
Yes 105 20 125
No 45 25 70
Total 150 45 195
Indicators of Agreement
Accuracy 66.67%
Sensitivity 70.00%
Specificity 55.56%
PPV 84.00%
NPV 35.71%
Prevalence (vaccination coverage)
Gold standard 76.92%
Mother´s report 64.10%
Polio 3 rd
Vaccinated children based on mother’s report at R1
Yes 120 16 136
No 43 26 69
Total 163 42 205
Indicators of Agreement
Accuracy 71.22%
Sensitivity 73.62%
Specificity 61.90%
PPV 88.24%
NPV 37.68%
Prevalence (vaccination coverage)
Gold standard 79.51%
Mother’s report 66.34%
Source: IPC-IG and UNICEF (2014), rounds 1 and 3.

in developing countries (where vaccination coverage while the PPVs were high, the NPVs were very low for
estimates often depend on parents’ information), we both vaccines.
recommend it to be mainly estimated for children aged There is no consensus about the most appropriate
12 – 23 months. The results for these children showed thresholds to determine whether an instrument is
that the sensitivity and specificity had moderate values, valid to estimate vaccination coverage. We used a more
except for BCG. This may be because this vaccine is given restrictive criterion proposed by Miles et al. (2013),
at birth, henceforth more subjected to parent memory in which each measure of validity must be >80%. For
errors when they are questioned, despite its typical scar. In service planning within the health sector, it is essential
this sense, an analysis that includes the temporal distance that the instruments used to evaluate the coverage of
between the vaccination and the interview, although services present high levels of sensitivity and specificity.
being an interesting complementary analysis, is beyond These features enhance the ability of policymakers to
the scope of this study. Regarding the predictive values, capture the actual distribution of a certain condition in

Volume 8 Issue 2 (2022) 11 https://doi.org/10.36922/ijps.v8i2.1274