Nigeria - Post Yellow Fever Campaign Coverage Survey 2019, First round

Data cleaning and analysis was conducted using the supplementary immunisation activity (SIA) module of Vaccination Coverage Quality Indicators (VCQI) software running on Stata version 15 (StataCorp. 2017. Stata Statistical Software: Release 15. College Station, TX: StataCorp LLC)4. All results presented in the report are based on the weighted data to account for the survey sampling design and nonresponse. Design weights were computed as the product of inverse probabilities of selection in the first, second and third stages. Next, the design weight was adjusted for nonresponse by the household or the individual selected for interview to get the sampling weights for households and for children, respectively. Non-response was adjusted at the sampling stratum level. After adjusting for non-response, the sampling weights were normalized and post stratified to get the final standard weights that appear in the data files. Post-stratification was conducted by multiplying the normalised weights with the estimated proportion of respondents aged 9 months - 44 years in each stratum. The estimated number of respondents in each stratum was obtained from recently concluded micro-planning activity.
Bivariate analysis of post yellow fever campaign vaccination coverage, reasons for non-vaccination, adverse effects following immunisation (AEFI) and routine immunisation measles vaccination coverage were presented by residence, gender and zones. Wilson's 95% confidence intervals and upper and lower confidence bounds have been computed throughout the report.

Data collection was conducted using CSPro (Census and Survey) software running on android tablet computers. Range checks and skip patterns were coded into the data entry program to ensure that only all valid responses were collected and that there were responses to all applicable questions. On completion of the household roster, only age-eligible respondents were presented to the interviewer for interviewing and information had to be collected on all selected respondents before a household completion status was generated by the CAPI software. Once an interview was completed, data from an enumerators tablet was synchronized with the supervisors' tablet for primary data editing. The supervisor then transmitted the data to a centralized database once all eligible within an enumeration area had been interviewed.