Received: 17 July 2020
Accepted: 9 November 2020
First Online: 3 December 2020
Ethics approval and consent to participate
: This study is a secondary data analysis of publicly available de-identified dataset. Participants’ consent was not required because the dataset used is the historical aggregated yearly U5MRs of Nigeria for 1964–2017 (Supplementary file 1). The dataset for this study is open and publicly available at the official website of the World Bank. In addition, this study was exempted from ethical review by the University of Saskatchewan Research Ethics Committee.
: Not applicable.
: No potential conflict of interest was reported by the authors.