Validation of Age Determination with Historical Events in Birnin Kebbi, Northwest Nigeria

Birth registration is not universal and remains elusive for some people living in developing countries, such as Nigeria; hence, age determination for healthcare and health-related research is often problematic.

The aim is to validate the use of a historical events' scale as a tool for estimating the age of Nigerian adults residing in Birnin Kebbi, Northwest Nigeria.

A cross-sectional survey was conducted in Birnin Kebbi, a metropolitan capital city of Kebbi state, Northwest Nigeria, and included adults aged 18 years and older with a valid document indicating their year of birth.

Seven historical events comprising major national events were cross-referenced to the individual's personal history to estimate their ages, which were then compared to their documented ages.

Relationship of the documented and estimated ages was assessed with the Spearman's rank-order correlation and intraclass correlation coefficient (ICC) analyses.

A total of 288 subjects (63.2% males) with a mean documented age of 34.5 ± 11.3 (range 18-75) years were surveyed. The mean estimated age was 32.5 ± 11.18 years. Spearman's rank-order correlation analysis showed a statistically strong positive correlation between the actual and estimated ages (0.953, P < 0.001). The ICC between documented and estimated ages was 0.968 (95% confidence interval = 0.959-0.975).

The use of this tool in Nigerian adults provides a reasonably accurate age estimation. Its use in populations and communities with inadequate birth registration may improve the quality of age-related health data in Nigerian adults.