EVALUATION OF QUALITIES OF AGE AND SEX DATA IN THE 2006 NIGERIA CENSUS AND 2008 NIGERIA DEMOGRAPHIC AND HEALTH SURVEY

EVALUATION OF QUALITIES OF AGE AND SEX DATA IN THE
2006 NIGERIA CENSUS AND 2008 NIGERIA DEMOGRAPHIC AND
HEALTH SURVEY
BY
Eleazar C. Nwogu and Hycinth C. Iwu
Department of Statistics,
Federal University of Technology,
P.M.B. 1526 Owerri
Abstract
Qualities of age and sex data in the 2006 census and 2008 Nigeria Demographic and
Health Survey (NDHS) have been investigated in this paper. Both graphical and algebraic
methods were applied to evaluate the data. Results of the analyses show that the age and
sex data in the 2008 NDHS are still characterised by pronounced preference for the end
digits 0 and 5 and avoidance of the end digits 1, 3, 7 and 9. Age shifting and age
exaggeration are also pronounced in both the surveys. However, there are indications that
data quality has improved substantially over the results from previous surveys in the
country. Therefore, a critical appraisal of the cause(s) of persistent poor data quality in
Nigeria, education of the populace, greater emphasis on registration of births, adequate
training, supervision and remuneration of enumerators, among others have been
recommended.
Key Words: Data quality, Myre’s index, Age-sex accuracy index, digit preference, age
shifting, age exaggeration.