A Mixed-Stratified Randomized Response Model for HIV Seroprevalence Surveys

A. Usman ； I. O. Oshungade

《Research Journal of Mathematics and Statistics》 4卷3期 (2012/08) Pp. 70-75

並列摘要

The objectives were to use research frontier to devise a mixed-stratified Randomized Response Model (RRM) and use same to estimate HIV seroprevalence rates in a given population and compare results with the existing seroprevalence rates. The Randomized Response Techniques (RRT) guarantees the anonymity of respondents in surveys aimed at determining the frequency of stigmatic, embarrassing or criminal behavior where direct techniques for data collection may induce respondents to refuse to answer or give false responses. The motivation was to improve upon the existing RRMs as well as to apply them to estimate HIV seroprevalence rates. Warner proposed the pioneering RRM for estimating the proportion of persons bearing a socially disapproved character. Quatember produced unified criteria for all RRTs, Kim and Warde proposed a stratified RRM and so many others. The proposed mixed-stratified RRM for HIV seroprevalence surveys was relatively more efficient than the Kim and Warde stratified estimator for a fixed sample size. Using the criteria of Quatember who derived the statistical properties of the standardized estimator for general probability sampling and privacy protection, the chosen design parameter was 0.7. The procedure of the field work and sampling design were well coordinated for the target population of 3,740 people aged 18 years and above using a sample size of 550. Furthermore, the model was used to estimate the HIV seroprevalence rate in a small population of adults attending a clinic in Kaduna, Nigeria. The findings revealed that HIV seroprevalence rate, as estimated by the Model, stood at 8.74% with a standard error of 0.0134 and a 95% confidence interval of (6.1 and 11.4%). These results are consistent with that of Nigerian sentinel survey (2003) conducted by NACA, USAID and CDC which estimated the HIV seroprevalence in Kaduna State as 6.0%. Accordingly, the sentinel projected seroprevalence rate, using the Epidemic Projection Package (EPP), for the next ten years (2013) was 9.7%; very consistent with the 95% confidence interval. Hence, the RRTs herein can serve as new viable methods for HIV seroprevalence surveys.

並列關鍵字

Design parameter ； efficiency, mixed-stratified ； randomized response models ； randomized response techniques ； sentinel surveys ； seroprevalence rates ； stratified random sampling