46
Vol.6.Issue.3.2018 (July-Sept.)
©KY PUBLICATIONS
SPATIAL AREAL DATA ANALYSIS WITH APPLICATION TO VARIOUS TUBERCULOSIS
OUTCOMES IN KENYA
Erick Okuto
School of Mathematics & Actuarial Science, Jaramogi Oginga Odinga University of Science &
Technology, Bondo-Usenge Road, P.O Box 210-40601, Bondo, Kenya
*
Erick Okuto (erickokuto@gmail.com )
ABSTRACT
Tuberculosis is second only to HIV as the greater killer worldwide due to a
single infectious agent. Improving the treatment outcome of tuberculosis is
part of the Millennium Development Goals. Given the infectious nature of
tuberculosis, its distribution and treatment outcomes should consider
spatial patterning. Information on the distribution of tuberculosis treatment
outcomes in Kenya is scarce, yet treatment outcome is an important
indicator of tuberculosis management. Spatial analysis tools can be used to
characterize spatial patterns of these treatment outcomes, thereby
identifying areas at risk of the given outcomes. This study presents a
Bayesian model for analysing spatial distribution of tuberculosis treatment
outcomes in Kenya. Data was obtained from the national tuberculosis
registers from January 2014 to March 2014 with incorporation of data from
the Kenya Demographic and Health Survey 2014 and Census 2009.
Treatment outcomes were categorized as cured, dead, defaulted, failure and
treatment complete. Exploratory data analysis was done to estimate the
proportions of the various covariates, and tests for global and local spatial
auto correlation done to assess the relationship of the various outcomes per
county. Covariates were selected using purposeful selection of variables,
and variables with a significant univariate test were selected as candidates
for the multivariate analysis. Augmentation of the linear predictors with a
set of spatially correlated random effects was done, using conditional
autoregressive prior distributions, specified by a set univariate full
conditional distributions. Inference was based on obtaining the posterior
distribution, of the different TB treatment outcomes, using the Integrated
Nested Laplace Approximation Methodology (INLA) as a way of
BULLETIN OF MATHEMATICS
AND STATISTICS RESEARCH
A Peer Reviewed International Research Journal
http://www.bomsr.com
RESEARCH ARTICLE
Email:editorbomsr@gmail.com