INFANT POLIO IMMUNIZATION

TIME SERIES MODELING TOWARDS COVERAGE IN PAKISTAN

Abstract

Poliomyelitis is a highly infectious disease but preventable by effective vaccines.
Children under five year of age affected by this disease as a result a permanent paralysis.
Objectives: To uncover the trend of infant polio immunization coverage through modeling is
a significant concern to formulate an adequate vaccination strategies and program after the
outbreak of new cases of polio in a recent year in Pakistan. Design: The reported data of
monthly infant polio immunization coverage to National Institute of Health, Islamabad, Pakistan
from January 2008 to July 2013 for the present study has been taken from Pakistan bureau of
statistics with total time series entities 67. National Institute of Health, Islamabad took the record
of per month number of doses administered ( 0-11 months )children by the registered health
centre in pakistan. Period: January 2008 - July 2013. Setting: Pakistan bureau of statistics
(Statistics House) Methods: A set of various short term time series forecasting models namely
Box-Jenkins, single moving average, double moving average, single parameter exponential
smoothing, brown, Holts and winter models were carried out to expose the infant polio
immunization coverage trend. Results: Among the several forecasting models ARIMA models
are chosen due to lower measure of forecast errors namely root mean square error (RMSE),
mean absolute error (MAE) and mean absolute percentage error (MAPE). ARIMA (2,1,1), ARIMA
(1,0,2), ARIMA (0,1,2) and ARIMA (2,1,1) models are established as an adequate models for the
prediction of OPV-0, OPV-1, OPV-2 and OPV-3 respectively. Conclusions: With the exception
of OPV-1 the infant polio immunization coverage is expected to rise in Pakistan.