Standardized Morbidity Ratio and Its Application to Chikungunya Disease Mapping in Malaysia
Standardized Morbidity Ratio dan Aplikasinya Terhadap Pemetaan Penyakit Chikungunya di Malaysia
Keywords:Chikungunya disease, disease mapping, relative risk estimation, SMR method
Disease mapping has recently become an important method in the fields of public health research and disease epidemiology. Disease mapping is a spatial representation of epidemiology data. Chikungunya disease is an endemic mosquito-borne illness in many tropical and sub-tropical countries, including Malaysia. The disease is quite similar with the dengue disease. However, the Chikungunya virus is not fatal. Precautionary steps must be taken to avoid spreading the Chikungunya virus, which has increasing number of cases every year. Therefore, the aim of this paper is to discuss the suitable methods to estimate its relative risk. The methods involved using the number of Chikungunya cases itself and the Standardized Morbidity Ratio (SMR). SMR method is the most common method used in disease mapping studies. The results include disease risk maps for all states in Malaysia showing the distribution of high and low risk areas of Chikungunya disease.
Barrett F.A. (1993). A Medical Geographical Anniversary. Social Science and Medicine, 37: 701710.
Cavrini, F., Gaibani, P., Pierro, A.M., Rossini, G., Landini, M.P. and Sambri, P. (2009). Chikungunya: an emerging and spreading arthropod-borne viral disease, Review Article, J Infect Dev Ctries 2009, 3(10), 744-752.
Esteve J., Benhamou, E. And Raymond, L. (1994). Statistical Methods in Cancer Research (IV): Descriptive Epidemiology . IARC Scientific Publications, No. 128, Lyon, IARC
Goldman, D. A. And Brender, J.D. (2000). Are standardized mortality ratios valid for public health data analysis?. Statistics in Medicine, 19: 1081-1088.
Jones, M.E. and Swerdlow, A.J. (1998). Bias in the standardized mortality ratio when using general population rates to estimate expected number of deaths. American Journal of Epidemiology, 148: 10.
Lam S.K., Chua K.B., Hooi P.S., Rahimah M.A., Kumari S., Tharmaratnam M., Chuah S.K., Smith D.W. and Sampson I.A. (2001). Chikungunya Infection – An Emerging Disease in Malaysia, Vol. 32 No. 3., 447-451.
Lawson, A. B., Biggeri, A.B., Boehning, D., Lesare, E., Viel, J.F., Clark, A., Schlattmann, P. and Divino, F. (2000). Disease Mapping Models: An empirical evaluation. Statistics in Medicine, 19: 2217-2241.
Lawson, A.B. (2001). Tutorial in biostatistics: Disease Map Reconstruction. Statistics in Medicine, 20: 2183-2204.
Lawson, A.B., Browne, W.J. and Rodeiro, C.L.V. (2003). Disease Mapping with WinBUGS and MlwiN. London: Wiley.
Lawson A.B. (2006). Statistical Methods in Spatial Epidemiology. London: Wiley.
Lilienfeld, D.E. and Stolley, P.D. (1994). Foundations of Epidemiology. Oxford: University Press.
Mantel, N. and Stark, C.R. (1968). Computation of indirect-adjusted rates in the presence of confounding. Biometrics, 24: 997-1005.
Meza, J.I. (2003). Empirical Bayes estimation smoothing of relative risks in disease maaping. Journal of Statistical Planning and Inference, 112: 43-62.
Ministry of Health Malaysia (2010). Current situation of dengue and Chikungunya in Malaysia for epidemiological week 1/2010 to 52/2010. Viewed on10 April 2013. Available from
http://www. moh.gov.my/press_releases/8 and http://www.moh.gov.my/press_releases/94
Pollard, A.H., Yusuf, F. and Pollard, G.N. (1981). Demographic Techniques. Sydney: Oxford Pergamon Press.
Samat, N.A. and Percy, D.F. (2012). Dengue Disease Mapping in Malaysia Based on Stochastic SIR Models in Human Populations. Proceedings of International Conference on Statistics in Science, Business and Engineering. IEEE Cat. No. CFP1272S-CDR. ISBN 978-1-4673-1580-7
Samat, N.A. and Percy (2008). Standardized Mortality and Morbidity Ratios and their Application to Dengue Disease Mapping in Malaysia. Proceedings of the Salford Postgraduate Annual research Conference. Pp 200 – 210. ISBN 978-1-905732-71-5.
Wong, R.H., Chen, O.C., Chen, C.L., Wong, J.D. and Cheng, T.J. (2002). An increased standardized mortality ratio for liver cancer among polyvinyl chloride workers in Taiwan. Occupational and Environmental Medicine, 59: 405-409.