Sains Malaysiana 40(5)(2011): 527–535

Pemetaan Kes Kemortalan Bayi di Semenanjung Malaysia Menggunakan Kaedah Bayes Empirik

(Mapping of Infant Mortality Cases in Peninsular Malaysia using Empirical Bayes Method)

Nuzlinda Abdul Rahman*

Pusat Pengajian Sains Matematik Universiti Sains Malaysia, 11800 USM, Penang, Malaysia

Abdul Aziz Jemain, Kamarulzaman Ibrahim& Ahmad Mahir Razali

Pusat Pengajian Sains Matematik, Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor D.E., Malaysia

Diserahkan: 22 Disember / Diterima: 20 Mei 2010

ABSTRAK

Kajian ini bertujuan untuk memetakan kes kemortalan bayi mengikut daerah di Semenanjung Malaysia bagi tahun 1991 hingga 2000. Penganggaran risiko relatif berdasarkan kaedah Bayes empirik telah digunakan dalam kajian ini. Tiga kaedah penganggaran parameter dihuraikan iaitu kaedah momen, kaedah kebolehjadian maksimum dan kaedah penganggaran gabungan momen dan kebolehjadian maksimum. Keteguhan anggaran parameter yang diperoleh diuji menggunakan kaedah Bootstrap. Hasil kajian mendapati jurang antara kawasan berisiko rendah dengan kawasan berisiko tinggi adalah lebih besar pada awal dekad 2000 berbanding pada awal dekad 1990-an walaupun pada dasarnya kadar mortaliti bayi secara keseluruhannya adalah semakin berkurangan pada peringkat nasional. Kawasan pantai timur Semenanjung Malaysia masih pada takuk yang sama iaitu masih berada dalam kategori berisiko tinggi sepanjang tempoh yang dikaji. Seterusnya, gambaran terdapatnya tompokan risiko juga turut terpapar dalam peta yang dihasilkan. Berdasarkan kaedah Bootstrap, parameter-parameter yang dianggarkan dalam kajian ini adalah teguh.

Kata kunci: Bootstrap; kaedah Bayes empirik; kemortalan bayi; risiko relative

ABSTRACT

The objective of this study was to map the infant mortality cases over Peninsular Malaysia by district for the period of 1991 to 2000. Relative risks estimation based on empirical Bayes method was used in this study. Three methods of estimation were described which include moment method, maximum likelihood method and combination of moment and maximum likelihood method. The robustness of the parameters estimation was examined using Bootstrap method. The study indicated that the gap between the low risk areas and the high risk areas are larger in the early decade of 2000 compared to the early 1990s eventhough the infant mortality rate is declining at the national level. The east coast areas of the Peninsular Malaysia still remain in the high risk category over the period of the study. Moreover, the maps obtained indicated the occurrence of clustering effect in the infant mortality risk. Based on the Bootstrap method, all parameters estimation obtained in this study were robust.

Keywords: Bootstrap; empirical bayes method; infant mortality; relative risk

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*Pengarang untuk surat-menyurat; email: nuzlinda@usm.my