Estimating the case fatality rate using a constant cure-death hazard ratio.
The case fatality rate is an important indicator of the severity of a disease, and unbiased and accurate estimates of it during an outbreak are important in the study of epidemic diseases, including severe acute respiratory syndrome (SARS). In this paper, estimation methods are developed using a constant cure-death hazard ratio. A semiparametric model is presented, in which the cure-death hazard ratio is a parameter of interest, and a profile likelihood-based technique is proposed for estimating the case fatality rate. An extensive simulation was carried out to investigate the performance of this technique for small and medium sample sizes, using both summary and individual data. The results show that the performance depends on the model validity but is not heavily dependent on the sample size. The method was applied to summary SARS data obtained from Hong Kong and Singapore.
Chen
Zheng
Z
Department of Biostatistics, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, China. zheng-chen@hotmail.com
Akazawa
Kohei
K
Nakamura
Tsuyoshi
T
D000704:Analysis of Variance; D003627:Data Interpretation, Statistical; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D015993:Life Tables; D016013:Likelihood Functions; D009026:Mortality; D016016:Proportional Hazards Models; D018401:Sample Size; D045169:Severe Acute Respiratory Syndrome / Q000401:mortality; D012846:Singapore / Q000453:epidemiology