Assessing health burden risk and control effect on dengue fever infection in the southern region of Taiwan

Cheng, Yi-Hsien; Lin, Yi-Jun; Chen, Szu-Chieh; You, Shu-Han; Chen, Wei-Yu; Hsieh, Nan-Hung; Yang, Ying-Fei; Liao, Chung-Min

where D is the disability weight (D=1 for premature death, 0 for perfect health), C and b are parameters from an ageweighted function, and a is the age at onset of the disease, L is the duration of the disability or years of life lost due to premature death, and r is the social discount rate used for discounting years of health life in the future. The incorporation of a discount rate in the calculation of DALYs reflects a similar practice in economic analysis and gives policymakers incentives to invest society's resources in currently available health interventions for immediate benefit, though they may be less effective than from saving resources for possible future eradication programs. 19 Disabilities are then classified into six categories or grades, with each grade allocated a scalar value weighting between 0 and 1. The lower the value, the less impact the disability has on a person's life. 19 Dengue cases were classified into different age groups at 0, 1, 2, 3, 4, 5-9, 10-14, 15-19, 20-24, 25-29, 30-34, 35-39, 40-44, 45-49, 50-54 , 55-59, 60-64, 65-69 and >70 years, based on data collected from Taiwan CDC (2015). 26 To capture the relationship among temperature, R 0 , and model-derived temperature-associated DALYs were estimated. Specifically, monthly DALYs during 2001-2014 were estimated using Eq. (2), but only mean temperatures ranging from 17°C to 31°C paired with nonzero DALY estimates were selected to establish the temperaturebasis DALY relationships using the curve fitting software TableCurve 2D (Version 5.01, AISN Software Inc., Mapleton, OR, USA). Likewise, temperature-R 0 relationships were constructed under the same temperature range of 17°C-31°C using TableCurve 2D. A three-dimensional model was then constructed to describe the temperature-R 0 -DALYs relationship. TableCurve 3D packages (Version 4.0, AISN Software Inc., Mapleton, OR, USA) was used to perform the model-fitting techniques. The optimal model was selected based on the least squares criterion from a set of linear and nonlinear models provided by TableCurve 3D packages.