Flexible assessment of trends in age-specific HIV incidence using two-dimensional penalized likelihood
✍ Scribed by Ian C. Marschner; Ronald J. Bosch
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 171 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0277-6715
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✦ Synopsis
We present a method for estimating age-and time-specific HIV incidence using back-calculation of AIDS incidence data. Two-dimensional penalized likelihood is employed, using a flexible bivariate step function model of HIV incidence, together with a quadratic roughness penalty which leads to thin-plate spline smoothing. This allows incidence estimates to vary flexibly and smoothly in both age and time. We propose generalized cross-validation as a guide for choice of an appropriate level of smoothing and describe an EM algorithm for computing the estimates. We propose the method primarily for qualitative assessment of trends in age-specific incidence over time and apply it to a small Italian data set on men who have sex with men. The analysis suggests a trend over time of increasing relative incidence among younger individuals, consistent with incidence patterns observed in other countries.