## Tesi etd-03222007-164121 |

Thesis type

Tesi di laurea specialistica

Author

Del Fava, Emanuele

email address

e.delfava@gmail.com

URN

etd-03222007-164121

Title

Modelling forces of infection for mumps, rubella and parvovirus: a statistical perspective

Struttura

ECONOMIA

Corso di studi

STATISTICA PER L'ECONOMIA E PER L'AZIENDA

Commissione

**Relatore**Prof. Manfredi, Piero

Parole chiave

- fractional polynomials
- generalized linear models
- nonlinear least squares models
- confidence intervals for a binomial proportion
- force of infection
- seroprevalence
- serological survey

Data inizio appello

26/04/2007;

Consultabilità

completa

Riassunto analitico

The force of infection is a fundamental epidemiological parameter of infectious diseases. For many infectious diseases it is assumed that the force of infection is age-dependant. Although the force of infection can be estimated directly from a follow up study, it is much more common to have cross-sectional seroprevalence data from which the seroprevalence and the force of infection can be estimated. Here we propose to model the seroprevalence with three different parametric models: a nonlinear least squares model proposed by Farrington (1990); a logistic model, estimated using the generalized linear models; two fractional polynomial models of different order. We illustrate the methods on three seroprevalence samples, taken by the literature, regarding the following infectious diseases: mumps, rubella and parvovirus. Besides, in order to determine the optimal sample size for a serological survey, we show the serious problems of the standard confidence interval for a binomial proportion and we introduce some alternative confidence intervals proposed by the literature.

File

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Modelling_FOI.pdf | 2.84 Mb |

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