Dear all,
Following stratified modelling (log-linear) to derive a population
prevalence, I have a number of point prevalence estimates and their
associated confidence intervals for various age/sex groups (15 - 24
years, 25 - 34 years and 35 - 54 years for males and females
separately). I need to have an estimate of the prevalence for the
entire 15 - 54 population. Fitting a global model produces a very
poor fit (due to heterogeneity). Summing the point estimates to
obtain an overall prevalence seems reasonable. However, although I
have seen this done, summing the individual lower and upper
confidence intervals to give a CI for the total prevalence does not
seem intuitive to me...for a start, the individual age/sex standard
errors are based on different numbers of individuals.
Any suggestions as to how I could tackle the above would be appreciated.
best wishes,
Alan Kelly
+-------------------------------------------------------+
Dr. Alan Kelly E-mail [email protected]
Biostatistician Phone: +353-1-608 1385 or 608 1087
Fax: +353-1-403 1211 or 403 1212
Director of the Small Area Health Research Unit
Department of Community Health & General Practice
Trinity Center for Health Sciences
AMNCH
Tallaght Hospital
Dublin 24
Ireland
