For countries with generalized epidemics but no national population surveys, we also developed an updated approach to calibrating prevalence curves derived from the ANC data in Spectrum 2013.
In order to have an appropriate calibration of the HIV prevalence trends determined in Spectrum, the point values of prevalence determined from the NFHS-3 in 2006 as a reference for calibrating the prevalence trend for general population, initially determined through ANC.
The key source of information used for calibrating HIV prevalence curves has the 2006 NFHS-3 2 where state-specific information on HIV prevalence is determined.
For this analysis, EPP was used to fit a simple 4-parameter epidemiological model to observed HIV surveillance data from ANC, calibrated to HIV prevalence data from NPS, using a maximum likelihood method separately for urban and rural areas.
The model was calibrated to produce prevalence curves for HPV infection [ 14, 15], cervical cancer lifetime risks and cervical cancer incidence in the UK [ 16].
The model was calibrated using HCV prevalence by age and gender in the year 2000, as reported by NHANES. 1 The incidence was back-calculated and the model was used to fit reported prevalence in 2000.
Full details of the methods and data sources used are in Table 1, Appendix D. The behavioural and biological parameter tables for the model are provided in Appendix E. The original model was calibrated to ANC prevalence for Cross River state, 8%, for both male and female groups.
The relatively simple prediction models proposed here provided a re-calibrated prevalence of hypertension estimate that more closely corresponded to the clinical hypertensive prevalence for the Detroit sample to which it was applied in this example.
Because we focused on heterosexual transmission, our model was largely driven by parameters associated with women; prevaccination prevalence was calibrated to approximate reported illnesses for women, and prevaccination prevalence for men was determined by the model.
For the Forward order, this process was first performed to calibrate to GERD Symptom prevalence, followed by BE prevalence, and then with final calibration to EAC incidence.
TB models are usually calibrated to an observed prevalence of disease by varying the transmission parameters [2], [6], [8].
