Cost-effectiveness of screening programs for Chlamydia trachomatis: a population-based dynamic approach.
BACKGROUND
Models commonly used for the economic assessment of chlamydial screening programs do not consider population effects.


OBJECTIVE
To develop a novel dynamic approach for the economic evaluation of chlamydial prevention measures and to determine the cost-effectiveness of a general practitioner-based screening program.


METHODS
The dynamic approach was used to estimate the cost-effectiveness of a screening program for the first 10 years of screening in The Netherlands. Screening involved a ligase chain reaction test on urine followed by standardized therapies and partner referral. Eligible persons were sexually active, 15 to 24 years, visited a general practitioner, and had no symptoms of sexually transmitted diseases. The heterosexual model population, which consisted of persons 15 to 64 years, had a total chlamydial prevalence of 4.1% before screening. Screening effects on chlamydial incidence were computed by using a population-based stochastic simulation model. Incidence data were connected with a decision analysis model to determine the health effects of the program. The net costs of the program were calculated (investment costs minus averted costs, in 1997 US$) from a societal perspective and expressed per major outcome averted (symptomatic pelvic inflammatory disease, chronic pelvic pain, ectopic pregnancy, infertility, neonatal pneumonia).


RESULTS
Unlike the standard static approach, our model adequately addresses dynamic processes such as chlamydial transmission and the impact of screening programs on chlamydial incidence in the population. During the first 10 years of screening, the investigated program yields savings of US $492 or US $1,086 per major outcome averted, excluding or including indirect costs, respectively. These results depend on chlamydial prevalence and partner referral.


CONCLUSIONS
The cost-effectiveness of chlamydial screening programs seems best to be determined by using dynamic modeling on a population basis. In addition to preventing negative health outcomes, the investigated screening program may save costs.
Welte
R
R
Department of Health Services Research, National Institute of Public Health and the Environment, Bilthoven, The Netherlands. Robert.Welte@rivm.nl
Kretzschmar
M
M
Leidl
R
R
van den Hoek
A
A
Jager
J C
JC
Postma
M J
MJ
D000293:Adolescent; D000328:Adult; D002690:Chlamydia Infections / Q000453:epidemiology* / Q000517:prevention & control*; D002692:Chlamydia trachomatis; D003198:Computer Simulation; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D005194:Family Practice; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000191:economics*; D008875:Middle Aged; D018803:Models, Economic; D009426:Netherlands / Q000453:epidemiology; D017063:Outcome Assessment, Health Care; D015995:Prevalence; D012680:Sensitivity and Specificity; D013269:Stochastic Processes