Indirect estimation of chlamydia screening coverage using public health surveillance data

Although routine screening of all sexually active adolescent females for Chlamydia trachomatis infection is recommended at least annually in the United States, no national or state-specific population-based estimates of chlamydia screening coverage are known to exist. Conclusions regarding screening coverage have often been based on surveys of health care provider or facility screening practices, but such surveys do not consider persons who do not seek care at these facilities or who seek care at more than one facility. The authors developed a method to estimate the proportion of sexually active females aged 15-19 years screened for chlamydia in 45 states and the District of Columbia by using national data on chlamydia positivity, estimates of sexual activity from the National Survey of Family Growth, and chlamydial infections reported to the Centers for Disease Control and Prevention. Because of uncertainty regarding these values and related assumptions, credibility intervals were calculated by using a Monte Carlo model. When this model was used, the median state-specific proportion of sexually active females aged 15-19 years screened in 2000 was 60% (90% credibility interval: 55, 66). These results and this method should be evaluated for their utility in guiding implementation of national and state chlamydia control programs.