The Effect of Changes in Cervical Cancer Screening Guidelines on Chlamydia Testing

Area of Science:

• Public Health
• Epidemiology
• Infectious Disease Screening

Background:

• Chlamydia trachomatis (chlamydia) infections are often detected through screening programs offered concurrently with cervical cancer screening for females.
• Recent shifts in cervical cancer screening guidelines advocate for less frequent and later initiation of screening.
• The impact of these guideline modifications on chlamydia testing and incidence requires thorough investigation.

Purpose of the Study:

• To assess the effect of the May 2012 Ontario, Canada, cervical cancer screening guideline revision on Papanicolaou (Pap) testing and chlamydia trachomatis (chlamydia) testing and incidence.
• To analyze changes in testing and incidence stratified by sex and age group.

Main Methods:

• Utilized population-based physician billing claims data for Pap and chlamydia tests.
• Employed public health surveillance data to identify chlamydia cases.
• Conducted interrupted time series analysis over 2 years pre- and post-guideline change using segmented linear regression and autoregressive integrated moving average models.

Main Results:

• Observed a significant reduction in chlamydia testing among females 2 years post-guideline change, with the largest decrease (25.5%) in the 15-19 age group.
• Reported decreased chlamydia incidence in females aged 15-19 (16.8% reduction) and 20-24 (14.4% reduction).
• Chlamydia incidence in males remained unchanged despite an increase in testing.

Conclusions:

• The revised cervical cancer screening guidelines in Ontario correlated with decreased chlamydia testing and reported cases in females.
• Females aged 15-19, a high-risk group for chlamydia, were disproportionately affected by the guideline changes.
• Emphasized the importance of risk-based chlamydia screening for females, irrespective of their need for Pap testing.