Background: Although recent trends in the use of recommended breast and cervical cancer screening have been well documented in the USA, little is known about trends in the prevalence of abnormal screening results.
Methods: Trends in abnormal screening results for mammography and Papanicolaou (Pap) smear were assessed descriptively using data from the 1987 and 2000 National Health Interview Surveys. Estimates were stratified by sociodemographic characteristics of the populations who reported ever receiving screening. All comparisons were evaluated with two-sided tests of statistical significance.
Results: The age-standardized prevalence of abnormal Pap smears increased from 12.9% (95% confidence interval [CI] 12.1-13.8%) of women ever screened in 1987 to 20.3% (95% CI 19.5-21.0%) in 2000, and the age-standardized prevalence of abnormal mammogram results increased from 18.8% (95% CI 17.0-20.7%) to 21.6% (95% CI 20.5-22.7%) of women ever screened over the same period. Among women aged 40 years and older who reported ever receiving both a Pap smear and a mammogram, 29.6% (95% CI: 27.3-32.2%) in 1987 and 35% (95% CI: 33.8-36.2%) in 2000 reported either an abnormal Pap smear or an abnormal mammogram. In 2000, abnormal screening results were positively associated with reported frequency of recent screening (P<0.001).
Conclusions: A substantial portion of women in the USA reporting cancer screening also report having had abnormal results, although the magnitude of trends between 1987 and 2000 vary by screening test. Additional research is needed to assess the relative contributions of changes in classification of test results, test characteristics and changes in underlying screening histories to increases in abnormal screening results.