Variables associated with squamous intraepithelial lesions among women with a cytologic diagnosis of atypical squamous cells of undetermined significance.

OBJECTIVE: To identify factors among women with atypical squamous cells of undetermined significance (ASCUS) cytologic diagnosis that are associated with either low grade squamous intraepithelial lesions (LSILs) or high grade squamous intraepithelial lesions (HSILs). STUDY DESIGN: From January 1992 to June 1995, 1,660 women with a diagnosis of ASCUS were followed until the next follow-up appointment after the ASCUS diagnosis. Logistic regression analysis with either LSIL or HSIL at follow-up examination as a dependent variable was done with the following independent variables: patient age, method of follow-up, follow-up time, type of health care coverage and household income. RESULTS: In multivariate analyses, there was a 2.7-fold increase in the odds of LSIL (OR = 2.7, 95% CI = 1.3-5.8) for young women (< or = 25 years), a 2-fold decrease in the odds of LSIL (OR = .5, 95% CI .3-.9) for long time to follow-up (> 18 weeks after ASCUS diagnosis) and an 7.8-fold increase in the odds of LSIL (OR = 7.8, 95% CI = 5.1-11.9) for follow-up by colposcopic biopsy. For the odds of HSIL, there was a 6.8-fold increase (95% CI = 3.2-14.5) for follow-up by colposcopic biopsy as compared to Pap smears and a 3-fold decrease in the odds of HSIL (OR = 3, 95% CI = .1-.7) for high-income women (> $34,857). CONCLUSION: Our findings suggest that among ASCUS patients, younger women and those with shorter follow-up time are more likely to be diagnosed with LSIL. Women with a high income showed a protective association for HSIL. Colposcopic biopsy identified more LSIL and HSIL as compared to repeat Pap smear.