How much does a reminder letter increase cervical screening among under-screened women in NSW?

Abstract

Objective: To evaluate a direct mail-out campaign to increase Pap screening rates in women who have not had a test in 48 months.

Methods: Ninety thousand under-screened women were randomised to be mailed a 48-month reminder letter to have a Pap test (n=60,000), or not to be mailed a letter (n=30,000). Differences in Pap test rates were assessed by Kaplan-Meier survival analysis, by chi2 tests of significance between Pap test rates in letter versus no-letter groups, and by proportional hazards regression modelling of predictors of a Pap test with letter versus no-letter as the main study variable. T-tests were conducted on mean time to Pap test to assess whether time to Pap test was significantly different between the intervention and control groups.

Results: After 90 days following each mail-out, Pap test rates in the letter group were significantly higher than in the non-letter group, by approximately two percentage points. After controlling for potential confounders, the hazard ratio of a Pap test within 90 days of a mail-out in the letter group was 1.5 compared with 1.0 in the no-letter group. Hazard ratios of having a Pap test within 90 days decreased significantly with time since last Pap test (p<0.0001); were significantly higher than 1.0 for most non-metropolitan areas of NSW compared with metropolitan areas; and increased significantly with age (p<0.0001). Pap test hazard ratios were not associated with socio-economic status of area of residence, but the hazard ratio was significantly higher than 1.0 if the reminder letter was sent after the Christmas/New Year break. No significant differences in mean time to Pap test were found between the letter and no-letter groups.

Conclusions and implications: Being sent a reminder letter is associated with higher Pap testing rates in under-screened women.