Impact of invitation and reminder letters on cervical cancer screening participation rates in an organized screening program.

Study's Objective was to explore the impact of invitation and reminder letters on cervical cancer screening participation among eligible Ontario women 30 to 69years of age. A cross-sectional study was used to describe factors and screening patterns for 1,150,783 eligible women. A cohort design was used to compare the impact of invitation and reminder letters on Pap uptake comparing women who received the intervention (n=99,278) with a historical non-intervention group (n=130,181). Factors that might influence screening participation were included as covariates in a multivariable logistic regression models. Overall, 26.7% of women who had a Pap test 3 to 5years prior and 9.8% of women with no Pap test in the previous 5years were screened within 9months after the intervention. On cohort analysis, 14.1% of women in the intervention group and 8.5% of women in the non-intervention group were screened within 9months. Being mailed an invitation letter was associated with greater likelihood of screening (OR=1.8, CI 1.7-1.8). Controlling for covariates, the letter intervention was associated with 9month screening for both women with a Pap test 3 to 5years prior (AOR=1.7, CI 1.6-1.8) and those with no Pap test in the previous 5years (AOR=1.8, CI 1.7-1.9). There was a significant effect of all covariates on the participation. The invitation and reminder letter strategy increased cervical cancer screening participation. Additional strategies that could encourage eligible women to participate and/or removing barriers to screening for eligible women may be necessary.