Evaluation of Invitation Strategies for Community-Based Papanicolaou Test Screening: A Randomized Controlled Trial

Background: In Taiwan, Papanicolaou test for cervical cancer screening has been implemented since 1995, previous study has shown that Papanicolaou test can substantially decrease the cervical cancer incidence and mortality rates. However, the regulated triennial participate rate, a policy key performance index, has never reached 70%, indicates the methods of inviting people to attend the Papanicolaou test still have room to improve. Aim: Our study aim was to evaluate the effectiveness of different invitation strategies stratified by frequency of clinic visiting per year using randomized controlled trial approach. Methods: The health bureau and local hospital collaborative program was initiated in Changhua County, the middle county in Taiwan. We enrolled the eligible women aged 30 or more who never attend to undergo cervical cancer screening in recent three years to initiate a randomized control trial based on different times of clinic visiting per year. Based on clinic visiting records in recent year as hospital loyalty, participants are classified into three levels, including no clinic visiting history, 1-3 times, and 4 times or more of clinic visiting in 2005, and then randomly allocated into no-intervention, postcard invitation, telephone call reminding only, and telephone call with reservation appointment. The study outcome was measured by whether the participant completes the Papanicolaou test within four months after the invitation was launched. We conducted univariate and multivariable Poisson regression models to evaluate the effectiveness in different strategies compared with no-invitation group, also used Cox proportional hazards regression taking hesitating period for participating the Papanicolaou test into account. Results: Using the intention-to-treat analysis, among those who without clinic visiting, compared with control group (no intervention), the result shows no significant benefit of postcard reminding. After adjustment for other potential factors, the results show the strategies of invitation were postcard (adj. RR=1.40, 95% CI: 1.22-1.61), telephone call reminding only (adj. RR=1.79, 95% CI: 1.52-2.10), and telephone call with scheduling appointment (adj. RR=1.90, 95% CI: 1.62-2.23). Regarding the different frequency of clinic visiting, compared with subjects without clinic visiting, those who were higher clinical visiting are tend to being attendee of screening and telephone call with scheduling appointment is higher effectiveness, respectively. Conclusion: Telephone-call reminding only and telephone-call with scheduling appointment significantly increased Papanicolaou test participation rates in those who were low and high loyalty patients as well.