A 3-step intervention to improve adherence to cervical cancer screening: The SCAN randomized controlled trial

The aim of this study was to test the effectiveness of a stepwise intervention with an increasing level of complexity and cost to increase adherence to organized cervical cancer screening. This was a randomized (1: 1) controlled trial, conducted among 13 Portuguese primary health care units. Participants (n = 1220) were women aged 25-49 years, eligible for cervical cancer screening, with a mobile phone number available. The tested intervention was a 3-step invitation to screening, based on automated text messages/phone calls (step 1), manual phone calls (step 2) and face-to-face interviews (step 3), applied sequentially to non-adherent women after each step. Participants in the control group were invited through a written letter (standard of care). The primary outcome was the proportion of women screened, which was assessed after step 1 (45 days after the initial invitation), steps 1 + 2 (90 days after the initial invitation) and steps 1 + 2 + 3 (150 days after the initial invitation). Adherence to cervical cancer screening was significantly higher among women assigned to the intervention than those in the control group for step 1 (39.9% vs. 25.7%, p < 0.001), steps 1 + 2 (48.6% vs. 30.7%, p < 0.001) and steps 1 + 2 + 3 (51.2% vs. 34.0%, p < 0.001). In conclusion, adherence to cervical cancer screening was higher by 17% among women invited through the 3-step intervention, compared to those receiving the standard invitation letter. The former strategy has the potential to be broadly implemented due to the low requirements of technology and training. Clinical Trial Registration: NCT03122275.