Effectiveness and utility of a patient decision aid for chemotherapy or exclusion in cisplatin-intolerant patients with locally advanced cervical cancer (CECIL): a randomized controlled trial

Background: In cervical cancer, adding chemotherapy to radiotherapy improves survival but increases toxicity. In patients with contraindications, cisplatin or its substitute may decrease radiotherapy compliance due to toxicity. We evaluated the effectiveness and utility of a previously validated patient decision aid (PtDA) for chemotherapy or its exclusion in patients the cisplatin-intolerant patients with locally advanced cervical cancer. Methods: A block-randomized controlled trial was conducted to evaluate the effectiveness of the PtDA (intervention) in reducing decisional conflict (primary outcome) as measured by the Decisional Conflict Scale (DCS) and its utility (secondary outcome) as measured by the Preparation for Decision Making Scale (PDMS), when added to standard counseling (control); providers of standard counseling were blinded. Age, education, socioeconomic status, and decision self-efficacy as measured by the Decision Self-Efficacy Scale (DSES), were studied as determinants of effectiveness and utility. Minimum sample sizes of 16 and 24 for the control and experimental groups were required, accepting a two-sided alpha error of 0.10 and a power of 0.90. Results: From February 2023 to August 2024, 8 and 10 participants were recruited into the control and experimental groups. Interim analysis showed a futility index of 0.99, pertaining to the primary study objective (difference in proportions with low post-intervention DCS); hence early study closure. However, mean post-intervention DCS was lower in the experimental than in the control group (11.6 versus 19.3, P=0.07); 80% of the PtDA users reported a PDMS of ≥3.5, indicating utility in preparation for decision-making. Among the studied variables, only decision self-efficacy was a strong determinant for post-intervention DCS (r=−0.879, P<0.001) and utility (r=0.836, P<0.001). Analysis of covariance confirmed that both decision self-efficacy (ω2=0.392, P<0.01) and PtDA use (ω2=0.146, P=0.02) were independent determinants of post-intervention DCS. Conclusions: The CECIL reduces mean decisional conflict scores by 8 points on the DCS scale and is utile in preparation for decision-making. Decision self-efficacy is a strong determinant for post-intervention decisional conflict and PtDA utility. These findings are based on a defined clinical setting and a small sample and must be validated in other clinical settings and bigger studies. A multidisciplinary approach and shared decision-making culture must be in place when integrating the decision aid in the workflow. The DSES tool may identify patients who may require other decision support intervention such as active coaching. Trial Registration: ClinicalTrials.gov Identifier: NCT05701735.