Reasons for non-participation in a psychological intervention trial for distress in colorectal cancer survivors.

Objective: High psychological distress is reported by one third of colorectal cancer survivors (CRCS). However, intervention studies for CRCS have reported low participation rates. In this study, reasons for non-participation and low uptake in a psychological intervention trial were investigated.

Methods: CRCS were recruited for a randomized clinical trial on the efficacy of blended cognitive behavior therapy for psychological distress via databases, follow-up consultations, advertisements and an ongoing population-based study. The recruitment flow and reasons for non-participation were analyzed for patients recruited between 2016 and 2020. Subgroups were compared based on demographic, clinical and screening data. High distress as study entry criterion was measured with the Distress Thermometer (DT ≥ 5) and the problem list (PL).

Results: From all recruitment methods together, 1326 CRCS responded to the invitation letter of whom 510 (38%) were interested in receiving a screening questionnaire. Interested CRCS were significantly younger than non-interested CRCS (p < 0.001). Most non-interested CRCS reported having no complaints. Of interested CRCS, 448 (88%) completed screening with the DT of which 213 (48%) CRCS scored above the DT cutoff for high distress. The majority expressed no need for help resulting in 84 (4% of eligible) CRCS included in the trial. Younger age, shorter time since diagnosis and more problems on the PL were positively related to participation.

Conclusions: In this study a low participation rate was found. However, patients with high distress and most in need for help were included in the trial. For future research it is recommended to perform pilot- and feasibility studies to optimize recruitment.