Reporting Quality of Endoscopic Colorectal Cancer Screening Randomized Controlled Trials: Adherence to...

In 2013, the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) steering group published recommendations to standardize reporting quality in randomized controlled trials (RCTs). We aim to assess adherence to SPIRIT reporting guidelines in RCTs on endoscopic colorectal cancer (CRC) screening and participants' adherence to trial protocols.

We searched databases for RCTs evaluating flexible sigmoidoscopy or colonoscopy for CRC screening published in English language through September 2023. Each eligible study was evaluated using the 8 core SPIRIT statement areas, totaling 51 points. Each item received 1 point if it met the criteria and 0 points if it did not. Adherence to SPIRIT items was calculated, and participant adherence to RCT protocols was assessed as the proportion of participants screened compared to those invited.

Five RCTs, including 4 on flexible sigmoidoscopy and 1 on colonoscopy, were analyzed. Adherence to SPIRIT guidance ranged from 82.4% to 92.2%. The most missed recommendation was item 2b (trial registrations), scored 0 across all studies. Additionally, item 32 (informed consent materials) scored 20%, and items 17a & b (blinding) scored 40% each. In total, 587,572 participants were randomized across the 5 RCTs. Of these, 37% (200,610) underwent CRC screening, with 69.8% (139,983/200,610) adhering to the protocol. The Nordic-European Initiative on Colorectal Cancer (NordICC) trial, employing a unique invitation method, had a lower adherence rate of 42%. Excluding this trial would raise the adherence rate to 74.3% (128,050/172,390).

The published CRC screening trials have acceptable adherence to the SPIRIT reporting guidelines. However, reporting appended consent form materials and disclosing all WHO trial registration data can be improved.