Strengths and limitations
anxiety
This study was part of a large pragmatic randomised controlled trial of the Cytosponge, in which nearly 1500 participants completed a 22-item patient experience survey (IAPS) covering all aspects of the Cytosponge appointment and procedure. Furthermore, detailed demographic and clinical information, in addition to anxiety data from the STAI-6 questionnaire, was available. This sample size and extensive data available allowed a more in-depth analysis looking specifically at predictors of the least positive experience. Moreover, the BEST3 trial took place in 109 general practice clinics in England, providing a socio-demographically diverse study population.The main limitation of our study is that the IAPS, which had been adapted from flexible sigmoidoscopy, had only been validated by piloting with a small number of patients. However, the Cronbach’s alpha of 0.83 shows good internal reliability of this adaptation. A further limitation was that the follow-up questionnaire was completed 7–14 days after the procedure, which could have affected recall. This might have been the reason for not all participants completing all items in the questionnaire. Moreover, 30 individuals who had completed less than 15 items of the IAPS were excluded from the analysis, and individuals who did not successfully swallow a Cytosponge (N = 96), who may be expected to have had the least positive experience, were not asked to complete a questionnaire. The STAI-6 used to measure anxiety before the Cytosponge test and at follow-up did not specifically ask about the procedure, but measures state anxiety, which could be influenced by other factors. The STAI-6 was chosen as it is a short and reliable measure [