Evaluating the Effectiveness and Safety of Colon Capsule Endoscope System for Capturing and Viewing Colon Images

According to the relevant requirements of Standard for Quality Management of Medical Device Clinical Trials (Order No. 25 of the National Health and Family Planning Commission of the People's Republic of China of China Food and Drug Administration), the sample size was estimated based on the excellent rate of the image quality of the main endpoint by referring to the domestic and foreign literatures using positive comparator devices. Combined with literatures and comments of clinical experts, the research set the excellent rate of image quality of comparator device Ps as 95%, and estimated the excellent rate of image quality of trial device Pt as 95%. In the research, the non-inferiority trial design was adopted, with α = 0.025 (unilateral), assurance 1 - β = 0.8, and non-inferiority boundary value of -10%, and self-control was adopted. It is assumed that the redundant parameter (that is, the proportion of subjects whose evaluation results of image quality between trial devices and comparator devices are inconsistent) was 0.095 (that is, Pt (1 - Ps) + Ps (1 - Pt)), the total sample size of the two groups was 102 cases calculated by PASS2021, with 51 cases in each swallowing orders I and II. Considering the shedding and rejection rate of 20% during the trial, a total of 128 subjects were needed, with 64 cases in each swallowing orders I and II.