Abstract
We estimated the participation rates in cancer screening by means of the sampling survey method and analyzed the problems caused by failures in sample collection. A newly developed questionnaire for the present survey was sent to a total of 3,000 randomly selected people in Sendai City; each participant was requested to answer whether or not he/she underwent each of the ten types of examination associated with gastric, lung, colorectal, cervical and breast cancer, also, if examined, whether those examinations were offered by the municipal government or by their workplace. The valid response rate was 65.5%. The influence of non-respondents on the estimation of the participation rates was evaluated by comparing the actual participation rates based on the data collected with those based on the framework of the regional public health and health promotion program. In addition, the estimated participation rates were also compared between responders who replied to the questionnaire rapidly and those who replied only after they received a reminder. The present results suggest that the data of the sampling survey obtained from those who responded readily might overestimate the actual participation rates in every cancer screening. This tendency was especially marked in people over 70 years of age. The present findings may contribute to the resolution of certain problems inherent in the procedure for investigating the participation rates in cancer screening; however, the existing method is of limited value since it does not reflect the results of the examinations through workplace unlike the specific health examination. Therefore, it seems necessary for us to introduce a cancer screening system that is able to record the entire history of the participations, as is the case with the specific health examination.
