Fig. 1

Flowchart of the selection process for the target group. Although the total number of municipalities in 2010 was 1746, 46 municipalities failed to submit the results of their cancer screening because of the Great East Japan Earthquake [8]. Two municipalities were not able to conduct the above-mentioned questionnaire survey on promotion strategies for improving the participation rate. Municipalities that had missing or inconsistent data related to the number of participants were excluded as follows: 7 municipalities for gastric cancer screening and 12 municipalities for colorectal cancer screening. In addition, there were municipalities whose number of participants was less than 100, namely, 52 municipalities for gastric cancer screening and 20 municipalities for colorectal cancer screening. These municipalities were also excluded from the analysis [8]. Finally, 1639 municipalities for gastric cancer screening and 1666 municipalities for colorectal cancer screening were analyzed