Effects of explaining the merits and demerits of thyroid ultrasound examination on participation intention among adolescents after the Fukushima nuclear accident: a questionnaire survey

The purpose of the present study was to investigate how the intention to participate in thyroid ultrasound examination (TUE) changed after reading an explanation of its merits and demerits among adolescents in Fukushima Prefecture following the nuclear disaster in a cross-sectional questionnaire study with a pre-post design. The study was conducted among adolescents eligible for TUE. In the pre-survey, data were collected on participants' background characteristics, history of TUE participation, willingness to participate in TUE, and prior knowledge of the merits and demerits of TUE. Next, participants were provided with a written explanation of the merits and demerits of TUE. Following this, they were surveyed again regarding the understandability of the explanation and their willingness to participate in TUE after reading it. The primary outcome was the change in intention to participate in TUE between the pre- and post-surveys. The overall proportion of willingness to participate in TUE did not change dramatically after reading the explanation. However, 77.8% (367/472) of participants in the group that already knew the merits and demerits did not change their intention to participate in TUE, whereas only 70.5% (537/762) in the previously unaware group did not change their intention. The highest proportion of change was observed among those who initially responded as "undecided" regarding participation in TUE. Providing information on the merits and demerits of TUE was especially important for undecided individuals, as this group showed the greatest change in intention following the explanation.