Association between visual message and health knowledge in a 4-month follow-up study at worksites

This study evaluated a simple workplace intervention that used visual messages to create awareness of two highly specific recommendations for good health.

Four worksites were recruited in Iwakuni, Japan. The 4-month intervention used three promotional media-A2-size posters, A4-size flyers and displays on the company intranet. The visual messages were designed with silhouettes, pictograms and slogans. Knowledge acquisition concerning the two recommendations (daily vegetable intake of 350 g and 23 exercises weekly) was evaluated using questionnaires. In addition, recall of media and attitudes toward health behavior were assessed.

Of the 2,322 workers, 827 responded to both the pre- and postintervention surveys. Correct responses at the four worksites increased from initial levels of 36-48% to 38-73% for the vegetable intake questions and from 7-14% to 7-59% for the physical activity questions. Media recall results were 35-73% for posters, 20-43% for flyers and 19% for intranet. The workers who recalled the posters and flyers had more correct answers on knowledge questions than those who did not recall the posters or flyers (p<0.01). In multivariate analyses, seeing the visual messages was associated with a positive change in response to physical activity questions (odds ratio=1.49-2.03), and the number of media recalled was also significant (odds ratio=1.16-1.17).

Interventions with a combination of media and simple visual messages should be considered for health promotion among general populations at worksites.