The experimental evaluation of an oral cancer information leaflet.

The aims of our series of studies were: (1) to prepare an information leaflet about oral cancer for the general public; (2) to design a questionnaire to assess the level of knowledge about oral cancer; and (3) to evaluate the newly prepared leaflet. A study was conducted for each aim. For study 1, multiple drafts of oral cancer leaflets were distributed for comment and editing. For study 2, a large number of statements (100) about oral cancer were compiled and judged. Redundant items were withdrawn. The final version was administered to criterion groups (students, dentists and the public) to assess reliability and validity. For study 3, a multigroup pre- and post-test randomised design (comprising an experimental and two control groups) was adopted to evaluate knowledge improvement from exposure to the oral cancer leaflet. The participants in each study were as follows: in study 1, questions were judged by the authors, colleagues (n=2) and a non-patient group (n=10); in study 2, undergraduate psychology students (n=41), medical students (n=60), dental students (n=82), members of the public (n=54) and general dental practitioners (n=22) were respondents for the reliability/validity assessment; and in study 3, the dental students and members of the public from the previous study participated. The measure was a true/false 36-item questionnaire with additional demographic questions. In study 1 the Flesch readability index for the leaflet equalled approximately 80, i.e. 'fairly easy'. In study 2 the Kuder-Richardson 20 reliability coefficient of the questionnaire equalled 0.76. Criterion validity was confirmed with general dental practitioners scoring greater knowledge than members of the public (p<0.05). In study 3 participants who had access to the leaflet showed a significant increase in knowledge at post-test in comparison to pre-test. Control group results were supportive of a positive effect from leaflet exposure. In conclusion, the design of a health information leaflet, the assessment of reliability and validity of an associated knowledge questionnaire and evaluation of the influence of such a leaflet should be conducted in a series of planned steps. This approach can be used for other health-related issues which require dissemination of information. Three studies have demonstrated the successful application of this design and evaluation model to the area of oral cancer education.