Promoting informed decisions about health interventions through the development and evaluation of an educational intervention for Australian high school students

  • Leila Cusack

Student thesis: Doctoral Thesis


Health claims about interventions are largely unregulated and often misleading, potentially leading to ill-informed decisions which can cause harm and waste resources. During adolescence, individuals begin making health decisions, and hence this may be an ideal time to provide education to shape decision-making processes. Research into how adolescents consider health claims is scarce and little is known about how to teach the knowledge and skills needed to appraise health claims.

This thesis aimed to: 1) explore the scope and effectiveness of educational programs for improving knowledge and skills in appraising health claims; 2) explore Australian high school students’ understanding of, and attitudes towards, concepts relevant to the assessment of health information and claims; and 3) develop and evaluate the effectiveness of an educational program for Australian high school students designed to help them identify and appraise health claims and become savvy consumers of intervention information.

Three inter-related studies were conducted. Study 1 was a systematic review of evaluated interventions which taught key concepts necessary for health claim appraisal. Study 2 was a qualitative study in which 27 high school students were interviewed to explore their understanding of, and attitudes towards, health information and claims. Study 3 involved developing an educational intervention (informed by Studies 1 and 2, literature, and an advisory group) and evaluating it with a cluster randomised controlled trial in Australian high schools. Teachers delivered the intervention over approximately four sessions and students completed a baseline and follow-up questionnaire.

Study 1 identified 14 randomised studies and 10 other evaluative study designs. Educational interventions appear to improve people’s knowledge and skills in evaluating health intervention information, at least in the short term. No existing randomised controlled trials evaluated an intervention for high school students.

Study 2 identified three themes: 1) variability in sources of health information and claims, and understanding of their creation and content accuracy; 2) the use of substitute indicators to assess health information and claims and make judgements about their trustworthiness; and 3) uncertainty about, and literal interpretation of, the language of health claims.

Study 3 involved nine schools (4 control, 5 intervention), comprising 974 students in grades 7-10. For the primary outcome of being able to identify and appraise health claims (measured using 19 questions from the Claim Evaluation Tools database), the intervention group, compared to the control group, had slightly better scores (mean follow-up score). There were also only minimal between-group differences for the secondary outcomes (the difference in the proportion of students with a ‘passing’ score and a ‘mastery’ score, behaviour and attitude, health advertisement appraisal skills).Intervention feedback from students and teachers was generally positive.

Conclusions and implications
Findings from these studies demonstrate deficits in adolescents’ knowledge of, and ability to appraise, health claims, with the potential for educational interventions to improve relevant knowledge and skills. However, future research should explore optimal ways of providing such education to adolescents to maximise engagement, and impact short and long-term outcomes. Such research, along with support from educational and curriculum stakeholders, is needed to advance the exposure of adolescents to education about health claim appraisal.
Date of Award29 Nov 2023
Original languageEnglish
SupervisorTammy Hoffmann (Supervisor) & Christopher Del Mar (Supervisor)

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