Candidate for the Lee B. Lusted Student Prize Competition
Purpose: In the Netherlands 12-year-old girls are offered the HPV vaccine free of charge and are legally entitled to take their own decision about vaccination uptake. To inform girls about HPV vaccination, they are sent a standardized information leaflet prior to the vaccination offer. While it is important that girls have decision-relevant knowledge – and can make an informed choice about uptake - it is unknown to which extent relevant information, e.g. the extent and duration of protection against cervical cancer through vaccination, is understood after reading the leaflet.
Method: A questionnaire was completed by 11 to 14-year-old girls at school. To assess whether completing a pre-test would trigger attentively reading the leaflet, respondents were randomly assigned to one of two groups: the intervention group completed a pre-test, read the leaflet and completed a post-test; the control group only read the leaflet and completed a post-test. In both pre and post-test we assessed knowledge about HPV (statements to be answered with ‘true’ or ‘false’); attitudes; and intentions towards having the vaccination. Knowledge scores ranged from 0-10, with scores of ≥ 6 indicating sufficient decision-relevant knowledge.
Result: The response was 237/287 (83%). After reading the leaflet the average knowledge score in the intervention group increased from 5.3 to 7.2 out of 10 (P<0.001). In the post-test 37% knew that HPV vaccinations do not protect completely against cervical cancer and 29% answered correctly that we don’t know for a fact that HPV vaccinations will protect against cervical cancer for a life-time. The rate of informed intentions about uptake increased from 21.9% at pre-test to 68.1% at post-test. The average knowledge score in the control group of 6.3 in the post-test was significantly lower than that of the intervention group. 36.3% of uptake intentions in the control group could be considered informed.
Conclusion: This study showed that although an information leaflet had a positive effect on the correspondence between attitude and intention, and on girls’ knowledge of HPV, knowledge about the degree and duration of protection against cervical cancer remained low. Inclusion of a control group allowed us to assess the effect of a pre-test on knowledge scores. By editing the leaflet and emphasizing these aspects, awareness of the degree and unknown duration of protection can be raised.