Efficacy of behaviour change interventions to influence human papillomavirus (HPV) vaccine uptake: a systematic review and behaviour change techniques analysis

Background: Behaviour change interventions that increase human papillomavirus (HPV) vaccine uptake in school children have been identified, but not which behaviour change techniques (BCTs) make them effective, or whether interventions are best targeted towards adolescents or their parent/carer(s). We aimed to assess the efficacy of behaviour change interventions to increase HPV vaccination compared to usual care according to BCTs implemented, and to identify whether parent/carer(s), adolescents or both are the optimal intervention target population. Methods: We searched Central, Embase, Medline and Eric databases from 1st September 2008 to 17th July 2023 for randomised controlled trials (RCTs) reporting on HPV vaccine uptake following behaviour change interventions. We coded BCTs in interventions using the BCT taxonomy (v1). Random-effects meta-analyses and subgroup analyses were performed with data from studies that provided count data on HPV vaccine uptake by BCTs implemented and intervention target population. Results: One thousand three hundred sixty-three unique records were identified, of which eight were eligible for inclusion. Implementing any behaviour change intervention was associated with a borderline significant increase in HPV vaccine uptake (OR 1.2 95% CI 1.0 to 1.4), interventions that implemented ‘Instruction on how to perform the behaviour’ (BCT 4.1) and ‘Information about health consequences’ (BCT 5.1) were not associated with increased HPV vaccine uptake (OR 1.7 95% CI 0.8 to 3.5), but analysis of two interventions implementing ‘Adding objects to the environment’ (BCT 12.5) in addition showed that this combination may be associated with significantly greater HPV vaccination (OR 13.6 95% CI 3.9 to 46.5). We found that interventions targeting parent/carer(s)-only were associated with a small significant increase in HPV vaccine uptake (OR 1.3 95% CI 1.1 to 1.5), but adolescent-only or parent/carer(s) and adolescent targeted interventions were not. Conclusions: To our knowledge this is the first systematic review and meta-analysis to quantify the efficacy of behaviour change interventions to increase HPV vaccine uptake according to BCTs implemented. We have demonstrated that implementing any behaviour change intervention marginally increases HPV vaccine uptake, and have identified a combination of BCTs that may be associated with significantly increased HPV vaccine uptake. Our work provides compelling evidence that public health interventions must be specific and evidence-based and calls for the implementation of changes to usual care in school-based vaccination programmes.