Understanding variations in determinants of medicationadherence to inform a tailored intervention: the case ofstatin adherence

Statins lower levels of 'bad' cholesterol, and stop or slowthe progression of cardiovascular disease (CVD). Statinadherence is associated with lower risk of CVD events (e.g.heart attack/stroke), and death from CVD or any cause(Martin-Ruiz 2018; Vrecer 2003). However, after two years,only around 25% of patients take statins as prescribed(Brown 2011).Despite this, there is a relative lack of research intopsychological determinants of statin adherence, orcategorisations of the behavioural components of effectivestatin interventions. The proposed PhD will use behaviouralscience approaches and qualitative and quantitativemethods to identify how determinants of non-adherencediffer between different patient groups and betweenindividuals. This will inform the design of a scalableadherence intervention, tailored to individual needs. Thisalternative to a one-size-fits-all approach can addressvarying barriers to taking medications.The project will be a collaboration between ImperialCollege London and Hammersmith and Fulham Partnership(a GP Partnership of 5 GP practices), building on existingresearch from this team.The first stage of the PhD will investigate determinants ofadherence across patient groups and individuals, using avariety of methods, all based on the Theoretical DomainsFramework: a comprehensive framework of behaviouralpredictors. Secondary analysis of our ongoing survey onpsychological determinants of statin adherence will testhow these differ in different groups, e.g. those on manymedications, those who have had a CVD event, ethnicminorities. An interview study will assess adherencedeterminants in adherent and non-adherent patients, andthe patterns seen across individuals. This will be complemented by a systematic review of statin adherencedeterminants, and a review of statin adherenceinterventions, with intervention components categorisedusing the Behaviour Change Techniques Taxonomy.The student will map all these findings to identifyadherence determinants across different groups, andcorresponding techniques to address each adherencebarrier.The second stage will design a tailored intervention toaddress the varying determinants, building on stage 1findings. The intervention will be co-designed usingworkshops with diverse patients, clinicians, behaviouralscientists and designers. The intervention will be scalable,and tailored to specific needs of each patient e.g. through apathway of intervention components, based on patientcharacteristics and reported barriers. A pilot and feasibilitystudy will assess whether recruitment is feasible, trialprocesses run smoothly, and the intervention is acceptable.The effect of the intervention on adherence will beexamined, along with differences between patient groups.An interview and survey will investigate patient andclinician views on the intervention, and potentialimprovements. The PhD findings will inform a subsequentfull trial of the intervention.