The ‘necessity–concerns framework’ as a means of understanding non-adherence by applying polynomial regression in three chronic conditions

Abstract

Objective: The ‘Necessity–Concerns Framework’ is an important framework which can support healthcare professionals in targeting patients’ medication beliefs and decisions on adherence. Our aim was to determine how the interdependence of ‘necessity’ and ‘concerns’ beliefs for medication adherence compares across three chronic conditions.

Methods: Patients diagnosed with asthma, cardiovascular conditions or diabetes attending out-patient clinics completed a self-administered questionnaire. The questionnaire gathered information regarding demographics, medication adherence using the ‘Tool for Adherence Behaviour Screening’, presence of unused medication in households and medication beliefs using the ‘Beliefs about Medicines Questionnaire-Specific’. Polynomial regression was applied to determine the multidimensional interdependence of ‘necessity’ and ‘concerns’ beliefs for adherence. P-values ≤ 0.05 were taken to be significant.

Results: Confirmatory polynomial regression rejected the differential score model in all three groups. For each condition, exploratory polynomial regression found that linear terms indicated the best fitting model for predicting adherence. In all groups, adherence increased as necessity beliefs increased and concerns decreased. Patients suffering from cardiovascular conditions and diabetes with low necessity and low concerns beliefs reported higher medication adherence compared to those with high necessity and high concerns beliefs.

Discussion: Alleviating patients’ concerns can enhance medication adherence and potentially curb the issue of medication wastage.