[Evaluation tools of drug adherence for elderly subjects: towards a new pattern of scale].

Introduction: Medication non-adherence can be defined as a non-compliance with prescribed drugs. The characteristics of elderly people constitute major risk factors for non-adherence to medication. The aim of this study was to study the relevance of medication adherence scales that are identified in a previous work.

Methods: The current study was based on a previous work in which several adherence scales were identified. We reviewed articles that validated these scales to assess their performances and to measure their adaptation for elderly people.

Results: Eight scales were studied, of whom five were validated in high blood pressure therapy. Intrinsic performance as well as construction and validation of scales were weak. Furthermore, none of these validation studies were conducted in elderly population aged 75 years and over. Four aspects appeared to be necessary for scale development: knowledge of the disease and its treatment, perception of the efficacy and tolerance of the treatment, getting the therapy, and drug administration. The use of an evaluation scale in elderly population should consider the living location, the ability of the subject to respond, and the presence of informal or formal caregivers.

Conclusions: Existing scales seem to be weak and elderly characteristics are not considered. Validated adherence medication scales adapted for elderly people are thus needed.