Achieving optimal adherence to medical therapy by telehealth: Findings from the ORBITA medication adherence sub-study

Abstract

Introduction: The ORBITA trial of percutaneous coronary intervention (PCI) versus a placebo procedure for patients with stable angina was conducted across six sites in the United Kingdom via home monitoring and telephone consultations. Patients underwent detailed assessment of medication adherence which allowed us to measure the efficacy of the implementation of the optimization protocol and interpretation of the main trial endpoints.

Methods: Prescribing data were collected throughout the trial. Self-reported adherence was assessed, and urine samples collected at pre-randomization and at follow-up for direct assessment of adherence using high-performance liquid chromatography with tandem mass spectrometry (HPLC MS/MS).

Results: Self-reported adherence was >96% for all drugs in both treatment groups at both stages. The percentage of samples in which drug was detected at pre-randomization and at follow-up in the PCI versus placebo groups respectively was: clopidogrel, 96% versus 90% and 98% versus 94%; atorvastatin, 95% versus 92% and 92% versus 91%; perindopril, 95% versus 97% and 85% versus 100%; bisoprolol, 98% versus 99% and 96% versus 97%; amlodipine, 99% versus 99% and 94% versus 96%; nicorandil, 98% versus 96% and 94% versus 92%; ivabradine, 100% versus 100% and 100% versus 100%; and ranolazine, 100% versus 100% and 100% versus 100%.

Conclusions: Adherence levels were high throughout the study when quantified by self-reporting methods and similarly high proportions of drug were detected by urinary assay. The results indicate successful implementation of the optimization protocol delivered by telephone, an approach that could serve as a model for treatment of chronic conditions, particularly as consultations are increasingly conducted online.

Keywords: cardiovascular diseases; chromatography, liquid; coronary artery disease; medication adherence; therapeutics.

FIGURE 1

Study flow diagram. Demographics and prescribed drugs were recorded at enrolment and patients were provided with a home blood pressure monitor and shown how to carry out home readings. Patients were asked to keep diary entries of these readings for review during scheduled telephone clinic assessments which took place 1–3 times weekly during the 6‐week optimization phase. At pre‐randomization, patients attended the study coordinating center where a final check of their prescribed drugs was done along with self‐reported adherence for each drug and patients were asked to give a urine sample for detection of drug using the HPLC MS/MS method. Patients then returned to their local center a few days later for the randomized study procedure, after which no further changes to therapy took place and no further study visits took place. At the follow‐up assessment prescribed drugs, a repeat of the pre‐randomization assessments was done. HPLC MS/MS – high‐performance liquid chromatography with tandem mass spectrometry, PCI – percutaneous coronary intervention