Main findings
This study introduces the Medication Adherence Score and demonstrates that it is feasible to score approximately three quarters of patients at the individual patient level. The score aims to enhance awareness of non-adherence at the individual level, assist clinicians with diagnosing likelihood of non-adherence and allow them to intervene when non-adherence is present. Importantly, the score enables identification of patients with a risk of low adherence – in our population, this accounted for 22% of the full cohort, with another 34% displaying an intermediate level of adherence. This provides clinicians the opportunity to potentially tailor treatment to the needs of the individual patient.
Diagnosing non-adherence
Accurate and timely assessment of adherence behavior is the crucial first step when addressing non-adherence with medical therapy. Current subjective assessment instruments are flawed as patients can deny their failure to adhere and report their behavior inaccurately during history taking or in self-reported questionnaires.(13) Objective methods such as counting the remaining pills at office visits are considered tedious, after the fact and insufficiently reliable.(14) Counting medications might also result in patients feeling policed by their physician. The benefits of the Medication Adhere Score are that it is simple to obtain, immediately available (e.g. if incorporated in the local electronic health record) and provides clinicians an estimate of the adherence behavior preceding the initiation of treatment. This may direct clinicians as to when to discuss with the individual patient the obstacles to full adherence that may be present and how these can be addressed.
Creating a single analytic from multiple socio-economic-geographic metrics can provide strong and objective predictive information for patient care. Indeed, predictive analytics have been successfully used in clinical care by the United States Department of Veterans Affairs in the REACH-VET program to identify veterans at high-risk of suicide not previously identified, and to guide the delivery of preventive interventions.(15) The initial implementation of REACH-VET resulted in more (mental) health care appointments and less all-cause mortality.(16)
Treatment differentiation
The current strategy to improve adherence often follows a one-size-fit-all approach where every patient, irrespective of their (future) adherence behavior, is subjected to the same intervention. This approach differs from other medical problems where first the diagnosis is established before treatment commences. With the Medication Adherence Score, we propose an approach of treatment differentiation where the score, in conjunction with the findings during history taking, help dictate whether interventions to improve adherence are needed.
Interventions to improve adherence
Lower pill burden and simplification of the treatment regimen have repeatedly been demonstrated to improve adherence in multiple conditions, and the effect might be greatest in underserved patients.(17–21) Adherence to cardiovascular drugs has been shown to improve in patients whose medication copayments were reduced or whose coverage improved.(11) Physicians can incorporate these evidence-based strategies by reducing the number of daily doses, prescribing fixed-dose combinations or have pre-sorted medications in daily blister packaging, actively describing non-essential medication, and when financial barriers are present seek cheaper drug regimens.
Additionally, alternatives to daily drugs in the form of devices or very long-acting drugs can potentially help mitigate non-adherence. For example, intrauterine devices (IUDs) provide highly effective, long-term contraception with failure rates between 0.1 and 0.8% compared to 9% of first-time users of combined oral contraceptive pills in the first year.(22) For patients with atrial fibrillation, left atrial appendage closure might replace a daily oral anticoagulant, and in dyslipidemia, a once a month and soon semi-annual subcutaneous injection can potentially replace a daily drug.(23, 24)
Effect adherence in clinical trials
Adherence in the setting of clinical trials is often better than during routine clinical care – but is even present in trials, thereby significantly affecting outcomes. In superiority trials aiming to demonstrate a benefit of one drug over another, the treatment effect in both studies arms is attenuated by non-adherence. Selecting patients with high predicted adherence may allow smaller and more efficient superiority studies. In non-inferiority trials, where the goal is to demonstrate that the new treatment is not significantly worse than an existing therapy, the effect of non-adherence may be even more impactful. In the hypothetical situation where all patients in both study arm are completely non-adherent, the “treatment” effect will be identical to control, leading to the inappropriate conclusion that the strategies are equal. The Medication Adherence Score can help identify patients who have a higher chance of demonstrating good adherence and thus increase the power of non-inferiority trials.
Ethical and privacy consideration
In the research setting of the current study, the institutional review board approved the study and waived the need for informed consent which allowed us to obtain an unbiased sample. In the future, when the Medication Adherence Score may be used to guide therapy, the score should only be obtained with the consent of the patient as with any medical diagnostic test or intervention. It should be explained that the score estimates adherence behavior and can help the clinician understand whether a patient would benefit from additional interventions that aim to improve adherence. Ideally, the consent question starts a conversation between the patient and clinician regarding adherence and which boundaries may apply to the patient’s situation.
To obtain the Medication Adherence Score for an individual patient, name and address need to be exchanged, but no other information from the patients’ medical file. The objective of the exchange in the context of the Medication Adherence Score is to improve treatment at the individual level, resulting in an immediate benefit for the patient whose information has been exchanged. FICO destroys the exchanged data immediately after the score has been generated and returned to the requestor. From a financial perspective, there is a charge per generated score.