Persistence as a Reliable Measure of Medication Adherence Quality and Performance

Martin Henry^*
*Correspondence: Martin Henry, Department of Pharmacoeconomics and Drug Utilization, University of California, Los Angeles, USA, University of California los Angeles, USA, Email:

Introduction

Persistence, defined as the duration of time a patient continues to take a prescribed medication without discontinuation, is increasingly recognized as a critical indicator of medication adherence. Adherence encompasses not only whether a patient takes their medication as prescribed but also the consistency and duration over which they do so. Among the various metrics used to evaluate adherence, persistence stands out as a particularly robust measure because it provides a temporal dimension, reflecting the sustained commitment of patients to their therapeutic regimens. This focus on persistence offers unique insights into adherence-related quality and performance, shedding light on the challenges and opportunities in optimizing long-term medication use. Medication adherence is a cornerstone of effective treatment for chronic diseases, influencing clinical outcomes, healthcare costs, and patient quality of life [1]. However, achieving high levels of adherence remains a persistent challenge. Non-adherence is a multifaceted problem, driven by factors such as complex treatment regimens, side effects, cost of medications, and lack of understanding about the importance of therapy. In this context, persistence emerges as a valuable metric because it captures a longitudinal view of adherence, unlike measures that simply assess whether a medication was taken at a specific time point. Persistence reflects the real-world complexities of medication-taking behavior, making it a reliable measure for evaluating adherence quality [2]. One of the primary strengths of persistence as an adherence metric lies in its ability to reveal patterns of medication use over time. For example, persistence can help identify critical periods during which patients are most likely to discontinue their medication, such as within the first few months of starting a new treatment. Understanding these patterns is essential for designing interventions to support adherence. Studies have shown that nonpersistence, particularly early in the treatment course, is associated with worse clinical outcomes and higher healthcare utilization. By focusing on persistence, healthcare providers and researchers can target the specific phases of treatment where patients are at the greatest risk of discontinuation, thereby improving overall adherence. The importance of persistence as a measure of adherence is particularly evident in chronic disease management. Conditions such as hypertension, diabetes, and asthma require long-term medication use to control symptoms and prevent complications. Persistence is critical in these settings because short-term adherence alone is insufficient to achieve meaningful health benefits. For instance, a patient with hypertension who takes their medication sporadically or discontinues treatment prematurely may experience little to no reduction in blood pressure, undermining the effectiveness of therapy. In contrast, a persistent patient who maintains their medication regimen over time is more likely to achieve sustained blood pressure control, reducing the risk of cardiovascular events. Thus, persistence is not only a marker of adherence but also a predictor of treatment success [3].

Description

In addition to its clinical implications, persistence also serves as a key indicator of healthcare system performance. From a population health perspective, high levels of persistence reflect effective systems of care that support patients in maintaining their medication regimens. Conversely, low persistence rates may signal gaps in care, such as inadequate patient education, insufficient follow-up, or barriers to medication access. Monitoring persistence can provide valuable feedback to healthcare organizations and policymakers, enabling them to identify areas for improvement and implement targeted interventions. For example, initiatives to reduce the cost of medications, simplify dosing regimens, or enhance patient-provider communication have been shown to improve persistence rates, ultimately leading to better health outcomes. Persistence also has significant implications for the economic evaluation of healthcare interventions. Adherence-related metrics are often used in costeffectiveness analyses to assess the value of different treatments or programs. Persistence provides a more comprehensive measure of adherence compared to static metrics, as it captures the dynamic nature of medication use over time. By incorporating persistence into economic models, analysts can better estimate the true costs and benefits of interventions, accounting for the longterm impact of adherence on health outcomes and resource utilization. For instance, a medication that is more expensive upfront but associated with higher persistence rates may prove to be more cost-effective in the long run due to its superior adherence and associated health benefits [4]. Despite its strengths, measuring persistence presents certain challenges. Persistence data are typically derived from administrative claims or prescription records, which may not capture all aspects of medication-taking behavior. For example, these data can indicate whether a prescription was filled but cannot confirm whether the medication was actually taken. Additionally, persistence metrics may be influenced by factors such as prescription refill policies or variations in healthcare practices, which can introduce bias into analyses. To address these limitations, researchers and practitioners often combine persistence data with other adherence measures, such as self-reported surveys or electronic monitoring devices, to obtain a more comprehensive picture of adherence behavior [5]. Efforts to improve persistence require a multifaceted approach, addressing both patient-related and system-level factors. On the patient side, interventions such as educational programs, reminder systems, and medication counselling can help patients understand the importance of persistence and overcome barriers to adherence. For instance, mobile health technologies, including smartphone apps and text message reminders, have shown promise in supporting patients to stay on track with their medications. On the system side, strategies such as simplifying medication regimens, reducing out-of-pocket costs, and enhancing care coordination can create an environment that facilitates persistence. For example, fixed-dose combination therapies, which combine multiple medications into a single pill, have been associated with higher persistence rates compared to separate prescriptions for each medication. The role of healthcare providers in promoting persistence cannot be overstated. Providers are often the primary source of information and support for patients, making their engagement critical to adherence efforts. Effective provider-patient communication is particularly important, as it helps build trust and ensures that patients have a clear understanding of their treatment plan. Providers can also play a proactive role by regularly monitoring persistence, identifying patients at risk of non-persistence, and intervening early to address any barriers. For instance, regular follow-up visits or phone calls can help reinforce the importance of adherence and provide an opportunity to address any concerns or challenges faced by patients.

Conclusion

Persistence is a robust and reliable measure of medication adherence quality and performance. It captures the temporal dimension of adherence, reflecting the sustained commitment of patients to their prescribed therapies. Persistence is particularly important in chronic disease management, where long-term adherence is essential for achieving meaningful health benefits. By focusing on persistence, healthcare providers, researchers, and policymakers can gain valuable insights into adherence behavior, identify areas for improvement, and design targeted interventions to support patients. While challenges in measuring persistence remain, advances in data collection and analysis methods are helping to address these limitations, enabling a more comprehensive understanding of adherence. Ultimately, promoting persistence is a shared responsibility that requires collaboration among patients, providers, and healthcare systems to achieve better health outcomes and optimize the value of medical interventions.

References

1. Menditto Enrica, Caitriona Cahir, Sara Malo and Isabel Aguilar-Palacio, et al. "Persistence as a robust indicator of medication adherence-related quality and performance." Int J Environ Res Public Health 18 (2021): 4872.

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2. Shah Kanya K, Daniel R. Touchette and Joel C. Marrs. "Research and scholarly methods: Measuring medication adherence."  JACCP 6 (2023): 416-426.

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