Pharmacoeconomic aspects of poor adherence: can better adherence reduce healthcare costs?

Abstract

Background:

Poor adherence to medical treatment is one of the main reasons why patients do not achieve the full benefits of their therapy. It also has a substantial financial weight in terms of money wasted for unused medication and increased healthcare costs including hospitalization due to clinical complications.

Objective:

To provide an overview and examples of the financial and economic consequences of poor adherence to treatment, techniques and devices for monitoring adherence and interventions for improvement of treatment adherence.

Results:

New electronic devices with monitoring features may help to objectively monitor patients’ adherence to a treatment regimen that can help a healthcare professional determine how to intervene to improve adherence and subsequent clinical outcome. Interventions that aim to enhance adherence may confer cost-effectiveness benefits in some indications and settings. The nature of the intervention(s) used depends on a range of factors, including patient preference, therapy area and cost of the intervention. However, there is a pressing need for rigorous trials, as current studies often have major flaws in the economic methodology, especially in terms of incremental analysis and sensitivity analysis.

Limitations:

This review has focused on a limited number of therapeutic areas as coverage of a more extensive range of diseases may be beyond the scope of such a summary. Nevertheless, the examples are representative of the challenges encountered in many other diseases.

Conclusions:

The clinical and economic consequences of non-adherence and interventions to improve compliance reflect the nature and severity of non-adherence, as well as the pathophysiology and severity of the disease. Interventions that aim to enhance adherence may confer cost-effectiveness benefits in some indications and settings, and good adherence can help payers and providers contain costs by extracting maximum value from their investment in therapies.     

The impact of persistence with therapy on inpatient admissions and emergency room visits in the US among patients with multiple sclerosis

Objective:

Disease-modifying therapy (DMT) for multiple sclerosis (MS) can reduce relapses and delay progression; however, poor adherence and persistence with DMT can result in sub-optimal outcomes. The associations between DMT adherence and persistence and inpatient admissions and emergency room (ER) visits were investigated.

Methods:

Patients with MS who initiated a DMT in a US administrative claims database were followed for 1 year. Persistence to initiated DMT was measured as the time from DMT initiation to discontinuation (a gap of >60 days without drug ‘on hand’) or end of 1-year follow-up. Adherence to initiated DMT was measured during the persistent period and was operationalized as the medication possession ratio (MPR). Patients with an MPR <0.80 were considered non-adherent. Claims during the 1-year follow-up period were evaluated for the presence of an all-cause inpatient admission or an ER visit. Adjusted odds ratios (AORs) for inpatient admission or ER visit comparing persistent vs non-persistent and adherent vs non-adherent patients were estimated using logistic regression models adjusted for patient characteristics.

Results:

The final sample included 16,218 patients. During the 1-year follow-up period, 35.3% of patients discontinued their initiated DMT and 13.9% were not adherent while on therapy. During that same period, 10.0% of patients had an inpatient admission and 24.9% had an ER visit. The likelihoods of inpatient admission and ER visit were significantly decreased in persistent patients (AOR [95% CI]?=?0.50 [0.45, 0.56] and 0.65 [0.60, 0.69], respectively) and in adherent patients (AOR [95% CI]?=?0.83 [0.71, 0.97] and 0.86 [0.77, 0.95], respectively).

Conclusions:

Persistence and adherence with initiated DMT are associated with decreased likelihoods of inpatient admission or ER visit, which may translate to improved clinical outcomes.     

Medication adherence and discontinuation of long-acting injectable versus oral antipsychotics in patients with schizophrenia or bipolar disorder

Aims: To examine medication adherence and discontinuation in two separate groups of patients with schizophrenia or bipolar disorder (BD), who began receiving a long-acting injectable antipsychotic (LAI) versus those who changed to a different oral antipsychotic monotherapy.

Materials and methods: The Truven Health Analytics MarketScan Multi-State Medicaid claims database was used to identify patients with schizophrenia; Truven Health Analytics MarketScan Commercial and Medicaid claims databases were used to identify patients with BD. The analyses included adult patients (≥18 years) who either began receiving an LAI (no prior LAI therapy) or changed to a different oral antipsychotic (monotherapy). The first day of initiating an LAI or changing to a new oral antipsychotic was the index date. Linear and Cox regression models were conducted to estimate medication adherence (proportion of days covered [PDC]) and time to medication discontinuation (continuous medication gap ≥60 days), respectively. Models adjusted for patient demographic and clinical characteristics, baseline medication use, and baseline ED or hospitalizations.

Results: Patients with schizophrenia (N?=?5638) who began receiving LAIs had better medication adherence (5% higher adjusted mean adherence) during the 1 year post-index period and were 20% less likely to discontinue their medication during the entire follow-up period than patients who changed to a different oral antipsychotic monotherapy, adjusting for differences between LAI users and oral users. Similarly, patients with BD (N?=?11,344) who began receiving LAIs also had 5% better medication adherence and were 19% less likely to discontinue their medication than those using oral antipsychotics.

Limitations: Clinical differences unmeasurable in this database may have been responsible for the choice of LAI versus oral antipsychotics, and these differences may be responsible for some of the adherence advantages observed.

Conclusions: This real-world study suggests that patients with schizophrenia or BD who began receiving LAIs had better medication adherence and lower discontinuation risk than those who changed to a different oral antipsychotic monotherapy.