Cost-related Medication Nonadherence in Older Patients with Rheumatoid Arthritis

DISCUSSION

This study is the first to our knowledge that has examined medication nonadherence due to cost and forgoing basic needs in patients with RA as compared to those without the condition, using the largest face-to-face panel survey of Medicare enrollees. We found that unadjusted rates of CRN were worse in those with RA compared to those without, even when compared to those with 3 or more morbid conditions. In addition, relative and absolute decreases in CRN were much smaller in the RA population compared to those without RA. During the study time period, patients with RA had no improvements in CRN and in spending less on basic needs to afford medications, and the rates in RA have been the highest found to date among Medicare beneficiaries^9,13,14,17. RA was associated with a 3.5-fold increase in the risk of CRN (OR 3.52, 95% CI 2.63–4.71) and almost a 2.5-fold risk of spending less on basic needs (OR 2.41, 95% CI 1.78–3.25) in adjusted analyses compared to those without a chronic condition.

Patients with RA are particularly at risk for CRN and forgoing basic needs to pay for medications because the condition is expensive to treat and may also result in underemployment or work disability^18,19. The vast majority of patients with RA require chronic therapy with medications. For patients who do not adequately respond to nonbiologic disease-modifying drugs, biologic agents are suggested, and they are costly. In 2006, the average annual costs of biologics for the treatment of RA were $15,000 to $20,000²⁰. Prior to 2006, the traditional Medicare benefit package did not cover outpatient prescription drugs. Thus options for Medicare beneficiaries with chronic conditions such as RA included drug coverage through employer-sponsored supplemental insurance, individually purchased Medigap plans, Medicare health maintenance organization plans, or public programs such as Medicaid and state pharmacy programs.

To address this gap in coverage, the 2003 Medicare Modernization Act (MMA) established a temporary drug benefit for self-administered agents such as etanercept and adalimumab for the treatment of RA. One goal of the MMA was to remove the need for infused drugs covered under Medicare Part B such as infliximab [called the Medicare Replacement Drug Demonstration (MRDD) program, 2004 to 2005] and to improve access to self-injectable biologics including etanercept and adalimumab. It was hoped that by extending Medicare coverage, Medicare beneficiaries would have added convenience (receipt of their medication at home rather than in an infusion center or doctor’s office), improved health outcomes by enabling access to other biologic agents, and reduced financial barriers to self-administered medications. Specifically, the costs of many of the self-administered medications covered under the demonstration program were previously prohibitive — they exceeded $20,000 a year for those without supplemental drug coverage. In 2006, the Medicare Part D prescription drug plan began covering oral and self-administered nonbiologic and biologic DMARD, a move that provided access to those without insurance but shifted costs to the patients as the specialty status of the biologic DMARD required higher cost-sharing for patients with RA enrolled in Part D plans¹⁰.

While the introduction of Medicare Part D has been associated with reductions in out-of-pocket expenditures for Medicare beneficiaries overall^13,17, this shift has not been greatly explored in RA. Our previous work suggested that these expenses have stabilized, with annual out-of-pocket costs of $842 in 2000 and $832 in 2006 (p = 0.68) for patients with RA²¹. Among vulnerable, low-income patients with RA enrolled in the MRDD and transitioned to Part D in 2006, costs have been shifted to the beneficiary, with out-of-pocket costs exceeding $4000 annually¹⁰. This has therapeutic implications. Research has shown that drug benefit generosity influences the likelihood that patients with RA will initiate and continue a biologic agent²². Medication nonadherence as well as forgoing optimal medical treatment adversely affects health outcomes²³. Our research suggests that patients with RA are exceptionally sensitive to cost-sharing. Policy makers may wish to consider tailored benefit designs to encourage better medication adherence for the RA patient population²⁴.

Rheumatologists and primary care providers who care for patients with RA should be aware of the financial obstacles involved in medication initiation and adherence and raise these issues with patients. Patients and their providers should have open and honest conversations about the clinical risks and benefits of medication therapy as well as the associated costs, and alter therapeutic plans accordingly. Unfortunately, while most patients and providers agree that discussion of out-of-pocket costs is important, it occurs infrequently²⁵. Specifically, rheumatologists were found to discuss medication costs in only one-third of visits where drug therapy was being changed²⁶. Additionally, communication about medication costs was less frequent with nonwhite and low-income patients²⁶. Clearly, providers need to raise these issues with all patients regardless of race and socioeconomic status when initiating therapy and again during the course of therapy, particularly as patients approach gaps in coverage (for example the Part D “doughnut hole”). Some providers may preferentially decide to prescribe infused agents, which may be covered more generously under Medicare Part B (typically patients are responsible for 20% of the costs), rather than the self-administered agents covered under Part D, in which patients pay on average 26%–28% of the medication price.

The strength of our study is that it used well-validated measures to provide detailed estimates of CRN among a nationally representative population. Additionally, we are able to compare rates of CRN and a closely related measure of hardship among patients with RA in contrast to those with multiple non-RA conditions. These data also provide evidence of unintended drug cost reduction strategies such as patients spending less on basic needs to afford their medications, which is worrisome.

Our study has several limitations. While RA was significantly associated with CRN and forgoing basic needs, the confidence intervals for the estimates presented in Figures 1 and 2 were overlapping because of the heterogeneity of the populations and sample sizes involved. We were unable to systematically assess which medications were affected by CRN and which medications were continued. In addition, we do not know what component of having RA contributed to the higher risk of CRN and spending less on basic needs, for example, whether it was the costs of specific medications or costs associated with other medical care. As with all studies using ICD-9 codes to identify patients, misclassification is a concern. However, studies using Medicare claims have reported a sensitivity of 65% to 90% for RA and a high positive predictive value^27,28.

We found that patients with RA are at much greater risk for CRN than Medicare beneficiaries with other morbid conditions. The extra burden of CRN is due, in part, to the multiple comorbidities associated with this costly condition. Additionally, economic access to medications has not improved for those with RA, while it has for those without the condition. The Medicare drug benefit is a complex program and clearly not all patient populations are receiving equal benefits. Our study highlights the importance of carefully monitoring the effect of recent policy changes on patients at high risk for CRN because of the clinical consequences of the disease as well as the associated treatments. In addition, to tailor therapy, providers need to be aware of the prevalence of CRN, keeping in mind both clinical and financial goals.