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Logo of nihpaAbout Author manuscriptsSubmit a manuscriptHHS Public Access; Author Manuscript; Accepted for publication in peer reviewed journal;
 
J Rheumatol. Author manuscript; available in PMC 2013 November 3.
Published in final edited form as:
PMCID: PMC3815617
NIHMSID: NIHMS505317

Cost-Related Medication Nonadherence in Older Rheumatoid Arthritis Patients

Abstract

Objectives

Economic access to costly medications including biologic agents can be challenging. Our objective was to examine whether patients with rheumatoid arthritis (RA) are at particular risk for cost-related medication nonadherence (CRN) and spending less on basic needs.

Methods

We identified a nationally-representative sample of older adults with RA (n=1100) in the (2004–2008) Medicare Current Beneficiary Survey and compared them to older adults with other morbidities categorized by chronic disease count: 0 (n=5,898), 1–2 (n=30,538), and ≥ 3 (n=34,837). We compared annual rates of self-reported CRN (skipping or reducing medication doses or not obtaining prescriptions due to cost) as well as spending less on basic needs to afford medications and tested for differences using survey-weighted logistic regression analyses adjusted for demographic characteristics, health status, and prescription drug coverage.

Results

In the RA sample, the unadjusted weighted prevalence of CRN ranged from 20.7% in 2004 to 18.4% in 2008 as compared to 18.5% and 11.9% respectively in patients with 3 or more nonRA conditions. In adjusted analyses having 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 2.5-fold risk of spending less on basic needs (OR: 2.41; 95% CI 1.78–3.25) as compared to those without a chronic condition.

Conclusions

Patients with RA experience a high prevalence of CRN and forgoing basic needs that is greater than that of older adults with multiple chronic conditions and did not improve during a period of policy change aimed at alleviating high drug costs.

Keywords: rheumatoid arthritis, biologics, disease modifying anti-rheumatic drugs, costs, adherence

Introduction

Rheumatoid arthritis (RA) is a chronic, inflammatory condition that affects 1.3 million Americans.(1) There is growing evidence that earlier and more aggressive treatment of RA with nonbiologic and biologic disease modifying anti-rheumatic drugs (DMARDs) reduces symptoms of the condition and slows disease progression.(23) The majority of RA patients are first treated with a traditional nonbiologic DMARD, which are typically oral medications taken daily. Patients with an inadequate response are often switched to a biologic or a biologic is added to their current therapy in order to achieve better control. Current biologic agents are only available as intravenous infusions or subcutaneous injections; most are administered over a range of 1 to 8 weeks. The exception is rituximab, which is given as 2 infusions separated by 2 weeks and repeated every 4 to 6 months. Biologic agents are expensive with average monthly costs ranging from $933–$2,748 in 2010.(4) This is in comparison to methotrexate, the most commonly used nonbiologic DMARD, which costs approximately $48 per month.(56)

Affording medications can be a challenge for older Americans. Several large surveys have reported cost-related medication nonadherence (CRN) to be a common problem affecting 13 to 29% of elderly patients.(79) Specifically, some patients will skip doses, reduce doses, or let prescriptions go unfilled for financial reasons. In addition, they may forego basic needs to afford medications including spending less on food, heat or other basic needs to afford medications. To address the challenges older Americans face in paying for chronic medications, Congress passed the Medicare Prescription Drug Improvement and Modernization Act in the fall of 2003. This Act established and subsidized a temporary drug benefit for self-administered agents including biologic DMARDs (called The Medicare Replacement Drug Demonstration program, which lasted from 2004 to 2005), and the Medicare Part D benefit, which became available in January 1, 2006. One goal of this legislation was to improve access to self-administered medications while decreasing the need for infused agents. Self-injectable biologic DMARDs are covered by Part D; however, their specialty status requires higher cost-sharing for RA patients enrolled in Part D plans (on average 26–28% of the medication price) as compared to nonbiologic DMARDs which are covered using traditional and generally lower copayments.(10)

There is little known regarding the rates of CRN in patients with RA as compared to those without and how they have changed during this time of dramatic policy change with respect to medication coverage. In this report we examined changes in the prevalence of CRN and spending less on basic needs (e.g., food) to afford medications among a nationally-representative community-dwelling cohort of Medicare enrollees based on the presence of RA in comparison to the number of nonRA diagnoses. We identified Medicare enrollees who participated in the Medicare Current Beneficiary Survey (MCBS) between 2004 and 2008. The purpose of our study was to assess the association of RA with CRN in a national sample of Medicare patients over time. In light of the costs associated with the treatment of rheumatoid arthritis, we hypothesized that the rates of CRN and spending less on basic needs would be higher in patients with RA as compared to those without.

Materials and Methods

Data Source

The Medicare Current Beneficiary Survey (MCBS) is a continuous face-to-face panel survey of a representative national sample of Medicare beneficiaries conducted by the Center for Medicare and Medicaid Services (CMS).(11) Since 1991, the MCBS has provided detailed longitudinal data on annual samples of approximately 15,700 Medicare beneficiaries. The rich variety of measures includes demographic information, income, health status and function, health behaviors, insurance coverage, drug coverage, health services utilization and cost. Medicare enrollment data and fee-for-service claims are also included.

The sample has a 4-year rotating panel design with staggered replenishments. Respondents are interviewed in person three times a year using Computer Assisted Personal Interviewing (CAPI), resulting in very high response rates (initially ~85%, average >70% during the observation period). We included all community dwelling respondents (>90% of all respondents) where administrative claims were available (>80% of community dwelling respondents). Accounting for overlap among years, the total number of individual respondents in this study was 32,857.

Our unit of analysis was the individual person-year. We identified patients with RA based on two administrative claims with the diagnosis (ICD-9 714.XX) per year of interest and classified the remaining patients as those without RA based on self-reported comorbidity burden (0, 1 to 2 and ≥3 self-reported nonRA conditions). CRN was our primary outcome measure of interest and was based on response to questions developed by members of the study team and implemented in the MCBS since 2004.(9) These measures have been shown to be valid and reliable measures of cost-related nonadherence.(79) As in previous studies, we constructed a summary indicator of CRN for analysis that took the value of “yes” if a respondent indicated yes/ever during the current year to any of the following “skipped doses to make the medicine last longer,” “taken smaller doses of a medicine to make the medicine last long,” or “any medicine prescribed for you that you did not get" in combination with “(a reason or the main reason) you did not obtain the medication was you thought it would cost too much” or "decided not to fill or refill a prescription because it was too expensive.”(9,1214) In addition, we examined spending less on basic needs as a separate indication of hardship related to medication costs based on a “yes” response to the question of whether they “spent less money on food, heat or other basic needs so that you would have money for medicine.”

We also examined demographic and clinical characteristics from the MCBS that could potentially influence medication adherence over time including sex, age group (<55, 55–64, 65–74, 75–84 and 85+), disability status, income (<$25,000 and ≥$25,000/year), race (black, white, Hispanic, other), education attainment (above high school, high school diploma, no diploma), prescription drug coverage (none, partial, full private [employer] and full public [Medicaid and Part D]), count of self-reported non-RA conditions (0, 1 to 2, and 3+) and a measure of self-rated health dichotomized into fair or poor vs good, very good or excellent.

All measures were collected in each study year, thus a respondent’s status on time varying characteristics could change during the study period. We controlled for the interview sequence as preliminary analyses revealed that the reported prevalence of CRN and spending less on basic needs was higher during the initial MCBS interview than in subsequent annual interviews.

Statistical Analysis

We compared the demographic and clinical characteristics among Medicare beneficiaries with RA separately among those with 0, 1 to 2 and ≥3 self-reported nonRA conditions in 2004, 2005, 2006, 2007 and 2008 using descriptive statistics. The results were weighted to represent the entire noninstitutionalized Medicare population using annual cross-sectional survey weights provided in the MCBS. Next we examined the relationship between morbidity burden (RA and 0, 1 to 2 and ≥3 self-reported nonRA conditions) and the unadjusted prevalence of CRN in 2004, 2005, 2006, 2007 and 2008 using chi square statistics. The absolute and relative decrease in CRN over time in the RA and nonRA populations were calculated. Using logistic regression we examined trends in CRN over time in the RA and nonRA populations. We evaluated whether morbidity burden was associated with CRN after controlling for year, interview sequence, demographic characteristics, and socioeconomic status. All models used MCBS cross-sectional survey weights.(15) We corrected for the clustering at the primary sampling unit level inherent in the MCBS design, thereby also controlling for repeated responses by individuals over time.(16) The odds of forgoing basic needs were modeled separately using the same approach. We assessed the robustness of our results by conducting an alternative analysis which adjusted for repeated measures on the same individuals across survey years by using unweighted general estimated equation regression models. In addition, we reran all the analyses using only those patients with drug coverage to see if that influenced the results. Lastly, we evaluated the prevalence of CRN and spending less on basic needs in RA patients as compared to those without the condition controlling for the number of non-RA comorbid conditions in both groups. All analyses were conducted using SAS version 9.2 and the a priori level of statistical significance was p=0.05. This study was reviewed and approved by the Institutional Review Board at the University of Massachusetts.

Results

Our sample size included 14,498 beneficiaries in 2004, 14,699 in 2005, 14,731 in 2006, 14,804 in 2007 and 13,651 in 2008. Annually, 1.4 to 1.7% of beneficiaries had a diagnosis of RA (range 184 to 241). The vast majority (>95%) of RA patients had at least 1 comorbid condition. As shown in Table 1, in 2004 patients with RA were more likely than those without to be female, and have more generous prescription drug coverage. For every year of the study period, RA patients as compared to those with 0 morbid condition, were more likely to be female, older and in poor health. As compared to those with 1–2 nonRA conditions, RA patients were more likely to be female and in poor health. Lastly, RA patients differed in terms of gender only with patients with 3 or more nonRA conditions. By 2008, the end of the study period, the proportion of Hispanic and nonHispanic black RA patients increased (18.4% vs. 26.1% in 2008, p=0.03). In both RA and nonRA patients fewer patients reported an annual income of less than $25,000 a year by the end of the study period and prescription drug coverage improved (Table 1).

Table 1
Baseline characteristics of Medicare beneficiaries with and without rheumatoid arthritis (RA) stratified by number of comorbid conditions in 2004 and 2008.

As shown in Figure 1, the absolute decrease in CRN was 2.2% in RA patients as compared to 4.0%, 5.3% and 6.5% in those with 0, 1–2, and ≥3 nonRA conditions respectively. The relative decrease in CRN was 10.8% in those with RA as compared to 54.0%, 40.5% and 35.5% in those with 0, 1–2, and ≥3 nonRA conditions respectively. The trend in CRN over time was significant in those with 0 (p=0.007), 1–2 (p=<0.0001), and ≥3 (p=<0.0001) nonRA conditions.

Figure 1
Prevalence of cost-related medication nonadherence between 2004 and 2008 in those with and without rheumatoid arthritis (RA).*

The proportion of patients reporting that they spent less on basic needs in order to pay for medications is shown in Figure 2. Overall fewer reported forgoing basic needs than reported CRN. Among the RA patients, from 2004 to 2008 the absolute decrease in spending less on basic needs was 1.9%. It was 4.3%. 3.7% and 4.4% in those with 0, 1 to 2 and ≥3 nonRA conditions respectively. The relative decrease in spending less on basic needs was 13.8% in those with RA as compared to 74.7%, 46.1% and 31.9% in those with 0, 1 to 2 and ≥3 nonRA conditions respectively. The trend in spending less on basic needs over time was significant for for those with 0 (p=0.0002), 1–2 (p=<0.0001), and ≥3 (p=<0.0001) nonRA conditions.

Figure 2
Prevalence of spending less on basic needs between 2004 and 2008 based on morbidity burden.*

Table 2 shows the unadjusted and adjusted analyses examining factors associated with CRN. In adjusted analyses, RA increased the likelihood of CRN by 3.5-fold (OR 3.52; 95% CI 2.63–4.71) with a greater magnitude of effect than having 1–2 or ≥3 nonRA conditions (OR 2.20; 95% CI 1.84–2.63 and OR 3.12; 95% CI 2.56–3.80 respectively). Similarly, RA was associated with a greater likelihood on spending less on basic needs in adjusted analyses (OR 2.41; 95% CI 1.78–3.25) (Table 3). The likelihood of spending less in those with 1–2 or ≥3 nonRA conditions was increased but the effect was less pronounced (OR 1.75; 95% CI 1.39–2.21 and OR 2.38; 95% CI 1.80–3.14respectively). The results were similar when limiting the population to those with drug coverage as well as adjusting for repeated measures on the same individuals across survey years using unweighted general estimated equation regression models. In analyses evaluating the impact of a diagnosis of RA alone after controlling non-RA comorbid conditions, we found that RA was associated with CRN (OR 1.25; 95% CI 1.01–1.55) and spending less on basic needs (OR 1.08; 95% CI 0.85–1.37).

Table 2
Unadjusted and adjusted analyses examining predictors of cost-related nonadherence (CRN).
Table 3
Unadjusted and adjusted analyses examining predictors of spending less on basic needs in order to afford medications.

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 as compared 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 as compared to those without RA. During the study time period, patients with RA had no improvements in CRN and spending less on basic needs to afford medications, and the rates in RA have been the highest found to date among Medicare beneficiaries (9,1314,17) with RA being associated with a 3.5-fold increase in the risk of CRN (OR: 3.52; 95% CI: 2.63–4.71) and almost 2.5- fold risk of spending less on basic needs (OR: 2.41; 95% CI 1.78–3.25) in adjusted analyses as compared to those without a chronic condition.

Patients with RA are particularly at risk for CRN and forgoing basic needs in order to pay for medications because the condition is expensive to treat and may also result in underemployment or work disability.(1819) The vast majority of RA patients 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 $20,000.(20) Prior to 2006, the traditional Medicare benefit package did not cover outpatient prescription drugs. Thus options for Medicare beneficiaries with chronic conditions including 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 replace the need for infused drugs covered under Medicare Part B such as infliximab (called The Medicare Replacement Drug Demonstration program, which lasted from 2004 to 2005) and 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 as 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 DMARDs which provided access to those without insurance but shifted costs to the patients as the specialty status of the biologic DMARDs required higher cost-sharing for RA patients enrolled in Part D plans.(10)

While the introduction of Medicare Part D has been associated with reductions in out-of-pocket expenditures for Medicare beneficiaries overall,(13,17) this has not been greatly explored in RA. Our prior work has suggested these expenses have stabilized with annual out-of-pocket costs of $842 in 2000 and $832 in 2006 (p=0.68)for patients with RA.(21) 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 annually.(10) This has therapeutic implications. Research has shown that drug benefit generosity influences the likelihood RA patients will initiate and continue a biologic agent.(22) Medication nonadherence as well as foregoing optimal medical treatment adversely affects health outcomes.(23) Our research suggests that RA patients are exceptionally sensitive to cost sharing. Policy makers may wish to consider tailored benefit designs to encourage better medication adherence for the RA patient population.(24)

Rheumatologists and primary care providers who care for patients with rheumatoid arthritis 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 plains accordingly. Unfortunately, while most patients and providers agree that discussion of out-of-pocket costs is important, they occur infrequently.(25) Specifically, rheumatologists were found to discuss medication costs in only one-third of visits where drug therapy was being changed.(26) Additionally communication about medication costs was less frequent in nonwhite and low income patients.(26) 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), over the self-administered agents covered under Part D in which patients pay on average 26–28% of the medication price.

The strength of this 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 nonRA conditions. These data also provide evidence of unintended drug cost reduction strategies such as spending less on basic needs on the part of patients in order to afford their medications which is concerning. This study has several limitations. While RA was significantly associated with CRUM and foregoing basic needs, the confidence intervals for the estimates presented in Figures 1 and and22 were overlapping due to 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.(2728)

In summary, we found that RA patients 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. This study highlights the importance of carefully monitoring the impact of recent policy changes in patients at high risk for CRN due to the clinical consequences of the disease as well as the associated treatments. In addition, providers need to be aware of the prevalence of CRN in patients with RA in order to tailor therapy keeping in mind both clinical and financial goals.

Acknowledgments

Funding: This work was supported by NIA (R01AG022362 and R01AG028745). Dr. Harrold was supported by Grant Number K23AR053856 from the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Dr. Briesacher was supported by a Research Scientist Development Award from the National Institute on Aging (K01AG031836). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Arthritis and Musculoskeletal and Skin Diseases, the National Institute on Aging or the National Institutes of Health.

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