Abstract
Objective
To assess potential impacts of formulary tier increases of apixaban—an efficacious oral anticoagulant (OAC) for preventing stroke in patients with atrial fibrillation (AF)—on patients’ prescription drug plan (PDP) switching and OAC treatment patterns.
Methods
Nationwide claims data for Medicare beneficiaries with Parts A, B, and D (100% sample) were used to assess apixaban-treated AF patients who faced a formulary tier increase for apixaban in 2017 by their Part D PDP. Patients’ out-of-pocket (OOP) costs for apixaban were described, along with PDP switching and OAC treatment patterns.
Results
Among 1845 included patients, 97.7% had apixaban on tier 3 of their plan’s formulary in 2016 and faced its increase to tier 4 for 2017. Approximately 4% (N = 81) of patients pre-emptively switched to a different PDP for 2017 with almost all switching to plans with apixaban on a lower formulary tier and 85.2% continuing apixaban treatment. Among the 96% (N = 1764) of patients who remained on the same PDP for 2017, over half (57.5%) continued apixaban treatment, despite increased OOP costs ($54 vs. $135 for a 30-day supply in 2016 vs. 2017). Only 12.4% of those who remained on the same plan for 2017 switched to another OAC, while as much as 30.1% discontinued OACs. These discontinuers exhibited higher comorbidity burdens than patients continuing on any OAC.
Conclusion
The majority of patients continued on apixaban despite higher OOP cost, suggesting patients’ reluctance to change treatment for non-medical reasons; however, 30% of patients discontinued OAC treatment after higher apixaban tier placement.
Introduction
Formulary tiers and patient cost sharing play essential roles in insurance benefit design, helping payers to control spending and preventing patients from overuse of treatments when they bear less than the full cost of treatmentCitation1. Formulary tiers have also become increasingly important negotiation tools for payers and pharmacy benefit managers to entice greater rebates from manufacturers in exchange for “preferred” tier placementCitation2,Citation3. These rebates can, in turn, lower payer costs, potentially enabling reductions in patient premiumsCitation2,Citation3. However, formulary-specified copayments and coinsurance can also act as financial barriers to treatment and present serious financial hardship to patientsCitation4–8. Such impacts can be particularly profound for older patients; these individuals frequently shoulder larger illness burdens with multiple chronic conditions while also having more modest incomesCitation9. Even with insurance coverage, treatments can be difficult for them to afford, despite often being considered nondiscretionary. Moreover, traditional Medicare has not capped patients’ annual out-of-pocket spending (in contrast to most Medicare Advantage plans), leaving seriously ill beneficiaries exposed to considerable financial riskCitation10. Additionally, it should be noted that Medicare patients are prohibited by the Federal Anti-Kickback Statute from using drugmakers’ copay assistance programs like coupons or copay cards to help defray their out-of-pocket costs for prescription medicationsCitation11. (The statute does not apply to patients in non-federal healthcare programs.)
In the face of treatment affordability challenges, patients may respond in different ways. Some may respond with non-adherence to treatment recommendations, including delaying treatment or skipping doses to reduce out-of-pocket costs. Others may even forgo treatment altogether, risking their health and potentially increasing costs to payers from inadequate disease management. Still, others may elect to continue treatment but face financial difficulties, including having to forgo other necessities or risking major medical debt. Finally, some patients, if able, may switch health plans to try to stay on their treatment at lower out-of-pocket costs or attempt to petition their plan for a formulary tier exception.
In a recent published paper, we presented a descriptive analysis of apixaban-treated patients with traditional Medicare coverage who faced formulary exclusion of apixaban by their Part D prescription drug plan (PDP) in 2017Citation12. Apixaban is an oral anticoagulant (OAC) with established efficacy/effectiveness and safety for preventing stroke and systemic embolism (SE), potentially life-threatening events, in patients with atrial fibrillation (AF)Citation13–27. In this article, we address a related subgroup—apixaban-treated patients who faced a formulary tier increase for apixaban by their PDP in 2017. In this companion piece to the previously published articleCitation12, we examine the potential impacts of formulary tier increases for apixaban in patients with AF. In particular, we focus on apixaban-treated patients with AF who had traditional Medicare coverage and faced a formulary tier increase for apixaban in 2017, a year in which multiple PDPs enacted such changes. We describe these patients’ tier increases for apixaban and estimate the increase in their out-of-pocket costs for apixaban. We also describe these patients’ observed behaviors, including treatment patterns and pre-emptive switching to a different PDP.
Methods
Data source and study sample
Nationwide administrative claims data for Medicare beneficiaries with Parts A, B, and D (100% sample) were used from the Centers for Medicare and Medicaid Services. For inclusion in the study sample, patients were required to meet the following eligibility criteria: 1) initiated on apixaban between January 2013– December 2016; 2) continuous apixaban treatment from initiation through December 31, 2016, defined as no supply gaps >30 days; 3) ≥1 diagnosis code for AF during the years of available data (2012–2018); 4) no codes for hip or knee replacement surgery during the 6 weeks prior to apixaban initiation or codes for transient AF, valvular heart disease, venous thromboembolism, or mechanical valve replacement during the 12 months prior to apixaban initiation; 5) continuous enrollment in Medicare Parts A, B, and D from 12 months prior to apixaban initiation through 2017 or until death if occurring in 2017; and 6) enrolled in a PDP in 2016 (baseline period) that implemented a formulary tier increase for apixaban for 2017 (follow-up period). Patients were excluded if any of the following criteria were met: 1) enrolled in a PDP in 2016 that underwent termination, consolidation, or service area changes in 2017, which could have forced patients to switch PDPs or created uncertainties in their coverage; 2) treated with another OAC prior to apixaban; or 3) received special subsidies, which could exempt them from their PDP’s formulary tier cost-sharing levels.
Part D PDP switching and treatment patterns
The following outcomes were assessed: 1) the proportion of patients who pre-emptively switched to a different PDP for 2017 and the characteristics of their new plan, 2) the proportion of patients who elected to remain on their same PDP for 2017, 3) treatment patterns in 2017 among the two aforementioned groups of patients, including apixaban continuation, switching to another OAC (warfarin or non-vitamin K antagonist oral anticoagulants like rivaroxaban, dabigatran, or edoxaban), and discontinuation without switching to another OAC (). Patients were considered to have pre-emptively switched to a different PDP if they elected to switch from their 2016 Part D PDP to a different PDP for the 2017 benefit year during their open enrollment. Definitions for the treatment patterns are described in a previous articleCitation12.
Figure 1. Patients’ Part D prescription drug plan switching and treatment patterns. Abbreviations. OAC, oral anticoagulant (includes warfarin as well as non-vitamin K antagonist oral anticoagulants); LC, low count (number not shown due to data restrictions).
Formulary tier placement
Formulary tier placement of apixaban was assessed for patients in the study sample for 2016 and 2017 and stratified by whether patients switched to a different PDP for 2017 or remained on the same plan.
Patient out-of-pocket costs for apixaban
Patient out-of-pocket costs were estimated for a 30-day supply of apixaban for 2016 and 2017 among patients who continued on apixaban in 2017. Results were stratified by whether patients switched to a different PDP for 2017 or remained on the same plan. The Medicare Part D benefit is organized in 4 phases: 1) deductible, 2) initial coverage period (during which formulary tier cost-sharing levels apply), 3) coverage gap, and 4) catastrophic coverage. As patients move through these phases, the out-of-pocket amounts paid by them may vary. Given this, patient out-of-pocket costs were estimated using two approaches: 1) using the patient’s second observed apixaban claim for the year (to avoid effects from deductibles and gap and catastrophic phases) and 2) using all of the patient’s apixaban claims for the year (averaged spending taking into consideration deductible, formulary tier, and gap and catastrophic phase effects). For both calculation approaches, days of supply were obtained from the patient’s prescription drug claim(s) for apixaban. (For instance, estimates using the second approach were calculated as follows: [(sum of the patient’s out-of-pocket costs across their apixaban claims for the year)/(sum of the days of supply across the patient’s apixaban claims for the year)*30 days].) Estimates were inflation-adjusted to 2020 USD using the Personal Consumption Expenditures health index.
Patient characteristics
Demographics (age, sex, race, and region) as of January 2017 and clinical and treatment history characteristics over the baseline period (2016) were described for the study sample.
Patient characteristics were also described and compared between patients who discontinued versus continued any OAC treatment among those who remained on the same PDP for 2017. OAC continuers consisted of patients who continued on apixaban as well as patients who switched from apixaban to a different OAC. Categorical and continuous variables were compared using chi-square tests and t-tests, respectively.
Results
Study sample
In total, 1845 patients met the eligibility criteria. Among these patients, mean age was 79 years, and over half of the patients (53.8%, n = 992) were male. Mean Charlson comorbidity index (CCI) was 2.0, while mean CHA2DS2-VASc score was 4.3 and mean HAS-BLED score was 3.1. presents the full baseline characteristic results.
Table 1. Baseline characteristics of patients treated with apixaban at the end of 2016 who faced an upcoming formulary tier increase for apixaban by their Part D plan for 2017.
Formulary tier placement
In 2016, nearly all of the study patients (97.7%, n = 1803) had apixaban on tier 3 of their plan’s formulary and faced its increase to tier 4 for 2017. The remaining patients (2.3%, n = 42) had apixaban on tier 2 of their plan’s formulary in 2016 and faced its increase to tier 3 for 2017.
Part D PDP switching and patient out-of-pocket costs for apixaban
Of the 1845 patients included in this study, 81 patients (4.4%) pre-emptively switched to a different PDP for the 2017 benefit year (). Notably, nearly all switched to a PDP that had apixaban on tier 3 of its formulary, a lower tier than their previous plan would have for 2017.
For patients who pre-emptively switched to a different PDP for 2017 and continued treatment with apixaban, only small to negligible changes were experienced in out-of-pocket costs for apixaban from 2016 to 2017, consistent with their new plan’s tier placement for apixaban. For instance, mean out-of-pocket costs for a 30-day supply of apixaban remained relatively constant at $54 and $52 for 2016 and 2017, while the median corresponded to $49 and $45 for these years, respectively, using Approach 1. Small changes were similarly observed using Approach 2 ().
Figure 2. Patient out-of-pocket costs for a 30-day supply of apixaban in 2016 and 2017. Note. Patient out-of-pocket costs for a 30-day supply of apixaban were calculated using two approaches to provide a holistic picture of patients’ spending on apixaban: Approach 1: using the patient’s second observed apixaban claim for the year (to help isolate the impact of formulary tier placement and avoid effects from deductibles and other Part D benefit phases). Approach 2: using all of the patient’s apixaban claims for the year (to capture averaged spending throughout the year taking into consideration deductible, formulary tier, and other Part D benefit phase effects).
By contrast, for patients who remained on the same PDP for 2017 and continued treatment with apixaban, large increases in patient out-of-pocket costs occurred for apixaban consistent with apixaban’s increased tier placement (). For instance, mean out-of-pocket costs for a 30-day supply of apixaban increased from $54 to $135 from 2016 to 2017, while the median increased from $46 to $167 using Approach 1. Similar but less pronounced trends were observed using Approach 2, consistent with this measure’s construction, which also captured deductible, gap, and catastrophic coverage effects ().
Figure 3. Formulary tier placement of apixaban in 2016 and 2017 among patients who remained on the same Part D plan for 2017.
Treatment patterns
Treatment patterns of patients who pre-emptively switched to a different PDP for 2017 and those who remained on the same PDP for 2017 are presented in . Among the 81 patients who switched to a different PDP, the majority (85.2%, n = 69) continued treatment with apixaban. Among the remaining patients, almost none switched to another OAC, while the remaining patients (13.6%, n = 11) discontinued treatment. Among the 1764 patients who remained on the same PDP for 2017, over half (57.5%, n = 1015) continued on apixaban. Only 12.4% (n = 218) switched to another OAC, and as much as 30.1% (n = 531) discontinued treatment.
Figure 4. Treatment patterns in 2017 among patients who pre-emptively switched to a different Part D plan for 2017 versus patients who chose to remain on the same Part D plan for 2017. Abbreviations. LC, low count (number not shown due to data restrictions). OAC, oral anticoagulant. *All patients switched to a Part D plan with coverage of apixaban, and nearly all switched to a Part D plan that had apixaban on a lower formulary tier than their previous plan would have in 2017.
Characteristics of OAC discontinuers vs. continuers among patients who remained on the same Part D PDP for 2017
presents baseline characteristics of OAC discontinuers versus continuers among patients who remained on the same Part D PDP for 2017. Discontinuers exhibited a significantly higher comorbidity burden than continuers with a CCI of 2.2 versus 1.9 (p = .017) and a higher proportion with coronary artery disease (47.5% vs. 37.6%; p = .003). Discontinuers also had a significantly higher HAS-BLED score (3.2 vs. 3.0; p = .001) than continuers. Among other characteristics, discontinuers had a higher proportion who initiated apixaban in 2016 versus prior to 2016 (82.7% vs. 69.0%; p < .001), a higher proportion with baseline amiodarone use (14.1% vs. 9.0%; p = .049), and a lower proportion with baseline statin use (60.6% vs. 67.2%; p = .020) compared to continuers.
Table 2. Baseline characteristics of patients who remained on the same Part D plan for 2017 and experienced a formulary tier increase for apixaban—stratified by patients who continued versus discontinued treatment with any anticoagulant in 2017.
Discussion
The sizable proportion of patients who continued apixaban treatment regardless of whether they remained on the same PDP (and faced higher costs) suggests patients’ reluctance to change their treatment regimen. These trends align with those observed in our previous article which assessed the potential impacts of formulary exclusion of apixabanCitation12. There, we similarly observed that most patients continued apixaban treatment despite undergoing the additional hurdles of petitioning their PDP for formulary exception and potentially facing higher costs. Although the exact drivers are unclear, these actions may reflect patients’ unease with switching therapies for non-medical reasons. A considerable body of evidence has demonstrated apixaban to have a lower risk of major bleeding and a similar or lower risk of stroke/SE compared to other OACsCitation13–27.
The financial implications of apixaban’s increase from tier 3 to tier 4 of PDPs’ formularies are non-trivial. For most plans over 2016–2017, tier 3 corresponded to “preferred branded drugs” with flat copayments, while tier 4 corresponded to “non-preferred branded drugs” with considerable coinsurance ratesCitation28. For instance, a Kaiser Family Foundation study found that among the ten largest Part D PDPs in 2016–2017, seven utilized copayments for preferred branded drugs ranging from $21–$47 (median values) in 2016, while only three utilized coinsurance rates ranging from 16–20%Citation28. By contrast, all of these plans utilized coinsurance rates for non-preferred drugs, ranging from 30% to as much as 50% (maximum permitted by CMS) over 2016–2017Citation28. These trends are borne out in the greatly increased apixaban costs for patients who remained on the same PDP for 2017 and continued treatment with apixaban. These cost increases raise the question of financial burden to these patients. In fact, when considering the average monthly Social Security benefit payable to retired workersCitation29,Citation30, the mean out-of-pocket costs for a 30-day supply of apixaban (Approach 2) rose from 5% to 9% of the average Social Security income from 2016 to 2017, while the median rose from 5% to 11%. Although Social Security benefits do not encompass the total resources that may be available to retirees (such as from pensions, 401 ks, IRAs, etc.), it is striking that after apixaban’s tier increase, for at least 50% of patients, the costs for apixaban alone totaled more than 10% of the average Social Security income without including any other healthcare expenses such as premiums, medical visits, or other medications. Indeed numerous studies have pointed to financial strains among seniors due to healthcare expensesCitation4–8. For instance, a recent West Health-Gallup survey found that approximately 25% of seniors reported cutting back on food, utilities, clothing, or medication due to healthcare costsCitation4. A 2017 Medicare Current Beneficiary Survey study found that 11% of Medicare beneficiaries reported difficulty affording healthcareCitation8. Concerningly, these affordability burdens were disproportionately concentrated among medically and socially vulnerable patients. For instance, older patients with 4–10 chronic conditions were more than twice as likely to have problems paying medical bills as those with 0–1 conditionCitation8. Additionally, near-poor individuals (annual incomes $15,000–$25,000)—who often don’t qualify for subsidies—had three times higher odds of problems paying medical bills compared to patients with annual incomes over $50,000Citation8.
The finding that 30% of patients discontinued OAC treatment after experiencing increased out-of-pocket costs for apixaban is concerning. Guidelines recommend continued use of OACs in patients with AF and elevated CHA2DS2-VASc scores of ≥2 in men and ≥3 in women to reduce stroke/SE riskCitation31. Discontinuation has been associated with a 2–3 times increased risk of ischemic strokeCitation32 as well as increased risk of myocardial infarction, and deathCitation33,Citation34. In fact, even temporary interruptions have been linked to an increased risk of thromboembolismCitation35. It is important to note that the discontinuers had high risk of stroke with a mean CHA2DS2-VASc score of 4.4, suggesting that stopping treatment could be detrimental for these patients. Additionally, these patients who discontinued OAC treatment had a higher comorbidity index than those who continued on any OAC. This finding aligns with other studies that have found patients to be more likely to skimp on medications to save money when they have more prescriptions or chronic conditions, revealing potential disparity issues that force the medically vulnerable to prioritize among their conditionsCitation4,Citation8.
Beyond clinical outcomes and disparity issues, potential costs related to the increased risk of cerebrovascular events associated with OAC discontinuation should also be taken into consideration. The economic burden of these events like stroke can be considerableCitation36, as strokes require intensive and prolonged management of multiple long-term sequelae such as musculoskeletal, psychosocial, and late medical complicationsCitation37,Citation38 often accompanied by long-term rehabilitation and nursing home careCitation39. A claims database analysis found the mean all-cause costs for Medicare patients in the twelve months following an acute ischemic stroke—the most common stroke subtype—to be $54,820Citation40, while another study estimated the mean lifetime costs of ischemic stroke to be $289,916Citation41, which include costs related to inpatient care, rehabilitation, and follow-up care. (For ease of interpretation, the numbers were converted to 2020 dollars by use of the medical component of the Consumer Price Index.) These cost estimates are likely underestimates for our focal subgroup given that AF-related strokes tend to be more severe than non-AF-related strokesCitation42,Citation43. Moreover, our study’s OAC discontinuers exhibited significantly greater comorbidity burdens than patients continuing OAC treatment, potentially further increasing costs when cerebrovascular events arise. As such, possible increases in stroke events precipitated by OAC treatment discontinuation could undermine or possibly negate payers’ anticipated cost savings from formulary tier escalation of apixaban. Payers may want to reconsider strategies that push patients towards non-medically switching from medications like apixaban as these policies may inadvertently trigger treatment discontinuation, increasing the risk of severe adverse outcomes that incur higher costs.
Finally, our results suggest that a proportion of patients may have switched PDPs to avoid increased tier placement for apixaban. Although we cannot observe the exact reasons for their switch, nearly all of these patients switched to PDPs with apixaban on a lower formulary tier than their original plan. Moreover, the vast majority continued treatment with apixaban. Such beneficiary plan switching may have broad effects for Part D plans—plan switching and member satisfaction are determinants in Part D plans’ Medicare star ratingsCitation44. These ratings can, in turn, act as quality signals to prospective beneficiaries, impacting plans’ future member enrollment.
Limitations
Our analyses are subject to some limitations. First, the administrative claims used in our analysis do not capture reasons for patients’ PDP switches or treatment changes. Consequently, we cannot ascribe direct causality between formulary tier increases of apixaban and patients’ behaviors. However, patients’ switches to other PDPs with apixaban in a more favored tier indicate that apixaban tier increases may have been a driver for their plan switch. Second, out-of-pocket cost estimates for apixaban may reflect factors other than formulary tier placement due to the various phases of the Part D benefit—deductible, initial coverage period, coverage gap, catastrophic coverage—during which the amount paid by beneficiaries may vary. We have tried to mitigate this with two data handling approaches, providing a holistic picture of patient out-of-pocket costs. Finally, our analyses do not assess safety and effectiveness outcomes as these are beyond our analytic scope; these could represent areas for future research.
Conclusion
In this analysis, more than half of patients remained on apixaban after experiencing a formulary tier increase for apixaban, despite considerably increased out-of-pocket costs for apixaban. Our results suggest that patients are generally reluctant to switch from apixaban for non-medical reasons. However, we also observed that as much as 30% of patients discontinued OAC treatment after experiencing a tier increase for apixaban, and these discontinuers tended to have greater comorbidity burdens. Alternative approaches are needed to balance the need to control healthcare spending with patient access to life-saving treatments.
Transparency
Declaration of financial/other relationships
Steven Deitelzweig (SD) has received consulting fees from BMS/Pfizer in connection with the development of this manuscript. Emi Terasawa (ET) is an employee of Analysis Group, Inc., which has received consulting fees from BMS/Pfizer in connection with the development of this manuscript. At the time of this study, Ahmed Noman (AN) was an employee of Analysis Group, Inc., which has received consulting fees from BMS/Pfizer in connection with the development of this manuscript. Nipun Atreja (NA), Amiee Kang (AK), Amol Dhamane (AD) and Melissa Hagan (MH) are employees of BMS and hold stock/options. Dionne M. Hines (DMH) and Xuemei Luo (XL) are employees of Pfizer and hold stock/options. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.
Author contributions
All authors have contributed to study concept and design, data analysis, or interpretation of the data. Emi Terasawa has drafted the manuscript; all authors have provided critical revisions. Ahmed Noman has provided statistical analysis support.
Acknowledgements
The authors would like to acknowledge David Steffen’s contributions in assisting with additional data investigations to support this manuscript.
Additional information
Funding
References
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