Generic alendronate use among Medicare beneficiaries: are Part D data complete?

Cost-Effectiveness of Sequential Teriparatide/Alendronate Versus Alendronate-Alone Strategies in High-Risk Osteoporotic Women in the US: Analyzing the Impact of Generic/Biosimilar Teriparatide

Teriparatide, currently only available in brand form in the United States, is a costly drug approved for the treatment of postmenopausal osteoporotic women who are at high risk of fracture. Because market exclusivity for brand teriparatide expired in August 2019 in the US, we sought to understand the potential health economic impact of the availability of generic or biosimilar (generic/biosimilar) teriparatide. We examined the cost‐effectiveness of daily teriparatide for 2 years followed by weekly alendronate for 10 years (ie, sequential teriparatide/alendronate) compared with alendronate alone for 10 years in community‐dwelling white osteoporotic women with prior vertebral fracture at ages 65, 70, 75, and 80. Using an updated version of previously validated Markov microsimulation models, we obtained incremental cost‐effectiveness ratios (ICERs) (dollars [$] per quality‐adjusted life year [QALY]) with a willingness‐to‐pay (WTP) of $150,000 per QALY from a societal perspective with a lifelong time horizon. In the base case, we estimated the annual cost of teriparatide to be $20,161, based on the assumption of 10% brand usage (at a cost of $27,618) and 90% generic/biosimilar usage (priced 30% lower than brand). The ICERs of sequential teriparatide/alendronate compared with alendronate alone were greater than $280,000 per QALY at all ages examined. In deterministic sensitivity analyses, results were sensitive to teriparatide's cost, with the cost of a generic/biosimilar product needing to be 65% to 85% lower than brand for sequential teriparatide/alendronate to be cost‐effective. In probabilistic sensitivity analyses, under the assumption that the annual cost of teriparatide was $20,161, the probabilities of sequential teriparatide/alendronate being cost‐effective were less than 4% at a WTP of $150,000 per QALY. In conclusion, among community‐dwelling older osteoporotic women with prior vertebral fracture in the US, even with the potential availability of generic/biosimilar teriparatide, sequential teriparatide/alendronate would not be cost‐effective unless the cost of generic/biosimilar teriparatide were heavily discounted with respect to the current brand cost. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Influencers of generic drug utilization: A systematic review

INTRODUCTION

With an increase in prescription drug spending and rising drug costs there is a need to encourage the use of generic prescription drugs. However, maximizing generic drug use is not possible without the public's positive perception and meeting their informational needs about generic drugs. Thus, improving the public's confidence in, and knowledge of generic drugs on the market is critical. The objective of this systematic review is to examine and evaluate the studies focusing on the nature and extent of key factors influencing generic drug use in the United States in order to help guide policy, education and practice interventions.

MATERIALS AND METHODS

Using multiple search engines and key word screening criteria, empirical studies published in English between January 1, 2005 and December 31, 2015 were identified. A qualitative synthesis of the evidence identified domains of key factors that influenced generic drug use across studies.

RESULTS

Over 3000 citations met the key word screening criteria; 67 of these met inclusion criteria for the systematic review. Seven domains of factors that influence generic drug utilization were identified: 1) patient-related factors, 2) formulary management or cost containment, 3) healthcare policies, 4) promotional activities, 5) educational initiatives, 6) technology, and 7) physician-related factors.

CONCLUSION

Patients, physicians, pharmacists, formulary managers, and policymakers play an important role in generic drug use. Understanding the factors influencing generic drug use can help guide future policy, education, and practice interventions to increase generic drug use.

Statin Discontinuation, Reinitiation, and Persistence Patterns Among Medicare Beneficiaries After Myocardial Infarction: A Cohort Study

BACKGROUND

Although the benefits of statins accrue over time, treatment discontinuation is common. Examining the patterns of statin discontinuation, reinitiation, and persistence after reinitiation among Medicare beneficiaries after hospital discharge for a myocardial infarction may help increase statin use in high-risk patients.

METHODS AND RESULTS

Medicare beneficiaries with a statin fill claim within 30 days after hospital discharge for myocardial infarction in 2007 to 2012 (n=158 795) were followed for 182 days post-discharge to identify discontinuation, defined as 60 continuous days without statins available. Reinitiation, defined by a statin fill, was identified in the 365 days post-discontinuation. High persistence was defined as proportion of days covered ≥80% with ≥1 day of statin supply 182 days after reinitiation. Follow-up ended on December 31, 2014. In the 182 days after myocardial infarction hospital discharge, 15.4% of beneficiaries discontinued statins. Of this group, 53.7% reinitiated statins. On reinitiation, 27.1% changed statin type, 6.9% up-titrated intensity, 14.4% down-titrated intensity, and 66.0% had the same statin and intensity. In the 182 days after reinitiation, 45.8% had high persistence. Moderate- and high- versus low-intensity statins were associated with a lower risk for statin discontinuation (moderate intensity: relative risk [RR], 0.93; 95% confidence interval [CI], 0.89-0.96; high-intensity: RR, 0.95; 95% CI, 0.91-0.99). High persistence was less common after reinitiating high- versus low-intensity statins (RR, 0.80; 95% CI, 0.75-0.86), but no association was present for those reinitiating a moderate- versus low-intensity statin (RR, 0.95; 95% CI, 0.90-1.01). Down-titrating versus reinitiating the same statin intensity (RR, 1.10; 95% CI, 1.05-1.16) and reinitiating a different versus the same statin (RR, 1.10; 95% CI, 1.06-1.14) were associated with high persistence after treatment reinitiation.

CONCLUSIONS

Although many people who discontinue a statin reinitiate treatment, statin persistence after reinitiation was low. Reinitiating therapy with moderate-intensity statins, down-titration, and using a different statin may promote persistence.

Assessing the feasibility of the Effectiveness of Discontinuing Bisphosphonates trial: a pilot study

The Effectiveness of Discontinuing Bisphosphonates (EDGE) study is a planned pragmatic clinical trial to guide "drug holiday" clinical decision making. This pilot study assessed work flow and feasibility of such a study. While participant recruitment and treatment adherence were suboptimal, administrative procedures were generally feasible and minimally disrupted clinic flow.

INTRODUCTION

The comparative effectiveness of continuing or discontinuing long-term alendronate (ALN) on fractures is unknown. A large pragmatic ALN discontinuation study has potential to answer this question.

METHODS

We conducted a 6-month pilot study of the planned the EDGE study among current long-term ALN users (women aged ≥65 with ≥3 years of ALN use) to determine study work flow and feasibility including evaluating the administrative aspects of trial conduct (e.g., time to contract, institutional review board (IRB) approval), assessing rates of site and participant recruitment, and evaluating post-randomization outcomes, including adherence, bisphosphonate-associated adverse events, and participant and site satisfaction. We assessed outcomes 1 and 6 months after randomization.

RESULTS

Nine sites participated, including seven community-based medical practices and two academic medical centers. On average (SD), contract execution took 3.4 (2.3) months and IRB approval took 13.9 (4.1) days. Sites recruited 27 participants (13 to continue ALN and 14 to discontinue ALN). Over follow-up, 22% of participants did not adhere to their randomization assignment: 30.8% in the continuation arm and 14.3% in the discontinuation arm. No fractures or adverse events were reported. Sites reported no issues regarding work flow, and participants were highly satisfied with the study.

CONCLUSIONS

Administrative procedures of the EDGE study were generally feasible, with minimal disruption to clinic flow. In this convenience sample, participant recruitment was suboptimal across most practice sites. Accounting for low treatment arm adherence, a comprehensive recruitment approach will be needed to effectively achieve the scientific goals of the EDGE study.

Cost-effectiveness of combined oral bisphosphonate therapy and falls prevention exercise for fracture prevention in the USA

We developed a Markov microsimulation model among hypothetical cohorts of community-dwelling US white women without prior major osteoporotic fractures over a lifetime horizon. At ages 75 and 80, adding 1 year of exercise to 5 years of oral bisphosphonate therapy is cost-effective at a conventionally accepted threshold compared with bisphosphonates alone.

INTRODUCTION

The purpose of this study was to examine the cost-effectiveness of the combined strategy of oral bisphosphonate therapy for 5 years and falls prevention exercise for 1 year compared with either strategy in isolation.

METHODS

We calculated incremental cost-effectiveness ratios [ICERs] (2014 US dollars per quality-adjusted life year [QALY]), using a Markov microsimulation model among hypothetical cohorts of community-dwelling US white women with different starting ages (65, 70, 75, and 80) without prior history of hip, vertebral, or wrist fractures over a lifetime horizon from the societal perspective.

RESULTS

At ages 65, 70, 75, and 80, the combined strategy had ICERs of $202,020, $118,460, $46,870, and $17,640 per QALY, respectively, compared with oral bisphosphonate therapy alone. The combined strategy provided better health at lower cost than falls prevention exercise alone at ages 70, 75, and 80. In deterministic sensitivity analyses, results were particularly sensitive to the change in the opportunity cost of participants' time spent exercising. In probabilistic sensitivity analyses, the probabilities of the combined strategy being cost-effective compared with the next best alternative increased with age, ranging from 35 % at age 65 to 48 % at age 80 at a willingness-to-pay of $100,000 per QALY.

CONCLUSIONS

Among community-dwelling US white women ages 75 and 80, adding 1 year of exercise to 5 years of oral bisphosphonate therapy is cost-effective at a willingness-to-pay of $100,000 per QALY, compared with oral bisphosphonate therapy only. This analysis will help clinicians and policymakers make better decisions about treatment options to reduce fracture risk.

Trends in Antihypertensive Medication Discontinuation and Low Adherence Among Medicare Beneficiaries Initiating Treatment From 2007 to 2012

Low antihypertensive medication adherence is common. During recent years, the impact of low medication adherence on increased morbidity and healthcare costs has become more recognized, leading to interventions aimed at improving adherence. We analyzed a 5% sample of Medicare beneficiaries initiating antihypertensive medication between 2007 and 2012 to assess whether reductions occurred in discontinuation and low adherence. Discontinuation was defined as having no days of antihypertensive medication supply for the final 90 days of the 365 days after initiation. Low adherence was defined as having a proportion of days covered <80% during the 365 days after initiation among beneficiaries who did not discontinue treatment. Between 2007 and 2012, 41 135 Medicare beneficiaries in the 5% sample initiated antihypertensive medication. Discontinuation was stable during the study period (21.0% in 2007 and 21.3% in 2012; P-trend=0.451). Low adherence decreased from 37.4% in 2007 to 31.7% in 2012 (P-trend<0.001). After multivariable adjustment, the relative risk of low adherence for beneficiaries initiating treatment in 2012 versus in 2007 was 0.88 (95% confidence interval, 0.83-0.92). Low adherence was more common among racial/ethnic minorities, beneficiaries with Medicaid buy-in (an indicator of low income), and those with polypharmacy, and was less common among females, beneficiaries initiating antihypertensive medication with multiple classes or a 90-day prescription fill, with dementia, a history of stroke, and those who reached the Medicare Part D coverage gap in the previous year. In conclusion, low adherence to antihypertensive medication has decreased among Medicare beneficiaries; however, rates of discontinuation and low adherence remain high.

Agreement between Medicare pharmacy claims, self-report, and medication inventory for assessing lipid-lowering medication use

BACKGROUND

Medicare claims have been used to study lipid-lowering medication (LLM) use among US adults.

METHODS

We analyzed the agreement between Medicare claims for LLM and LLM use indicated by self-report during a telephone interview and, separately, by a medication inventory performed during an in-home study visit upon enrollment into the REasons for Geographic And Racial Differences in Stroke (REGARDS) study. We included REGARDS participants ≥65 years enrolled in 2006-2007 with Medicare pharmacy benefits (Part D) from 120 days before their telephone interview through their medication inventory (n = 899).

RESULTS

Overall, 39.2% and 39.5% of participants had a Medicare claim for an LLM within 120 days prior to their interview and medication inventory, respectively. Also, 42.7% of participants self-reported using LLMs, and 41.8% had an LLM in their medication inventory. The Kappa statistic (95% confidence interval [CI]) for agreement of Medicare claims with self-report and medication inventory was 0.68 (0.63-0.73) and 0.72 (0.68-0.77), respectively. No Medicare claims for LLMs were present for 22.1% (95%CI: 18.1-26.6%) of participants who self-reported taking LLMs and 18.9% (15.1-23.3%) with LLMs in their medication inventory. Agreement between Medicare claims and self-report was lower among Black male individuals (Kappa = 0.34 [95%CI: 0.14-0.54]) compared with Black female individuals (0.70 [0.61-0.79]), White male individuals (0.65 [0.56-0.75]), and White female individuals (0.79 [0.72-0.86]). Agreement between Medicare claims and the medication inventory was also low among Black male individuals (Kappa = 0.48 [95%CI: 0.29-0.66]).

CONCLUSIONS

Although substantial agreement exists, many Medicare beneficiaries who self-report LLM use or have LLMs in a medication inventory have no claims for these medications. Copyright © 2016 John Wiley & Sons, Ltd.

Statin use following hospitalization among Medicare beneficiaries with a secondary discharge diagnosis of acute myocardial infarction

Background

Patients with coronary heart disease are recommended to use statins following hospital discharge. Acute myocardial infarction (AMI) is a common complication of hospitalization, but the use of statins following discharge among patients who were not initially hospitalized for AMI has not been assessed adequately.

Methods and Results

Using the Medicare 5% national random sample, we determined statin use among beneficiaries who were hospitalized and who had a secondary discharge diagnosis of AMI and among beneficiaries who had a primary discharge diagnosis of AMI, coronary artery bypass grafting, or percutaneous coronary intervention in 2007–2009. Statin use was defined by a pharmacy (Medicare Part D) claim within 90 days following discharge. Of 8175 Medicare beneficiaries who did not take statins prior to hospitalization, 31.2% with AMI as a secondary discharge diagnosis, 60.5% with AMI as the primary discharge diagnosis, 67.6% with coronary artery bypass grafting, and 63.9% with a percutaneous coronary intervention initiated statins. After multivariable adjustment, the risk ratio for statin initiation comparing beneficiaries with a secondary versus primary discharge diagnosis of AMI was 0.59 (95% CI 0.54 to 0.65). Among 5468 Medicare beneficiaries taking statins prior to hospitalization, statin use following discharge was lower for those with AMI as a secondary discharge diagnosis (71.8%) compared with their counterparts with AMI, coronary artery bypass grafting, and percutaneous coronary intervention (84.1%, 83.8%, and 87.3%, respectively) as the primary discharge diagnosis.

Conclusion

Medicare beneficiaries with a secondary hospital discharge diagnosis of AMI were less likely to fill statins compared with those with other coronary heart disease events.

Antihypertensive medication classes used among medicare beneficiaries initiating treatment in 2007-2010

Background

After the 2003 publication of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) guidelines, there was a 5–10% increase in patients initiating antihypertensive medication with a thiazide-type diuretic, but most patients still did not initiate treatment with this class. There are few contemporary published data on antihypertensive medication classes filled by patients initiating treatment.

Methods and Findings

We used the 5% random Medicare sample to study the initiation of antihypertensive medication between 2007 and 2010. Initiation was defined by the first antihypertensive medication fill preceded by 365 days with no antihypertensive medication fills. We restricted our analysis to beneficiaries ≥65 years who had two or more outpatient visits with a hypertension diagnosis and full Medicare fee-for-service coverage for the 365 days prior to initiation of antihypertensive medication. Between 2007 and 2010, 32,142 beneficiaries in the 5% Medicare sample initiated antihypertensive medication. Initiation with a thiazide-type diuretic decreased from 19.2% in 2007 to 17.9% in 2010. No other changes in medication classes initiated occurred over this period. Among those initiating antihypertensive medication in 2010, 31.3% filled angiotensin-converting enzyme inhibitors (ACE-Is), 26.9% filled beta blockers, 17.2% filled calcium channel blockers, and 14.4% filled angiotensin receptor blockers (ARBs). Initiation with >1 antihypertensive medication class decreased from 25.6% in 2007 to 24.1% in 2010. Patients initiated >1 antihypertensive medication class most commonly with a thiazide-type diuretic and either an ACE-I or ARB.

Conclusion

These results suggest that JNC 7 had a limited long-term impact on the choice of antihypertensive medication class and provide baseline data prior to the publication of the 2014 Evidence-Based Guideline for the Management of High Blood Pressure in Adults from the Panel Members Appointed to the Eighth Joint National Committee (JNC 8).

Patterns and predictors of osteoporosis medication discontinuation and switching among Medicare beneficiaries

BACKGROUND

Low adherence to bisphosphonate therapy is associated with increased fracture risk. Factors associated with discontinuation of osteoporosis medications have not been studied in-depth. This study assessed medication discontinuation and switching patterns among Medicare beneficiaries who were new users of bisphosphonates and evaluated factors possibly associated with discontinuation.

METHODS

We identified patients initiating bisphosphonate treatment using a 5% random sample of Medicare beneficiaries with at least 24 months of traditional fee-for-service and part D drug coverage from 2006 through 2009. We classified medication status at the end of follow-up as: continued original bisphosphonate, discontinued without switching or restarting, restarted the same drug after a treatment gap (≥ 90 days), or switched to another anti-osteoporosis medication. We conducted logistic regression analyses to identify baseline characteristics associated with discontinuation and a case-crossover analysis to identify factors that precipitate discontinuation.

RESULTS

Of 21,452 new users followed respectively for 12 months, 44% continued their original therapy, 36% discontinued without switching or restarting, 8% restarted the same drug after a gap greater than 90 days, and 11% switched to another anti-osteoporosis medication. Factors assessed during the 12-month period before initiation were weakly associated with discontinuation. Several Factors measured during follow-up were associated with discontinuation, including more physician visits, hospitalization, having a dual-energy X-ray absorptiometry test, higher Charlson comorbidity index scores, higher out-of-pocket drug payments, and upper gastrointestinal problems. Patterns were similar for 4,738 new users followed for 30 months.

CONCLUSIONS

Among new bisphosphonates users, switching within and across drug classes and extended treatment gaps are common. Robust definitions and time-varying considerations should be considered to characterize medication discontinuation more accurately.

A critical review of brand and generic alendronate for the treatment of osteoporosis

Objective

Compare in vitro and in vivo characteristics and clinical outcomes of brand and generic alendronate.

Research design and methods: Relevant search terms were input into Medline ("alendronate" AND "generic" up to August 5, 2013) and any abstracts deemed possibly relevant selected for full paper review and abstraction.

Results

Multicentre, randomized, placebo-controlled Phase III clinical trials of substantial size and duration have established the anti-fracture efficacy and safety of brand amino-bisphosphonates. For regulatory approval, generic versions of brand drugs need to demonstrate bioequivalence in young, healthy volunteers and have similar dissolution times. While the potency and amount of active drug within generic formulations must be identical to the brand, differences are permitted in the excipients. Significant differences in tablet disintegration time among different versions of generic and brand alendronate have been reported. Rapidly disintegrating alendronate pills may increase oesophageal bioadhesion and adverse event risk. Oesophageal-bound alendronate or slow disintegrating alendronate tablets may be made inert and ineffective by subsequently ingested food or drink. Investigations have reported a lower persistence to therapy with generic brands of alendronate as compared to brand bisphosphonates and patients switched from brand to generic alendronate have increased adverse event rates and losses in bone mineral density.

Conclusion

Numerous differences exist between brand and generic alendronate including: disintegration time, bioadhesion to the oesophagus, patient persistence to therapy, adverse event incidence, and maintenance of bone mineral density. Generic forms of alendronate warrant closer clinical study before they are ascribed the clinical effectiveness and tolerability of brand alendronate.

Electronic supplementary material

The online version of this article (doi:10.1186/2193-1801-2-550) contains supplementary material, which is available to authorized users.