Cost-effectiveness of zoledronic acid vs clodronic acid for newly-diagnosed multiple myeloma from the United Kingdom healthcare system perspective

OBJECTIVE

In the Medical Research Council Myeloma IX Study (MMIX), zoledronic acid (ZOL) 4 mg 3-4/week reduced the incidence of skeletal-related events (SREs), increased progression free survival (PFS), and prolonged overall survival (OS), compared with clodronic acid (CLO) 1600 mg daily, in 1970 patients with newly-diagnosed multiple myeloma (MM).

METHODS

An economic model was used to project PFS, OS, the incidence of SREs and adverse events and expected lifetime healthcare costs for patients with newly-diagnosed MM who are alternatively assumed to receive ZOL or CLO. The incremental cost-effectiveness ratio [ICER] of ZOL vs CLO was calculated as the ratio of the difference in cost to the difference in quality-adjusted life years (QALYs). Model inputs were based on results of MMIX and published sources.

RESULTS

Compared with CLO, treatment with ZOL increases QALYs by 0.30 at an additional cost of £1653, yielding an ICER of £5443 per QALY gained. If the threshold ICER is £20,000 per QALY, the estimated probability that ZOL is cost-effective is 90%.

LIMITATIONS

The main limitation of this study is the lack of data on the effects of zoledronic acid on survival beyond the end of follow-up in the MMIX trial. However, cost-effectiveness was favourable even under the highly conservative scenario in which the timeframe of the model was limited to 5 years.

CONCLUSIONS

Compared with clodronic acid, zoledronic acid represents a cost-effective treatment alternative in patients with multiple myeloma.

P1-12-24: Adherence and Persistence with Lapatinib in Women with Metastatic Breast Cancer Who Were Previously Treated with Trastuzumab

Background. Lapatinib is an oral small molecule dual tyrosine kinase inhibitor that binds intracellularly to the ATP binding site of the EGFR and HER2 receptors. In a randomized controlled trial (RCT) of women with HER2+ metastatic breast cancer (MBC) previously treated with trastuzumab, an anthracycline, and taxanes, lapatinib plus capecitabine improved time to progression versus capecitabine monotherapy. In an RCT of postmenopausal women with HR+ MBC, 1st-line therapy with lapatinib plus letrozole improved progressionfree survival vs. letrozole monotherapy in the primary analysis HER2+ population. Data on adherence and persistence with lapatinib in typical clinical practice are unavailable.

Methods. This was retrospective observational study of adherence and persistence with lapatinib in women with MBC who were previously treated with trastuzumab. Data were from the Thomson MedStat MarketScan® Commercial and Medicare health insurance claims databases spanning 1/2000-3/2010 and representing >90 million covered lives. Subjects included women with ≥1 claims with a diagnosis of breast cancer, ≥1 claims with a diagnosis of distant metastases, ≥1 trastuzumab claim after first distant metastases diagnosis, and ≥1 lapatinib claim after first trastuzumab claim (date of first lapatinib claim="index date”). Pts with <12 mos. continuous enrollment pre-index or <3 mos. continuous enrollment post-index were excluded. Measures of lapatinib adherence and persistence were calculated from days supplied information on pharmacy claims and included medication possession ratio (MPR), time to discontinuation (end of supply), time to first treatment interruption (gap during treatment of ≥30 days without supply), and duration of continuous therapy (time to gap of ≥30 days without supply or end of supply).

Results. A total of 1299 pts had ≥1 claims with a diagnosis of breast cancer, ≥1 claims with a diagnosis of distant metastases, ≥1 claims for trastuzumab, and ≥1 claims for lapatinib (1106 Commercial, 93 Medicare). Of these, 666 met all inclusion criteria (572 Commercial, 94 Medicare). Mean (SD) age was 52 (8) years in Commercial pts and 72 (6) years in Medicare pts. Among all pts, 73% had claims history of prior taxanes, 27% prior anthracylines, and 24% prior taxanes and prior anthracyclines. Mean (SD) initial lapatinib dosage was 1161 (339) mg daily; 84% initiated lapatinib on 1250 mg daily. Sixty-three percent received index lapatinib in combination with capecitabine; 6% in combination with an aromatase inhibitor. Median follow-up was 12 mos. Mean (SD) number of lapatinib claims was 7.1 (4.9). Mean (SD) MPR was 87% (19%); median MPR was 96%. Kaplan-Meier estimated median time to discontinuation of lapatinib was 7.4 months (95%CI 6.7−8.0 mos). Seventy three percent of patients had no treatment interruption during follow-up. Median duration of continuous therapy was 5.2 mos (95%CI 4.8−5.7 mos).

Conclusions. In women with MBC previously-treated with trastuzumab, adherence and persistence with lapatinib in typical clinical practice are relatively high. Further research is needed to identify predictors and consequences of non-adherence so that efforts may be targeted to enhance adherence to effective treatment.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-12-24.

Abstract P223: Cost-Effectiveness of Adding Aliskiren to Losartan and Optimal Antihypertensive Therapy in Patients with Hypertension, Type 2 Diabetes and Nephropathy with Residual Proteinuria

Background: AVOID was a randomized, double-blind, 6-mo. trial of adding aliskiren to losartan and optimal antihypertensive therapy in patients with hypertension, type 2 diabetes, and nephropathy with residual proteinuria (urinary albumin creatinine ratio [UACR]>100mg/g) after ≥3 mo. of 100mg/d losartan. Aliskiren reduced mean UACR by 20% vs. placebo (P=.009). A previous study examined cost-effectiveness of aliskiren, but did not examine the potential effects of aliskiren on risks, costs, and quality of life effects of cardiovascular disease (CVD).

Methods: A Markov model was used to project lifetime incidence of cardiovascular disease (CVD) and end-stage renal disease (ESRD), life years (LYs), quality-adjusted life years (QALYs), and expected lifetime costs (US healthcare system perspective) with losartan plus optimal antihypertensive therapy +/− aliskiren. Albuminuria progression by treatment was projected by generalized linear model regression equations fit to UACR from AVOID. Probabilities of CVD/ESRD by UACR and death without CVD/ESRD by age were obtained by calibrating the model to results for losartan and placebo in the RENAAL study. Other parameters were from published sources.

Results: With losartan, mean UACR is projected to increase from approximately 790 mg/g at baseline to approximately 1700 mg/g at 3.5 years and to remain at this level for the duration of the model. Assuming the beneficial effects of aliskiren on the rate of progression of UACR persist for as long as patients remain on therapy, mean UACR with aliskiren plus losartan is projected to decline from 790 mg/g at baseline to 730 mg/g after 1 year, then increase to 740 mg/g after 4 years and remain at that level for the remainder of the model. Under these assumptions, adding aliskiren to losartan and optimal antihypertensive therapy is projected to reduce lifetime incidence of ESRD by 5% and CVD by 4%, increase LY by 0.19 and QALYs by 0.13. Expected lifetime costs are reduced by $7700, as savings from averted CVD ($1500) and ESRD ($12 800) more than offset additional costs associated with aliskiren treatment ($5400).

Conclusion: Adding aliskiren to losartan in this setting leads to reduced cost and increased QALYs.

Retrospective comparison of early versus late treatment with fluticasone propionate/salmeterol after an asthma exacerbation

BACKGROUND

The benefits of inhaled corticosteroids in asthma are well established. Early use of inhaled anti-inflammatories following and exacerbation could be beneficial.

METHODS

A retrospective observational cohort study compared the risk of asthma-related exacerbations [hospitalization, emergency department visit, and/or treatment with systemic corticosteroid] in patients receiving treatment with fluticasone propionate/salmeterol in a single inhaler (FSC) within 90 days following an initial asthma-related exacerbation (early treatment) versus patients receiving the treatment subsequently (late treatment). Data were from a large health insurance claims database spanning from January 1998 to April 2008. Subjects included patients with ≥1 prescription for FSC ≤ 1 year after first asthma-related exacerbation. Patients with early treatment were matched to those with late treatment by propensity score and compared in terms of healthcare utilization and costs after initiation of FSC.

RESULTS

A total of 14,861 patients met study inclusion criteria, including 10,793 early and 4068 late treatment patients. After matching, 3555 pairs were well matched on all pretreatment characteristics and duration of follow-up (mean 722 vs. 717 days, p = .634). Early versus late treatment was associated with longer time to first asthma-related exacerbation (hazard ratio = 0.82, 95% CI 0.75-0.88, p < .001), fewer short-acting β-agonists prescriptions (3.3 vs. 3.6, p = .031), higher outpatient yearly per patient pharmacy costs ($1320 vs. $1163, p = .008), and lower yearly per patient asthma-related emergency department visit costs ($80 vs. $105, p = .032). Total yearly per patient asthma-related costs were similar ($2197 vs. $2064, p = .203).

CONCLUSIONS

Earlier use of FSC following an asthma exacerbation was associated with reduced risk of future asthma-related exacerbation and lower use of rescue medications.

The association between adherence to levodopa/carbidopa/entacapone therapy and healthcare utilization and costs among patients with Parkinson's disease: a retrospective claims-based analysis

BACKGROUND

Suboptimal adherence to long-term therapies is common and may potentially have adverse consequences on patient outcomes and healthcare costs.

OBJECTIVE

To assess the association between adherence to levodopa/carbidopa/entacapone therapy and healthcare utilization and costs in patients with Parkinson's disease.

METHODS

A retrospective historical cohort study, conducted in the US, using a health insurance claims database, with data spanning from 1 January 2000 to 31 December 2005. Subjects included patients with Parkinson's disease who were treated with levodopa (L), carbidopa (C) and entacapone (E) either as separate tablets (LC + E) or as a single-tablet formulation (LCE). The association between satisfactory adherence (defined as 'proportion of days covered' for LCE or LC + E during 1-year follow-up ≥80%) and healthcare utilization and costs was examined using multivariate regression to control for pretreatment adherence to LC and other patient characteristics.

RESULTS

Compared with unsatisfactory adherence (n = 598), satisfactory adherence (n = 617) was associated with 39% fewer Parkinson's disease-related hospitalizations (95% CI 20, 54; p < 0.001), 47% lower all-cause inpatient costs (95% CI 18, 65; p = 0.004) and 18% lower all-cause total costs (95% CI 11, 24; p < 0.001). On an adjusted basis, all-cause total costs were $US3508 less for those with satisfactory versus unsatisfactory adherence. In both the LC + E and LCE groups, satisfactory adherence was associated with significant reductions in all-cause hospitalizations (39% and 46%, respectively), and all-cause total costs (10% and 31%, respectively). The association between adherence and total healthcare costs was stronger for patients receiving LCE.

CONCLUSIONS

Better adherence to levodopa/carbidopa/entacapone therapy is associated with lower healthcare utilization and costs. Non-adherence to LCE is associated with a greater increase in costs than non-adherence to LC + E. Efforts should be made to ensure adherence to both therapies.

Cost-effectiveness of zoledronic acid plus endocrine therapy in premenopausal women with hormone-responsive early breast cancer

PURPOSE

The aim of this study was to estimate the cost-effectiveness of adding zoledronic acid 4 mg intravenously every 6 months to endocrine therapy in premenopausal women with hormone receptor-positive early breast cancer from a US health care system perspective.

MATERIALS AND METHODS

A Markov model was developed to predict disease progression, mortality, and costs of breast cancer care for premenopausal women with hormone receptor-positive early breast cancer receiving up to 3 years of (1) endocrine therapy (goserelin plus tamoxifen or anastrozole); or (2) endocrine therapy plus zoledronic acid. Model parameters were obtained from ABCSG-12 (Austrian Breast and Colorectal Cancer Study Group Trial-12) and the literature. The incremental cost per quality-adjusted life year (QALY) gained with zoledronic acid was calculated under 2 scenarios: (1) benefits of zoledronic acid persist to maximum (7 years) follow-up in ABCSG-12 ("trial benefits") or (2) benefits persist until death ("lifetime benefits").

RESULTS

Adding zoledronic acid to endocrine therapy was projected to yield a gain of 0.41 life years (LYs) and 0.43 QALYs assuming trial benefits and 1.34 LYs and 1.41 QALYs assuming lifetime benefits. Assuming trial benefits, the incremental cost per QALY gained with zoledronic acid was $9300. Assuming lifetime benefits, zoledronic acid was estimated to increase QALYs and reduce costs. Cost per QALY gained was <or= $56,000 in all deterministic sensitivity analyses and was <or= $50,000 in 94% and 97% of probabilistic sensitivity analyses for trial and lifetime benefits scenarios, respectively.

CONCLUSION

Adding zoledronic acid to endocrine therapy in premenopausal women with hormone receptor-positive early breast cancer is cost-effective from a US health care system perspective.

Cost effectiveness of letrozole versus anastrozole in postmenopausal women with HR+ early-stage breast cancer

BACKGROUND

The Breast International Group (BIG) 1-98 and Arimidex, Tamoxifen Alone or in Combination (ATAC) trials demonstrated that, in postmenopausal women with hormone receptor positive (HR+) early-stage breast cancer, 5 years of initial adjuvant endocrine therapy with letrozole or anastrozole is superior to tamoxifen. With expected generic availability of anastrozole in July 2010 and letrozole in June 2011, there may be financial pressures prior to letrozole's generic availability to start treatment-naïve patients on anastrozole vs. letrozole or to switch patients already receiving letrozole to anastrozole.

METHODS

A Markov model was used to estimate cost per quality-adjusted life-year (QALY) gained with letrozole vs. anastrozole from the US healthcare system perspective. Cost effectiveness was examined separately in treatment-naïve patients and in patients already receiving letrozole. For the latter, cost effectiveness of continued letrozole vs. therapeutic substitution (TS) to generic anastrozole was evaluated separately in cohorts defined on years of endocrine therapy remaining. TS to generic anastrozole was assumed to result in an additional 5% of patients discontinuing endocrine therapy. Probabilities of distant recurrence and death were taken from reports of BIG 1-98, ATAC, the Early Breast Cancer Trialists' Collaborative Group meta-analysis of tamoxifen, and other published sources. Carry-over effects of aromatase inhibitors were assumed to be proportional to treatment duration. Costs of aromatase inhibitors were assumed to decline by 75% with generic availability.

RESULTS

In treatment-naïve patients, total expected lifetime costs are $3916 greater with letrozole vs. anastrozole. However, initiation of treatment with letrozole results in a gain of 0.15 QALYs. Cost per QALY gained with letrozole vs. anastrozole is $25,846. In patients already receiving letrozole, the increase in total expected lifetime costs with continued letrozole vs. TS to anastrozole is between $4200 and $4500 in all cohorts. QALYs gained with letrozole range from 0.21 in those with 4 years of endocrine therapy remaining to 0.13 in those with 1 year of therapy remaining. Cost per QALY gained ranges from $20,276 to $34,356.

CONCLUSION

For postmenopausal women with HR+ early-stage breast cancer, letrozole is more likely to be cost effective vs. anastrozole in treatment-naïve patients and in patients already receiving letrozole. Limitations of the study include a lack of direct evidence comparing letrozole and anastrozole and lack of data on rates of discontinuation due to therapeutic substitution with aromatase inhibitors.

Adherence with levodopa/carbidopa/entacapone versus levodopa/carbidopa and entacapone as separate tablets in patients with Parkinson's disease

BACKGROUND

Observational studies suggest that single-tablet formulations are associated with improved adherence versus the same components taken as separate tablets. The objective of this study was to compare adherence in patients with Parkinson's disease (PD) receiving levodopa therapy as levodopa/carbidopa/entacapone tablets (LCE) versus levodopa/carbidopa (LC) tablets and entacapone (E) as separate tablets (LC and E).

METHODS

This was a retrospective, observational cohort study using a large health insurance claims database. Subjects included persons with a PD diagnosis who were receiving LC without E and then received either an add-on therapy with E as a separate tablet (LC and E) or LCE as one tablet (LCE). The primary study outcome was treatment adherence, estimated from pharmacy refills based on the 'percent of days covered' (PDC) with LCE or LC and E during follow-up and compared for patients receiving LCE and LC and E using multivariate regression analyses.

RESULTS

In multivariate analyses controlling for differences between groups in baseline characteristics, including pre-index dosage of and adherence with LC, receipt of LCE (n = 388) was associated with 79% lower mean non-adherence during follow-up (95% CI: 73-83%; p < 0.001) versus LC and E (n = 823), 86% lower odds of unsatisfactory adherence (95% CI: 80-91%; p < 0.001), and a 26% lower risk of discontinuation (95% CI: 6-42%; p < 0.013).

LIMITATIONS

This was an observational study with the inherent potential for selection bias. Pharmacy claims may not provide an accurate estimate of adherence. Requiring subjects to have a certain number of prescriptions before and after the index date may yield a sample that is not representative of all patients initiating levodopa therapy in typical clinical practice.

CONCLUSIONS

Better adherence with LCE may have important implications for maintaining function in patients receiving chronic oral levodopa therapy. Further research is needed to confirm these results and examine the association between improved adherence and clinical and economic outcomes.

Adding salmeterol to fluticasone propionate or increasing the dose of fluticasone propionate in patients with asthma

The National Asthma Education and Prevention Program guidelines recommend two options for patients uncontrolled on inhaled corticosteroid (ICS) alone: add a long-acting bronchodilator or increase the dose of the ICS. The purpose of this study was to compare asthma-related exacerbations and asthma control in asthma patients receiving fluticasone propionate (FP) monotherapy with an increased dose of FP compared with maintaining the dose and adding salmeterol (SAL) via a single device (FP/SAL combination [FSC]). A retrospective observational study was performed using health insurance claims spanning from January 2001 to August 2006 ("study period"). Subjects were > or =12 years of age, with asthma (International Classification of Diseases [ICD] 493.xx), and were stepped up from FP 44 microg to either FP 110 microg (FP110) or FP 100 microg/SAL 50 microg (FSC), or from FP110 to either FP 220 microg or FP 250 microg/SAL 50 microg (FSC). There were 1744 subjects identified, 557 (32%) increased FP and 1187 (68%) added SAL. The cohorts were relatively similar, and after adjusting for baseline characteristics, patients who added SAL to their same dose of FP had 41% lower odds of an asthma exacerbation (odds ratio = 0.59; 95% confidence interval [CI] = 0.46-0.76; p < 0.001), 36% fewer prescriptions for a short-acting beta-agonist (rate ratio = 0.64; 95% CI = 0.58-0.70; p < 0.001), and a 32% increase in ICS refill persistence compared with increasing the dose of FP. In asthma patients who are not adequately controlled with ICS (FP), adding SAL as FSC is associated with lower risk of an asthma-related exacerbation and better asthma control compared with increasing the dose of ICS (FP).

Stepping down to fluticasone propionate or a lower dose of fluticasone propionate/salmeterol combination in asthma patients recently initiating combination therapy

Clinical guidelines recommend add-on therapy with long-acting beta2-agonists (LABA) in patients with mild-to-moderate persistent asthma whose disease is not adequately controlled with inhaled corticosteroids (ICSs) alone. For those achieving control with add-on therapy, careful reduction in ICS dose followed by withdrawal of LABA is recommended. This study was designed to compare asthma-related outcomes in patients receiving fluticasone propionate/salmeterol combination (FSC) who stepped down to a lower dose of FSC versus those who stepped down to fluticasone propionate (FP) at the same dose of FP. A retrospective observational cohort study was performed using two large health insurance claims databases spanning from January 2000 to June 2007. Subjects were age > or =12 and <65 years, had a diagnosis of asthma (International Classification of Diseases [ICD-493.xx]), and who within 1 year of initiating FSC either stepped down to a lower dose of FSC ("FSC patients") or to FP only at the same dose of FP ("FP patients"). FSC and FP patients were matched based on propensity scores to control for potential differences in baseline demographic and clinical characteristics and preindex asthma-related and costs. Of 4350 subjects identified, 3881 stepped down to a lower dose of FSC and 469 stepped down to FP. After matching, there were 447 pairs of FSC and FP patients. FSC patients had 30% fewer prescriptions for short-acting beta-agonists, a 26% lower risk of receiving systemic corticosteroids, and a 48% lower risk of asthma-related hospitalization or Emergency Department visit during follow-up. Stepping down to FP monotherapy is associated with worsening asthma symptoms and greater risk of severe asthma-related exacerbations compared with staying on FSC at a lower ICS dose.

Cost-effectiveness of aliskiren in type 2 diabetes, hypertension, and albuminuria

The Aliskiren in the Evaluation of Proteinuria in Diabetes (AVOID) trial demonstrated that adding aliskiren, an oral direct renin inhibitor, at a dosage of 300 mg/d to the highest approved dosage of losartan and optimal antihypertensive therapy reduces albuminuria over 6 mo among patients with type 2 diabetes, hypertension, and albuminuria. The cost-effectiveness of this therapy, however, is unknown. Here, we used a Markov model to project progression to ESRD, life years, quality-adjusted life years, and lifetime costs for aliskiren plus losartan versus losartan. We used data from the AVOID study and the Irbesartan in Diabetic Nephropathy Trial (IDNT) to estimate probabilities of progression of renal disease. We estimated probabilities of mortality for ESRD and other comorbidities using data from the US Renal Data System, US Vital Statistics, and published studies. We based pharmacy costs on wholesale acquisition costs and based costs of ESRD and transplantation on data from the US Renal Data System. We found that adding aliskiren to losartan increased time free of ESRD, life expectancy, and quality-adjusted life expectancy by 0.1772, 0.1021, and 0.0967 yr, respectively. Total expected lifetime health care costs increased by $2952, reflecting the higher pharmacy costs of aliskiren and losartan ($7769), which were partially offset by savings in costs of ESRD ($4860). We estimated the cost-effectiveness of aliskiren to be $30,500 per quality-adjusted life year gained. In conclusion, adding aliskiren to losartan and optimal therapy in patients with type 2 diabetes, hypertension, and albuminuria may be cost-effective from a US health care system perspective.

Cost-effectiveness of zoledronic acid plus endocrine therapy in premenopausal women with early stage breast cancer based on results of the ABCSG-12 study

Abstract #2112

Background: Zoledronic acid (ZOL) has demonstrated antitumor and antimetastatic activity in preclinical and early clinical studies. The Austrian Breast and Colorectal Cancer Study Group Trial 12 (ABCSG-12) examined the efficacy of ovarian suppression using goserelin combined with 3 years of endocrine therapy (ET) with anastrozole (ANA) or tamoxifen (TAM) with or without ZOL (4 mg q6m) in 1803 premenopausal women with endocrine-responsive early breast cancer. After a median follow-up of 47.8 months, there was no significant difference (p&gt;0.05) between patients who received TAM vs. ANA in disease-free survival (DFS), recurrence-free survival (RFS) and overall survival (OS). However, the addition of ZOL to ET significantly reduced the risk of DFS events by 36% (HR = 0.64, p = 0.011) and RFS by 35% (HR=0.65, p=0.014) compared with ET alone. There was a nonsignificant trend in OS favoring ZOL (p= 0.101). ZOL was generally well tolerated, and there were no confirmed cases of ONJ or renal toxicity.&#x2028; Methods: A Markov model was used to generate preliminary estimates the cost-effectiveness (cost per quality adjusted life year [QALY] gained) of 3 years of ZOL+ET compared to 3 years of ET alone, in premenopausal women with early stage breast cancer. A lifetime timeframe was employed. Probabilities of recurrence with ZOL+ET and ET alone were based on the results of ABCSG-12 trial (ASCO 2008; #LBA4). Outcomes after recurrence were based on published studies and assumed to be the same for ZOL+ET and ZOL only. A US healthcare system perspective was employed. Costs of study medications were based on wholesale acquisition costs. Costs of ZOL administration were based on Medicare fees. Costs of breast cancer care were based on published sources. Costs and QALYs were discounted at 3% annually. Results were generated under 2 scenarios regarding duration of benefit (reduction in risk of recurrence) with ZOL: (1) benefits persist until death (“lifetime benefit scenario”): (2) benefits persist to the maximum follow-up reported for ABCSG-12 (84 months) (“trial benefit scenario”).&#x2028; Results: The additional cost of 3 years of ZOL 4 mg q6m is approximately $5,000 (including drug administration costs). Under the lifetime benefit scenario, the additional costs of ZOL are more than offset by savings in costs of recurrences, and ZOL+ET is the “dominant strategy”, reducing total costs while increasing QALYs. Under the trial benefit scenario, the additional costs of ZOL are partially offset by savings in the costs of recurrences. However, the cost effectiveness of ZOL+ET vs. ET only is highly favorable (i.e., &lt;$10,000 per QALY gained).&#x2028; Conclusion: In premenopausal women with early stage breast cancer, adding zoledronic acid to adjuvant endocrine therapy is likely to be cost-effective use of healthcare resources from a US healthcare system perspective. Further analyses are ongoing to refine these estimates and examine sensitivity of model results to key assumptions and parameter estimates.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2112.

Healthcare use and costs in patients with chronic bronchitis initiating maintenance therapy with fluticasone/salmeterol vs other inhaled maintenance therapies

OBJECTIVE

To compare risk of hospitalization or emergency department (ED) visit and healthcare costs in patients with chronic bronchitis initiating inhaled maintenance therapy with fluticasone propionate/salmeterol 250/50 mcg combination (FSC) versus other inhaled maintenance therapies.

DESIGN AND METHODS

This retrospective cohort study assessed 9,217 patients from the PharMetrics administrative claims database enrolled from July 1997 to January 2005. Study subjects were persons with medical claims with diagnoses of chronic bronchitis (ICD-9-CM 491.xx) who also had pharmacy claims for FSC, salmeterol (SAL), inhaled corticosteroid (ICS), ipratropium (IPR), or ipratropium/albuterol combination (IAC). Persons with <12 months of continuous eligibility after the first prescription for initial maintenance therapy ("index date") were excluded as were those receiving fluticasone propionate/salmeterol 100/50 mcg or 500/50 mcg (not indicated for patients with chronic bronchitis). For remaining persons, time to first hospitalization or ED visit during follow-up was compared for those receiving FSC versus other therapies using Cox proportional hazards regression. Healthcare costs during the first 12 months of follow-up were analyzed using generalized linear model regression.

RESULTS

Receipt of FSC as initial inhaled maintenance therapy for chronic bronchitis (n = 1361) was associated with 41% lower risk of COPD-related hospitalization or ED visit compared with IPR (n < 1316) (p < 0.001). Adjusted costs of COPD-related hospitalization/ED visit were $507 (95% CI $218-$1083) less with FSC than IPR. However, patients receiving FSC had $261 (95% CI $205-$322) higher COPD-related pharmacy costs than those receiving IPR. Total COPD-related costs were $90 lower with FSC than IPR although this difference was not significant (95% CI $330-$443). Compliance, as measured by medication possession ratio, was 12% greater with FSC compared with IPR (p < 0.05). Comparisons of FSC with IAC yielded generally similar results. The limitations of the study are similar to those of other observational studies of secondary data regarding potential misclassification and omitted variable bias and residual confounding.

CONCLUSIONS

In persons with chronic bronchitis, initial maintenance therapy with FSC 250/50 mcg was associated with improved outcomes versus ipratropium-based therapy and although FSC was associated with greater pharmacy costs, it did not significantly increase total costs of COPD-related care.

Retrospective study of the association between transfusion frequency and potential complications of iron overload in patients with myelodysplastic syndrome and other acquired hematopoietic disorders

BACKGROUND

Patients with myelodysplastic syndrome (MDS) and other acquired hematopoietic disorders frequently require chronic transfusion therapy. Although red cell transfusions are known to cause iron overload, data on the risk of iron-related complications in these patients are limited.

METHODS

This was a retrospective, case-control study to assess the association between exposure to transfusions and complications of iron overload in patients with MDS and other hematopoietic disorders using a large US health-insurance claims database spanning 1997-2004. Subjects included members with one or more claims with a diagnosis of 'neoplasm of uncertain behavior of other lymphatic and hematopoietic tissues' (ICD-9-CM 238.7) and no claims for potential complications of iron overload (cardiomyopathy/heart failure, conduction/rhythm disorders, diabetes, liver disease) prior to the diagnosis date. Cases were defined as subjects with claims for complications of iron overload after the diagnosis date and were compared with a corresponding number of controls (patients without complications) with respect to receipt of transfusions, controlling for demographic and clinical characteristics using multivariate conditional logistic regression.

RESULTS

A total of 4546 patients met inclusion criteria including 511 cases and a corresponding number of controls. Receipt of transfusions was significantly associated with risk of potential complications of iron overload (odds ratio [OR] = 2.90; p = 0.0008). Results for specific potential complications were as follows: cardiomyopathy/heart failure (OR = 1.62; p = 0.2955), conduction/rhythm disorders (OR = 4.18; p = 0.0005), diabetes (OR = 5.06; p = 0.0025), and liver disease (OR = 3.31; p = 0.0008).

CONCLUSION

These results suggest that transfusion therapy may increase risk of complications of iron overload in patients with MDS or other hematopoietic disorders. Further research is needed to assess whether the associations observed in this retrospective observational study are due to iron overload or other factors.

Association between adherence with fixed dose combination fluticasone propionate/salmeterol on asthma outcomes and costs*

OBJECTIVE

To assess the association between adherence with fluticasone propionate/salmeterol combination (FSC) product in a single inhaler and asthma care utilization and costs in asthma patients in typical US clinical practice.

METHODS

Retrospective longitudinal analysis using linked medical and pharmacy claims from a managed care database representing >70 US health plans. Subjects included those with two prescriptions for FSC after January 1, 2000 (first prescription = 'index date') and diagnosis of asthma. Follow-up was defined as time from index date to disenrollment or discontinuation of FSC (180 days without supply), receipt of different controller, or 24 months post-index. Patients were excluded if: <12 months continuous enrollment pre-index, <12 months of follow-up, diagnoses of COPD or respiratory cancer, use of ipratropium, or age <12 years. Effect of FSC adherence on asthma-related outcomes (short-acting beta-agonist use (SABA), corticosteroid use (CS), emergency department (ED) visit/hospitalizations) and asthma-related health plan costs during each quarter post-index and FSC adherence in prior quarter controlling for demographics, time since index, season, comorbidities, pre-index medications, utilization, and cost.

RESULTS

12 907 patients were identified: mean age, 40 years; mean follow-up, 20 months; mean quarterly FSC adherence, 54%; mean quarterly incidence of asthma-related ED visit/hospitalization, 1.12%. After adjusting for baseline characteristics, each 25% improvement in adherence was associated with a 10% reduction in the odds of asthma-related ED visit or hospitalization (p < 0.001), a 10% reduction in the odds of receiving SABA (p < 0.001), a 3% reduction in the odds of receiving a CS (p = 0.027). However, total asthma-related costs also increased 23% for each 25% increase in the use of FSC.

CONCLUSIONS

Despite the limitations of the study, this analysis shows that improving compliance with an asthma controller medication such as FSC may help reduce the burden of asthma.

Effects of fluticasone propionate/salmeterol combination on asthma-related health care resource utilization and costs and adherence in children and adults with asthma

BACKGROUND

Clinical trials suggest that in patients with asthma inadequately controlled on low- to medium- dose inhaled corticosteroids (ICSs), the addition of a long-acting beta-agonist such as salmeterol (SAL is more effective than the addition of montelukast (MON) or a higher-dose ICS.

OBJECTIVE

This study was designed to expand on these earlier findings by comparing asthma-related health care resource utilization and costs, as well as adherence to ICSs, in children and adults with asthma receiving ICS monotherapy who either were switched to fluticasone propionate plus SAL from a single inhaler (FSC) or initiated add-on therapy with SAL from a separate inhaler or MON.

METHODS

This retrospective study used an integrated managed-care database from >30 health plans. Patients were >or=5 years of age with a diagnosis of asthma (International Classification of Diseases, Ninth Revision, Clinical Modification 493.xx) and >or=2 claims for FSC, SAL, or MON. The date of first claim for the medication of interest was the index date. Patients were also required to have >or=1 claim for an ICS during the 12 months preindex and 12 months postindex. Utilization and costs of asthma-related care and adherence to ICS treatment postindex were compared using multivariate methods.

RESULTS

After adjusting for preindex characteristics, patients receiving FSC (n=1287) had fewer claims for short-acting beta-agonists, oral corticosteroids, and lower adjusted asthma-related costs postindex compared with ICS + SAL (n=562) and ICS + MON (n=420). FSC patients also had greater adherence to ICS therapy. Those who received FSC had lower risks for treatment failure (defined as asthma-related emergency department visits or hospitalization or receipt of alternative study medication or oral corticosteroids during the postindex period).

CONCLUSION

In this health insurance claims-based study of patients with asthma inadequately controlled with an ICS alone, those who received stepped-up therapy with FSC used fewer rescue medications and had greater persistence with ICSs compared with those in whom SAL or MON was added to ICS monotherapy.

Outcomes, utilization, and costs among thalassemia and sickle cell disease patients receiving deferoxamine therapy in the United States

Deferoxamine mesylate (DFO) reduces morbidity and mortality associated with transfusional iron overload. Data on the utilization and costs of care among U.S. patients receiving DFO in typical clinical practice are limited however. This was a retrospective study using a large U.S. health insurance claims database spanning 1/97-12/04 and representing 40 million members in >70 health plans. Study subjects (n = 145 total, 106 sickle cell disease [SCD], 39 thalassemia) included members with a diagnosis of thalassemia or SCD, one or more transfusions (whole blood or red blood cells), and one or more claims for DFO. Mean transfusion episodes were 12 per year. Estimated mean DFO use was 307 g/year. Central venous access devices were required by 20% of patients. Cardiac disease was observed in 16% of patients. Mean total medical costs were $59,233 per year including $10,899 for DFO and $8,722 for administration of chelation therapy. In multivariate analyses, potential complications of iron overload were associated with significantly higher medical care costs. In typical clinical practice, use of DFO in patients with thalassemia and SCD receiving transfusions is low. Administration costs represent a large proportion of the cost of chelation therapy. Potential complications of iron overload are associated with increased costs.

Consequences and costs of noncompliance with iron chelation therapy in patients with transfusion-dependent thalassemia: a literature review

BACKGROUND

Patients with thalassemia major require iron chelation therapy (ICT) to prevent complications from transfusional iron overload. Deferoxamine is effective, but requires administration as a slow continuous subcutaneous or intravenous infusion five to seven times per week. Deferiprone is a three-times-daily oral iron chelator, but has limited availability in the United States. Deferasirox is a once-daily oral iron chelator that was approved in the United States in 2005 for patients older than 2 years of age with transfusional iron overload.

STUDY DESIGN AND METHODS

Published evidence on rates of compliance with ICT and the association between compliance, and the incidence and costs of complications of iron overload, in patients with thalassemia major was reviewed.

RESULTS

A total of 18 studies were identified reporting data on compliance with ICT, including 7 that examined deferoxamine only, 6 that examined deferiprone only, and 5 that compared deferoxamine and deferiprone; no studies reporting compliance with deferasirox were identified. In studies of deferoxamine only, estimated mean compliance ranged from 59 to 78 percent. Studies of deferiprone generally reported better compliance, ranging from 79 to 98 percent. Results of comparative studies of deferoxamine and deferiprone suggest that compliance may be better with oral therapy. Numerous studies demonstrate that that poor compliance with ICT results in increased risk of cardiac disease and endocrinopathies, as well as lower survival. Although data on the costs of noncompliance are limited, a recent model-based study estimated the lifetime costs of inadequate compliance with deferoxamine to be $33,142.

CONCLUSIONS

Inadequate compliance with ICT in thalassemia major is common and results in substantial morbidity and mortality, as well as increased costs.

Cost-effectiveness of letrozole versus tamoxifen as initial adjuvant therapy in hormone receptor-positive postmenopausal women with early-stage breast cancer

BACKGROUND

In Breast International Group (BIG) 1-98, a randomized, double-blind trial comparing 5 years of initial adjuvant therapy with letrozole versus tamoxifen in postmenopausal women with hormone receptor-positive early breast cancer, letrozole significantly improved disease-free survival by 19% and reduced risk of breast cancer recurrence by 28% and distant recurrence by 27%.

PATIENTS AND METHODS

A Markov model was used to estimate the incremental cost per quality-adjusted life year (QALY) gained with 5 years of initial adjuvant therapy with letrozole versus tamoxifen from a US health care system perspective. Probabilities and costs of breast cancer recurrence and treatment-related adverse events and health-state utilities were based on published results of BIG 1-98 and other published studies. Costs and QALYs were estimated over the lifetime of a cohort of postmenopausal women with hormone receptor-positive early breast cancer, aged 60 years at initiation of therapy. In our base case, we assumed that benefits of letrozole on risk of breast cancer recurrence are maintained for 5 years after therapy discontinuation ("carry-over effect") and examined the effects of this assumption on results in sensitivity analyses.

RESULTS

Under base-case assumptions, letrozole yields an additional 0.409 QALYs versus tamoxifen at an additional cost of $9705, yielding a cost per QALY gained for letrozole versus tamoxifen of $23,743 (95% confidence interval, $14,087-$51,129). Assuming no carry-over effects, letrozole yields 0.264 QALYs at a cost of $10,341, for a cost per QALY gained of $39,098 (95% confidence interval, $23,968- $83,501).

CONCLUSION

In postmenopausal women with hormone receptor-positive early breast cancer, initial adjuvant treatment with letrozole is cost-effective from the US health care system perspective.

Cost-effectiveness of letrozole versus tamoxifen as initial adjuvant therapy in postmenopausal women with hormone-receptor positive early breast cancer from a Canadian perspective

BACKGROUND

In the primary core analysis of BIG 1-98, a randomized, double-blind trial comparing 5 years of initial adjuvant therapy with letrozole versus tamoxifen in postmenopausal women with hormone receptor-positive (HR+) early breast cancer, letrozole significantly improved disease-free survival by 19% and reduced the risk of breast cancer recurrence by 28% and distant recurrence by 27%.

METHODS

A Markov model was used to estimate the incremental cost per quality-adjusted life year (QALY) gained with 5 years of initial adjuvant therapy with letrozole versus tamoxifen from a Canadian healthcare system perspective. Probabilities of recurrence and side effects for tamoxifen were based on published results of BIG 1-98 and other published population-based studies. Corresponding probabilities for letrozole were calculated by multiplying probabilities for tamoxifen by estimated relative risks for letrozole versus tamoxifen from BIG 1-98. Other probabilities, costs of breast-cancer care and treatment of side effects, and health-state utilities were obtained from published studies. Costs and QALYs were estimated over the lifetime of a cohort of postmenopausal women with HR+ early breast cancer, aged 60 years at initiation of therapy, and discounted at 5% annually.

RESULTS

Compared with tamoxifen, letrozole yields an additional 0.368 life-years (12.453 vs. 12.086) and 0.343 QALYs (11.582 vs. 11.239). These benefits are obtained at an additional cost of Can$ 8,110 (Can$ 30,819 vs. Can$ 22,709). Cost per QALY gained for letrozole versus tamoxifen is Can$ 23,662 (95% CI Can$ 15,667-Can$ 52,014).

CONCLUSION

In postmenopausal women with HR+ early breast cancer, initial adjuvant treatment with letrozole is cost-effective from the Canadian healthcare system perspective.

Valsartan versus lisinopril or extended-release metoprolol in preventing cardiovascular and renal events in patients with hypertension

PURPOSE

The objective of this study was to compare cardiovascular and renal events in patients with hypertension receiving the angiotensin II-receptor blocker valsartan versus those receiving the angiotensin-converting-enzyme lisinopril or the beta-blocker metoprolol succinate in an extended-release formulation.

METHODS

A retrospective study was conducted using a health insurance claims database spanning the period from January 1997 through December 2003 and representing approximately 40 million members enrolled in over 70 health plans across the United States. Study subjects included all persons in the database with two or more outpatient prescriptions for valsartan, lisinopril, or extended-release metoprolol and two or more prior claims with a diagnosis of hypertension. Those with a history of major cardiovascular or renal events (diagnosis of myocardial infarction, stroke, heart failure, ventricular arrhythmias, or cardiac arrest; coronary revascularization procedure; diagnosis of renal failure; or dialysis or kidney transplantation) or using other antihypertensive medications except diuretics during the 12 months before treatment with valsartan, lisinopril, or extended-release metoprolol were excluded. Risks of major cardiovascular or renal event during follow-up were analyzed using Cox proportional hazards regression.

RESULTS

A total of 29,357 antihypertensive patients were identified who initiated therapy with valsartan (n = 6,645), lisinopril (n = 17,320), or extended-release metoprolol (n = 5,392). In multivariate analyses, therapy with valsartan was associated with a significantly lower risk of a major cardiovascular or renal event versus extended-release metoprolol (heart rate [HR], 0.70; 95% confidence interval [CI], 0.56-0.87; p = 0.0015). Patients receiving valsartan had a nominally lower risk of a major cardiovascular or renal event than those receiving lisinopril, although this difference was not statistically significant (HR, 0.89; 95% CI, 0.74-1.07; p = 0.1987).

CONCLUSION

Results of this observational study suggest that the use of valsartan may reduce the risk of major cardiovascular and renal events compared with extended-release metoprolol.

Administrative claims analysis of utilization and costs of care in health plan members with atopic dermatitis who had prior use of a topical corticosteroid and who initiate therapy with pimecrolimus or tacrolimus

BACKGROUND

In the United States, pimecrolimus cream and tacrolimus ointment are approved as second-line therapy for short-term and intermittent noncontinuous long-term treatment of atopic dermatitis (AD) in nonimmunocompromised patients aged 2 years or older who have failed to respond adequately to other topical prescription treatments (e.g., topical corticosteroids), or when those treatments are not advisable; pimecrolimus is indicated for mild to- moderate AD and tacrolimus for moderate-to-severe AD. Comparative data on the effects of pimecrolimus versus tacrolimus on AD-related health care utilization and costs among similar patients seen in typical clinical practice are currently unavailable.

OBJECTIVE

To compare utilization and costs of AD-related medical care in health plan members with AD who had prior use of a topical corticosteroid and who subsequently initiate therapy with pimecrolimus cream or tacrolimus ointment.

METHODS

This was an observational, retrospective study using an administrative claims database with dates of service from August 1, 2000, through October 31, 2003, and representing approximately 2.5 million members in health maintenance organizations, preferred provider organizations, and Medicare and Medicaid plans mostly located in the cities of Chicago, Kansas City, and Phoenix and in the states of Kentucky, Florida, and Texas. The study sample included all members with 1 or more pharmacy claims for a topical corticosteroid and a diagnosis of AD (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 691.XX (excluding 691.0X), or 692.XX (excluding 692.0X-692.8X)] who subsequently had 1 or more pharmacy claims for pimecrolimus or tacrolimus. AD-related utilization and medical care costs (plan payments plus member cost share) over 12 months of follow-up were compared between the pimecrolimus and tacrolimus groups. Because information on disease severity was not available in the administrative claims data, propensity matching was used to control for differences between groups in baseline demographic and clinical characteristics and pretreatment utilization of AD-related medical care services.

RESULTS

Before matching, compared with the tacrolimus group (n = 197), members in the pimecrolimus group (n = 197) were older (mean age of 38 vs. 32 years, P = 0.022), had fewer topical corticosteroid pharmacy claims (mean 2.08 vs. 3.01, P = 0.002), and had fewer grams of corticosteroids dispensed (mean 132 vs. 193, P = 0.029) in the 12 months prior to treatment. After matching, there were 157 members in each group with no statistically significant differences in pretreatment characteristics. During the 12-month follow-up period, the mean (median) number of pharmacy claims was 1.8 (1.0) for pimecrolimus versus 2.0 (1.0) for tacrolimus and the mean (median) grams of study medication were 102 (60) and 105 (60), respectively. Members in the pimecrolimus group received a lower average number of prescriptions for any topical corticosteroids (1.37 vs. 2.04, P = 0.021) and for high-potency topical corticosteroids (0.61 vs. 1.04, P = 0.023) and were less likely to initiate alternative therapy (5% vs. 17%, P <0.001) or receive antistaphylococcal antibiotics (16% vs. 27%, P = 0.014). Members in the pimecrolimus group had lower average (median) AD-related expenditures (75% to 78% attributable to AD drug cost) compared with matched tacrolimus members ($263 [$270] vs. $361 [$398], P = 0.012).

CONCLUSIONS

In health plan members with AD who had previously received at least 1 topical corticosteroid prescription, the customary use of pimecrolimus or tacrolimus was 1 to 2 prescriptions in 12 months of followup and only a median of 60 grams of topical medication. The difference in AD-related utilization and costs between pimecrolimus and tacrolimus was small, less than $100 per year, but favored pimecrolimus. Further research using validated measures of disease severity to control for potential confounding is needed to confirm the results of this observational study.

Cost effectiveness of once-daily oral chelation therapy with deferasirox versus infusional deferoxamine in transfusion-dependent thalassaemia patients: US healthcare system perspective

BACKGROUND

Deferasirox is a recently approved once-daily oral iron chelator that has been shown to reduce liver iron concentrations and serum ferritin levels to a similar extent as infusional deferoxamine.

OBJECTIVE

To determine the cost effectiveness of deferasirox versus deferoxamine in patients with beta-thalassaemia major from a US healthcare system perspective.

METHODS

A Markov model was used to estimate the total additional lifetime costs and QALYs gained with deferasirox versus deferoxamine in patients with beta-thalassaemia major and chronic iron overload from blood transfusions. Patients were assumed to be 3 years of age at initiation of chelation therapy and to receive prescribed dosages of deferasirox and deferoxamine that have been shown to be similarly effective in such patients. Compliance with chelation therapy and probabilities of iron overload-related cardiac disease and death by degree of compliance were estimated using data from published studies. Costs ($US, year 2006 values) of deferoxamine administration and iron overload-related cardiac disease were based on analyses of health insurance claims of transfusion-dependent thalassaemia patients. Utilities were based on a study of patient preferences for oral versus infusional chelation therapy, as well as published literature. Probabilistic and deterministic sensitivity analyses were employed to examine the robustness of the results to key assumptions.

RESULTS

Deferasirox resulted in a gain of 4.5 QALYs per patient at an additional expected lifetime cost of $US126,018 per patient; the cost per QALY gained was $US28,255. The cost effectiveness of deferasirox versus deferoxamine was sensitive to the estimated costs of deferoxamine administration and the quality-of-life benefit associated with oral versus infusional therapy. Cost effectiveness was also relatively sensitive to the equivalent daily dose of deferasirox, and the unit costs of deferasirox and deferoxamine, and was more favourable in younger patients.

CONCLUSION

Results of this analysis of the cost effectiveness of oral deferasirox versus infusional deferoxamine suggest that deferasirox is a cost effective iron chelator from a US healthcare perspective.