Postmenopausal Osteoporosis PHARMACOECONOMIC CONSIDERATIONS

A review of the literature indicates that published data on the pharmacoeconomics of PMO therapy in the U.S. are limited and inconclusive. Most pharmacoeconomic analyses were conducted retrospectively or were cost-model studies, and most analyses focused on alendronate canadian. Pharmacoeconomic studies are summarized in Table 4.

Only one prospective pharmacoeconomic evaluation was identified in the area of PMO treatment. Derived from the Fracture Intervention Trial (FIT), this analysis identified fracture-related use of emergency departments, hospitals, nursing homes, or rehabilitation hospital services but did not identify drugs in women 55 to 81 years of age with low BMD (T-scores below 0). Chrischilles et al. estimated the cost of fracture-related health care utilization based on Medicare reimbursement rates and other public program fee schedules. In this study, alen-dronate was associated with significantly lower fracture-related costs, compared with placebo. The estimated cost-benefit was $181 per treated patient over three years (P = 0.036). Total fracture-related costs were also reduced with alendronate by $190 per treated patient, compared with placebo, although the reduction did not reach significance (P = 0.114).

Schousboe et al. published results from three modeling studies by using fracture outcomes data from FIT.

Table 4 Summary of Pharmacoeconomic Studies for Postmenopausal Osteoporosis (PMO) Therapies

Study / Population Cost and Source Drug Cost (AWP) Result
ALEN vs. no treatmentAge: 55 to 81 years;T-score, < 0 Fracture-related medical care over 3 years Public fee schedules Notincluded $181 savings per treated patient
ALEN vs. no treatment Age: 55-75 years; T-score,-1.5 to -2.4 No prior fracture Fracture-related medical care/Medicare Reduced productivity/ literature $894/year $70,732/QALY (age 65,T-score of -2.5) $382,250/QALY (age 80,T-score of -1.5)
ALEN vs. no treatmentAge: 60 to 80 years; T-score, -1.5 to -2.4 Fracture-related medical care, incl. VFA screening/Medicare $842/year >$250,000/QALY (any age, no vert. deform.) $35,63I/QALY (age 80,T-score <—2.5 + vert. deform.) $I8,864/QALY (age 60,T-score <—2.5 + vert. deform.)
ALEN vs. no treatment Age: 60 to 80 years; T-score, -1.5 to -2.4 Fracture-related medical care (x-ray screening/ Medicare, reduced productivity/literature) $842/year >$250,000/QALY (T-score -I.5)$30,420/QALY (age 70, with or without vert. deform.)

$42,I92 (age 80, no vert. deform.)

ALEN / RISD vs. no treatment Age: 65 years; T-score, < -2 Fracture-related medical care/literature ALEN:$843/year RISD: $763/year ALEN: $30,000/QALY,approx. $36,000 per averted hip fractureRISD:$I6,I58/QALY, $17,649 per avoided hip fracture
ALEN versus RALAge: 55 years; new treatment Fracture, breast cancer, and CHD-related medical care/literature Notprovided ALEN: $2,850 per PMO event averted RAL: $4,180 per PMO event averted, or $600 per CHD or PMO event avoided
ALEN,TPD, or TPD + ALENPMO women;

T-score, -2.5

Prior vertebral fracture

Fracture-related medical care/Medicare ALEN:$894/year TPD:

6,720/year

ALEN:$II,600/QALYTPD:$I72,300/QALY

TPD + ALEN: $I56,500/QALY

< $50,000/QALY (age < 70+,T-score of -4.0)

Model 1

The first study modeled direct medical costs based on Medicare reimbursement rates, drug treatment costs, and in­direct societal costs related to productivity losses associated with PMO fractures. Assumptions related to quality-adjusted life-years (QALY), associated with PMO and fractures, were drawn from the literature. An economic model based on five years of treatment was developed to predict the incremental cost-effectiveness ratio (ICER) associated with alendronate therapy, compared with no treatment, by age and T-scores. Specifically, the study estimated the cost to gain one fully productive year of life (one QALY) with alendronate versus not treating a patient with alendronate. The willingness to pay for such a gain depends on the stakeholder; however, the models discussed in this section used $50,000 per QALY as the cost-effectiveness threshold.

Using a Markov cost-utility model, the investigators estimated the cost for QALY gained for treating women aged 55 to 75 years of age with T-scores in the osteopenia range (-1.5 to -2.4) without a prior history of fracture. ICERs ranged from $70,732 in a 65-year-old with a T-score of -2.5 to $382,250 in an 80-year-old woman with a T-score of -1.5. Thus, using alendronate as prophylaxis in osteopenic women without a history of fracture was not cost-effective.

Models 2 and 3

Two additional alendronate models estimated the cost-effectiveness of treating women 60 to 80 years of age and with T-scores of-1.5 to -2.4 with after screening for vertebral deformities, or vertebral compromise. The screening techniques consisted of vertebral fracture assessment (VFA) using dual-energy densitometry and traditional x-rays.

One study, which evaluated cost-effectiveness of treatment after VFA, assessed drug costs and direct medical costs, including VFA screening, based on Medicare and other public fee schedules, over five years. These cost estimates were used to model the cost for a QALY gain associated with alendronate therapy compared with no treatment by age, T-score, and prevalence of vertebral deformities.

A Markov model was used to estimate the cost per QALY gained for treating a woman with a T-score of -1.5 and no existing vertebral deformities with alendronate (compared with no treatment). The study suggested that fracture prevention with alendronate was not cost-effective; the cost per QALY exceeded $250,000 regardless of age. However, the cost per QALY gained for treating a woman with a T-score approaching -2.5 and with evidence of spinal deformities, as identified by VFA, ranged from $18,864 for a 60-year-old woman to $35,631 for an 80-year-old woman. Thus, treating postmenopausal women was cost-effective if T-scores indicated osteoporosis and if there was a previous vertebral deformity.

The third model, which included x-ray screening, calculated the incremental cost per QALY gained with five years of alen-dronate treatment versus no treatment. In this model, treatment with alendronate was not cost-effective, compared with no treatment, in women with T-scores of -1.5; the cost per QALY exceeded $250,000. However, alendronate therapy was cost-effective in women with T-scores from -1.5 to -2.5 and a vertebral deformity. ICERs ranged from $4,073 for women 70 years of age with T-scores of -2.4 to $36,457 for women 80 years of age with T-scores of -1.5.

Treating all women with T-scores of -2.5 with alendronate was cost-effective whether or not they had vertebral deformities. The model estimated costs per QALY gained from $30,420 for a woman 70 years of age regardless of vertebral deformity to $42,192 for an 80-year-old and no prior vertebral deformity. Thus, alendronate seems to be cost-effective in treating PMO in women with T-scores above -2.5 with evidence of vertebral deformity and in those women with T-scores approaching the osteoporosis range with or without vertebral deformities.

Two additional studies describe the cost benefit of alendronate compared with other antiresorptive agents.

Grima et al. compared the cost per QALY gained and per hip fracture averted over three years for alendronate and rise-dronate in women 65 years of age with T-scores of -2.5 or below. Using a Markov model, the study authors found that costs were lower and treatment outcomes were better than with alendronate. Compared with no treatment, the model estimated that the cost per QALY gained with risedronate was $16,158, and the cost of an averted hip fracture was $17,649. Compared with no treatment, the estimated cost per QALY gained of alendronate exceeded $30,000, and the estimated cost of averting a hip fracture was $36,000.

Mullins and Ohsfeldt estimated the cost of preventing one event in women 55 years of age who started alendronate or canadian raloxifene therapy, compared with no treatment, over the first seven years of treatment. They evaluated the budgetary impact, taking into account persistence with medication. Outcome events were defined as a fracture, breast cancer, or myocardial infarction.

Barrett-Connor et al., in a more recent trial, however, found that raloxifene did not demonstrate a reduction in coronary heart disease (CHD), thereby bringing into question the models’ assumptions about CHD risk reduction. When CHD risk reduction was not considered, the cost per event avoided was $600 for raloxifene and $2,850 for alendronate. When CHD and breast cancer risk reductions were removed from the model, isolating the effects of treatment on fracture risk reduction, the cost per event avoided with raloxifene was $4,180. Thus, the cost benefit, compared with alendronate, was primarily a result of the reduction in events unrelated to PMO.

The pharmacoeconomic data on teriparatide are limited; only one published study was identified. Liu et al. evaluated the cost of gaining one QALY with alendronate alone for five years, teri-paratide alone for two years, and teriparatide for two years, followed by five years of alendronate in women with PMO and T-scores of -2.5 and a prior vertebral fracture. This micro-simulation model found that alendronate alone cost $11,600 per QALY, compared with calcium and/or vitamin D supplementation. The cost per QALY was $172,300 for teriparatide alone and $156,500 for teriparatide followed by alendronate.

The cost-effectiveness of alendronate alone and of teri-paratide, followed by alendronate, improved with increasing age and lower BMD T-scores. The cost-effectiveness of sequential therapy was below $100,000 per QALY for women 50 years of age and older with T-scores of -4.0 and for women 60 years of age and older and T-scores of -3.5.

ICERs were at or below $50,000 for women 70 years of age and older with T-scores of -4.0. Thus, the use of teriparatide was cost effective with alendronate in very-high-risk women.