8 INTERNATIONAL RESEARCH & OPINION

Cardiovascular news from the 4th annual ISPOR meeting Arlington, Virginia, US May 1999

The following selection of research findings related to the study of cardiovascular health economics was presented at the 4th annual meeting of the International Society for PharmacoEconomics and Outcomes Research (ISPOR) [Arlington, Virginia, US; May 1999].

Tnilazad cost effective in SAH At a 'Talking Poster' session, Dr Henry Glick from

the University of Pennsylvania Medical Center in Philadelphia, US, described the results of a study showing that tirilazad ['Freedox'; Pharmacia & Upjohn] is cost effective, compared with placebo, for the treat­ment of patients with severe aneurysmal subarachnoid haemorrhage (SAH). 1 Notably, tirilazad was more cost effective among women than among men with SAH.

Using data collected prospectively during 4 multi­national phase III clinical trials, Glick and colleagues found that tirilazad recipient<> had a significantly lower 3-month mortality rate than placebo recipients, and that this difference was significant for both men and women [see table]. Three-month direct costs (1997 values) were higher in the tirilazad group than in the placebo group (by $US8700/patient), and higher among men than among women (in both treatment groups).*

Costs and outcomes associated with the treatment of aneurysmal subarachnoid haemorrhage•

Tlrllazed (n = 216) Plecebo (230)

Mortality at 110 days (% of patients):

all patients 26 41

men 6 45

women 30 40

Direct cast at 110 days (SUS/patient) .. :

all palients 34578 25851

men 40978 35469

women 33417 24321

• 3-month outcomes collected prospectively during 4 phase Ill clinical trials

** 1997 US dollars; multivariate prediction

More cost effective among women Glick and colleagues projected outcomes beyond 3

months by linking 3-month outcomes with data on 2-year survival and 20-year survival from a Danish SAH registry.

They estimated that, over the 20 years following SAH, patients who received tirilazad would have a discounted survival benefit of 1.54 life-years gained (LYG) or around 1 quality-adjusted life-year (QALY) gained, compared with those who received placebo. 20-year direct costs were estimated at $US 113 690 per tirilazad recipient and $US85 215 per placebo recipient, making tirilazad the more costly option by $US28 4 75/patient. The survival advantage of tirilizad was found to be greater for men than for women (3 vs 1 QALYs gained, respectively), as was the additional 20-year direct cost associated with tirilazad treatment ($US86 341 vs $US16 984 per patient).

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Thus, the 3-month clinical trial findings projected out to 20 years gave an incremental cost-utility ratio for tirilazad of $US29 600/QALY gained, compared with placebo, for the treatment of SAH. This value was $US24 500/QALY gained among women and $US34 100/QALY gained among men. Glick and colleagues concluded that these ratios 'compare favorably with many other medical technologies'.

Alteplase more cost effective than streptokinase A group of researchers from the University of

Southern California, US, presented a poster showing the results of an economic analysis comparing the societal costs of treating acute myocardial infarction (MI) with either alteplase or streptokinase.2

Using a decision-analysis model and 1-year mortality data from the GUSTO** trial, the researchers estima­ted that alteplase treatment produced 10.325 QALYs at a cost of $US 15 777, whereas streptokinase produced 10.175 QALY s at a cost of $US 12 050. This resulted in alteplase having an incremental cost-utility ratio of $US22 400/QALY saved, compared with streptokinase.

Sensitivity analysis showed that the incremental cost utility of alteplase was sensitive to the drug's acquisition cost; alteplase remained cost effective until its cost increased by nearly 75% (based on a threshold value of $US50 000/QALY). The model was developed using data from GUSTO and other thrombolytic studies. This economic analysis used data for 124 patients with acute MI from the GUSTO trial who were randomised to receive either alteplase (n = 62) or streptokinase (62). Costs included both direct costs such as hospitalisation, drug acquisition, follow-up hospitalisation and physician services, as well as indirect costs.

Enoxaparin not superior to warfarin? In another poster, T Egan from the University

of Sciences in Philadelphia, US, described how 'the purported advantages of enoxaparin over warfarin were not seen' in patients undergoing hip surgery at the Graduate Hospital in Philadelphia.3

Retrospective analysis of database records for 48 patients who underwent hip surgery at the hospital between October 1994 and September 1995 showed that the complication rate was lower among warfarin recipients than among enoxaparin recipients (39.6 vs 50.7%, respectively). Furthermore, the duration of hospitalisation was smaller in the warfarin group (6.6 vs 10.5 days), as was the total direct cost ($US6860 vs $US 10 320 per patient). These findings still favoured warfarin after risk adjustment. There was no evidence of either deep vein thrombosis or pulmonary embolism in the 2 patient groups during the 6-month follow-up period after discharge.

* Costs included tfwse related to drug acquisition, fwspitalisation, imaging studies, surgical procedures and outpatient care. *"' Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Artery [see also Pharmaco­Economics & Outcomes News 29:3-4,25 May 1995; 800314442]

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INTERNATIONAL RESEARCH & OPINION

Citicoline vs standard care in stroke Investigators from Lewin-TAG in Boston US

exhibited a poster reporting the results of a ~ode,lling study comparing the !-year direct cost of stroke-related care in patients receiving either citicoline or standard care, including the use of alteplase in 3.6% of cases.4

In the base-case analysis (in which the cost of citicoline was assumed to be $USO), stroke-related care was estimated to cost $US37 066/patient/year ~n the citicoline group and $US38 456/patient/year m the standard-care group; expected utilities were greater in the citicoline group (0.547 vs 0.479, respectively). In the sensitivity analysis (in which medication costs in the citieoline group were assumed to be $US2200/patient), stroke-related care was estimated to cost $US39 !55/patient/year in the citicoline group and $US38 456/patient/year in the standard-care group.

Stroke costs vary with treabnent phase functional status '

Notably, the investigators found that the direct cost of stroke-related care varied with both the treatment phase and patient functional status. For example, in the base-case analysis, the median per-patient annual cost in the citicoline group wa~ estimated at $US8844 in the acute phase of treatment (index hospitalisation), $US15 073 in the recovery phase (discharge to 3 months) ~d U~ 13 149 in the maintenance phase (3-12 months). Ltkewtse, median costs in the standard-care group were es~ated at $U~8941, $US14 944 and $US14 571 per patient per year m the acute, recovery and maintenance phases, respectively.

Depending on a patient's functional status, the direct cost of stroke-related care during the mainte­nance period varied from $US4274/patient (Barthel Index score of95-100 at 3 months) to $US35 533 (0---50).

The decision-analysis model used by the investiga­tors was developed using expert opinion, national claims data and data from the literature. Costs were :eported from the payer perspective ( 1996 values) and mcluded those related to drug acquisition, hospitalisa­tion, rehabilitation, home care and other forms of outpatient care.

Amlodipine: higher drug costs vs nifedipine The calcium antagonists amlodipine and nifedipine

have both been approved for use in hypertension by the l!S FDA:. However, amlodipine is more costly, and 1t has still not been established whether the 2 drugs have equivalent antihypertensive efficacy.

A group of US-based researchers (including 3 from Bayer.Corporation, Connecticut) presented a paper reportmg the results of a retrospective analysis of Pennsylvania Medicaid database records for patients (aged 18-64 years) with hypertension who had begun treatment with either nifedipine (n = 151) or amlodipine (316) in 1994.5

Although there were no significant differences between treatment groups in terms of patient compli­ance, among noncompliant patients, significantly

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more amlodipine than nifedipine recipients crossed over to another class of antihypertensive agent. Moreover, patients taking amlodipine had signifi­cantly higher total per-patient medication costs than patients taking nifedipine ($US2407 vs $US 1960, respectively); this was due to significantly higher study-drug acquisition costs ($US455 vs $US325) and antihypertensive drug costs ($US626 vs $US435) in the amlodipine group. ·

Hypertension DM strategies compared Researchers from the Cedars-Sinai Health System

presented a poster describing the outcomes of a randornised trial comparing 2 different disease manage­ment (DM) strategies for patients with uncontrolled hypertension. 6

They found that a DM programme in which patient care was integrated through co-management by the pharmacists and primary-care provider (PCP) generated superior clinical and economic outcomes, compared with a 'Physician Alert Program' in which the PCP received education and support.

Under the 'Pharmacist-PCP Co-Management Program', patients with uncontrolled hypertension were enrolled in a pharmacist-run clinic where they received guideline-based therapy (no equivalent drug substitutions), patient-specific education, pharmacist interviews, BP measurement and close follow-up, and compliance review and reinforcement. The programme was overseen by a PCP who made the final clinical decisions.

In contrast, patients randomised to the 'Physician Alert Program' received care from PCPs according to treatment guidelines based on met recommendations. These PCPs received physician education and academic detailing, and patients were informed of BP findings and the intention to follow patient progress.

Lower PMPM costs with co-management By intent-to-treat analysis, patients in both groups

had significant reductions in both systolic and diastolic BP at 6 and 12 months, compared with baseline. However, the reductions in systolic BP were signifi­cantly greater in the 'Co-Management' group than in the 'Alert' group. Moreover, per-member per­month (PMPM) visit costs were significantly lower in the 'Co-Management' group at 12 months ($US12 vs $US 16, respectively) and at 18 months ($US 11 VS $US17). t US National Heart, Blood, and Lung Institute Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure

1. Polsky D, et al. Economic analysis of tirilazad mesylate for aneurysmal subarachnoid hemorrhage: economic evaluation combining four phase III clinical trials. Value m Health 2: 152-153, May Jun 1999 2. Kamath T, eta!. CosHffectiveness of thrombolytic agents in the treattnent of acute myocardial infarction. Value in Health 2: 163-164, May-Jun 1999 3. Egan T Pharmacoeconomic analysis of warfarin versus enoxaparin used prophylactically in hip surgery. Value in Health 2: 158, May-Jun 1999 4. Wilson DA, eta!. Cost of ischemic stroke treaunent by functional status: a model comparing citicoline to standard care. Value in Health 2: 152, May-Jun 1999 S. Lenert LA. et a!. Outcomes of treattnent uncomplicated hypertension with dihydropyridine calcium channel blockers. Value in Health 2: 159, May-Jun 1999 6. Borenstein J, eta!. Hypertension disease management: a randomized comparative trial. Value in Health 2: 163, May-Jun 1999

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