20 Jan

Test and treat strategies for Helicobacter: Cost inputs

Several sources were used to estimate locally relevant direct costs for the resources consumed in the model (Table 2). Wholesale drug costs were determined through a survey of local pharmacies including the Hamilton Health Sciences Corporation (McMaster Site) Outpatient Phar­macy, Hamilton, Ontario. A 10% pharmacy markup was added to the wholesale price, as well as a dispensing fee of $4.11 per prescription ($6.11 minus a copayment of $2.00). Costs for physician services were taken from the 1998 On­tario Ministry of Health Schedule of Benefits.

The costs of outpatient endoscopy, endoscopic biopsy and RUT were derived from the Hamilton Health Sciences Corporation costing model, developed in accordance with the Ontario Case Cost Project (OCCP). The latter is a joint venture of the Ontario Ministry of Health and the Ontario Hospital Association, wherein each of 13 participating insti­tutions uses a standardized methodology to maintain a data­base of resource utilization and resource unit cost indexed by individual patient encounter. The cost of admission for management of complicated PUD was derived from a previ­ously published cost model based in part on the OCCP data­base.

Because no local cost estimate for C-UBT was avail­able, the average cost per test was determined from its fixed and variable cost components. Following convention, the capital cost of purchasing a mass spectrometer was converted to an equivalent annual capital outlay by amortizing over an expected life of 10 years using an interest rate of 5%. Annual fixed costs included technician salary and an institu­tional overhead cost proportionate to the square footage oc­cupied by the laboratory, while variable costs included the purchase price of the test kits and the cost of collecting and shipping the samples to the central laboratory. An annual throughput of 5000 samples was assumed, and the mean cost per test was determined to be $66 (range $40 to $120).

Because serological testing for H pylori is performed out­side the authors’ centre at the regional public health labora­tories, its cost is not captured by their administrative database. Therefore, a similar process was used to combine annual fixed costs, including facility overhead, technician salary, and washer/reader rental and calibration, with vari­able costs for test kits, specimen collection, transportation and processing. By this method, the mean cost per test was determined to be $20 (range $5 to $55) for an annual volume of 5000 samples.

TABLE 2 Cost inputs applied in the decision analysis model.

Item

Base case cost (CDN$)

Range for sensitivity analysis (CDN$)

First-line Helicobacter
pylori
eradication regimen (MOC, 7 days)

88

N/A

Second-line H pylori
eradication regimen (AOC, seven days)

94

N/A

Third-line H pylori
eradication regimen (R-BMT, 14 days)

57

N/A

Ranitidine (generic) for four weeks

30

N/A

Omeprazole (Losec*) for four weeks

146

N/A

Omeprazole (Losec*) for eight weeks

289

N/A

Outpatient endoscopy with biopsy and rapid urea
test

528

250-1250

13Carbon urea breath test

66

40-120

H pylori serology

20

5-80

Primary care visit

25

N/A

Specialist consultation

105

N/A

Specialist follow-up visit

39

N/A

All costs are reported in 1997 CDN$ (CDN$1 is approxi­mately US$0.70).

Cost effectiveness analysis: Consistent with current guid­ance on economic evaluation, the expected costs per patient over one year for each strategy were estimated as the probability-weighted sum of costs outlined above. Similarly, the health outcomes per patient for each strategy were quan­tified as the expected number of H pylori-related ulcers cured with eradication of the organism.

The analytic strategy was twofold – to rule out any strat­egy ‘dominated’ by another, having both higher costs and worse outcomes, and to estimate between nondominated strategies the incremental cost effectiveness of the more costly alternative, the ratio of the difference in costs to the difference in outcome. One- and two-way sensitivity analy­ses were then performed to determine the effect of variation in key model parameters on each relevant incremental cost effectiveness ratio (ICER).
Don’t let the pharmacy companies beat you. 

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