Swedish study provides first evidence of TNF-inhibitor cost-effectiveness in routine clinical practice

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Rheumawire

Dec 22, 2003

Swedish study provides first evidence of TNF-inhibitor

cost-effectiveness in routine clinical practice

Speracedes, France - The first comprehensive analysis of actual

clinical-practice outcomes for patients with rheumatoid arthritis (RA)

treated with TNF inhibitors shows that such treatment halves the need

for surgery and durably improves disability scores in patients treated

for at least 1 year. This can be achieved at a cost well within usually

accepted cost-benefit ranges, Dr Gisela Kobelt (European Health

Economics, Speracedes, France) reports in the January 2004 ls of

Rheumatic Disease [1].

" For this patient group, cost-effectiveness ratios are within the

generally accepted threshold of ?50 000 but need to be confirmed with

larger samples, " Kobelt writes.

Kobelt and Swedish colleagues from the Karolinska Institute and Lund

University Hospital asked whether the clinical and quality-of-life (QOL)

benefits from TNF-inhibitor treatment justified the additional cost;

which patients benefited most from the new treatments; and whether the

results in clinical practice differed from those reported in clinical

trials and in early economic analyses. They conclude that the benefits

justify the cost, especially for patients with more severe disease, and

that " real-world " experience does generally confirm the results seen in

more academic settings.

Sweden has a well-known fondness for patient registries, and the

investigators were able to use data from a follow-up registry set up in

southern Sweden in 1999, which includes over 90% of all patients in the

area who have ever been prescribed etanercept (Enbrel®, Wyeth/Amgen) or

infliximab (Remicade®, Centocor). Patients came from 4 rheumatology

centers (Helsingborg, Kristianstad, Trelleborg, and Lund).

Eligibility for TNF-inhibitor therapy required RA and either failure to

respond to or intolerance of at least 2 disease-modifying antirheumatic

drugs (DMARDs), including methotrexate. The registry included 160

patients who began treatment with either etanercept (n=113) or

infliximab (n=47) between March 1999 and June 2000. The analysis

included the 116 patients who continued to receive treatment for 1 full

year. Of these, 71 had completed at least 2 years of treatment and 40

had completed 3 years.

Outcome measures included the Health Assessment Questionnaire (HAQ), the

28-joint Disease Activity Score (DAS28), and the EQ-5D health-related

QOL questionnaire. Economic data included resource consumption, work

capacity, hospital admissions, surgical interventions, drug use, and

short- and long-term work absence.

" For patients who continued to receive treatment, use of all types of

resources decreased during the first year, and consumption of anti-TNF

treatments remained stable in the second year. The direct cost reduction

was mostly due to a decrease in hospital care and surgery, " Kobelt

reports. Outpatient visits increased due to the requirements for

administering and monitoring TNF-inhibitor treatment.

The result is that direct costs in the first year dropped by 40%, or

?2250, driving the net cost of adding TNF-inhibitor treatment down to

?12,200. Assuming that improvement in symptoms and quality of life began

after 6 weeks of treatment (when the HAQ and DAS28 began to show

improvement), Kobelt estimates that the cost per quality-adjusted

life-year (QALY) was ?36 900 for the entire group of patients.

The cost per QALY gained with 1 year of treatment dropped from ?128 500

for patients with HAQ <0.6 at baseline to ?61 000 for those with HAQ

1.1-1.6 and ?37 300 for those with HAQ 1.6-2.1. It bounced back to ?43

000 for patients with HAQ >2.1 at baseline. " [T]he estimates indicate

that over 1 year, anti-TNF treatment is more cost effective in patients

with more advanced disease. However, in view of the small number of

patients in each group, and the possibility that the gain in utility is

overstated, no firm conclusion can be drawn from these estimates, "

Kobelt writes.

Work capacity increased from 31% to 33% for patients younger than age

65, but Kobelt comments that this is not surprising, because the

majority of patients were already severely disabled and on long-term

sick leave at study entry.

Kobelt emphasizes that the cost per QALY gained ranged from ?36 900 to

?53 600 during the first year and that the cost-effectiveness ratios

were calculated in comparison with the baseline year, not in comparison

with patients receiving other RA treatments. By comparison, new

treatments have been considered acceptable at a net benefit threshold of

about ?35 000 to ?50 000 in Sweden, ?45 000 in the UK, and ?95 000 in

the US.

The researchers write, " [C]onsidering that both HAQ and DAS28 remain at

their 12-month level during the second (and third) year for patients who

continue treatment, one can speculate that costs and utilities also

remain stable, " suggesting that cost-effectiveness might be maintained

beyond 1 year. They also point out that this might actually

underestimate long-term cost-effectiveness, as it ignores a possible

effect of treatment on progression.

Janis

Source

1. Kobelt G, Eberhardt K, Geborek P. TNF inhibitors in the treatment of

rheumatoid arthritis in clinical practice: costs and outcomes in a

follow up study of patients with RA treated with etanercept or

infliximab in southern Sweden. Ann Rheum Dis 2004 Jan; 63(1):4-10.