Update on Comparative Benefit/Risk Analysis of DMARD Therapies

[Guest guest]

Update on Comparative Benefit/Risk Analysis of DMARD Therapies

Category:  30 Health services research

Wayne J Wallis, F Sabath, Thy P Do, J Burge, Garrison,

Dawn Viveash

Immunex Corporation, Seattle, WA

Presentation Number: 144

Poster Board Number: 144

Keywords: etanercept, benefit/risk, DMARD

Background: Composite efficacy scores such as American College of

Rheumatology (ACR) scores and Disease Activity Scores (DAS) are well

established as useful rheumatoid arthritis (RA) outcome measures in disease

modifying anti-rheumatic drug (DMARD) trials. However, there are no

analogous safety composite scores. Additional insights into benefit/risk may

result when standardized efficacy and safety data are represented

contiguously. One method for evaluating medication benefit/risk is

representation of trial data as NNTB and NNTH.1 NNTB is the number of

patients who need to be treated with a DMARD in order for one additional

patient to benefit beyond the effect observed with placebo. NNTH is the

number of patients who need to be treated with a DMARD in order for one

additional patient to have an adverse experience beyond the effect observed

with placebo. Comparisons of DMARDs across trials require the assumption

that patient populations are comparable.

Methods: A literature search was performed to identify all

placebo-controlled DMARD trial reports published before May 2002 that

included ACR 20 scores and at least 2 of 3 safety outcome measures (all

adverse events (AEs), serious AEs, or withdrawals due to AEs) observed after

6 months of therapy. To simplify the analysis, NNTB was revised to NAB100,

i.e. the number of patients out of 100 treated achieving an ACR20 (beyond

that observed in the placebo arm). NNTH was revised to NAH100, i.e. the

number of patients out of 100 treated achieving an adverse experience

(beyond that observed in the placebo arm). An optimum DMARD would have a

high NAB100 and a low NAH100.

Results: 6 studies of 7 DMARDs met the pre-defined inclusion criteria. Mean

duration of RA across trials ranged from 6 to 13 years. NAB100 analysis

adjacent to NAH100 analysis (defined by withdrawal due to AEs, a risk or

harm outcome available for all studies) yielded the following results:

etanercept 48/0; etanercept plus methotrexate (MTX) 45/2; infliximab plus

MTX 30/0; sulfasalazine 27/12; leflunomide 25/8; adalimumab 17/1; and

anakinra plus MTX 15/4.

Conclusions: NNTB and NNTH (and NAB100 and NAH100) are quantitative measures

of benefit and risk that permit indirect DMARD comparisons. Further

standardization of RA safety outcome measures will advance understanding of

DMARD benefit/risk profiles and support informed prescribing.

References:

1. Cook R., et al. Brit. Med. J. 1995; 301:452-454.

 

Add to My Itinerary

American College