Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.


Distribution of Tumor Necrosis Factor Inhibitor Use Across Indications in Sweden: Nationwide Register-Linkage Study.

Neovius1,  Martin, Eriksson1,  Jonas, Simard1,  Julia F., Askling1,  Johan, ARTIS Study Group,  

Clinical Epidemiology Unit, Dept of Medicine, Karolinska Institutet, Stockholm, Sweden

Background/Purpose:

Despite widening use of anti-TNF drugs, most long-term safety data come from patients with rheumatoid arthritis (RA). Similarly, most assessments of the societal benefits and costs of anti-TNF drugs are based on presumed distribution across indications. Few large studies have investigated the distribution of use across indications to determine which patients are actually using these drugs today. We estimated this distribution across indications using data from national registers.

Methods:

All individuals in Sweden who were dispensed etanercept and adalimumab in 2009 were identified from the nationwide Prescribed Drug Register. Infliximab was excluded as it is primarily used in hospitals, not on prescription in ambulatory care, and therefore not registered on a patient level. The dataset was linked to the National Patient Register, which holds information on all inpatient and specialist outpatient visits, including associated main and subdiagnoses. On the basis of visit diagnoses in 2001–2009, patients were identified as having RA, ankylosing spondylitis (AS), psoriatic arthritis (PsA), psoriasis and/or inflammatory bowel disease (IBD).

Results:

12,142 unique patients exposed to etanercept (n=7,261) or adalimumab (n=5,402) were identified. The highest proportion of users had RA (59%), followed by PsA (17%), IBD (12%), other (10%), AS (10%), and psoriasis (7%). Rheumatic indications (RA, AS and PsA) constituted 77% of overall use. The distribution differed markedly for etanercept and adalimumab: only 2% of etanercept users had IBD compared to 24% of adalimumab users (Table).

Distribution of Etanercept and Adalimumab Use in the Swedish Population in 2009

IndicationBoth (n=12,142)N (%) Etanercept (n=7,261)Adalimumab (n=5,402)
Rheumatology9,375 (77%)6,082 (84%)3,722 (69%)
  Rheumatoid Arthritis7,132 (59%)4,763 (66%)2,676 (50%)
  Ankylosing Spondylitis1,202 (10%)625 (9%)635 (12%)
  Psoriatic Arthritis2,039 (17%)1,318 (18%)852 (16%)
Dermatology   
  Psoriasis (excl PsA)686 (7%)473 (8%)251 (6%)
Gastroenterology   
  Inflammatory bowel disease1,435 (12%)179 (2%)1,286 (24%)
Juveniles and/or Other Conditions1,212 (10%)819 (11%)449 (8%)
Diagnostic categories not mutually exclusive. Therefore column percentage sums may exceed 100% due to overlap, i.e. patients having more than one diagnosis.

Conclusion:

While long-term safety data are dominated by studies on patients with RA, RA accounted for only about half of anti-TNF users in Sweden in 2009. This surprisingly low proportion underscores the need for safety, cost and effectiveness studies in patients with diseases other than RA, especially as some of these patient groups display very different age-, sex-, and birth cohort-distributions, as well as dosing regimen.

To cite this abstract, please use the following information:
Neovius, Martin, Eriksson, Jonas, Simard, Julia F., Askling, Johan, ARTIS Study Group, ; Distribution of Tumor Necrosis Factor Inhibitor Use Across Indications in Sweden: Nationwide Register-Linkage Study. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :1884
DOI:

Abstract Supplement

Meeting Menu

2011 ACR/ARHP