PT  - JOURNAL ARTICLE
AU  - Elana Meer
AU  - Telma Thrastardottir
AU  - Xingmei Wang
AU  - Maureen Dubreuil
AU  - Yong Chen
AU  - Joel M.  Gelfand
AU  - Thorvardur Jon  Love
AU  - Alexis Ogdie
TI  - Risk factors for diagnosis of psoriatic arthritis, psoriasis, rheumatoid arthritis, and ankylosing spondylitis: A set of parallel case-control studies
AID  - 10.3899/jrheum.210006
DP  - 2021 Aug 01
TA  - The Journal of Rheumatology
PG  - jrheum.210006
4099  - http://www.jrheum.org/content/early/2021/07/25/jrheum.210006.short
4100  - http://www.jrheum.org/content/early/2021/07/25/jrheum.210006.full
AB  - Objective To compare potential risk factors for the diagnosis of psoriatic arthritis (PsA), psoriasis, rheumatoid arthritis (RA), and ankylosing spondylitis (AS). Methods Four parallel case-control studies were conducted within The Health Improvement Network using data between 1994 and 2015. Patients with PsA, psoriasis, RA, or AS were identified using validated code lists and matched to controls on age, sex, practice, and year. Risk factors were selected in the time prior to diagnosis. Multivariable logistic regression models were constructed for each disease using automated stepwise regression to test potential risk factors. Results Patients with incident PsA (N=7,594), psoriasis (N=111,375), RA (N=28,341), and AS (N=3, 253) were identified and matched to 75,930, 1,113,345, 282,226, and 32,530 controls, respectively. Median diagnosis age was 48 (IQR 38-59), 41 (31-54), 43 (31-54), and 60 (48-71), respectively. In multivariable models, there were some shared and some differing risk factors across all 4 diseases: PsA was associated with obesity, pharyngitis, and skin infections; PsA and psoriasis were associated with obesity and moderate alcohol intake; PsA and AS were associated with uveitis; and PsA and RA were associated with preceding gout. Both RA and AS were associated with current smoking, former moderate drinking, anemia, osteoporosis, and inflammatory bowel disease. All shared former or current smoking as a risk factor; statin use was inversely associated with all 4 diseases. Conclusion Shared and different risk factors for PsA, psoriasis, RA, and AS were identified. Statin use was inversely associated with all 4 conditions.