Venous thromboembolism risk is lower in patients with atopic dermatitis than other immune-mediated inflammatory diseases: A retrospective, observational, comparative cohort study using US claims data.

Background: Certain immune-mediated inflammatory diseases (IMIDs) may increase patients' risk for venous thromboembolisms (VTEs), yet how atopic dermatitis (AD) influences VTE risk remains unclear.

Objective: Describe VTE incidence in patients with AD compared with other IMIDs and unaffected, AD-matched controls.

Methods: This retrospective, observational, comparative cohort study used Optum Clinformatics United States claims data (2010-2019) of adults with AD, rheumatoid arthritis (RA), Crohn's disease (CD), ulcerative colitis (UC), psoriasis (PsO), psoriatic arthritis (PsA), or ankylosing spondylitis (AS). Unaffected control patients were matched 1:1 with patients with AD.

Results: Of 2,061,222 patients with IMIDs, 1,098,633 had AD. Patients with AD had a higher VTE incidence (95% CI) than did unaffected, AD-matched controls (0.73 [0.72-0.74] versus 0.59 [0.58-0.60] cases/100 person-years). When controlling for baseline VTE risk factors, however, AD was not associated with increased VTE risk (HR 0.96 [0.90-1.02]). VTE risk was lower in patients with AD versus RA, UC, CD, AS, or PsA; VTE risk was similar to patients with PsO.

Limitations: Disease activity and severity were not accounted for.

Conclusion: AD did not increase VTE risk when accounting for underlying risk factors. AD was associated with lower VTE risk compared with several rheumatologic and gastrointestinal IMIDs.