Fig. 1From: Treatment patterns and costs for anti-TNFα biologic therapy in patients with psoriatic arthritisPatient selection flowchart. aThe index date is the date of the use of the first anti-TNFα biologic. bA diagnosis of PsA was established according to the ICD-9-CM code 696.0. cThe ICD-9-CM codes for RA (ICD-9-CM code: 714.x) or AS (ICD-9-CM code: 720.0) were used for diagnosis. AS, ankylosing spondylitis; ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification; PsA, psoriatic arthritis; RA, rheumatoid arthritis; TNFα, tumor necrosis factor-αBack to article page