Assial - Anti Tnf Treatment in Ankylosing Spondylitis: an Observational Cohort Study in Italy

First line anti-TNF treatment included adalimumab, etanercept, golimumab and infliximab. In this outcome, percentage of participants who were taking any one of the first line anti-TNF treatment at baseline and maintained the same up to Month 18 without any change in prescription, were reported.

BASDAI was a validated self-assessment tool used to determine disease activity in participants with AS. Utilizing a numerical rating scale (NRS) of 0-10 (0 = no problem to 10 = worst problem) participants answered 6 questions measuring symptoms of AS (spinal pain, fatigue, joint pain or swelling, areas of localized tenderness, morning stiffness duration and severity). The BASDAI total score was calculated by computing the mean of questions 5 and 6 and adding it to the sum of questions (Q) 1-4. This score was then divided by 5. BASDAI=Q1+Q2+Q3+Q4+[Q5+Q6/2]/5. The total BASDAI score ranges from 0=none to 10=severe, where lower score indicated less disease activity.

Low disease activity was defined as a BASDAI score of less than or equal to (<=) 2. BASDAI was a validated self-assessment tool used to determine disease activity in participants with AS. The total BASDAI score ranges from 0=none to 10=severe, where lower score indicated less disease activity. In this outcome, percentage of participants with unchanged first line anti-TNF drug (nor dose neither frequency, but drug only) in the state of low disease activity, during the specified time points were reported.

ASQoL was a disease-specific questionnaire that assessed the impact of AS on participant's quality of life (QoL). It consisted of 18 questions to be completed by the participant. Each question was answered by the participant as a 'Yes' (scored as 1) or 'No' (scored as 0). Scores of each individual question was summed to give a total score that ranges from 0 (good QoL) to 18 (poor QoL), where lower scores indicated good quality of life. Data for this outcome was planned to be reported separately for switchers (participants who switched to a second anti-TNF drug during observation period) and non-switchers (participants who did not switched to a second anti-TNF drug during observation period).

C reactive protein was measured from blood samples as a marker for inflammation. Higher levels were indicative of more inflammation.

Erythrocyte sedimentation rate was a laboratory test that provided a non-specific measure of inflammation. The test assessed the rate at which red blood cells fell in a test tube and was measured in millimeter per hour (mm/h).