Participants measured their present pain intensity on a visual analogue scale (VAS), where the responses were on a continuous range from 0 (no pain) to 100 (worst pain imaginable).

All participants with an assessment. n=number of participants with an assessment at time point.

Physicians measured participants' present pain intensity on a visual analogue scale (VAS), where the responses were on a continuous range from 0 (no pain) to 100 (worst pain imaginable).

All participants with an assessment. n=number of participants with an assessment at time point.

Participants measured their present pain intensity by specifying their level of pain in response to the question "How intensive is your pain at present?" on a 4-point Likert scale, where 0 = no pain; 1 = mild pain, 2 = moderate pain, 3 = severe pain.

All participants with an assessment at time point.

Participants measured their pain intensity in the past 3 months on a visual analogue scale (VAS), where the responses were on a continuous range from 0 (no pain) to 100 (worst pain imaginable).

All participants with an assessment. n=number of participants with an assessment at time point.

Participants measured their pain intensity in the past 3 months by specifying their level of pain in response to the question "How intensive was your pain on average in the past 3 months?" on a 4-point Likert scale, where 0 = no pain; 1 = mild pain, 2 = moderate pain, 3 = severe pain.

All participants with an assessment.

Participants assessed the pattern of their pain progression in the past 3 months according to the following descriptors: intermittent (daytime and/or nocturnal); mostly daytime; mostly nocturnal; continuous (daytime and nocturnal).

All participants with an assessment. n=number of participants with an assessment at time point.

Participants assessed the pattern of their pain progression in the past 3 months according to the following descriptors: the type of beginning of pain was mostly sudden; the type of beginning of pain was mostly creeping.

All participants with an assessment. n=number of participants with an assessment at time point.

Participants assessed how often on average they noted the presence of nocturnal pain in the past 3 month according to the following descriptors: never; rarely (not exceeding once a week), every night (awake from sleep at least once a night), more than once a night per week.

All participants with an assessment.

The SF-36 determines participants' overall quality of life by assessing 1) limitations in physical functioning due to health problems; 2) limitations in usual role because of physical health problems; 3) bodily pain; 4) general health perceptions; 5) vitality; 6) limitations in social functioning because of physical or emotional problems; 7) limitations in usual role due to emotional problems; and 8) general mental health. Items 1 to 4 primarily contribute to the physical component summary score (PCS) of the SF-36. Items 5 to 8 primarily contribute to the mental component summary score (MCS) of the SF-36. Scores on each item are summed and averaged (range = 0 [worst] to 100 [best ]). The standard recall period is 4 weeks. Increases from Baseline indicate improvement.

All participants with an assessment. n=number of participants with an assessment at time point.

The HAQ-DI is a participant-reported questionnaire. It consists of 20 questions referring to 8 domains: dressing/grooming, arising, eating, walking, hygiene, reach, grip, and daily activities. Participants assessed their ability to do each task over the past week using the following response categories: without any difficulty (0); with some difficulty (1); with much difficulty (2); and unable to do (3). Scores on each task were summed and averaged to provide an overall score ranging from 0 to 3, where 0 represents no disability and 3 represents very severe, high-dependency disability. The minimal clinically important difference defined for the HAQ-DI is ≥0.22. HAQ remission, indicating normal physical function, is defined as HAQ-DI < 0.5.

All participants with an assessment. n=number of participants with an assessment at time point.

The RADAI is a questionnaire for patients used for measuring disease activity. The index consists of 6 questions. The items ask the participants about (1) global disease activity in the last 6 months, (2) disease activity in terms of current swollen and tender joints, (3) arthritis pain, (4) the current status of health, (5) duration of morning stiffness and (6) tender joints to be rated in a joint list. The joint list asks about pain in the left and right shoulders, elbows, wrists, fingers, hips, knees, ankles and toes. The first 4 items are all rated on a numeric rating scale from 0 to 10, where higher scores indicate more disease activity. The scores on the last 2 items range from 0 to 6 and 0 to 48, respectively, but are transformed on the same scale of 0 to 10. The RADAI total score is the sum of individual items divided by 5 (range 0-10), with a higher score signifying more disease activity.

All participants with an assessment. n=number of participants with an assessment at time point.

The BASFI is a set of 10 questions designed to determine the degree of functional limitation in those with AS. The 10 questions were chosen with a major input from patients with AS. The first 8 questions consider activities related to functional anatomy. The final 2 questions assess the participants' ability to cope with everyday life. A visual analogue scale (with 0 being "easy" and 10 "impossible") is used to answer the questions on the test.

Participants with AS or PsA and an assessment. n=number of participants with an assessment at time point.

The BASDAI is used for measuring and evaluating disease activity in AS. This index consists of 6 questions pertaining to the 5 major symptoms of AS: fatigue, spinal pain, joint pain/swelling, areas of localized tenderness (or enthesitis, defined as inflammation of tendons and ligaments), duration of morning stiffness, severity of morning stiffness. A visual analogue scale ranging from 0 (none) to 10 (very severe) is used to answer the questions. The final BASDAI score averages the individual assessments for a final score range of 0-10 (0 being no problem and 10 being the worst problem).

All participants with an assessment. n=number of participants with an assessment at time point.

The ESR is a practicable and sensitive but not specific parameter for measuring disease progression. By means of the ESR it can be generally distinguished between an active and nonactive rheumatic disease. The normal reference range is, as a rule, 0 to 10 mm/h for men and 0 to 15 mm/h for women. The higher the ESR value out of the normal range, the higher is the disease activity.

All participants with an assessment. n=number of participants with an assessment at time point.

The CRP is an acute phase reactant plasma protein, normally produced by the liver, which is commonly used as an indirect measure of the extent and activity of an inflammation. The CRP normal reference range in the blood is, as a rule, from 0 to 1.0 mg/dL.

All participants with an assessment. n=number of participants with an assessment at time point.

Participants indicated their perception of average distress caused by pain in the past 3 months on a 5-point Likert scale, where; 0 = no pain, 1 = not distressed, 2 = slightly distressed, 3 = moderately distressed, 4 = greatly distressed by pains.

All participants with an assessment.