BASDAI is a validated self-assessment tool used to determine disease activity in participant with AS. Utilizing a 11-point Likert-scale (0= none and 10=very severe) participant's answered 6 questions measuring discomfort, pain and fatigue. The index was computed by adding questions 1 to 4 plus the mean of questions 5 and 6. The resulting 0 to 50 score was divided by 5 to give a final 0-10 BASDAI score (0 being no problem and 10 being the worst problem).

BASFI is a validated self assessment tool that determines the degree of functional limitation in AS. Participants answered 10 questions, consisting of 8 specific questions regarding function in AS and 2 questions reflecting the participant's ability to cope with everyday life. Each question was answered on a 0-10 scale (0 being no problem and 10 being the worst problem), the sum of which (divided by 10) resulted in the BASFI score (0-10).

Occiput-to-wall distance is the distance between the occiput (posterior or back portion of the head) and the wall when the participant stood with heels and shoulder against the wall and the back straight.

Lateral lumbar flexion was determined by the difference of the finger-floor-distance in normal position and in lateral bending position.

Participants were asked to assess their global pain intensity within the past 7 days. Pain was evaluated on an 11-point Likert scale: min = 0 (best), max = 10 (worst).

Participants were asked to assess their disease activity within the past 7 days. Disease activity was evaluated on an 11-point Likert scale: min = 0 (best), max = 10 (worst).

Physicians were asked to assess the disease activity of participants within the past 7 days. Disease activity was evaluated on an 11-point Likert scale: min = 0 (best), max = 10 (worst).

Duration of morning stiffness is defined as the time elapsed when participant woke up in the morning and was able to resume normal activities without stiffness in minutes.

Duration of morning stiffness is defined as the time elapsed when participant woke up in the morning and was able to resume normal activities without stiffness in minutes. A significant reduction of duration of morning stiffness is defined as a reduction of the duration in minutes by at least 20 percent or reduction to 'no morning stiffness' (absence of morning stiffness).

Peripheral arthritis is the inflammation of joints that involved asymmetrically. It involved the hips, shoulder girdle (glenohumeral, acromioclavicular, and sternoclavicular joints), joints of the chest wall (costovertebral joints, costosternal junctions) and symphysis pubis.

Peripheral arthritis is the inflammation of joints that involved asymmetrically. It involved the hips, shoulder girdle (glenohumeral, acromioclavicular, and sternoclavicular joints), joints of the chest wall (costovertebral joints, costosternal junctions) and symphysis pubis. In case of no presence of peripheral arthritis the number of affected joints was set to 0.

Enthesitis is the inflammation of the enthesis, where the joint capsules, ligaments or tendons attach to the bone. This inflammation can lead to severe pain and discomfort.

Enthesitis is the inflammation of the enthesis, where the joint capsules, ligaments or tendons attach to the bone. This inflammation can lead to severe pain and discomfort. In case of no presence of enthesitis the number of affected body parts was set to 0.

The test for CRP is a laboratory measurement for evaluation of an acute phase reactant of inflammation through the use of an ultrasensitive assay. A decrease in the level of CRP indicates reduction in inflammation and therefore improvement.

ESR is a laboratory test that provides a non-specific measure of inflammation. The test assesses the rate at which red blood cells fall in a test tube. Normal range is 0-30 millimeter/hour (mm/hr). A higher rate is consistent with inflammation.

ASAS measures symptomatic improvement in AS participants. ASAS = 4 domains: participant global assessment of disease activity, pain, function, inflammation. ASAS 20= at least >= 20 percent improvement from baseline and an absolute change >=1 unit on a 0-10 numeric scale (0=no disease activity; 10=high disease activity) in at least 3 of the domains (on a 0-10 numerical scale): Global assessment of disease activity by participant, participant's global pain intensity, function measured by BASFI and inflammation measured by the average of the last two Likert-scales in BASDAI concerning morning stiffness intensity and duration and no worsening in the remaining domain.

ASAS measures symptomatic improvement in Ankylosing Spondylitis (AS) participants. ASAS =4 domains: participant global assessment of disease activity, pain, function, inflammation. ASAS 40= at least (>=) 40 percent improvement from baseline and an absolute change >=2 unit on a 0-10 numeric scale (0=no disease activity; 10=high disease activity) in at least 3 of the domains (on a 0-10 numerical scale): Global assessment of disease activity by participant, participant's global pain intensity, function measured by BASFI and inflammation measured by the average of the last two Likert-scales in BASDAI concerning morning stiffness intensity and duration and no worsening in the remaining domain.

EQ 5D: participant rated questionnaire to assess health-related quality of life. Health State Profile component assesses level of current health for 5 domains: mobility, self-care, usual activities, pain and discomfort, and anxiety and depression; 1 indicates better health state (no problems); 3 indicates worst health state (extreme problems). Score of each domain is transformed into a single TTO value using formula developed by Greiner et al and results in a total score range -0.205 to 0.999, higher score indicates a better health state.

EQ-5D: participant rated questionnaire to assess health-related quality of life. Health. State Profile component assesses level of current health for 5 domains: mobility, self care, usual activities, pain and discomfort, and anxiety and depression; 1 indicates better health state (no problems); 3 indicate worst health state. Score of each domain is transformed into a single VAS score using formula developed by Greiner et al and results in a total score range of 0 to 100, where higher score indicates a better health state.

WPAI:SHP is 6-question participant rated questionnaire to determine the amount of absenteeism, presenteeism, work productivity loss and daily activity impairment attributable to rheumatoid arthritis for a period of 7 days prior to each visit. It yields 4 sub-scores: work time missed (absenteeism), impairment while working (presenteeism or reduced on-the-job effectiveness), overall work impairment (work productivity loss or absenteeism plus presenteeism) and activity impairment (daily activity impairment). These sub-scores are transformed to impairment percentages (range from 0 to 100), with higher numbers indicating greater impairment and less productivity.

Participants utilization of healthcare resources was evaluated as number of events for healthcare resources utilization including: number of visits to general practitioners, visits to rheumatologist, visits to other medical specialists, inpatient hospitalizations, inpatient rehabilitations, inpatient follow-up treatment, outpatient rehabilitations, physiotherapy, and other healthcare utilizations. At baseline, number of events for participants' healthcare resources utilization during last 12 months before enrollment into the study were documented. After enrollment, number of events for participants' healthcare resources utilization were documented for last 6 months after previous documentation.

Participants duration of healthcare resources utilization was evaluated as number of days for healthcare resources utilization including: duration of visits to general practitioners, to rheumatologist, to other medical specialists, inpatient hospitalizations, inpatient rehabilitations, inpatient follow-up treatment, outpatient rehabilitations, physiotherapy, and other healthcare utilizations. At baseline, number of days for participants' healthcare resources utilizations during last 12 months before enrollment into the study were documented. After enrollment, number of days for participants' healthcare resources utilization were documented for last 6 months after previous documentation.

Participants taking any non-study medications which were administered either prior to or during the study treatment for AS were reported.

An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship.

Percentage of participants achieving partial remission was determined by ASAS criteria. Partial remission defined as a score of less than 2 units (on a scale of 0-10, where 0= no disease activity and 10= high disease activity) in each of the 4 assessment in ASAS domains: participant global assessment of disease activity, pain, function, and inflammation.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, who received etanercept therapy for the first time and had post-baseline documentation. Here 'N' signifies participants who were evaluable for this outcome measure.

An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life- threatening experience (immediate risk of dying); persistent or significant disability or incapacity; congenital anomaly. Percentage of participants with AEs included participants affected with both SAEs and non--SAEs.

Safety population included all treated participants with available post-baseline safety data.

Safety population included all treated participants with available post--baseline safety data.

BASDAI is a validated self-assessment tool used to determine disease activity in participant with AS. Utilizing a 11-point Likert-scale (0= none and 10=very severe) participant's answered 6 questions measuring discomfort, pain and fatigue. The index was computed by adding questions 1 to 4 plus the mean of questions 5 and 6. The resulting 0 to 50 score was divided by 5 to give a final 0-10 BASDAI score (0 being no problem and 10 being the worst problem).

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

BASFI is a validated self assessment tool that determines the degree of functional limitation in AS. Participants answered 10 questions, consisting of 8 specific questions regarding function in AS and 2 questions reflecting the participant's ability to cope with everyday life. Each question was answered on a 0-10 scale (0 being no problem and 10 being the worst problem), the sum of which (divided by 10) resulted in the BASFI score (0-10).

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

Occiput-to-wall distance is the distance between the occiput (posterior or back portion of the head) and the wall when the participant stood with heels and shoulder against the wall and the back straight.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

Lateral lumbar flexion was determined by the difference of the finger-floor-distance in normal position and in lateral bending position.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

Participants were asked to assess their global pain intensity within the past 7 days. Pain was evaluated on an 11-point Likert scale: min = 0 (best), max = 10 (worst).

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

Participants were asked to assess their disease activity within the past 7 days. Disease activity was evaluated on an 11-point Likert scale: min = 0 (best), max = 10 (worst).

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

Physicians were asked to assess the disease activity of participants within the past 7 days. Disease activity was evaluated on an 11-point Likert scale: min = 0 (best), max = 10 (worst).

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

Duration of morning stiffness is defined as the time elapsed when participant woke up in the morning and was able to resume normal activities without stiffness in minutes.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

Duration of morning stiffness is defined as the time elapsed when participant woke up in the morning and was able to resume normal activities without stiffness in minutes. A significant reduction of duration of morning stiffness is defined as a reduction of the duration in minutes by at least 20 percent or reduction to 'no morning stiffness' (absence of morning stiffness).

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'N' signifies participants evaluable for this outcome measure and 'n' signifies participants evaluable for this measure at given time points.

Peripheral arthritis is the inflammation of joints that involved asymmetrically. It involved the hips, shoulder girdle (glenohumeral, acromioclavicular, and sternoclavicular joints), joints of the chest wall (costovertebral joints, costosternal junctions) and symphysis pubis.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'N' signifies participants evaluable for this outcome measure and 'n' signifies participants evaluable for this measure at given time points.

Peripheral arthritis is the inflammation of joints that involved asymmetrically. It involved the hips, shoulder girdle (glenohumeral, acromioclavicular, and sternoclavicular joints), joints of the chest wall (costovertebral joints, costosternal junctions) and symphysis pubis. In case of no presence of peripheral arthritis the number of affected joints was set to 0.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'N' signifies participants evaluable for this outcome measure and 'n' signifies participants evaluable for this measure at given time points.

Enthesitis is the inflammation of the enthesis, where the joint capsules, ligaments or tendons attach to the bone. This inflammation can lead to severe pain and discomfort.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'N' signifies participants evaluable for this outcome measure and 'n' signifies participants evaluable for this measure at given time points.

Enthesitis is the inflammation of the enthesis, where the joint capsules, ligaments or tendons attach to the bone. This inflammation can lead to severe pain and discomfort. In case of no presence of enthesitis the number of affected body parts was set to 0.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

The test for CRP is a laboratory measurement for evaluation of an acute phase reactant of inflammation through the use of an ultrasensitive assay. A decrease in the level of CRP indicates reduction in inflammation and therefore improvement.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

ESR is a laboratory test that provides a non-specific measure of inflammation. The test assesses the rate at which red blood cells fall in a test tube. Normal range is 0-30 millimeter/hour (mm/hr). A higher rate is consistent with inflammation.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

ASAS measures symptomatic improvement in AS participants. ASAS = 4 domains: participant global assessment of disease activity, pain, function, inflammation. ASAS 20= at least >= 20 percent improvement from baseline and an absolute change >=1 unit on a 0-10 numeric scale (0=no disease activity; 10=high disease activity) in at least 3 of the domains (on a 0-10 numerical scale): Global assessment of disease activity by participant, participant's global pain intensity, function measured by BASFI and inflammation measured by the average of the last two Likert-scales in BASDAI concerning morning stiffness intensity and duration and no worsening in the remaining domain.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

ASAS measures symptomatic improvement in Ankylosing Spondylitis (AS) participants. ASAS =4 domains: participant global assessment of disease activity, pain, function, inflammation. ASAS 40= at least (>=) 40 percent improvement from baseline and an absolute change >=2 unit on a 0-10 numeric scale (0=no disease activity; 10=high disease activity) in at least 3 of the domains (on a 0-10 numerical scale): Global assessment of disease activity by participant, participant's global pain intensity, function measured by BASFI and inflammation measured by the average of the last two Likert-scales in BASDAI concerning morning stiffness intensity and duration and no worsening in the remaining domain.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

EQ 5D: participant rated questionnaire to assess health-related quality of life. Health State Profile component assesses level of current health for 5 domains: mobility, self-care, usual activities, pain and discomfort, and anxiety and depression; 1 indicates better health state (no problems); 3 indicates worst health state (extreme problems). Score of each domain is transformed into a single TTO value using formula developed by Greiner et al and results in a total score range -0.205 to 0.999, higher score indicates a better health state.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

EQ-5D: participant rated questionnaire to assess health-related quality of life. Health. State Profile component assesses level of current health for 5 domains: mobility, self care, usual activities, pain and discomfort, and anxiety and depression; 1 indicates better health state (no problems); 3 indicate worst health state. Score of each domain is transformed into a single VAS score using formula developed by Greiner et al and results in a total score range of 0 to 100, where higher score indicates a better health state.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

WPAI:SHP is 6-question participant rated questionnaire to determine the amount of absenteeism, presenteeism, work productivity loss and daily activity impairment attributable to rheumatoid arthritis for a period of 7 days prior to each visit. It yields 4 sub-scores: work time missed (absenteeism), impairment while working (presenteeism or reduced on-the-job effectiveness), overall work impairment (work productivity loss or absenteeism plus presenteeism) and activity impairment (daily activity impairment). These sub-scores are transformed to impairment percentages (range from 0 to 100), with higher numbers indicating greater impairment and less productivity.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

Participants utilization of healthcare resources was evaluated as number of events for healthcare resources utilization including: number of visits to general practitioners, visits to rheumatologist, visits to other medical specialists, inpatient hospitalizations, inpatient rehabilitations, inpatient follow-up treatment, outpatient rehabilitations, physiotherapy, and other healthcare utilizations. At baseline, number of events for participants' healthcare resources utilization during last 12 months before enrollment into the study were documented. After enrollment, number of events for participants' healthcare resources utilization were documented for last 6 months after previous documentation.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'N' signifies participants evaluable for this outcome measure and 'n' signifies participants evaluable for this measure at given time points.

Participants duration of healthcare resources utilization was evaluated as number of days for healthcare resources utilization including: duration of visits to general practitioners, to rheumatologist, to other medical specialists, inpatient hospitalizations, inpatient rehabilitations, inpatient follow-up treatment, outpatient rehabilitations, physiotherapy, and other healthcare utilizations. At baseline, number of days for participants' healthcare resources utilizations during last 12 months before enrollment into the study were documented. After enrollment, number of days for participants' healthcare resources utilization were documented for last 6 months after previous documentation.

Effectiveness population: all treated participants >=18 years of age, with confirmed diagnosis of ankylosing spondylitis, received etanercept therapy for first time and had post-baseline documentation. Here 'n' signifies participants evaluable for this measure at given time points.

Participants taking any non-study medications which were administered either prior to or during the study treatment for AS were reported.

Safety population included all treated participants with available post-baseline safety data.

An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship.

Safety population included all treated participants with available post--baseline safety data.