Multi-country Post-Marketing Observational Study on Maintenance of Effectiveness of Adalimumab (Humira®) in Patients With Ankylosing Spondylitis and Psoriatic Arthritis

The BASDAI score was calculated using a questionnaire with 6 questions that the participants completed by marking responses on a 10-centimeter visual analog scale ranging from 0 (none) to 10 (very severe) regarding severity of fatigue, spinal and peripheral joint pain, localized tenderness and morning stiffness. The final BASDAI score ranges from 0 to 10. A positive response was defined as a 50% or more decrease in the BASDAI score at 12 months as compared to baseline.

The DAS28 is a validated index of rheumatoid arthritis disease activity. Twenty-eight tender joint counts, 28 swollen joint counts, C- reactive protein, and general health are included in the DAS28 score. Scores on the DAS28 range from 0 to 10. A DAS28 score >5.1 indicates high disease activity, a DAS28 score <3.2 indicates low disease activity, and a DAS28 score <2.6 indicates clinical remission.

The ASDAS tool is a self-administered questionnaire plus an objective laboratory evaluation. The questionnaire covers disease activity, back pain, and peripheral pain/swelling assessed on a visual analogue scale (from 0 (normal) to 10 (extreme pain or disability) cm) and duration of morning stiffness on a numerical rating scale (from 0 to 10, with 0 being none and 10 representing a duration of 2 hours or longer). The laboratory parameter is a measurement of C-reactive protein (mg/L) (CRP) or erythrocyte sedimentation rate (mm/h) (ESR). Data from five variables (disease activity, back pain, duration of morning stiffness, peripheral pain/swelling, and either CRP or ESR values) are combined to yield a score ranging from 0 to no defined upper limit. Remission is defined as ASDAS score <1.3. Clinically important improvement is defined as a change ≥ 1.1 units, and major improvement is defined as a change ≥ 2.0 units.

BASDAI score (ranging from 0 to 10) was calculated using a questionnaire. Participants marked responses on a 10 cm visual analog scale ranging from 0 (none) to 10 (very severe) regarding fatigue, spinal and peripheral joint pain, localized tenderness and morning stiffness. A positive response was defined as a 50% or more decrease in the BASDAI score at 12 months as compared to baseline. ASDAS is a self-administered questionnaire plus an objective laboratory evaluation. The questionnaire covers disease activity, back pain, duration of morning stiffness and peripheral pain/swelling assessed on a visual analogue scale (from 0 to 10 cm) or on a numerical rating scale (from 0 to 10). The laboratory parameter is a measurement of C-reactive protein (mg/L) or erythrocyte sedimentation rate (mm/h). Spearman's rank correlation coefficient (CC) was calculated for BASDAI vs. ASDAS(subscript)CRP(subscript) and BASDAI vs. ASDAS(subscript)ESR(subscript ).

A mathematical technique called logistic regression was performed to identify factors that could be used to predict maintained treatment response and remission. The following baseline variables were used in the logistic regression analyses: age, gender, disease of interest, result of tuberculosis screening, time since diagnosis and extra-articular manifestations (symptoms and diseases that occur in parts of the body other than joints) at baseline. The BASDAI score at baseline was forced to serve as a predictor in each model.

HAQ-DI 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 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, with a higher score representing a high-dependency disability. The minimal clinically important difference defined for the HAQ-DI is ≥0.22. HAQ-DI remission, indicating normal physical function, is defined as HAQ-DI < 0.5. The BASFI is a set of 10 questions designed to determine the degree of functional limitation in those with AS. A visual analogue scale (with 0 being "easy" and 10 "impossible") is used. The BASFI score ranges from 0 to 10 and is derived as the mean of the single items. A higher score indicates a higher impairment of functioning.

Extra-articular manifestations (EAMs) are symptoms and diseases that occur in parts of the body other than joints. The number of EAMs was determined at each study visit. These included the presence of enthesitis (inflammation of ligaments and/or tendons at the site of insertion into bones), uveitis (inflammation of the middle layer of the eye), psoriasis (a skin condition that causes itchy or sore patches of thick, red skin with silvery scales), and Inflammatory bowel disease (Crohn's disease or ulcerative colitis).

The duration of treatment with adalimumab was calculated separately for participants who discontinued the medication during the study and for those who did not.

Participants were surveyed at each study visit for their use of NSAID medication.

Work Productivity and Activity Impairment (WPAI) Questionnaire is a quantitative assessment of the amount of absenteeism, presenteeism, total work productivity impairment, and total activity impairment attributable to a specific health problem (WPAI-SHP), expressed as a percentage. Participants were queried regarding their current employment status, hours missed from work because of problems associated with their AS, hours missed from work because of any other reason, number of hours worked, how much AS affected work productivity (0=AS had no effect,10= AS completely prevented me from working), and how much AS affected ability to do regular daily activities, other than work at a job (0= AS had no effect, 10= AS completely prevented me from doing my daily activities) in the past 7 days.

Working status (Working full-time, working part-time, working at home, unemployed but seeking work, work disabled, retired, student) was documented at each study visit.

The BASDAI score was calculated using a questionnaire with 6 questions that the participants completed by marking responses on a 10-centimeter visual analog scale ranging from 0 (none) to 10 (very severe) regarding severity of fatigue, spinal and peripheral joint pain, localized tenderness and morning stiffness. The final BASDAI score ranges from 0 to 10. A positive response was defined as a 50% or more decrease in the BASDAI score at 12 months as compared to baseline.

The DAS28 is a validated index of rheumatoid arthritis disease activity. Twenty-eight tender joint counts, 28 swollen joint counts, C- reactive protein, and general health are included in the DAS28 score. Scores on the DAS28 range from 0 to 10. A DAS28 score >5.1 indicates high disease activity, a DAS28 score <3.2 indicates low disease activity, and a DAS28 score <2.6 indicates clinical remission.

BASDAI score (ranging from 0 to 10) was calculated using a questionnaire. Participants marked responses on a 10 cm visual analog scale ranging from 0 (none) to 10 (very severe) regarding fatigue, spinal and peripheral joint pain, localized tenderness and morning stiffness. A positive response was defined as a 50% or more decrease in the BASDAI score at 12 months as compared to baseline. ASDAS score consists of a self-administered questionnaire plus an objective laboratory evaluation. The questionnaire covers disease activity, back pain, duration of morning stiffness and peripheral pain/swelling assessed on a visual analogue scale (from 0 to 10 cm) or on a numerical rating scale (from 0 to 10). The laboratory parameter is a measurement of C-reactive protein (mg/L) or erythrocyte sedimentation rate (mm/h). Spearman's rank correlation coefficient (CC) was calculated for BASDAI vs. ASDAS(subscript)CRP(subscript) and BASDAI vs. ASDAS(subscript)ESR(subscript).

A mathematical technique called logistic regression was performed to identify factors that could be used to predict maintained treatment response and remission. The following baseline variables were used in the logistic regression analyses: age, gender, disease of interest, result of tuberculosis screening, time since diagnosis and extra-articular manifestations (symptoms and diseases that occur in parts of the body other than joints) at baseline. The BASDAI score at baseline was forced to serve as a predictor in each model.

HAQ-DI 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 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, with a higher score representing a high-dependency disability. The minimal clinically important difference defined for the HAQ-DI is ≥0.22. HAQ-DI remission, indicating normal physical function, is defined as HAQ-DI < 0.5. The BASFI is a set of 10 questions designed to determine the degree of functional limitation in those with AS. A visual analogue scale (with 0 being "easy" and 10 "impossible") is used. The BASFI score ranges from 0 to 10 and is derived as the mean of the single items. A higher score indicates a higher impairment of functioning.

The Work Productivity and Activity Impairment (WPAI) Questionnaire is a quantitative assessment of the amount of absenteeism, presenteeism, total work productivity impairment, and total activity impairment attributable to a specific health problem (WPAI-SHP), expressed as a percentage. Participants were queried regarding their current employment status, hours missed from work because of problems associated with their PsA, hours missed from work because of any other reason, number of hours worked, how much PsA affected work productivity (0= PsA had no effect,10= PsA completely prevented me from working), and how much PsA affected ability to do regular daily activities, other than work at a job (0= PsA had no effect, 10= PsA completely prevented me from doing my daily activities) in the past 7 days.

Working status (Working full-time, working part-time, working at home, unemployed but seeking work, work disabled, retired, student) was documented at each study visit.