A Study Comparing Upadacitinib (ABT-494) Monotherapy to Methotrexate (MTX) Monotherapy in Adults With Rheumatoid Arthritis (RA) Who Have an Inadequate Response to MTX (SELECT-MONOTHERAPY)

Change From Baseline in in Disease Activity Score 28 (CRP) at Week 14

The DAS28 is a composite index used to assess rheumatoid arthritis disease activity, calculated based on the tender joint count (out of 28 evaluated joints), swollen joint count (out of 28 evaluated joints), Patient's Global Assessment of Disease Activity (0-100 mm), and hsCRP (in mg/L). Scores on the DAS28 range from 0 to approximately 10, where higher scores indicate more disease activity. A negative change from baseline in DAS28 (CRP) indicates improvement in disease activity.

Time frame: Baseline to week 14

Change From Baseline in Heath Assessment Questionnaire and Disability Index (HAQ-DI) at Week 14

The Health Assessment Questionnaire - Disability Index is a patient-reported questionnaire that measures the degree of difficulty a person has in accomplishing tasks in 8 functional areas (dressing, arising, eating, walking, hygiene, reaching, gripping, and errands and chores) over the past week. Participants assessed their ability to do each task on a scale from 0 (without any difficulty) to 3 (unable to do). Scores were averaged to provide an overall score ranging from 0 to 3, where 0 represents no disability and 3 represents very severe, high-dependency disability. A negative change from Baseline in the overall score indicates improvement.

Time frame: Baseline to week 14

Change From Baseline in Short-Form 36 (SF-36) Physical Component Score (PCS) at Week 14

The Short Form 36-Item Health Survey (SF-36) Version 2 is a self-administered questionnaire that measures the impact of disease on overall quality of life during the past 4 weeks. The SF-36 consists of 36 questions in eight domains (physical function, pain, general and mental health, vitality, social function, physical and emotional health). The physical component score is a weighted combination of the 8 subscales with positive weighting for physical functioning, role-physical, bodily pain, and general health. The PCS was calculated using norm-based scoring so that 50 is the average score and the standard deviation equals 10. Higher scores are associated with better functioning/quality of life; a positive change from baseline score indicates an improvement.

Time frame: Baseline to week 14

Percentage of Participants Achieving Clinical Remission (CR) Based on DAS28(CRP) at Week 14

The DAS28 is a composite index used to assess rheumatoid arthritis disease activity, calculated based on the tender joint count (out of 28 evaluated joints), swollen joint count (out of 28 evaluated joints), Patient's Global Assessment of Disease Activity (0-100 mm), and hsCRP (in mg/L). Scores on the DAS28 range from 0 to approximately 10, where higher scores indicate more disease activity. A DAS28 score less than 2.6 indicates clinical remission.

Time frame: Week 14

Change From Baseline in Duration of Morning Stiffness at Week 14

Participants were asked to indicate the time it took for them to get as limber as possible after awakening with morning stiffness over the past 7 days. A negative change from Baseline indicates improvement.

Time frame: Baseline to week 14

Percentage of Participants With an American College of Rheumatology 50% (ACR50) Response at Week 14

Participants who met the following 3 conditions for improvement from baseline were classified as meeting the ACR50 response criteria: 1. ≥ 50% improvement in 68-tender joint count; 2. ≥ 50% improvement in 66-swollen joint count; and 3. ≥ 50% improvement in at least 3 of the 5 following parameters: * Physician global assessment of disease activity * Patient global assessment of disease activity * Patient assessment of pain * Health Assessment Questionnaire - Disability Index (HAQ-DI) * High-sensitivity C-reactive protein (hsCRP).

Time frame: Baseline and week 14

Percentage of Participants With an American College of Rheumatology 70% (ACR70) Response at Week 14

Participants who met the following 3 conditions for improvement from baseline were classified as meeting the ACR50 response criteria: 1. ≥ 70% improvement in 68-tender joint count; 2. ≥ 70% improvement in 66-swollen joint count; and 3. ≥ 70% improvement in at least 3 of the 5 following parameters: * Physician global assessment of disease activity * Patient global assessment of disease activity * Patient assessment of pain * Health Assessment Questionnaire - Disability Index (HAQ-DI) * High-sensitivity C-reactive protein (hsCRP).

Time frame: Baseline and week 14