Investigating the Effects of the Digital App Rheumabuddy4.1 in a Clinical RCT Set-up in Patients With Rheumatoid Arthritis

Disease activity of rheumatoid arthritis (RA) is usually assessed by using Disease Activity Score 28-joint count (DAS28). DAS28 is a validated composite measure combining patient-reported outcomes and clinical measures of inflammation and has been widely adopted in RA trials and clinical practice, providing a robust measure for assessing intervention efficacy. DAS28 scores range from 0 to 9.4 and are calculated using tender joints, swollen joints, general health, and a laboratory measure of acute inflammation. DAS28 for RA with C-reactive protein (DAS28-CRP) describes the severity of RA using clinical and laboratory data, specifically CRP.

The ASES was developed to measure patients 'arthritis-specific self-efficacy, or patients' beliefs that they could perform specific tasks or behaviors to cope with the consequences of arthritis. ASES-8 has been used in evaluations of self-management education programs, physical activity interventions, and associations of self-efficacy with various health outcomes. The ASES-8 includes 2 items from the ASES pain subscale, 4 items from the ASES other symptoms subscale, and 2 new items related to preventing pain and fatigue from interfering with things you want to do. The total scale includes 8 items with no subscales: 1 (very uncertain) to 10 (very certain). Item stem for each question begins "How certain that you can....". The score for the scale is the mean of the eight items.

Pain are the most common and debilitating symptoms of RA, significantly impacting patients' quality of life. Pain will be assessed using the 0-100 mm visual analogue scale (VAS) with anchors 0 = "no pain" and 100 = "Worst imaginable pain".

Fatigue is a very common and debilitating symptoms of RA, significantly impacting patients' quality of life. Fatigue will be assessed using the 100 mm visual analogue scale (VAS) with anchors 0 = "no fatigue" and 100 = "Worst imaginable fatigue".

The EQ-5D questionnaire is developed by the EuroQoL. The EQ-5D is a five-dimensional health state classification. The five dimensions are mobility, self-care, usual activities, pain/discomfort and anxiety/depression. It is a preference-based measure that can be regarded as a continuous outcome scored on a -0.59 to 1.00 scale, with 1.00 indicating 'full health' and 0 representing dead. The negative EQ-5D scores represent certain health states valued as worse than dead. Each topic is rated on a 3-point Likert scale: 1) no problems, 2) some problems, and 3) extreme problems. Instructions on how to response is included in the questionnaire. In addition, a VAS scale functions as a 6-question to report on self-reported overall health on a 0-100 scale where 100= best imaginable health and 0=worst health you can imagine. The VAS can be used as a quantitative measure of the patient's own judgement of overall health.

The Multi-Dimensional Health Assessment Questionnaire (MD-HAQ) is derived from the HAQ Health Assessment Questionnaire, which includes an index of the three rheumatoid arthritis (RA) core data set measures (physical function, pain and global estimate). It consists of 10 questions addressing eight different areas of functional ability and yields a total score between 0 and 3, with a higher score representing increasing disability. The MD-HAQ is useful in all rheumatic diseases by saving time, documenting changes in status over long periods and by improving rheumatology care and outcomes.

Mental health is a state of mental well-being that enables people to cope with the stresses of life, realize their abilities, learn well and work well, and contribute to their community. Well-Being will be assessed using the 5-item Well-Being Index (WHO-5). The WHO-5 is a validated assessment tool used to measure mental well-being in a variety of patient populations. The raw score is calculated by totalling the figures of the five answers. The raw score ranges from 0 to 25; 0 representing worst possible quality of life and 25 representing best possible quality of life.

Adherence to medication will be assessed using the 8-item Morisky Medication Adherence Scale (MMAS-8). The MMAS-8 is a validated assessment tool used to measure non-adherence in a variety of patient populations. The scale consists of eight questions, MMAS-8 scores can range from 0 to 8 points. According to the MMAS-8, adherence can be categorized as high adherence (score, 8), medium adherence (score, 6 to<8) and low adherence (score, <6).

The Perceived Efficacy in Patient-Physician Interactions (PEPPI) scale was developed to measure older patients' self-efficacy in both obtaining medical information and attention to their chief health concern from a physician. The PEPPI 5-item short form will be used to assess adherence and was developed from the items demonstrating the most variability while maintaining adequate internal consistency and construct validity from the original PEPPI. The PEPPI-5 includes five items; each item starts with "how confident are you in your ability to..? " Items are rated by participants from one to five; 1 = "not at all confident",5= "very confident". The totalled results are in the range of 5 to 25; higher scores indicate that the participant has higher self-efficacy in patient-physician interactions .