Effect of an Information- and Self-management App for People With Knee Osteoarthritis

11 statements about osteoarthritis and treatment options, answered on a 5-point scale from 1 (=true) to 5 (=not true), summed up to a scale from 11 to 55

16 statements with 5 response categories about the patients uncertainty with treatment options. The total score range from 0 (no decisional conflict) to 100 (extreme decisional conflict). The DCS also has five subscales (all 0-100): 1) uncertainty, 2) informed, 3) values clarity, 4) support, and 5) effective decision.

Measured with one qustion form the Decision Conflict Scale (DSC), 5 response options.

Measured with section 3 (decision process scale) in the Decision Quality Index for Knee Osteoarthritis (K-DQI) which consists of 5 questions. Four of these questions are summed to a 0-4 score with higher score indicating more shared decision-making.

Mesured with the CollaboRATE questionnaire, comprising 3 questions measured on a 0-9 scale, with a higher score indicating better experience. Scores are calculated using the top score method indicating the percentage of patients scoring top score for all three questions, or

Measured on a numeric rating scale (0-10, with higher score indicating more satisfaction)

Measured on a numeric rating scale from 0 to 10 with higher score indicating higher motivation

Measured on a numeric rating scale from 0 to 10 with higher score indicating higher motivation

Measured with the Knee Injury and Osteoarthritis Outcome Score (pain section), comprising 9 questions scored on a 5-point scale and calculated to a 0-100 score with higher score indicating less pain

Measured with the Knee Injury and Osteoarthritis Outcome Score (function section), comprising 17 questions scored on a 5-point scale and calculated to a 0-100 score with higher score indicating less pain

Measured with the Knee Injury and Osteoarthritis Outcome Score (quality of life section), comprising 4 questions scored on a 5-point scale and calculated to a 0-100 score with higher score indicating less pain

Mesured with EQ-5D-5L, comprising 5 questions with 5 response options. Summed to an utility index from 1 to 0, with 1 being best health-related quality of life. Additionally a visual analog scale from 0 to 100 with 100 indicating best health.

Measured with 7 statements from the MAPPIN'SDM Therapist, measured on a 5-point scale

Measured with the Control Preference Scale, comprising a question with 5 statements about roles, corresponding to active role, collaborative role and passive role

Measured with the Brief Illness Perception Questionnaire (B-IPQ) comprising 8 questions scored on a 0-10 scale, summed to a 0 to 80 score with higher score indicating poorer illness perception

Measured with the Pain Self-Efficacy Questionnaire (PSEQ-2) comprising 2 questions about pain self-efficacy, answered on a 0 (not at all confident) to 6 (completely confident) scale.

Measured with one question about consern about pain, measured on a 0 (not at all) to 4 (all the time) scale.

Measured with four questions from the Brief Pain Inventory, assessed on numeric rating scales from 0 (no pain) to 10 (worst possible pain).

Measured with one question about pain intensity now on a numeric rating scale from 0 (no pain) to 10 (worst possible pain).

Measured with a numeric rating scale from 0 (no disease activity) to 10 (worst disease activity)

Measured on a numeric rating scale from 0 (no fatigue) to 10 (worst possible fatigue)

Measured with five questions from Dicision Quality Index for Knee Osteoarthritis (section 1). Assessed on numeric rating scales from 0 (not at all important) to 10 (extremely important)

Measured with a question about if they prefer surgery or non-surgical treatment

Measured with the HLS19-Q12 comprising 12 questions about health literacy answered on a 4-point likert scale from 1 (very difficult) to 4 (very easy). Calculated as percentage (0-100) of items with valid responses that were answered with very easy or easy

Measured with six questions about the self-efficacy of using different digital solutions (mobile phone, tablet, computer, apps, identification portal, helsenorge.no), assessed on a 6-point scale from never tried to manage very well

Assessment of previous treatment, answered with yes/no on questions related to previous physiotherapy treatment, previous osteoarthritis school,

Measured with one question from the Work Productivity and Activity Impairment questionnaire (WPAI) (question 6), anwered on a numeric rating scale from 0 (no effect on daily activities) to 10 (completely prevent from doing daily activities)

Measured with item 2 from the Decision regret scale, answered on a 5-point scale from totally agree to totally disagree

Assessed with an open-ended question about the use of pain medication last three months (type and dosage)

Measured with questions about gender, age, education level, working status, smoking, living arrangements, sosioeconomic status, and support

Measured as self-reported hight and weight

Measured with questions about most trouble some knee, duration of complaints, other joints with complaints

Measured with one question about exercise level answered on a 5-point scale from do not exercise to exercise 3 or more times per week

Assessed with 15 questions about the presens of different diseases (yes/no)

Measured with System Usability Scale (SUS) comprising 10 statements answered on a 5-point scale from strongly disagree to strongly agree, converted to a 0 to 100 score with higher score indicating better usability

Measured with two questions about the satisfaction with the information videos and exercise videos in the app, answered on numeric rating scales from 0 (not statisfied) to 10 (very satisfied)

Measured with two questions about the suitability of providing information and exercises through an app, answered on numeric rating scales from 0 (not suitable) to 10 (very suitable)

Measured with a question about whether the patient has undergone surgical treatment (yes/no) and for those answering yes; five questions about the improvement/satisfaction with the surgical treatment, measured on a 5-point scale from very satisfied to very dissatisfied