Table 5 Adherence, cost effectiveness and other measures
| Â | Data collection instrument and scale | Time points |
|---|---|---|
Adherence: | ||
 Hand exercises (intervention group only) | Treatment diary, recording of days with exercising, length of exercising in minutes | t3 |
 Orthoses (intervention group only) | Treatment diary, recording of days and nights with using orthosis and length of use (day and night) in hours and minutes | t3 |
 Possession and use of assistive devices | Questionnaire with 20 specified devices with possibility of adding more, possession of each device yes/no, if yes; use regularly, use only when in pain, do not use | t1, t3, t4, t5 |
Cost-effectiveness: | ||
 Utility | European Quality of Life Scale (EQ-5D), which comprises the EQ-5D index and the EQ-5D visual analogue scale | t1, t3, t4, t5 |
 Treatment sessions | Number and length of each treatment session | t1, t2, t3, t4, t5 |
 Orthoses | Number and type of orthoses | t1, t2, t3, t4, t5 |
 Hand exercises | Number and type of exercise material | t1, t2, t3, t4, t5 |
 Assistive devices | Number and type of device | t1, t2, t3, t4, t5 |
 Sick leave and absence from work | Number of days | t3, t4, t5 |
 Use of medication | Name and dosage of medicine | t1, t3, t4, t5 |
 Health care utilisation | Number of visits and/or hospital stays | t3, t4, t5 |
 Medical or technical equipment | Type and costs of equipment purchased | t3, t4, t5 |
Other measures | ||
 Age | Years | t1 |
 Gender | Female/male | t1 |
 Marital status | Living alone or not | t1 |
 Employment status | Working full time/ working part time/ not working/ student/ working full time in the home/ unemployed or seeking work /age retired/ disability pension/ sick leave | t1 |
 Level of education | 7–10 years of education, 10–12 years of education, 13–15 years of education, more than 15 years of education | t1 |
 Hand dominance | Right or left | t1 |
 Other diseases/previous injuries that may negatively impact hand function | Yes/no, if yes-what kind of disease/injury | t1 |
 Previous hand surgery | Yes/no, if yes-right hand, left hand or both hands | t1 |
 Referred for surgery in | Right hand, left hand or both hands | t1 |
 Main reason for wanting surgery | Description of the main reason | t1 |
 Previously received hand therapy due to HOA | Yes/no, if yes-what kind of therapy | t1 |
 Motivation for surgery | Numeric rating scale: 0–10, 0 is no motivation | t1 |
 Joints with osteoarthritis (as diagnosed by physician or finger joints with bony enlargement) | Marked by the OT on a map with joints of the body | t1 |
 Degree of CMC1-HOA | Conventional radiography of both hands, graded according to the Kellgren-Lawrence method, with grades from 0 to 4, (grade 4 indicating large osteophytes, severe sclerosis and narrowing joint space) |  |
 Degree of radial trapeziometacarpal subluxation | Conventional radiography of both hands, graded as subluxation ratio using a digital calculation calliper |  |
 Presence of erosive HOA | Conventional radiography of both hands, ≥1 joint with erosion = erosive OA. |  |
 Comorbidity | Presence of 16 diseases/health problems (yes/no) | t1 |
 Comfort with use of assistive devices | Numeric rating scale: 0–10, 0 is very uncomfortable | t1, t3, t4, t5 |