Home-based Exercise for Improving Health-related Quality of Life in Systemic Sclerosis

The EQ-5D-5L is a five-dimension, patient-reported outcome measure designed to assess generic health-related quality of life. The descriptive index ranges from -0.757 (worst health state) to 1.000 (best health state), while the EQ visual analogue scale (EQ-VAS) ranges from 0 (worst imaginable health) to 100 (best imaginable health).

The 30-second sit-to-stand test assesses lower-extremity functional performance. Participants are instructed to stand up from and sit down on a standard chair as many times as possible within 30 seconds without using their arms. The outcome is the total number of completed repetitions, with higher scores indicating better functional performance.

The 2-minute walk test assesses aerobic capacity and functional walking performance. Participants are instructed to walk as far as possible for 2 minutes along a course of up to 30 metres. The outcome is the total distance walked in metres, with greater distances indicating better aerobic capacity and functional performance.

The 30-second arm curl test assesses upper-body functional strength. Participants are instructed to perform as many arm curl repetitions as possible within 30 seconds while seated, using their dominant arm and a standardized weight (2 kg for women and 4 kg for men). The outcome is the total number of completed repetitions, with higher scores indicating better upper-body functional strength.

The Mini-BESTest assesses dynamic balance and postural control. The test consists of 14 tasks covering anticipatory postural adjustments, reactive postural control, sensory orientation, and dynamic gait. Each task is scored from 0 to 2, resulting in a total score ranging from 0 to 28 points, with higher scores indicating better dynamic balance and postural control.

The Systemic Sclerosis Impact of Disease (ScleroID) is a patient-reported outcome measure designed to assess the impact of systemic sclerosis on patients' daily lives. It comprises 10 domains covering Raynaud's phenomenon, hand function, upper and lower gastrointestinal symptoms, pain, fatigue, life, body mobility, breathlessness, and digital ulcers. Item scores are combined using validated domain-specific weights to generate a total score ranging from 0 to 10, with higher scores indicating greater disease impact.

The International Physical Activity Questionnaire - Short Form (IPAQ-SF) is a patient-reported questionnaire that assesses physical activity performed during the previous 7 days. It records time spent in vigorous-intensity activity, moderate-intensity activity, walking, and sedentary behaviour. Responses are used to calculate physical activity as metabolic equivalent (MET)-minutes per week and to classify participants into low, moderate, or high physical activity categories according to the IPAQ scoring protocol. Higher MET-minutes per week and higher physical activity categories indicate greater levels of physical activity.

The Major Depression Inventory (MDI) is a patient-reported questionnaire designed to assess depressive symptoms experienced during the previous 2 weeks. The questionnaire consists of 10 items scored on a 6-point scale, resulting in a total score ranging from 0 to 50. Higher scores indicate more severe depressive symptoms.

The iMTA Productivity Cost Questionnaire (iPCQ) is a patient-reported questionnaire that assesses productivity losses due to health problems. It includes three modules measuring productivity losses related to absenteeism (absence from paid work), presenteeism (reduced productivity while at work), and unpaid work. Higher productivity losses indicate a greater impact of health problems on work and daily activities.

The Healthcare Utilization Questionnaire (HUQ) is a patient-reported questionnaire designed to assess healthcare utilization and medication use. It collects information on contacts with healthcare providers, hospital services, and prescribed and over-the-counter medication use during the recall period. The questionnaire is used to estimate healthcare resource use for the health economic evaluation.

Adverse events (AEs) and serious adverse events (SAEs) will be monitored throughout the study. During the intervention period, physiotherapists supervising the exercise programme will record any reported or observed AEs and SAEs. In addition, participants will be asked about any AEs and SAEs at the 6- and 12-month follow-up assessments using open-ended questions.

Adherence will be assessed using participants' exercise diaries. The number of completed exercise sessions will be divided by the number of planned exercise sessions and multiplied by 100 to calculate adherence as a percentage. An exercise session is considered completed when the participant performs at least 10 minutes of walking and at least one set of each resistance exercise. High adherence is defined as completion of at least 70% of the 72 planned exercise sessions during the 24-week intervention period.

The number and proportion of participants who withdraw from the study before completing the 12-month follow-up will be recorded. Reasons for withdrawal will be documented when available.