Quality of Life and Medical Care of Long-term Sarcoma Survivors in Germany (PROSa+)

The EORTC QLQ-SURV100 is a 100-item questionnaire assessing general quality of life among cancer survivors. It includes multiple functional scales covering physical, role, emotional, cognitive, and social functioning, as well as symptom scales (fatigue, pain) and several single-item measures. Most items are rated on a 1-4 scale, while two global items on overall quality of life and general health are rated on a 1-7 scale. Higher scores on the functional and global health status scales indicate better quality of life, whereas higher scores on symptom scales reflect worse quality of life.

With the exception of five acute symptoms, the SURV100 includes all items from the EORTC QLQ-C30. To enable comparative analyses, the investigators supplemented the SURV100 with these five missing items: appetite loss, nausea, vomiting, constipation, and diarrhea.

Satisfaction with medical care and communication will be assessed using three items adapted from the EORTC OUT-PATSAT7 and three self-developed items, all rated on a 1-5 scale. Higher scores indicate greater satisfaction with the medical care received.

Service utilization will be assessed with self-developed items based on the Cancer Survivors' Unmet Needs measure (CaSUN). Participants indicate their use of 24 different non-rehabilitation care services and 11 rehabilitation care services. Response options include two types of "No" (offer not available or offer available but not used) and, if "Yes," a rating from 1-3 indicating how helpful the offer was, with higher scores reflecting greater helpfulness.

Unmet needs will be assessed with self-developed items based on the CaSUN, asking participants about the lack of adequate support or services in 20 areas. Response options include two types of "No" (no need or need has already been met) and, if "Yes," a rating from 1-3 indicating the current intensity of the unmet need, with higher scores reflecting greater unmet need.

Fatigue will be assessed using the 12-item EORTC QLQ-FA12 scale, which measures physical, emotional, and cognitive aspects of cancer-related fatigue on a 1-4 scale. Higher scores indicate greater fatigue.

Psychological distress will be measured using the four-item PHQ-4, including the diagnostic core criteria for depression (PHQ-2) and generalized anxiety disorder (GAD-2), ranging from 1-4. Higher scores indicate greater psychological distress.

Loneliness will be assessed using the three-item UCLA Loneliness Scale, measuring subjective feelings of loneliness and social isolation, ranging from 1-3. Higher scores indicate greater loneliness.

Physical complaints will be measured using the EORTC WISP module, allowing participants to report up to three symptoms and rate the degree of burden from 1-4. Higher scores indicate greater impairment due to the respective symptom.

Communication experiences will be assessed using nine items adapted from the EORTC COMU26 and nine self-developed items, focusing on perceived quality and clarity of communication with healthcare providers. Rated on a 1-4 scale, higher scores indicate greater satisfaction with communication.

Information sources will be assessed using nine self-developed items, asking participants where they obtain cancer-related information. Response options include two types of "No" (not known or known but not used) and, if "Yes," a rating from 1-3 indicating how helpful the source was, with higher scores reflecting greater helpfulness.

Sociodemographic characteristics, including age, sex, and migration background will be collected.

Socioeconomic status will be assessed through items measuring i.a. education, employment status, and income.

Physical activity will be measured using an adapted version of the Godin-Shephard Leisure-Time Physical Activity Questionnaire. This 4-item questionnaire evaluates the frequency and duration of mild, moderate and vigorous aerobic activities, as well as moderate-to-vigorous strength training, performed during the week. Scores reflect whether participants meet exercise guidelines:

• Aerobic guidelines: ≥75 min of vigorous or ≥150 min moderate activity (meeting guidelines) vs. 0-149 minutes of moderatre and vigorous activity per week (not meeting guidelines)
• Resistance guidelines: ≥2 resistance sessions/week (meeting guidelines) vs. <2 sessions (not meeting guidelines) Higher scores indicate better adherence to physical activity recommendations.

Information on comorbid conditions (e.g., cardiovascular disease, diabetes, depression) will be collected, capturing co-existing health conditions. The total number of comorbidities will be summed and used as a control variable in the analyses.