Table 1.
Study outcome measures and corresponding questionnaires
| Variable | Questionnaire | Number/type of items | Time frame | Score range | Psychometric details |
|---|---|---|---|---|---|
| Primary outcomes | |||||
| Cancer related fatigue | MFI [41] | 20 four-point Likert scale | Past few days | Subscale scores: 4–20; higher scores indicate more fatigue | Subscales: general fatigue, mental fatigue, physical fatigue, reduced motivation, reduced activity. Cronbach’s alpha: 0.84 |
| VAS-scale [42] | 1 eleven-point Likert scale | This moment | 0–10; higher scores indicate more fatigue | ||
| Restrictions caused by fatigue | WSAS [43, 70] | 5 nine-point Likert scale | Influence of fatigue on daily life | 0–40; higher scores indicate higher levels of disability | Cronbach’s alpha: > 0 .79 |
| Secondary outcomes | |||||
| Sleep quality | PSQI [44] | 19 four-point Likert scale and open-ended questions | Past month | Total score: 0–21 Subscale scores: 0–3; higher scores indicate more acute sleep disturbances |
Subscales: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, daytime dysfunction. Cronbach’s alpha: 0.83 |
| Depression | CES-D [46, 71] | 20 four-point Likert scale | Past week | 0–60; higher scores indicate greater depressive symptoms | Cronbach’s alpha: 0.85–0.90 |
| Anxiety | STAI-6 [47] | 6 four-point Likert scale | This moment | 20–80; higher scores indicate increased anxiety | Cronbach’s alpha: 0.83 |
| Quality of life | SF-36 [48, 72] | 36 Dichotomous three to six-point Likert scale | Past 4 weeks | Subscale scores: 0–100; higher scores indicates higher levels of functioning/well-being | Subscales: physical functioning, role limitations due to physical health problems, bodily pain, social functioning, general mental health, role limitations due to emotional problems, vitality, general health perceptions Cronbach’s alpha: 0.84 |
| Cognitive complaints | MOS-CF6 [49, 73] | 6 six-point Likert scale | Past week | 0–100; higher scores indicated better cognitive functioning | Cronbach’s alpha: ≥ 0.89 |
| MDASI [50] | 8 eleven-point Likert scale | Past 24 h | 0–80; higher score indicates worse or more disturbing cognitive complaints | ||
| Cancer worries | CWS [54] | 8 + 1 four-point Likert scale | Past week | 9–36; higher score indicates more frequent worries about cancer | Cronbach’s alpha: 0.87 |
| Fatigue catastrophizing | FCS [55, 74] | 10 five-point Likert scale | Current attitude | 10–40; higher score indicates more catastrophizing | Cronbach’s alpha: 0.85 |
| Self-efficacy | SES-28 [56, 75] | 7 four-point Likert scale | Current attitude | 7–28; higher score indicates higher level of perceived control over fatigue symptoms | Cronbach’s alpha: 0.68–0.77 |
CES-D Center for Epidemiological Studies – Depression scale, CWS Cancer Worry Scale, FCS Fatigue catastrophizing Scale, MDASI MD Anderson Symptom Inventory, MFI Multidimensional Fatigue Inventory, MOS-CF6 Medical Outcomes Studies Cognitive functioning, PSQI Pittsburgh Sleep Quality Index, SF-36 Medical Outcome Studies short form, SES-28 Self-efficacy Scale 28, STAI-6 State Trait Anxiety Inventory-6 items, VAS Visual Analogue Scale, WSAS Work and Social Adjustment Scale