Rueegg 2013.

Methods	Study design: cross‐sectional study (questionnaire survey as part of Swiss childhood cancer survivor study) Instrument used to assess fatigue: SF‐36 Vitality subscale Validated questionnaire: yes Cut‐off score or criterion for severe fatigue: NAa Time points at which outcome data were collected: NA, cross‐sectional study Inclusion criteria: registered in the Swiss Childhood Cancer Registry, survived for ≥ 5 years, were diagnosed < 16 years of age between 1976 and 2005, age ≥ 16 years at the time of survey Exclusion criteria: nm
Participants	Sample characteristics: N of participants original cohort: unknown; N of participants described study group: 1593; N of participants study group of interest: 1593; N of participants fatigue assessed: 1576 Participant characteristics: Tumour type: leukaemia n = 573, lymphoma n = 290, CNS tumour n = 210, neuroblastoma n = 67, retinoblastoma n = 37, renal tumour n = 107, hepatic tumour n = 10, bone tumour n = 77, soft tissue sarcoma n = 89, germ cell tumour n = 45, other tumour n = 19, langerhans cell histiocytosis n = 69 Tumour stage: nm Age at diagnosis: mean 7.6 years (SD 4.7) Time since diagnosis: mean 17.4 years (SD 6.9) Age at assessment: mean 25.1 years (SD 6.9) F/M: 746/847 BMI: Overweight (≥ 25 BMI) n = 360 Race/ethnicity: migration background; Swiss n = 1543, foreign background n = 140b Marital status: nm Highest completed education level: nm Employment: nm Physical activity level: nm Sleeping problems: nm Psychosocial problems: nm Comorbidities/late effects: self‐reported; vision impairment n = 175, hearing problem n = 158, memory problem n = 192, digestive problem n = 218, musculoskeletal/neurological problem n = 434, thyroid problem n = 151 Genetic factors/mutations: nm
Interventions	N of participants chemotherapy: 1340 N of participants surgery: 684 N 0f participants radiotherapy: 611 N of participants body and limb irradiation: 314 N of participants cranial and spinal irradiation: 297 N of participants BMT: 67
Outcomes	Severe fatigue: N of participants with severe fatigue: NDa Risk and associated factors: Dependent factor: fatiguedc Multivariable: Significant: hearing problems (OR 2.85 (95% CI 1.84 to 4.42), P < 0.001), memory problems (OR 3.74 (95% CI 2.40 to 5.84), P < 0.001), digestive problems (OR 3.15 (95% CI 2.13 to 4.66), P < 0.001), musculoskeletal/neurological problems (OR 2.03 (95% CI 1.42 to 2.88), P < 0.001), thyroid problems (OR 2.12 (95% CI 1.31 to 3.43), P = 0.002), vision impairments (OR 1.87 (95% CI 1.15 to 3.05), P = 0.012)) Non‐significant: overweight (OR 1.44 (95% CI 0.97 to 2.15), P = 0.071)
Notes	Funding sources: Swiss Cancer League (KLS‐01605‐10‐2004, KLS‐2215‐02‐2008, KLS‐02783‐02‐2011), Cancer League Aargau, Cancer League Zurich, Swiss Bridge, and Stiftung zur Krebsbekämpfung. Gisela Michel and Claudia Kuehni were funded by the Swiss National Science Foundation (G.M.—Ambizione Fellowship grant PZ00P3_121682/1 and PZ00P3_141722; C.K.—PROSPER grant 3233‐069348) Declaration of interest: No conflict of interest stated for any of the authors aAuthors report fatigue on continuous scale. Additional information on severe fatigue was requested and not available. bNumbers do not add up to total N of described study group. Unclear what correct numbers were. cAnalyses were performed with fatigued as outcome (defined as scoring below the 10th percentile of sibling scores and described in the paper as Energy and vitality). The authors tested the effect of each chronic health problem using multivariable logistic regression models, adjusting for age, gender, and parents’ education. Due to multiple testing concerns, the authors interpreted the results cautiously, looking only at associations with P < 0.001. OR and P values were not reported in the article for the adjusting factors.
Risk of bias
Bias	Authors' judgement	Support for judgement
Representative study group (selection bias)	High risk	Size of original cohort is unclear, 2526 eligible participants, 1593 described study group, < 90%
Adequate follow‐up assessment (attrition bias)	Low risk	Outcome was assessed for > 95% of the study group of interest
Blinded outcome assessor (detection bias) All outcomes	High risk	Outcome assessors were not blinded to the investigated determinant
Adjustment important confounders	High risk	Multiviariable analyses, but treatment was not taken into account
Well‐defined study group (reporting bias)	Unclear risk	Type of cancer and cancer treatment are mentioned but information about specific chemotherapeutic agents and doses are not reported. Inclusion and exclusion criteria are described
Well‐defined follow‐up (reporting bias)	Low risk	Length of follow‐up is mentioned
Well‐defined outcome fatigue (reporting bias)	Low risk	Authors reported which instrument they used to assess fatigue, and how they described fatigue (defined fatigued as scoring below the 10th percentile of the siblings' scores)
Well‐defined risk estimation	Low risk	Odds ratios were calculated