Rottoli 2020.

Study characteristics
Notes	English title How important is obesity as a risk factor for respiratory failure, intensive care admission and death in hospitalised COVID‐19 patients? Results from a single Italian centre Study setting Start of study recruitment (MM/YYYY): 03/2020 End of study recruitment (MM/YYYY): 04/2020 Study design: Retrospective cohort Study centre(s): Single centre/clinic/area within a country Number of centres, clinics or areas: 1 Study setting: Inpatient Number of participants recruited: 482 Sampling method: Consecutive participants Participants Female participants (absolute number): 180 Age measure, value: Mean (SD), 66.2 (16.8) Inclusion criteria: Patients who had a confirmed COVID‐19 diagnosis using a positive RT‐PCR test on nasopharyngeal swabs Exclusion criteria: Patients without an available BMI Smoking frequency: 85 Diabetes frequency: 73 Hypertension frequency: 254 Cardiovascular disease frequency: 102 Asthma frequency: NR Chronic obstructive pulmonary disease frequency: 63 Other pulmonary disease frequency: NR Immunosuppression frequency: NR Chronic kidney disease frequency: NR Cancer frequency: 55 Steroid administration frequency: NR Supplemental oxygen administration frequency: NR Other treatments (frequency): NR Prognostic factor(s) Study’s definition for obesity: Normal weight, overweight and obesity classes were defined according to the WHO guidelines. The time when obesity has been measured: Before disease or right at presentation Main variable used for determination of obesity: BMI Threshold used for definition: 30 Obesity frequency (absolute number): 104 Prognostic factor(s):  BMI ≥ 35 kg/m2 Obesity Class I (BMI of 30‐35 kg/m2) BMI (per kg/m2 increase) Outcome(s) Mortality ICU admission  Outcome (prognostic factor) Mortality (BMI ≥ 35 kg/m2) Follow‐up Number of patients followed completely for the outcome: 482 Number of obese patients followed completely for the outcome: 84 Number of non‐obese patients followed completely for the outcome: 378 Univariable unadjusted analysis for obesity Effect measure for obesity: NR Effect measure value (95% CI), P value: NR Multivariable analysis for obesity Modelling method: Cox regression The set of prognostic factors used for adjustment: Age (60‐69, 70‐79.9, ≥ 80), diabetes, hypertension, renal disease, sex, stroke Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 1.72 (1.00, 2.99), 0.051 Outcome (prognostic factor) Mortality (Obesity Class I (BMI of 30‐35 Kg/m2)) Follow‐up Number of patients followed completely for the outcome: 482 Number of obese patients followed completely for the outcome: 20 Number of non‐obese patients followed completely for the outcome: 378 Univariable unadjusted analysis for obesity Effect measure for obesity: NR Effect measure value (95% CI), P value: NR Multivariable analysis for obesity Modelling method: Cox regression The set of prognostic factors used for adjustment: Age (60‐69, 70‐79.9,≥ 80), diabetes, hypertension, renal disease, sex, stroke Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 1.21 (0.64, 2.27), 1 Outcome (prognostic factor) Mortality (BMI (per kg/m2 increase)) Follow‐up Number of patients followed completely for the outcome: 482 Number of obese patients followed completely for the outcome: 104 Number of non‐obese patients followed completely for the outcome: 378 Univariable unadjusted analysis for obesity Effect measure for obesity: NR Effect measure value (95% CI), P value: NR Multivariable analysis for obesity Modelling method: Cox regression The set of prognostic factors used for adjustment: Age (60‐69, 70‐79.9, ≥ 80), diabetes, hypertension, renal disease, sex, stroke Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 1.07 (1.02, 1.13), 0.007 Outcome (prognostic factor) ICU admission (BMI ≥ 35 kg/m2) Follow‐up Number of patients followed completely for the outcome: 482 Number of obese patients followed completely for the outcome: 84 Number of non‐obese patients followed completely for the outcome: 378 Univariable unadjusted analysis for obesity Effect measure for obesity: NR Effect measure value (95% CI), P value: NR Multivariable analysis for obesity Modelling method: Cox regression The set of prognostic factors used for adjustment: Age (60‐69, 70‐79.9, ≥ 80), diabetes, hypertension, renal disease, sex, stroke Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 5.71 (2.53, 12.90), < 0.001 Outcome (prognostic factor) ICU admission (Obesity Class I (BMI of 30‐35 kg/m2)) Follow‐up Number of patients followed completely for the outcome: 482 Number of obese patients followed completely for the outcome: 20 Number of non‐obese patients followed completely for the outcome: 378 Univariable unadjusted analysis for obesity Effect measure for obesity: NR Effect measure value (95% CI), P value: NR Multivariable analysis for obesity Modelling method: Cox regression The set of prognostic factors used for adjustment: Age (60‐69, 70‐79.9, ≥ 80), diabetes, hypertension, renal disease, sex, stroke Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 3.81 (2.22, 6.51), < 0.001 Outcome (prognostic factor) ICU admission (BMI (per kg/m2 increase)) Follow‐up Number of patients followed completely for the outcome: 482 Number of obese patients followed completely for the outcome: 104 Number of non‐obese patients followed completely for the outcome: 378 Univariable unadjusted analysis for obesity Effect measure for obesity: NR Effect measure value (95% CI), P value: NR Multivariable analysis for obesity Modelling method: Cox regression The set of prognostic factors used for adjustment: Age (60‐69, 70‐79.9, ≥ 80), diabetes, hypertension, renal disease, sex, stroke Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 1.15 (1.10, 1.20), < 0.001
Item	Authors' judgement	Support for judgement
Study Participation	Yes	Appendix 3
Study Attrition Mortality	Unclear	Appendix 3
Study Attrition ICU admission	Unclear	Appendix 3
Prognostic Factor Measurement	Yes	Appendix 3
Outcome Measurement Mortality	Yes	Appendix 3
Outcome Measurement ICU admission	Yes	Appendix 3
Confounding Bias Mortality	Yes	Appendix 3
Confounding Bias ICU admission	Yes	Appendix 3
Statistical Analysis Bias	Yes	Appendix 3