Ioannou 2020.

Study characteristics
Notes	English title Risk factors for hospitalization, mechanical ventilation, or death among 10 131 US veterans with SARS‐CoV‐2 infection Study setting Start of study recruitment (MM/YYYY): 02/2020 End of study recruitment (MM/YYYY): 05/2020 Study design: Retrospective cohort Study centre(s): Multiple centres/clinics/areas within a country Number of centres, clinics or areas: NR Study setting: Outpatient and inpatient Number of participants recruited: 10,131 Sampling method: Consecutive participants Participants Female participants (absolute number): 912 Age measure, value: Mean (SD), 63.6 (16.2) Inclusion criteria: All VA enrollees who had nasopharyngeal swabs tested for SARS‐CoV‐2 nucleic acid by polymerase chain reaction in inpatient or outpatient VA facilities (including VA nursing homes) between February 28 and May 14, 2020 Exclusion criteria: VA employees Smoking frequency: 5207 (including ex‐smokers) Diabetes frequency: 3860 Hypertension frequency: 6291 Cardiovascular disease frequency: 3323 Asthma frequency: 750 Chronic obstructive pulmonary disease frequency: 1905 Other pulmonary disease frequency: Obstructive sleep apnoea (2715) Immunosuppression frequency: NR Chronic kidney disease frequency: 1864 Cancer frequency: 2300 Steroid administration frequency: NR Supplemental oxygen administration frequency: NR Other treatments (frequency): NR Prognostic factor(s) Study’s definition for obesity: BMI ≥ 30 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): 4539 Prognostic factor(s): Obesity I Obesity II or III Outcome(s) Hospitalisation Mechanical ventilation Death Outcome (prognostic factor) Hospitalisation (obesity I) Follow‐up Number of patients followed completely for the outcome: 10,131 Number of obese patients followed completely for the outcome: 4542 Number of non‐obese patients followed completely for the outcome: 5337 Univariable unadjusted analysis for obesity Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 0.81 (0.74, 0.90), NR Multivariable analysis for obesity Modelling method: Cox regression The set of prognostic factors used for adjustment: Sex, age, race, ethnicity, urban vs rural, BMI, DM, cancer, HTN, CVD, CKD, cirrhosis, asthma, COPD, smoking Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 0.8 (0.72, 0.89), NR Outcome (prognostic factor) Hospitalisation (obesity II or III) Follow‐up Number of patients followed completely for the outcome: 10,131 Number of obese patients followed completely for the outcome: 4542 Number of non‐obese patients followed completely for the outcome: 5337 Univariable unadjusted analysis for obesity Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 0.94 (0.84, 1.05), NR Multivariable analysis for obesity Modelling method: Cox regression The set of prognostic factors used for adjustment: Sex, age, race, ethnicity, urban vs rural, BMI, DM, cancer, HTN, CVD, CKD, cirrhosis, asthma, COPD, smoking Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 0.87 (0.77, 0.98), NR Outcome (prognostic factor) Mechanical ventilation (obesity I) Follow‐up Number of patients followed completely for the outcome: 10,131 Number of obese patients followed completely for the outcome: 4542 Number of non‐obese patients followed completely for the outcome: 5337 Univariable unadjusted analysis for obesity Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 1.23 (0.97, 1.57), NR Multivariable analysis for obesity Modelling method: Cox regression The set of prognostic factors used for adjustment: Sex, age, race, ethnicity, urban vs rural, BMI, DM, cancer, HTN, CVD, CKD, cirrhosis, asthma, COPD, smoking Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 1.03 (0.80, 1.33), NR Outcome (prognostic factor) Mechanical ventilation (obesity II or III) Follow‐up Number of patients followed completely for the outcome: 10,131 Number of obese patients followed completely for the outcome: 4542 Number of non‐obese patients followed completely for the outcome: 5337 Univariable unadjusted analysis for obesity Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 1.71 (1.33, 2.2), NR Multivariable analysis for obesity Modelling method: Cox regression The set of prognostic factors used for adjustment: Sex, age, race, ethnicity, urban vs rural, BMI, DM, cancer, HTN, CVD, CKD, cirrhosis, asthma, COPD, smoking Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 1.22 (0.93, 1.61), NR Outcome (prognostic factor) Death (obesity I) Follow‐up Number of patients followed completely for the outcome: 10,131 Number of obese patients followed completely for the outcome: 4542 Number of non‐obese patients followed completely for the outcome: 5337 Univariable unadjusted analysis for obesity Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 0.86 (0.71, 1.03), NR Multivariable analysis for obesity Modelling method: Cox regression The set of prognostic factors used for adjustment: Sex, age, race, ethnicity, urban vs rural, BMI, DM, cancer, HTN, CVD, CKD, cirrhosis, asthma, COPD, smoking Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 0.84 (0.69, 1.01), NR Outcome (prognostic factor) Death (obesity II or III) Follow‐up Number of patients followed completely for the outcome: 10,131 Number of obese patients followed completely for the outcome: 4542 Number of non‐obese patients followed completely for the outcome: 5337 Univariable unadjusted analysis for obesity Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 1.12 (0.91, 1.37), NR Multivariable analysis for obesity Modelling method: Cox regression The set of prognostic factors used for adjustment: Sex, age, race, ethnicity, urban vs rural, BMI, DM, cancer, HTN, CVD, CKD, cirrhosis, asthma, COPD, smoking Effect measure for obesity: Hazard ratio Effect measure value (95% CI), P value: 0.97 (0.77, 1.21), NR
Item	Authors' judgement	Support for judgement
Study Participation	Yes	Appendix 3
Study Attrition Mortality	Unclear	Appendix 3
Study Attrition Mechanical ventilation	Unclear	Appendix 3
Study Attrition Hospitalisation	Unclear	Appendix 3
Prognostic Factor Measurement	Yes	Appendix 3
Outcome Measurement Mortality	Yes	Appendix 3
Outcome Measurement Mechanical ventilation	Yes	Appendix 3
Outcome Measurement Hospitalisation	Yes	Appendix 3
Confounding Bias Mortality	Yes	Appendix 3
Confounding Bias Mechanical ventilation	Yes	Appendix 3
Confounding Bias Hospitalisation	Yes	Appendix 3
Statistical Analysis Bias	Yes	Appendix 3