Salari 2020.

Study characteristics
Notes	English title An investigation of risk factors of in‐hospital death due to COVID‐19: a case‐control study in Rasht, Iran Study setting Start of study recruitment (MM/YYYY): 04/2020 End of study recruitment (MM/YYYY): 08/2020 Study design: Case‐control Study centre(s): Single centre/clinic/area within a country Number of centres, clinics or areas: 1 Study setting: Inpatient Number of participants recruited: 250 Sampling method: Non‐random sample Participants Female participants (absolute number): 126 Age measure, value: Mean (SD), 59.6 (16.5) Inclusion criteria: Adult COVID‐19 patients aged older than 18 years who were admitted to Razi University hospital, the COVID‐19 referral hospital in Rasht, Guilan, Northern Iran, from April 21 to August 21, 2020 Exclusion criteria: Subjects younger than 18 years and those without anthropometric or laboratory findings Smoking frequency: NR Diabetes frequency: 20 Hypertension frequency: 33 Cardiovascular disease frequency: 64 Asthma frequency: NR Chronic obstructive pulmonary disease frequency: NR Other pulmonary disease frequency: NR Immunosuppression frequency: NR Chronic kidney disease frequency: NR Cancer frequency: NR Steroid administration frequency: NR Supplemental oxygen administration frequency: NR Other treatments (frequency): NR Prognostic factor(s) Study’s definition for obesity: NR 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: NR Obesity frequency (absolute number): NR Prognostic factor(s): BMI quartile 4 (median = 30.12 kg/m2) Outcome(s) Mortality Outcome (prognostic factor) Mortality (BMI quartile 4 (median = 30.12 kg/m2)) Follow‐up Number of patients followed completely for the outcome: 250 Number of obese patients followed completely for the outcome: NR Number of non‐obese patients followed completely for the outcome: NR Univariable unadjusted analysis for obesity Effect measure for obesity: Odds ratio Effect measure value (95% CI), P value: 2.66 (1.27, 5.58), NR Multivariable analysis for obesity Modelling method: Logistic regression The set of prognostic factors used for adjustment: Age, length of hospitalisation, sex Effect measure for obesity: Odds ratio Effect measure value (95% CI), P value: 2.49 (1.15, 5.41), NR
Item	Authors' judgement	Support for judgement
Study Participation	Yes	Appendix 3
Study Attrition Mortality	Yes	Appendix 3
Prognostic Factor Measurement	Yes	Appendix 3
Outcome Measurement Mortality	Yes	Appendix 3
Confounding Bias Mortality	No	Appendix 3
Statistical Analysis Bias	Unclear	Appendix 3