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. 2023 May 24;2023(5):CD015201. doi: 10.1002/14651858.CD015201

Klang 2020.

Study characteristics
Notes English title
Severe obesity as an independent risk factor for COVID‐19 mortality in hospitalized patients younger than 50
Study setting
Start of study recruitment (MM/YYYY): 03/2020
End of study recruitment (MM/YYYY): 05/2020
Study design: Registry data
Study centre(s): Multiple centres/clinics/areas within a country
Number of centres, clinics or areas: 5
Study setting: Inpatient
Number of participants recruited: 572 (cohort 1), 2834 (cohort 2)
Sampling method: Consecutive participants
Participants
Female participants (absolute number): 175 (cohort 1), 1270 (cohort 2)
Age measure, value: NR
Inclusion criteria: All adult patients who were positive for COVID‐19 by nasopharyngeal swab polymerase chain reaction test and were admitted to the hospital. Patients who were discharged or had died during the study period were included.
Exclusion criteria: Patients who were still hospitalised at the time of analysis and patients with missing BMI data
Smoking frequency: 76 (cohort 1), 717 (cohort 2)
Diabetes frequency: 153 (cohort 1), 1446 (cohort 2)
Hypertension frequency: 175 (cohort 1), 2124 (cohort 2)
Cardiovascular disease frequency: 67 (cohort 1), 1190 (cohort 2)
Asthma frequency: NR
Chronic obstructive pulmonary disease frequency: NR
Other pulmonary disease frequency: NR
Immunosuppression frequency: NR
Chronic kidney disease frequency: 70 (cohort 1), 597 (cohort 2)
Cancer frequency: 39 (cohort 1), 491 (cohort 2)
Steroid administration frequency: NR
Supplemental oxygen administration frequency: 79 (cohort 1), 730 (cohort 2)
Other treatments (frequency): NR
Prognostic factor(s)
Study’s definition for obesity: Obesity was defined as BMI ≥ 30 kg/m2; obesity groups included the following: BMI of 30 to < 40 and BMI ≥ 40
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): 275 (cohort 1), 956 (cohort 2)
Prognostic factor(s): BMI of 30 to < 40
BMI ≥ 40
Outcome(s)
Mortality
Mechanical ventilation
Outcome (prognostic factor)
Mortality (BMI of 30 to < 40) (cohort 1)
Follow‐up
Number of patients followed completely for the outcome: 572
Number of obese patients followed completely for the outcome: 275
Number of non‐obese patients followed completely for the outcome: 297
Univariable unadjusted analysis for obesity
Effect measure for obesity: NR
Effect measure value (95% CI), P value: NR, 0.313
Multivariable analysis for obesity
Modelling method: Logistic regression
The set of prognostic factors used for adjustment: Age decile, male sex, CAD, CHF, HTN, DM, hyperlipidaemia, CKD, history of cancer, smoking (past or present), BMI 30‐40, BMI ≥ 40, and race
Effect measure for obesity: Odds ratio
Effect measure value (95% CI), P value: 1.1 (0.5, 2.3), 0.755
Outcome (prognostic factor)
Mortality (BMI ≥ 40) (cohort 1)
Follow‐up
Number of patients followed completely for the outcome: 572
Number of obese patients followed completely for the outcome: 275
Number of non‐obese patients followed completely for the outcome: 297
Univariable unadjusted analysis for obesity
Effect measure for obesity: NR
Effect measure value (95% CI), P value: NR, < 0.001
Multivariable analysis for obesity
Modelling method: Logistic regression
The set of prognostic factors used for adjustment: Age decile, male sex, CAD, CHF, HTN, DM, hyperlipidaemia, CKD, history of cancer, smoking (past or present), BMI 30‐40, BMI ≥ 40, and race
Effect measure for obesity: Odds ratio
Effect measure value (95% CI), P value: 5.1 (2.3, 11.1), < 0.001
Outcome (prognostic factor)
Mortality (BMI of 30 to < 40) (cohort 2)
Follow‐up
Number of patients followed completely for the outcome: 2834
Number of obese patients followed completely for the outcome: 956
Number of non‐obese patients followed completely for the outcome: 1878
Univariable unadjusted analysis for obesity
Effect measure for obesity: NR
Effect measure value (95% CI), P value: NR, 0.117
Multivariable analysis for obesity
Modelling method: Logistic regression
The set of prognostic factors used for adjustment: Age decile, male sex, CAD, CHF, HTN, DM, hyperlipidaemia, CKD, history of cancer, smoking (past or present), BMI 30‐40, BMI ≥ 40, and race
Effect measure for obesity: Odds ratio
Effect measure value (95% CI), P value: 1.1 (0.9, 1.3), 0.421
Outcome (prognostic factor)
Mortality (BMI ≥ 40) (cohort 2)
Follow‐up
Number of patients followed completely for the outcome: 2834
Number of obese patients followed completely for the outcome: 956
Number of non‐obese patients followed completely for the outcome: 1878
Univariable unadjusted analysis for obesity
Effect measure for obesity: NR
Effect measure value (95% CI), P value: NR, 0.532
Multivariable analysis for obesity
Modelling method: Logistic regression
The set of prognostic factors used for adjustment: Age decile, male sex, CAD, CHF, HTN, DM, hyperlipidaemia, CKD, history of cancer, smoking (past or present), BMI 30‐40, BMI ≥ 40, and race
Effect measure for obesity: Odds ratio
Effect measure value (95% CI), P value: 1.6 (1.2, 2.3), 0.004
Outcome (prognostic factor)
Mechanical ventilation (BMI of 30 to < 40) (cohort 1)
Follow‐up
Number of patients followed completely for the outcome: 572
Number of obese patients followed completely for the outcome: 275
Number of non‐obese patients followed completely for the outcome: 297
Univariable unadjusted analysis for obesity
Effect measure for obesity: NR
Effect measure value (95% CI), P value: NR
Multivariable analysis for obesity
Modelling method: Logistic regression
The set of prognostic factors used for adjustment: Age decile, male sex, CAD, CHF, HTN, DM, hyperlipidaemia, CKD, history of cancer, smoking (past or present), BMI 30‐40, BMI ≥ 40, and race
Effect measure for obesity: Odds ratio
Effect measure value (95% CI), P value: 1.5 (0.8, 2.7), 0.2
Outcome (prognostic factor)
Mechanical ventilation (BMI ≥ 40) (cohort 1)
Follow‐up
Number of patients followed completely for the outcome: 572
Number of obese patients followed completely for the outcome: 275
Number of non‐obese patients followed completely for the outcome: 297
Univariable unadjusted analysis for obesity
Effect measure for obesity: NR
Effect measure value (95% CI), P value: NR
Multivariable analysis for obesity
Modelling method: Logistic regression
The set of prognostic factors used for adjustment: Age decile, male sex, CAD, CHF, HTN, DM, hyperlipidaemia, CKD, history of cancer, smoking (past or present), BMI 30‐40, BMI ≥ 40, and race
Effect measure for obesity: Odds ratio
Effect measure value (95% CI), P value: 1.5 (1.1, 2.1), 0.025
Outcome (prognostic factor)
Mechanical ventilation (BMI of 30 to < 40) (cohort 2)
Follow‐up
Number of patients followed completely for the outcome: 2834
Number of obese patients followed completely for the outcome: 956
Number of non‐obese patients followed completely for the outcome: 1878
Univariable unadjusted analysis for obesity
Effect measure for obesity: NR
Effect measure value (95% CI), P value: NR
Multivariable analysis for obesity
Modelling method: Logistic regression
The set of prognostic factors used for adjustment: Age decile, male sex, CAD, CHF, HTN, DM, hyperlipidaemia, CKD, history of cancer, smoking (past or present), BMI 30‐40, BMI ≥ 40, and race
Effect measure for obesity: Odds ratio
Effect measure value (95% CI), P value: 1.3 (1, 1.6), 0.016
Outcome (prognostic factor)
Mechanical ventilation (BMI ≥ 40) (cohort 2)
Follow‐up
Number of patients followed completely for the outcome: 2834
Number of obese patients followed completely for the outcome: 956
Number of non‐obese patients followed completely for the outcome: 1878
Univariable unadjusted analysis for obesity
Effect measure for obesity: NR
Effect measure value (95% CI), P value: NR
Multivariable analysis for obesity
Modelling method: Logistic regression
The set of prognostic factors used for adjustment: Age decile, male sex, CAD, CHF, HTN, DM, hyperlipidaemia, CKD, history of cancer, smoking (past or present), BMI 30‐40, BMI ≥ 40, and race
Effect measure for obesity: Odds ratio
Effect measure value (95% CI), P value: 1.5 (1.1, 2.1), 0.025
 
Item Authors' judgement Support for judgement
Study Participation Yes Appendix 3
Study Attrition
Mortality No Appendix 3
Study Attrition
Mechanical ventilation No Appendix 3
Prognostic Factor Measurement Yes Appendix 3
Outcome Measurement
Mortality Yes Appendix 3
Outcome Measurement
Mechanical ventilation Yes Appendix 3
Confounding Bias
Mortality Yes Appendix 3
Confounding Bias
Mechanical ventilation Yes Appendix 3
Statistical Analysis Bias Yes Appendix 3