Table 3 Primary study case example: effects of bariatric surgery on mortality in Swedish obese subjects
From: Observational evidence and strength of evidence domains: case examples
Strength of evidence factors | Strength of evidence domains |
|---|---|
Required domains | Study limitations: |
• Reduced risk of selection bias: matched sample to address potentially influential confounding variables, minimal exclusion criteria, prospective study design, very large sample size | |
• Reduced risk of detection bias: objective outcome and independent outcome assessors | |
• Reduced risk of attrition bias: high rate of follow-up | |
• Reduced risk of reporting bias: a priori protocol identifying primary outcomes | |
Directness: minimal exclusion criteria from a large sample at many hospitals and clinics provided direct evidence of key outcomes for the population of interest | |
Precision: adequately powered study resulted in a precise effect estimate |