A propensity-matched observational study compares beta-blocker therapy versus no beta-blocker after myocardial infarction in 500 post-MI patients. After matching, investigators report a standardized mean difference of 0.03 for age between groups. Baseline characteristics show similar troponin I levels and ejection fraction (35-40%) between cohorts. No significant differences exist in prior medication use. Which interpretation of this standardized mean difference is most appropriate?
- A)Matching failed because the value is below zero
- B)Age is well balanced between groupsGABARITO
- C)The study has low external validity
- D)Age remains strongly imbalanced between groups
- E)The age difference is statistically significant
Explicação
Standardized mean difference is used to assess baseline covariate balance between comparison groups, especially after matching or weighting. Values close to zero indicate good balance, and values below about 0.1 are commonly considered acceptable. A value of 0... Ver explicação completa e trilha adaptativa →