Table 2.
Quality criteria for comparative observational database studies
| Section | Quality criteria |
|---|---|
| Background | Clear underlying hypotheses and specific research question(s) |
| Methods | |
| Study design | Observational comparative effectiveness database study Independent steering committee involved in a priori definition of the study methodology (including statistical analysis plan), review of analyses, and interpretation of results Registration in a public repository with a commitment to publish results |
| Database(s) | High-quality database(s) with few missing data for measures of interest Validation studies |
| Outcomes | Clearly defined primary and secondary outcomes, chosen a priori The use of proxy and composite measures justified and explained The validity of proxy measures checked |
| Length of observation | Sufficient duration to reliably assess outcomes of interest and long-term treatment effects |
| Patients | Well-described inclusion and exclusion criteria, reflecting target patients’ characteristics in the real world |
| Analyses | Study groups compared at baseline using univariate analyses Avoidance of biases related to baseline differences using matching and/or adjustments Sensitivity analyses are performed to check the robustness of results |
| Sample size | Sample size calculations based on clear a priori hypotheses regarding the occurrence of outcomes of interest and target effect of studied treatment versus comparator |
| Results | Flow chart explaining all exclusions Detailed description of patients’ characteristics, including demographics, characteristics of the disease of interest, comorbidities, and concomitant treatments Characteristics of patients lost to follow-up are compared with those of patients remaining in the analyses Extensive presentation of results obtained in unmatched and matched populations (if matching was performed) using univariate and multivariate, as well as unadjusted and adjusted, analyses Sensitivity analyses and/or analyses of several databases go in the same direction as primary analyses |
| Discussion | Summary and interpretation of findings, focusing first on whether they confirm or contradict a priori hypotheses Discussion of differences with results of efficacy RCTs Discussion of possible biases and confounding factors, especially related to the observational nature of the study Suggestions for future research to challenge, strengthen, or extend study results |
Reprinted with permission of the American Thoracic Society. Copyright © 2018 American Thoracic Society [28]
RCT randomized control trial