Hierarchy of Evidence: From Case Reports to Randomized Controlled Trials
Bibliographic record
Abstract
In the hierarchy of research designs, the results of randomized controlled trials are considered the highest level of evidence. Randomization is the only method for controlling for known and unknown prognostic factors between two comparison groups. Lack of randomization predisposes a study to potentially important imbalances in baseline characteristics between two study groups. There is a hierarchy of evidence, with randomized controlled trials at the top, controlled observational studies in the middle, and uncontrolled studies and opinion at the bottom. This hierarchy has not been supported in two recent publications in the New England Journal of Medicine which identified nonsignificant differences in results between randomized, controlled trials, and observational studies. The current authors provide an approach to organizing published research on the basis of study design, a hierarchy of evidence, a set of principles and tools that help clinicians distinguish ignorance of evidence from real scientific uncertainty, distinguish evidence from unsubstantiated opinions, and ultimately provide better patient care.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.900 | 0.950 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.023 | 0.011 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.015 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; both teacher heads agree on what is shown here.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".