Overall Distribution
Classification priority: PubMed MeSH publication-type tags (most reliable, covers ~65–70 % of the corpus) → OpenAlex work type → title-keyword heuristics. Papers without a detectable study design are classified as Other.
Trends Over Time (2000–2024)
Annual paper counts by study type (2000–2024).
Summary Table
| Study type | Papers | % | Citations |
|---|---|---|---|
| Other | 9,299 | 91.1% | 320,418 |
| Review | 576 | 5.6% | 65,337 |
| Observational | 185 | 1.8% | 14,220 |
| RCT | 132 | 1.3% | 7,074 |
| Systematic Review / Meta-analysis | 15 | 0.1% | 127 |
| Clinical Trial | 6 | 0.1% | 474 |