Methodology of reports of original research
| Methodology | No of articles per 100 000 MEDLINE publications | Percentage change (95% CI)† | p value† | |
|---|---|---|---|---|
| Before IOM report | After IOM report | |||
| †p values and 95% confidence intervals were calculated from a Poisson comparison of publication rates before and after publication of the IOM report. | ||||
| Qualitative studies | 1.1 | 3.0 | +272% (+72% to +431%) | <0.001 |
| Case reports/case series | 13.3 | 14.9 | +12% (−4% to +30%) | 0.144 |
| Correlational studies | 0.5 | 0.8 | +56% (−25% to +326%) | 0.235 |
| Cross-sectional surveys | 3.0 | 9.7 | +326% (+248 to +427%) | <0.001 |
| Case-control studies | 1.9 | 3.3 | +72% (+19% to +249%) | 0.004 |
| Cohort studies | 2.3 | 2.6 | +15% (−20% to +66%) | 0.451 |
| Intervention studies | 1.2 | 4.0 | +344% (+224% to +528%) | <0.001 |
| Systematic reviews | 0.3 | 1.5 | +558% (+237% to +1319%) | <0.001 |
| Decision analyses | 0.3 | 1.0 | +358% (+147% to +873%) | 0.005 |