Table III. —Distribution of studies by research question and study design, according to the Agency for Healthcare Research and Quality.41.
| Research question | RCT | Cross-sectional | Cohort | Quasi-experimental studies and Before-after or time series | Total current update N. (%) |
Total 3rd edition N. (%) |
|---|---|---|---|---|---|---|
| Epidemiology: clinical presentation | 0 | 0 | 0 | 0 | 0 | 0 |
| Epidemiology: prevalence | 0 | 17 | 0 | 0 | 17 (44.7%) | 90 (48.4%) |
| Epidemiology: natural history, determining and modifying factors | 0 | 0 | 15 | 0 | 15 (39.5%) | 55 (29.6%) |
| Micro-level: individuals | 0 | 2 | 0 | 4 | 6 (15.8%) | 41 (22.0%) |
| Meso-level: health services | 0 | 0 | 0 | 0 | 0 | 0 |
| Macro-level: health systems | 0 | 0 | 0 | 0 | 0 | 0 |
| Total current update N. (%) | 0 | 19 (50%) | 15 (39.5%) | 4 (10.5%) | 38 (100%) | 186 (100%) |
| Total 3rd edition, N. (%) | 17 (9.1%) | 91 (48.9%) | 64 (34.4%) | 14 (7.5%) | 186 (100%) |