| Appendix 1: Levels of evidence and grades of recommendations of the Canadian Task Force on Preventive Health Care |
|
| Levels of evidence |
| I | | Evidence from at least one well-designed randomized controlled trial |
| II-1 | | Evidence from well-designed controlled trials without randomization |
| II-2 | | Evidence from well-designed cohort or case–control analytic studies, preferably from more than one centre or research group |
| II-3 | | Evidence from comparisons between times and places with or without the intervention; dramatic results from uncontrolled studies (e.g., results of treatment with penicillin in 1940s) |
| III | | Opinions of respected authorities, based on clinical experience; descriptive studies or reports of expert committees |
| |
| Grades of recommendations |
| A | | There is good evidence to support the recommendation that the condition or manoeuvre be specifically considered in a periodic health examination |
| B | | There is fair evidence to support the recommendation that the condition or manoeuvre be specifically considered in a periodic health examination |
| C | | There is poor evidence relating to the inclusion or exclusion of a condition or manoeuvre in a periodic health examination, but recommendations can be made on other grounds |
| D | | There is fair evidence to support the recommendation that a condition or manoeuvre be specifically excluded from a periodic health examination |
| E | | There is good evidence to support the recommendation that a condition or manoeuvre be specifically excluded from a periodic health examination |
