| Type of Evidence | Description of Evidence |
| Ia | Evidence obtained from meta-analysis or systematic reviews of randomized controlled trials, and/or synthesis of multiple studies primarily of quantitative research. |
| Ib | Evidence obtained from at least one randomized controlled trial |
| IIa | Evidence obtained from at least one well-designed controlled study without randomization |
| IIb | Evidence obtained from at least one other type of well-designed quasi-experimental study, without randomization. |
| III | Synthesis of multiple studies primarily of qualitative research |
| IV | Evidence obtained from well-designed, non-experimental, observational studies, such as analytical studies or descriptive studies, and/or qualitative studies. |
| V | Evidence obtained from expert opinion or committee reports, and/or clinical experiences of respected authorities. |
Healthy Work Environment
Developing and Sustaining Effective Staffing and Workload Practices
Healthy Work Environment Recommendations