Therapy — how to select treatments for patients that do more good than harm and that are worth the efforts and costs of using them.
Diagnosis — how to select and interpret diagnostic tests, in order to confirm or exclude a diagnosis, based on considering their precision, accuracy, acceptability, expense, safety, etc.
Prognosis — how to estimate our patient's likely clinical course over time and anticipate likely complications of the disorder.
Etiology — how to identify causes for disease
* Adapted from Sackett et al. Evidence-Based Medicine: How to Practice and Teach EBM (London: Churchill Livingstone, 2000): 19.
A true experiment, (one that delivers an intervention or treatment), the strongest design to support cause and effect relationship, in which subjects are randomly assigned to control and experimental groups.
A prospective longitudinal study that begins with the gathering of two groups of patients (the cohorts), one that received the exposure (e.g., to a disease) and one that does not, and then following these groups over time to measure the development of different outcomes (diseases).
An intensive investigation of a case involving a person or small group of persons, an issue, or an event.
A type of research that retrospectively compares characteristics of an individual who has a certain condition with one who does not; often conducted for the purpose of identifying variables that might predict the condition.
| Question about | Look for this type of study |
|---|---|
| THERAPY | Randomized Controlled Trial (RCT) |
| DIAGNOSIS | RCT or other Controlled Trial |
| PROGNOSIS | Cohort Studies, Case-Control Studies, Case Studies |
| ETIOLOGY | Cohort Studies |
Adapted from Sackett et al. Evidence-Based Medicine: How to Practice and Teach EBM. London: Churchill Livingstone, 2000:19.
Melnyk, Bernadette Mazurek and Ellen Fineout-Overholt. Evidence-based practice in nursing and healthcare. Philadelphia : Lippincott Williams & Wilkins, 2005:10.
