Skip to main content

Table 4 Contributions of evidence from the major categories of research approaches

From: Hierarchies of evidence applied to lifestyle Medicine (HEALM): introduction of a strength-of-evidence approach based on a methodological systematic review

Research Method

Unique contribution to understanding

Basic science

Mechanisms of action

Intervention studies in humans / RCTs

Reliable attribution; control of bias, confounding

Observational epidemiology; large and diverse population-based samples

Effects at scale

Observational epidemiology; long time periods

Duration of effects

Back to article page

BMC Medical Research Methodology

ISSN: 1471-2288

Contact us