Environmental
Always ask yourself if the intervention is relevant or practical in your setting?
An evaluation of the effects of an action conducted in a controlled environment may not provide a reliable estimate of its effects and safety in other (e.g. field) settings. Equally an intervention conducted in one place may produce effects that are not repeatable elsewhere.
REMEMBER: Be aware that interventions available to you may be sufficiently different from those in the research studies that the results may not apply to you.