NIH Definitions

NIH’S Definitions

Quick definitions to understand the NIH Policy

What is Valid Analysis?

It is an unbiased assessment

• "Such an assessment will, on average, yield the correct estimate of the difference in outcomes  between two groups of subjects.  
• Valid analysis can and should be conducted for both small and large studies.
• A valid analysis does not need to have a high  statistical power for detecting a stated effect.  
• The principal requirements for ensuring a valid analysis of the question of interest are:
  • allocation of study participants of both sexes/genders (males and females) and different racial/ethnic groups to the intervention and control groups by an unbiased process such as randomization,
  • unbiased evaluation of the outcome(s) of study participants, and
  • use of unbiased statistical analyses and proper methods of inference to estimate and compare the intervention effects among the sex/gender and racial/ethnic groups."

What is a Significant Difference?

It is a difference based on medical/ scientific data that is of clinical or public health importance

• "This definition differs from the commonly used "statistically significant difference," which refers to the event that, for a given set of data, the statistical test for a difference between the effects in two groups achieves  statistical significance.  
• Statistical significance depends upon the amount of  information in the data set.