Examining test-retest reliability: an intra-class correlation approach

Nurs Res. 2002 Jan-Feb;51(1):59-62. doi: 10.1097/00006199-200201000-00009.


Background: There are limitations of inter-class correlation (usually, the Pearson's product-moment correlation) in evaluating reliability of an instrument. An intra-class correlation approach would be appropriate to examine the test-retest reliability of an instrument.

Objectives: To introduce an intra-class correlation approach to examine the test-retest reliability of an instrument.

Method: The method of constructing an intra-class correlation coefficient was presented.

Results: The instrument with visual analog scales to measure the perceived competence to practice breast self-examination and perceived barriers to breast self-examination was tested. The intra-class correlation coefficient was 0.640.

Conclusion: The intra-class correlation is an alternative to test the reliability of an instrument and it is more sensitive to the detection of systematic error.

Publication types

  • Review

MeSH terms

  • Breast Self-Examination
  • Female
  • Humans
  • Nursing Research / statistics & numerical data*
  • Psychometrics / statistics & numerical data*
  • Reproducibility of Results