Comparison of two dependent within subject coefficients of variation to evaluate the reproducibility of measurement devices
2008

Comparing Measurement Device Reliability

Sample size: 50 publication Evidence: high

Author Information

Author(s): Shoukri Mohamed M, Colak Dilek, Kaya Namik, Donner Allan

Primary Institution: Department of Epidemiology and Biostatistics, Schulich School of Medicine, University of Western Ontario, London, Ontario, Canada

Hypothesis

Can we develop methods to compare the reproducibility of two measurement devices using the same subjects?

Conclusion

The methodology developed allows for effective comparison of the reproducibility of two measuring instruments, showing that the Wald's test and likelihood ratio test are powerful tools for this purpose.

Supporting Evidence

  • The Wald test is as powerful as the likelihood ratio test.
  • Both tests have greater power than the score test.
  • The methodology was illustrated using data from microarray gene expressions and CAT scans.

Takeaway

This study helps us understand how to check if two devices measure things reliably by comparing their results on the same people.

Methodology

The study developed several statistical tests, including the Wald test and likelihood ratio test, to compare the within-subject coefficients of variation from two measurement devices.

Limitations

The statistical properties may not be appropriate in small samples, and the methods assume normality in the data.

Participant Demographics

50 psychiatric patients were involved in the study.

Statistical Information

P-Value

p<0.001

Confidence Interval

(0.28, 0.39)

Statistical Significance

p<0.001

Digital Object Identifier (DOI)

10.1186/1471-2288-8-24

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