+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Confidence and coverage for Bland-Altman limits of agreement and their approximate confidence intervals

Confidence and coverage for Bland-Altman limits of agreement and their approximate confidence intervals

Statistical Methods in Medical Research 27(5): 1559-1574

Bland and Altman described approximate methods in 1986 and 1999 for calculating confidence limits for their 95% limits of agreement, approximations which assume large subject numbers. In this paper, these approximations are compared with exact confidence intervals calculated using two-sided tolerance intervals for a normal distribution. The approximations are compared in terms of the tolerance factors themselves but also in terms of the exact confidence limits and the exact limits of agreement coverage corresponding to the approximate confidence interval methods. Using similar methods the 50th percentile of the tolerance interval are compared with the k values of 1.96 and 2, which Bland and Altman used to define limits of agreements (i.e. [Formula: see text]+/- 1.96Sd and [Formula: see text]+/- 2Sd). For limits of agreement outer confidence intervals, Bland and Altman's approximations are too permissive for sample sizes <40 (1999 approximation) and <76 (1986 approximation). For inner confidence limits the approximations are poorer, being permissive for sample sizes of <490 (1986 approximation) and all practical sample sizes (1999 approximation). Exact confidence intervals for 95% limits of agreements, based on two-sided tolerance factors, can be calculated easily based on tables and should be used in preference to the approximate methods, especially for small sample sizes.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 057489148

Download citation: RISBibTeXText

PMID: 27587594

DOI: 10.1177/0962280216665419

Related references

The appropriateness of Bland-Altman's approximate confidence intervals for limits of agreement. Bmc Medical Research Methodology 18(1): 45, 2018

Exact parametric confidence intervals for Bland-Altman limits of agreement. Optometry and Vision Science 92(3): E71-E80, 2015

Using Bland-Altman to assess agreement between two medical devices--don't forget the confidence intervals!. Journal of Clinical Monitoring and Computing 21(6): 331-333, 2007

Confidence interval estimation for the Bland-Altman limits of agreement with multiple observations per individual. Statistical Methods in Medical Research 22(6): 630-642, 2014

Interpreting method comparison studies by use of the bland-altman plot: reflecting the importance of sample size by incorporating confidence limits and predefined error limits in the graphic. Clinical Chemistry 50(11): 2216-2218, 2004

The empirical coverage of confidence intervals: point estimates and confidence intervals for confidence levels. Biometrical Journal. Biometrische Zeitschrift 54(4): 537-551, 2013

Approximate standard errors and confidence intervals for indices of positive and negative agreement. Journal Of Clinical Epidemiology. 51(9): 763-771,., 1998

Limits of agreement may have large confidence intervals. British Journal of Anaesthesia 116(3): 430-431, 2016

Limits of Agreement With Confidence Intervals Are Necessary to Assess Comparability of Measurement Devices. Anesthesia and Analgesia 125(3): 1075, 2017

Bland-Altman beyond the basics: creating confidence with badly behaved data. Clinical and Experimental Pharmacology and Physiology 37(2): 141-142, 2010

A measure of confidence in Bland-Altman analysis for the interchangeability of two methods of measurement. Journal of Clinical Monitoring and Computing 22(4): 257-259, 2008

Confidence in Altman-Bland plots: a critical review of the method of differences. Clinical and Experimental Pharmacology and Physiology 37(2): 143-149, 2010

Confidence limits, error bars and method comparison in molecular modeling. Part 1: the calculation of confidence intervals. Journal of Computer-Aided Molecular Design 28(9): 887-918, 2015

Limits of agreement (Bland-Altman method). BMJ 346: F1630-F1630, 2013

A framework for the meta-analysis of Bland-Altman studies based on a limits of agreement approach. Statistics in Medicine 36(23): 3621-3635, 2017