Intraclass correlation coefficients

If the material being sampled consists of discrete particles such that an average particle mass can be calculated, then still another method is useful. In this procedure the constants and B of Equation 5 are obtained from the intraclass correlation coefficient between pairs of small, single-increment samples of equal mass, the increments of each pair being collected near each other and the pairs distributed over the population under study. The value of r can be estimated from the relation ... 

Test-retest reliability refers to the relationship between scores obtained from the same instrument on two or more separate occasions when all pertinent conditions remain relatively unchanged. It is usually evaluated using the intraclass correlation coefficient (ICC). However, QOL is not assumed to be constant over the course of time. In fact, most clinical studies attempt to assess how QOL changes. Test-retest reliability estimates may have limited value in evaluating measures that are designed to assess a dynamic process. 

HIV/AIDS human immunodeficiency virus/acquired immunodeficiency syndrome HUI Health Utilities Index HYEs healthy-year equivalents ICC intraclass correlation coefficient KDQOL Kidney Disease Quality of Life instrument MCS mental component summary scale of the SF-36 MOS-HTV Medical Outcomes Study HIV Health Survey MOT Medical Outcomes Trust MSQOL Migraine Specific Quality of Life NHP Nottingham Health Profile PCS physical component summary scale of the SF-36 QALY quahty-adjusted hfe year QOL quahty of life QOLIE Quality of Life in Epilepsy QWB Quality of WeU-Being scale SF-36 MOS 36-Item Short-Form Health Survey SIP Sickness Impact Profile VAS visual analog scale WY well year YHL years of healthy life... 

Intraclass correlation coefficient Kappa statistics (categorical data)... 

Weir, J.P., 2005. Quantifying test-retest reliability using the intraclass correlation coefficient and the SEM. 

A statistical analysis was performed using XLSTAT 2014. The correlation between the readings made by the three and four methods were analyzed using the intraclass correlation coefficient (ICC) [11] and the graphical method of Bland and Altman [12]. 

---