Kappa系数一种衡量评估者间一致性的常用方法.pdfVIP

• 62 • Shanghai Archives of Psychiatry, 2015, Vol. 27, No. 1 •Biostatistics in psychiatry (25)• Kappa coefficient: a popular measure of rater agreement 1 2 3 4 1,5 Wan TANG *, Jun HU , Hui ZHANG , Pan WU , Hua HE Summary: In mental health and psychosocial studies it is often necessary to report on the between-rater agreement of measures used in the study. This paper discusses the concept of agreement, highlighting its fundamental difference from correlation. Several examples demonstrate how to compute the kappa coefficient – a popular statistic for measuring agreement – both by hand and by using statistical software packages such as SAS and SPSS. Real study data are used to illustrate how to use and interpret this coefficient in clinical research and practice. The article concludes with a discussion of the limitations of the coefficient. Keywords: interrater agreement; kappa coefficient; weighted kappa; correlation [Shanghai Arch Psychiatry. 2015; 27(1): 62-67. doi: /10.11919/j.issn.1002-0829.215010] 1. Introduction coefficient for the two scores is 1, indicating perfect For most physical illnesses such as high blood pressure correlation. The paradox occurs because there is a bias and tuberculosis, definitive diagnoses can be made in the scoring that results in a consistent difference of using medical devices such as a sphygmomanometer for 2 points in the scores of the two raters for all 6 items blood pressure or an X-ray for tuberculosis. However, in the instrument. Thus, although perfectly correlated there are