Intraclass correlations of periodontal measurements in beagle dogs.

Abstract

The intraclass correlations of Gingival Index, probing depth, and attachment level scores were estimated in a sample of beagle dogs. These estimates were made over a ten‐week period at the time of ligature placement, eight weeks later at ligature removal, and two weeks postremoval. Estimates of the intraclass correlation were computed for the actual scores and for differences in scores between the first and second, and second and third observation points.All intraclass correlations were of sufficient magnitude to preclude statistical analyses which do not consider the subject as the sampling unit. For all conditions. intraclass correlations decreased upon experimental intervention and were generally larger than those reported in human studies. Intraclass correlations of Gingival Index scores were larger than those of probing depth and attachment level measurements. The results were discussed in terms of sources of variation within and between subjects.