Study on biological variability of haematological components in dogs
- 94 Downloads
The aim of the present study was to estimate the between-dog, within-dog and analytical components of variance for red blood cell (RBC) concentration, white blood cell (WBC) concentration, haematocrit (HT) and haemoglobin (HGB) in clinically healthy dogs and to use these estimates to calculate the critical difference for significance between serial results, to assess the utility of the conventional population-based reference intervals, and to set desirable performance standards for the analytical imprecision. RBC, WBC, HCT and HGB were measured in duplicate in blood samples collected monthly for 10 consecutive months from 23 clinically healthy dogs and the test results were subjected to nested analysis of variance. For RBC, the between-dog variation was 4.4%, the within-dog variation was 5.4%, the analytical variation was 2.8%, the critical difference was 17%, the index of individuality was 1.38 and the maximum allowable analytical imprecision was 2.7%. For WBC, the values were 12.3%, 12.1%, 3.7%, 35%, 1.03 and 6.1%. For HCT, the values were 5.2%, 6.4%, 1.1%, 18%, 1.25 and 3.2%, and for HGB, the values were 4.7%, 5.9%, 2.9%, 18%, 1.40, and 3%.
In practical terms, the present study indicates that the analytical imprecision of RBC, HCT and HGB should be below 3% and below 6% for WBC. Single measurements of RBC, HCT, HGB, and to a lesser extent WBC, in single dogs can be compared usefully to the corresponding reference intervals. The critical differences expressing the difference needed between two serial test results from the same dog to be significant at a 5% level was about 18% for RBC, HCT and HGB, and 35% for WBC.
KeywordsAnalytical variance Canine Inprecision
Unable to display preview. Download preview PDF.
- Büttner J, Borth R, Boutwell HJ et al. (1980) International Federation of Clinical Chemistry. Approved Recommendations (1978) on Quality control in clinical chemistry. Part 2. Assessment of Analytical Methods for Routine Use. J Clin Chem Clin Biochem 18:78–88.Google Scholar
- Fraser CG (1981) Analytical goals in clinical biochemistry. In: Stefani M, Benson ES (eds) Progress in clinical pathology Vol. VII, Grune & Stratton, New York, pp 101–122Google Scholar
- Fraser CG, Harris EG (1989) Generation and application of data on biological variation in clinical chemistry. CRC Crit Rev Clin Lab Sci 27:409–430Google Scholar