RT Journal Article SR Electronic T1 Practical Program for Statistical Evaluation of Normal Range Data JF Journal of Nuclear Medicine Technology JO J. Nucl. Med. Technol. FD Society of Nuclear Medicine SP 101 OP 104 VO 5 IS 2 A1 Battaglia, Danielle J. A1 Burkhead, Christie A1 Cianci, Michael YR 1977 UL http://tech.snmjournals.org/content/5/2/101.abstract AB A program utilizing three methods of normal range estimation for radioassay is described. The methods are chosen for their variable dependence upon test sample characteristics such as size of population sampled, skewing, and spread of values T3 uptake, T4 CPB, TSH, B12, and folate normal specimens are screened using the standard deviation, data point ranking, and percentile interpolation methods. While three of the five test populations are normally distributed, two are best evaluated by methods other than the standard deviation. The folate test population is positively skewed and the data point ranking method provides the most valid estimate. The test population for the B12 assay is small (32) and the spread between values large; therefore, the percentile interpolation method provides the most valid normal range estimate.