Determining the accuracy of a rapid point-of-care test for determining Rh(D) phenotype.

Abstract

To determine the sensitivity, specificity, and accuracy of a point-of-care method for identifying Rh(D) phenotype. Rh(D) was determined using preserved whole blood via standard laboratory methods. Comparison testing was conducted using the HealthTEST Rh(D) card (Akers Laboratories, Thorofare, NJ). Results of the card test were visually interpreted and recorded. To achieve sensitivity and specificity of 99% (95% confidence interval [CI] = 98% to 100%), 380 Rh-positive and 380 Rh-negative samples were required. During card testing, convenience sampling was used. Card results were compared with official results, and statistical analysis was conducted. In identifying Rh(D)-positive phenotype, the card had a sensitivity of 98.9% and a specificity of 99.7% (95% CI = 0.99 +/- 0.01). For Rh(D)-negative phenotype, the card had a sensitivity of 99.7% and a specificity of 98.9% (95% CI = 0.99 +/- 0.01). In identifying type D (Rh positive or Rh negative), the card achieves sensitivity, specificity, and accuracy to warrant further study.