GSTM1 and anemia (phenotype): The sensitivity and specificity for detecting anemia were 63.9% and 48.2% for the Apple® app, 36.1% and 67.6% for the Android® app, 45.7% and 85.3% for the Masimo Pronto®, 54.3% and 97.6% for the HemoCue® Hb-301 and 66.7% and 97.6% for the HemoCue® Hb-801.