Comparison of four methods to measure haemoglobin concentrations in whole blood donors (
COMPARE
): A diagnostic accuracy study
Bell S., Sweeting M., Ramond A., Chung R., Kaptoge S., Walker M., Bolton T., Sambrook J., Moore C., McMahon A., Fahle S., Cullen D., Mehenny S., Wood AM., Armitage J., Ouwehand WH., Miflin G., Roberts DJ., Danesh J., Di Angelantonio E.