In a method for measuring healthcare quality, a plurality of computers operating in parallel receive from a patient dataset representative of patients within a healthcare organization, the patient dataset being distributed across the plurality of computer as subsets of patient datasets. The plurality of computers receive at least one healthcare quality measure definition comprising a numerator and a denominator. The plurality of computers identify, in the subsets of patient datasets, patient data that corresponds to the measure definition. The plurality of computers attribute the identified patient data to at least one provider based on an attribution rule. The plurality of computers calculate at least one healthcare quality measure for the at least one provider, according to the healthcare quality measure definition, based on the attributed patient encounters. The plurality of computers store the at least one calculated healthcare quality measure in a measure dataset.