 He strove to define every aspect of quality in health systems and proposed models for its measurement in over 100 papers and 11 books.These include access to health care, completeness and accuracy in medical records, observer bias, patient satisfaction, and cultural preferences in health care.The summation of his efforts is found in his trilogy, Explorations in quality assessment and monitoring (1980–85), a massive work of personal scholarship and analytical thought brought to bear on every aspect of health care provision.