The emerging field of Health administration informatics is concerned with the evaluation, acquisition, implementation and day-to-day operation of information technology systems in support of all administration and clinical functions within the health care industry. The closely related field of biomedical informatics is primarily focused on the use of information systems for acquisition and application of patients' medical data, whereas nursing informatics deals with the delivery, administration and evaluation of patient care and disease prevention. What remains unclear, however, is how this emerging discipline should relate to the myriad of previously existing sub specializations within the broad umbrella of health informatics - including clinical informatics (which itself includes sub areas such as oncology informatics), bioinformatics and healthcare management informatics - particularly in light of the proposed 'fundamental theorem' of biomedical informatics posed by Friedman in early 2009. The emerging field of Health administration informatics is concerned with the evaluation, acquisition, implementation and day-to-day operation of information technology systems in support of all administration and clinical functions within the health care industry. The closely related field of biomedical informatics is primarily focused on the use of information systems for acquisition and application of patients' medical data, whereas nursing informatics deals with the delivery, administration and evaluation of patient care and disease prevention. What remains unclear, however, is how this emerging discipline should relate to the myriad of previously existing sub specializations within the broad umbrella of health informatics - including clinical informatics (which itself includes sub areas such as oncology informatics), bioinformatics and healthcare management informatics - particularly in light of the proposed 'fundamental theorem' of biomedical informatics posed by Friedman in early 2009.