diagnosis primary diagnosis https://athena.ohdsi.org/search-terms/terms?domain=Condition+Status https://www.definitivehc.com/resources/glossary/primary-diagnosis OMOP4976972 https://athena.ohdsi.org/search-terms/terms/32902 Oliver He, Long Tran The primary diagnosis is a diagnosis of the patient condition that demands the most provider resources during the patient’s stay. primary diagnosis There is often confusion surrounding primary and principal diagnoses and, consequently, the terms are commonly used interchangeably. While these can be (and frequently are) the same diagnosis in practice, their definitions are distinct. While a principal diagnosis is the underlying cause of patient symptoms, the primary diagnosis is used for healthcare billing purposes. Reference: https://www.definitivehc.com/resources/glossary/primary-diagnosis