Health studies using administrative hospital data

Traditionally administrative hospital discharge databases have been mainly used for administrative purposes. Recently, health services researchers and population health researchers have been using the databases for a wide variety of studies; in particular health care outcomes. Tools, such as comorbidity indexes, have been developed to facilitate this analysis. Every time the coding system for diagnoses and procedures is revised or a new one is developed, these comorbidity indexes need to be updated. These updates are important in maintaining consistency when trends are examined over time.