the changes of international classification diseases-10th version in updating process

introduction: world health organization (who) attempts to update icd-10 (international classification diseases-10 th version) according to the required information of the scientific community. in this study, changes of icd-10 will be reviewed in updating process. methods: the data of the present descriptive study was extracted from the world health organization website. the data were interpreted based on descriptive statistics after classification of changes, type of instructions to make change, source of changes, and approved and implementation date of the changes. results: out of 1914 changes occurred in icd-10 during 1995 and 2009, the greatest change happened in the third volume with 1249 cases (65.5%). most of the major changes were in the first volume with 264 cases (50.1%) and most of the minor changes were in the second volume with 69 cases (49.6%). the majority of the instruction changes were adding an item to the system in every three volumes. among the active groups for creating modification, mortality reference group (mrg) had the highest role in the first and second volumes with 107 (20.3%) and 116 cases (83.4%), respectively. germany with 305 cases (24.4%) in the third volume had the highest role. conclusion: maintaining the fluidity of a classification system in the field of health is an enormous and necessary task. this fluidity has occurred in icd-10 with making significant changes due to new discoveries in the field of medicine, diagnostic and therapeutic equipments and health information subsequently. in iran, due to the governmental policy to create the iranian electronic health records, the updated health classification is further needed.