Error	In which component can the error occur?	Under what conditions or circumstances will it occur?	Impact of the error	How to prevent or reduce likelihood of error? (this should include constraints and data quality checks before data is stored)	How to detect error if it occurs? (this should include data quality checks after data is stored)	How to remediate error if it occurs?
Duplicate patient entry	Central EMPI	This could happen when different demographic information is entered for a patient at different visits. This is usually due to registering a patient without their ID or Health Care Card. For example, some homeless people frequently visit emergency departments without any ID and sometimes introduce themselves by different names, addresses, etc.	This will result in duplicate entries in EMPI for the same patient. When a patients information is being retrieved, the system will not be able to determine the best record; also, not all diagnoses of a patient will be stored under the same patient ID, which will result in errors when reporting or retrieving information.	Although it may not be practical or ethical to enforce requirements for presenting ID and Health Care Card at all times, tighter restrictions and requirements should be implemented so that patient ID and Health Care Card be checked at the time of registration, to the extent possible.	There should be routine (e.g. daily) checks on the EMPI to find and review entries that have several demographic pieces of information that are the same. Especial attention should be given to entries that have been registered without a Health Care Card number.	The two (or more) duplicate records need to be merged. The diagnoses that have been entered for each entry must also be merged.
Duplicate diagnoses entered for a patient for the same visit
One of the diagnoses in the picklist of valid diagnoses is retired in the next release of SNOMED CT (note that SNOMED CT is released every six months and each new release will have a number of added, changed, and retired concepts)
Diagnosis-gender mismatch

This assignment builds on Week 3 Assignment (in which you created a registration screen) and extends it to include 3 new components: