The data element NCHRONIC contains the count of unique chronic diagnoses reported on the discharge. A chronic condition is defined as a condition that lasts 12 months or longer and meets one or both of the following tests: (a) it places limitations on self-care, independent living, and social interactions; (b) it results in the need for ongoing intervention with medical products, services, and special equipment.

The process of counting the number of chronic conditions involves multiple steps. First, each diagnosis is assigned to a Clinical Classification Software (CCS) category. This information is available in the DXCCSn data elements. Second, the diagnosis is classified as a chronic or non-chronic condition by the Chronic Condition Indicator. This information is available in the CHRONn data elements. Third, the number of chronic conditions is counted. If the discharge has multiple diagnoses that map to the same CCS and are all considered chronic, then the chronic condition is only counted once.

More information on the Clinical Classification Software (CCS) and Chronic Condition Indicators is available under Tools & Software on the HCUP-US website.

For data beginning in the fourth quarter of 2015, the number of chronic conditions is stored in the data element I10_NCHRONIC to indicate the implementation of the ICD-10-CM/PCS coding system.