The State of Connecticut Office of Healthcare Access has provided New Haven Health with charges by Major Diagnostic Category for FY 1991-97. The twenty-five MDCs represent an extremely broad grouping of the ICD-9 diagnostic nosology and its thousands of diagnostic codes. The HCFA Public Use Files Web site has information about the MDC's and their relationships with Diagnostic Related Groups (DRG's) and ICD-9 codes.

The data are subject to these limitations:

1. The data come from the hospitals listed. This list does not include every hospital in the State of Connecticut.
   
   
2. Data are not reported consistently by every hospital by every year.
   
   
3. A value of "4" is an estimated value; a value of "3" means less than 6, where the value cannot be estimated.