Which is an example of a public health classification system?

• A. ICD-9-CM
• B. ICD-10-CM
• C. ICD-0
• D. Both ICD-9-CM and ICD-10-CM

Answer: (D)

Public health classification systems rely on standardized codes to categorize diagnoses so data can be collected, compared, and analyzed for surveillance and health planning. The ICD family provides these codes in a clinical modification form for use in the United States. Both ICD-9-CM and ICD-10-CM are examples: they assign specific codes to diagnoses, enabling consistent reporting of illnesses and mortality, data sharing across hospitals and public health agencies, and trend analysis over time. ICD-10-CM is the newer, more detailed version, while ICD-9-CM was used previously; together they illustrate how a single classification approach supports public health data. ICD-0 is not a recognized public health coding system, so it does not apply.