Chapters in ICD-10-CM classify diseases and injuries according to body systems as well as what else?

The classification of diseases and injuries in ICD-10-CM is primarily organized by body systems and etiology, which refers to the causes or origins of diseases. Understanding the etiology is essential in coding because it provides critical information about the underlying reasons for a medical condition, allowing healthcare providers to make more informed decisions regarding diagnosis and treatment.

By focusing on etiology, ICD-10-CM enhances the specificity of coding, which is crucial for accurate data collection, analysis, and reimbursement processes. This classification enables coders to capture not just what the disease is, but also what caused it, which can lead to better patient management and public health strategies.

The other options do not align with the primary organization of the ICD-10-CM chapters. For instance, while patient age groups, geographical regions, and healthcare settings may influence treatment and service delivery, they are not the foundational principles upon which the ICD-10-CM coding system is structured. Instead, the emphasis is on disease classification based primarily on the nature of the conditions and their causes, making etiology the correct answer in this context.