Which of the following is NOT a health indicator?

Income levels are not considered a health indicator in the same way that obesity rates, tobacco use, and substance use are. Health indicators are specific metrics that directly reflect the health status of a population and can be directly linked to health outcomes.

Obesity rates provide insight into the prevalence of a significant health issue that can result in various diseases, including diabetes and heart disease. Tobacco use is another direct health indicator as it correlates with multiple health problems, such as cancer and respiratory diseases. Similarly, substance use is monitored closely in public health as it is associated with a range of health and social issues.

In contrast, while income levels can influence health outcomes and access to healthcare services, they do not directly measure health conditions or behaviors. Instead, income serves as a social determinant of health, affecting an individual's environment, lifestyle choices, and overall access to resources that can promote good health. Thus, it is classified differently from the other options listed, which are specific behaviors or conditions directly related to health status.