Also referred to as health status, the health state indicates to which category an individual belongs in a particular health economic analysis. For example, people can be “healthy”, “sick” or “deceased”. As disease progresses, patients move from one health state to another (Figure 1) and estimating or predicting such transitions draws on evidence from clinical trials. An effective intervention will move a patient from a health state of “sick” to a state of “healthy”. However, patients may also remain in the same health state for prolonged periods of time.

Assuming there are three health states that individuals can progress through (downward arrows), or remain within (circular arrows), a health intervention can help the sick return to a healthy state.

Figure 1. Disease progression as modelled by health economists