The WHO defines total health expenditure as the sum of all public and private health expenditures in a country as a ratio of the total population of that country. Total health expenditure covers the provision of health services (preventive and curative), family planning activities, nutrition activities, and emergency aid designated for health. It does not include the provision of water and sanitation.

Traditional medicine refers to all knowledge, skills and health practices based on theories, beliefs and experiences that are indigenous to a culture. These practices may be used to maintain health as well as to prevent, diagnose, improve or treat physical and mental illness.

A treatment episode is a standard period of treatment during which a patient is given a specific medicine. Treatment episodes are used as a base for comparison in healthcare statistics. They are also an important feature for the forecasting and quantification of medicines, the second step in the supply chain cycle.