[A theoretical approach to health and its measurement]

For a long period of time analyses of health status have been based on mortality data, while in this century indicators of morbidity have been introduced as well. However, these two indicators also have limitations because health of the total population was estimated on the basis of data referring to the diseased or deceased during a certain period of time. The definition of health by the World Health Organization was a progress, because the medical model of health was extended to the sociological model with emphasis on well-being, achievement of goals, functioning in the society and social rules. Subjective interpretation of health also has a significant place in assessment of health status of an individual or population groups.

Health has a subjective and an objective dimension. It can be analyzed as a global quality, but also as a sum of specific qualities--physical, social and psychological. Health analyses include the following parameters: mental well-being (affective status, mental functioning), physical health (ability to proceed with activities, body integrity, general physical capacity), general well-being and functioning (perceiving general health and expectations in regard to health in the future). Health is a prerequisite of social and economic status, and that is why emphasis is on social adaptation, but social support as well.

Health measurement can be functional with diagnostic, prognostic or evaluation purpose. Health indicators can also be descriptive, focused on a certain organ, diagnostic methods, but complex as well measuring syndromes, global health and quality of life. Development of health promotion and programs of disease prevention, follow-up of their application, progress and results require various categories of measurement. Some of them identify or quantify the problem, others describe the determinants. There exists a need to measure the contents and processes of intervention and evaluation. Numerous scales of health measurement, that is different aspects of health and quality of life, have been developed, but many of them have limitations, particularly concerning validity and reliability.

Most of existing indicators reflect the model of disease, while contemporary approach to health deals primarily with health itself. This model is oriented towards everyday life and relationships between individuals or groups of people and their physical and social environment as well as towards the way they influence health and well-being. The model also emphasizes well-being, achievement of goals, functioning in the society and social roles. Subjective assessment of health is significant in evaluation of health status, that is quality of life in regard to health, which is being done by different scales. The development of such scales is slow due to different opinions concerning the definition of health and health measurement. Efforts to develop scales which would satisfy the basic characteristics of measurement have largely focused on validity, reliability, accuracy, sensibility, specificity and feasibility.