Can Life Expectancies Be Used to Determine if Health Promotion Works?
Purpose. The goal of this study was to develop a method to measure the impact and cost-effectiveness of health promotion. Design. Age- and sex-specific changes in life expectancy in Canada between 1970 to 1972 and 1985 to 1987, after the introduction of national health insurance (1970) and health promotion (1975), are used to assess the impact due to biological hardiness, improvements in the health care field, and the effects of health promotion. Subjects. The subjects were the total male and female population of Canada between the years 1970 to 1972 and 1985 to 1987. Measures. Life expectancy by years of age by sex was the measurement used. Results. A method is presented that allows the calculation of the differential effects of health promotion, heath care, and biological hardiness on changes in life expectancy based on sequential subtraction of life expectancies for one-year age cohorts over a 15-year period. Results were obtained for each year of age for men and women, showing gender and age differences in the relative impact of the three factors. In this illustrative example using Canadian data, health promotion was found to have less impact on longevity than health care or biological hardiness. However, of the three, health promotion was the most cost-effective. Conclusion. This method can be used to quantify changes in life span due to health promotion, health care, and biological hardiness for men and women at each year of age and to relate this to health expenditures for the whole population. The method is limited in that it cannot determine the relative impact of other factors that can affect life expectancy such as environmental changes or social trends.