Health outcomes can be assessed in a qualitative or, if feasible, in a
quantitative way. Qualitatively the direction of effect can be stated or
the size of effect can be categorically described. However, a critical
issue in the assessment of health outcomes is the possibility of quantification.
It needs a decision on what kind of health measures, i.e. epidemiological
frequency measures, to use as input and output data of the
calculation process. In addition, consideration of the availability of valid
baseline frequency data of the health condition and of dose/exposure–
response functions thatmay apply dose–response coefficients or relative
risks is indispensable for the success. Values of frequency measures of
health conditions and of exposures must be available for the affected
population. They usually derive from routine statistics, populationbased
registries or fromsurveys. Availability and validity of data is crucial
in the process and therefore should be clearly described. The result
of quantitative outcome assessment can be expressed in a frequency
measure, like frequency of occurrence, morbidity, hospitalization and
mortality (Example 1), or favourably in a complex measure of disease
burden, like attributable death, potential years of life lost or disability adjusted
life years (Example 2). The latter is an advantageous choice for expressing
results of a risk assessment in a quantitative way, since it is a
complexmeasure of disease burden combining effect on both morbidity
and mortality. The cost-benefit analysis of policy introduction may also
become possible based on the numerical expression of health outcomes.