The measurement iterative loop: a framework for the critical appraisal of need, benefits and costs of health interventions.

A framework for organizing health services data is presented that subdivides the spectrum of health information into subgroups that constitute a logical progression from quantifying the burden of illness, through identifying its likely causes, to validating interventions that prevent or ameliorate it and evaluating their efficiency, to monitoring the application of these interventions and coming full-circle to determine whether the burden of illness has been reduced.