The HAQ is one of the first instruments deliberately designed to capture prospectively and by protocol the long term influence of multiple chronic illnesses and to allow supplementation by additional measures for particular studies. The HAQ has played an influential role in establishing health outcome assessment as a quantifiable set of reliable, valid and responsive hard data points.
Because the HAQ emanated from the rheumatology field, it sometimes has been characterized as a "disease-specific" instrument rather than having been adjudicated on the basis of its structure, content, and history of use. The HAQ has been and continues to be administered across diverse disciplines and in different cultures, with properly designed adaptations that do not impact its reliability and validity. It should be considered a "generic" rather than a "disease-specific" instrument, since it assesses the dimensions of death, disability, drug side effects, discomfort, and economic costs, none of which are "disease-specific".