ABSTRACT
Health-related quality of life (HRQoL) assessments are widely used as outcome measures. However, one of the main issues they raise relates to interpretation of their results for health data collected for the general population as well as for specific disorders. To answer self-reported questionnaires, people must consider what QoL means to them and what and how their experiences have changed their QoL. They must structure and combine appraisals to arrive at a QoL rating. Many generic questionnaires can be used to compare patients with different diseases. Patients with fibromyalgia showed the greatest impairment of perceived health, although clinical or imaging examination results for this disease are usually poor, which illustrates the concept and importance of perceived health. Comparison to a reference population is of great importance for interpreting level of impaired HRQoL in patients with a specific disease. However, such comparisons of course are only available with generic instruments, only for a few of them and not for all countries.
