Health-related quality of life questionnaires in bronchiectasis: the simplest way to quantify complexity

Abstract

The human mind is probably the most complex machine in the known universe. Billions of neuronal interconnections lead each individual to respond differently to a specific stimulus, but this response can quickly alter, and it can also be modulated by interaction between the individual’s environment and the genetic load that he or she has inherited. Any precise quantification of all this information is still beyond our capabilities, but a concerted effort is underway to increase the number of objective measurements that could provide us with data about the severity and activity of diseases and bring us closer, sooner or later, to what has become known as personalised medicine. Nevertheless, none of the objective measurements currently available are ideal for analysing the overall impact of a disease. The key questions in this respect are: How does each individual experience the disease, not merely from a physical viewpoint but also in psychological, social, and spiritual terms? What factors modulate this response? How do these vary over time? Severity, activity, and impact are three different dimensions of a disease and therefore they should never be confused. At present, a disease’s impact on an individual is evaluated by means of health-related quality of life questionnaires, which are the best tools available for gleaning the maximum information about the complexities of such an impact while simplifying it as far as possible. This has led most regulatory bodies to insist on the inclusion of health-related quality of life as one of the main outcomes of clinical trials evaluating different therapeutic measures.