5. Current approaches to measuring HRQoL
Current approaches to measuring HRQoL
HRQoL are patient reported outcomes. HRQoL measures are types/subsets of patient-reported outcome measures (PROMs) distinguished by incorporating different domains.
There are many dimensions or domains related to HRQoL that need adequate methods of measurement. Simply asking a patient, ‘How is your health-related quality of life, on a scale of 1 to 10?’ provides limited information. Patients perceive and report the same conditions in different ways. Measuring HRQoL usually requires capturing various dimensions of what is important to patients.
For example, the overall answer to the simple question could be the same from day to day but does not consider that a person’s level of independence might be improving while psychologically they are deteriorating. That is, it may not distinguish between a severely depressed and very mobile patient and another patient who has very limited physical functionality but who is emotionally well. It should be considered that some domains (such as psychological vs physical functions) are valued more by patients than others, and this will be reflected in a patient’s reported HRQoL status.
HRQoL is frequently measured with ‘tools’ in the form of questionnaires, for instance the 36 Item Short-Form (SF-36®) Survey5 or the EuroQoL 5 Domain (EQ-5D)6 tool. These tools are used extensively in the realm of economic evaluation and HTA, since their results can be converted to numerical values. This allows researchers to compare changes of HRQoL in one type of patient with those in other types of patients. More specific tools exist for certain disease areas such as HIV-QL31 for HIV or EORTC QLQ-C30 for cancer.
Like with other PROs, the use of HRQoL measures in clinical studies must be carefully planned and and the instruments validated before the study begins, in order to avoid that instruments measure the wrong responses or misrepresent reality.
See also Lesson 2 of this Course for Patient Reported Outcomes (PROs).