Achieving consensus on assessing health-related quality of life (HRQoL) in people with cognitive impairments (CI) - a Delphi study

Background: The prevalence of impairments of cognitive functions is expected to increase. Enhancing the QoL of those affected is important. HRQoL in people with CI can be assessed by self-report, proxy-report or observation but there is uncertainty how to best assess HRQoL in people with CI, and which assessment method is most appropriate. Therefore the aim of our study was to use Delphi methodology in order to achieve consensus on how HRQoL should be assessed in people with CI and which content domains should be assessed. Methods: The Delphi process consisted of three online survey rounds and a concluding consensus conference. Participants were experts as well as individuals and relatives of people affected by CI. The Delphi survey was developed based on existing literature and included 55 statements at the first round. Consensus was considered to be achieved when a minimum of 75 % of responses fell into the categories 6 (agree) and 7 (strongly agree) (positive consensus) or in categories 1 (strongly disagree) and 2 (disagree) (negative consensus). Results: Consensus was reached for a total of 41 of 56 statements/substatements. In the 1st survey round 102 experts and 11 relatives participated. In the 2nd survey round 68 experts and 11 relatives continued to participate. In the 3rd survey round 41 experts and 9 relatives participated. In the consensus conference 17 experts and 4 relatives of individuals with CI and in the second one-hour online conference session 14 experts and 2 relatives of individuals with CI participated. Conclusion: The combination of the three assessment methods self-report, proxy-report and observation across all stages of CI is the preferred method and should be used whenever possible. As domains Physical capacity, Psychological, Level of Independence, Social Relationships, Environment and Spirituality/Relogion/Personal Beliefs should be assessed.