The applicability of patient-reported outcomes in primary care : monitoring of patients with asthma or chronic obstructive pulmonary disease

Abstract

Aims of the thesis: The general objective of this project was to identify and to some extent remove obstacles in the incorporation of disease-specific quality of life and/or health-status assessments in the management of asthma and COPD patients in primary care. The measurement properties, the design and the administrative complexity of the instruments at hand have been scrutinized with the intent to make it possible for primary care to integrate a patient perspective in the treatment and monitoring of asthma and COPD.

Methods: Psychometric analysis of the measurement properties and performance of the questionnaires ACQ and MiniAQLQ in primary care (paper I). Psychometric analysis of the measurement properties and the performance of the CCQ in primary care (paper II). A cluster randomised study of the influence of information and monitoring on asthma control. Analysis were made of group differences on the ACQ and the MiniAQLQ and estimates of responsiveness of both questionnaires were calculated (paper III). Semi-structured interviews with patients with COPD with an extended version of the SEIQoL-DW (paper IV).

Results: The Mini-AQLQ and ACQ correlated well with the criterion measure AQLQ(S). Reliability coefficients were good. Both questionnaires detected improvement or deterioration of patients at the group level (paper I). Overall correlations between the criterion measure SGRQ and CCQ were strong for all patients with clinical COPD (0.84). These correlations between CCQ and SGRQ were moderate to good, regardless of COPD severity. Reliability was good but not sufficient for individual level assessment (paper II). ACQ score changes differed between the study groups (p < 0.05). In the intervention group, these changes in asthma control were close to clinical significance (MID 0.5). Both groups improved in disease-specific quality of life scores. For the intervention group, which changed the most (p < 0.05), the change exceeded the threshold for the MID. (paper III). The cue areas rated as most important with the generic part was the subjects' own health and relation to partner and family. The cue areas rated most important with the disease-specific part was; worries about own health, and independence. When comparing the results of the SEIQoL with standardised questionnaires content it seems as several areas of importance as nominated by the COPD patients are not addressed in standardised questionnaires, especially the areas of social life and mental health (paper IV).

Conclusions: The asthma-specific instruments ACQ and MiniAQLQ exhibited measurement properties that allow use on an individual level in primary care. The CCQ did not meet the measurement requirements set for use on an individual level. Further, development is proposed in order to enhance performance of the instrument.