HEALTH RELATED QUALITY OF LIFE AMONG PERSONS 65 YEARS OR OLDER WITH CHRONIC HEART FAILURE: AN EMPIRICAL AND METHODOLOGICAL STUDY

Sammanfattning: The aim of this thesis was to empirically and methodologically investigate health related quality of life (HRQoL) among persons 65 years or older with chronic heart failure. The design was cross-sectional and the sample was recruited from a southeast region of Sweden. The sample included 357 respondents in Paper I, II and IV and 349 respondents in Paper III. For all respondents the mean age was 79 years. Collection of data was through use of a questionnaire that included demographic data, self-rated disease severity, the Minnesota Living with Heart Failure (LHFQ), the Short Form-12 Health Survey (SF-12) and the Interview Schedule for Social Interactions (ISSI). Univariate, bivariate and multivariate statistical methods were used to analyse data. The empirical results demonstrated that the impact of chronic heart failure on daily life was extensive. Physical limitations due to chronic heart failure were rated to be more common and have a higher impact on daily life compared to emotional limitations, even though these limitations were also common. In addition, physical and emotional dimensions of HRQoL correlated significantly with each other (Paper I). Age, sex, comorbidity, living accommodation and cohabiting had a subordinate role in explaining variations in HRQoL when analysed together with self-rated disease severity in multiple regression analyses. Self-rated disease severity was the only predictor related to all HRQoL outcomes (Paper II). Low rated social network and social support demonstrated relationships to low HRQoL in emotional and physical dimensions (Paper III). The methodological results demonstrated that overall the Minnesota Living with Heart Failure Questionnaire has satisfactory psychometric properties among persons 65 years or older, when the instrument was tested according to classical test theory. However, there were two methodological concerns with the results. The first concern was the high frequency of internal missing values for the two items that asked about difficulties in performing sexual and leisure activities. These finding may indicate such items were not viewed as appropriate by this age group. Another concern was that discriminant validity could not be established for the physical and emotional subscales (Paper I). In contrast, the Rasch analysis revealed that the original physical and emotional subscales lacked unidimensionality, lacked in targeting, that the response scales did not work as intended and that four items demonstrated differential item functioning for sex and/or age (Paper IV). In conclusion, even though physical limitations were most common and had greatest impact on daily life, the relationship between physical and emotional dimensions of HRQoL implies an effect on each other. Thus, both physical and emotional limitations related to chronic heart failure are equally important to highlight for nurses to recognize when caring for elderly persons in order to improve their HRQoL. While the Minnesota Living with Heart Failure Questionnaire demonstrated satisfactory validity and reliability according to classical test theory, the Rasch analysis revealed a need for further development in the physical and emotional subscales in order to measure HRQoL in a sound psychometric way among persons 65 years or older.