Association of depression and anxiety with adherence in primary care patients with heart failure-cross-sectional results of the observational RECODE-HF cohort study.

BACKGROUND: Psychological distress has a negative impact on the prognosis and quality of life for patients with heart failure. We investigated the association between psychological distress and the patients' adherence to medical treatment (medication adherence) and self-care advice (lifestyle adherence) in heart failure. We further examined whether there are different factors associated with low medication compared to low lifestyle adherence. METHOD: This secondary analysis of the RECODE-HF cohort study analyzed baseline data of 3099 primary care heart failure patients aged 74 ± 10 years, 44.5 % female. Using multivariable regression, factors relating to medication and lifestyle adherence were investigated in order to estimate the extent to which these factors confound the association between psychological distress and adherence. RESULTS: Psychological distress was significantly associated with poorer medication adherence but not with lifestyle adherence after controlling for confounders. We identified different factors associated with medication compared to lifestyle adherence. A higher body mass index, a less developed social network, living alone, fewer chronic co-morbidities and unawareness of the heart failure diagnosis were only related to lower lifestyle adherence. Higher education was associated with poorer medication adherence. Male sex, younger age, lower self-efficacy and less familiar relation with the general practitioner were common factors associated with both lower medication and lifestyle adherence. CONCLUSION: Promising factors for increasing medication adherence (reduction of psychological distress) and lifestyle adherence (explaining the patient his/her heart failure diagnosis more than once and increase in the patients' self-efficacy), which were found in this cross-sectional study, must be further investigated in longitudinal studies.

Bivariate measure of redundant information.

We define a measure of redundant information based on projections in the space of probability distributions. Redundant information between random variables is information that is shared between those variables. But, in contrast to mutual information, redundant information denotes information that is shared about the outcome of a third variable. Formalizing this concept, and being able to measure it, is required for the non-negative decomposition of mutual information into redundant and synergistic information. Previous attempts to formalize redundant or synergistic information struggle to capture some desired properties. We introduce a new formalism for redundant information and prove that it satisfies all the properties necessary outlined in earlier work, as well as an additional criterion that we propose to be necessary to capture redundancy. We also demonstrate the behavior of this new measure for several examples, compare it to previous measures, and apply it to the decomposition of transfer entropy.