Association between fatigue and self-care in patients with heart failure: a cross-sectional study.

The design is cross-sectional, so it cannot show that fatigue causes poor self-care or that any other variable causes fatigue. Data came from one public teaching hospital outpatient clinic in João Pessoa, Brazil, so results may not apply elsewhere. Participants were adults with heart failure who were not in NYHA class IV, not receiving treatment for anxiety or depression, not using documented sleep-inducing medications, and not cognitively impaired or disoriented, so the sample excludes several groups often seen in practice. Fatigue and self-care were measured by self-report, which can be affected by recall and by wanting to give socially acceptable answers. The study included 99 participants, close to the estimated minimum of 94, and several correlations were weak or moderate, so small or absent associations should be interpreted cautiously.

Do not conclude that fatigue causes poor self-care in heart failure. In this study, fatigue scores and self-care scores were not significantly correlated, and the cross-sectional design cannot show cause and effect.