Comparing comorbidity measures and fatigue post myocardial infarction

The purpose of this study was to examine comorbidity measures that may relate to the symptom of fatigue post MI: self-reported comorbidities, medication-validated comorbidities, weighted comorbidities for fatigue, and number of comorbidities.

Using a cross sectional design, we interviewed a convenience sample of 98 adults, 65 and older, who were 6 to 8 months post myocardial infarction.

Participants self-reported their comorbidities using a list of 23 comorbid conditions. All medications were visually inspected, and medications were reviewed by a geriatric pharmacist for a common side effect of fatigue. The Revised Piper Fatigue Scale was used to measure fatigue.

The mean age of the participants was 76 (SD = 6.3), and most of the sample were White (84%). Neither medication-validated comorbidities nor those medications with fatigue as a common side effect explained fatigue. When controlling for age, sex, and marital status, self-reported comorbidities explained 10% of the variance in fatigue (F (4, 93) = 2.65; p = 0.04). Having 5 or more self-reported comorbidities explained 7% of variance in fatigue scores (F (1, 96) = 7.53; p = 0.007).

Comorbidities are associated with fatigue post MI. Adults post MI with 5 or more comorbidities should be screened for fatigue.