Demographic correlates of fatigue in the US general population: Results from the patient-reported outcomes measurement information system (PROMIS) initiative

Objective: To investigate demographic correlates of fatigue in the US general population using a new instrument developed by the Patient-Reported Outcome Measurement Information System (PROMIS). First, we examined correlations between the new PROMIS instrument and the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) and the SF-36v2 Vitality subscale. Based on prior findings, we further examined several demographic correlates of fatigue: whether women would report higher levels of fatigue compared to men, and whether married people would experience lower levels of fatigue compared to unmarried people. We also explored the relationship between age, education, and fatigue. Methods: Analyses were based on fatigue ratings by 666 individuals from the general population. Fatigue was assessed with the new PROMIS instrument, the FACIT-F, and the SF-36v2 Vitality subscale. Differences in fatigue were examined with independent samples t-tests and univariate ANOVAs. Results: The three fatigue instruments were highly intercorrelated. Confirming prior reports, women reported higher levels of fatigue than men. Married participants reported significantly less fatigue than their unmarried counterparts. Univariate ANOVAs yielded a main effect for participants' age: younger participants gave significantly higher fatigue ratings. We also found a main effect for participants' education. Participants with a masters or doctoral degree had significantly lower ratings of fatigue than participants with some college education and education up to high school. Conclusion: Female gender, not being married, younger age and lower educational attainment were each associated with increased fatigue in the general population and the three fatigue instruments performed equally well in detecting the observed associations. (C) 2011 Published by Elsevier Inc.