Association of income and health-related quality of life in atrial fibrillation

Abstract

Objective: Health-related quality of life (HRQoL) is a patient-centred benchmark promoted by clinical guidelines in atrial fibrillation (AF). Income is associated with health outcomes, but how income effects HRQoL in AF has limited investigation.

Methods: We enrolled a convenience cohort with AF receiving care at a regional healthcare system and assessed demographics, medical history, AF treatment, income, education and health literacy. We defined income as a categorical variable (<$20 000; $20 000-$49 999; $50 000-$99 999; >$100 000). We used two complementary HRQoL measures: (1) the atrial fibrillation effect on quality of life (AFEQT), measuring composite and domain scores (daily activity, symptoms, treatment concerns, treatment satisfaction; range 0-100); (2) the 12-item Short Form Survey (SF-12), measuring general HRQoL with physical and mental health domains (range 0-100). We related income to HRQoL and adjusted for relevant covariates.

Results: In 295 individuals with AF (age 71±10, 40% women), we observed significant differences in HRQoL by income. Higher mean composite AFEQT scores were observed for higher income groups: participants with income <$20 000 had the lowest HRQoL (n=35, 68.2±21.4), and those with income >$100 000 had the highest HRQoL (n=64, 81.9±17.0; p=0.04). We also observed a significant difference by income in the AFEQT daily activity domain (p=0.02). Lower income was also associated with lower HRQoL in the mental health composite score of the SF-12 (59.7±21.5, income <$20 000 vs 79.3±16.3, income >$100 000; p<0.01).

Conclusion: We determined that income was associated with HRQoL in a cohort with prevalent AF. Given the marked differences, we consider income as essential for understanding patient-centred outcomes in AF.

Keywords: atrial fibrillation; epidemiology; public health.

Figure 1

Distribution of atrial fibrillation effect on quality of life (AFEQT) composite score, by income. Bar graph relating composite AFEQT score to income as a categorical variable. Graded relationship with lower annual income associated with inferior health-related quality of life. Error bars represent SD. BMI, body mass index; CHF, congestive heart failure; HTN, hypertension; S-TOFHLA, short-test of functional health literacy in adults.

Figure 2

Distribution of atrial fibrillation effect on quality of life (AFEQT) domain scores, by income. bar graph relating AFEQT domain scores to income as a categorical variable. Significant graded relationship with lower annual income associated with inferior health-related quality of life in the daily activity domain. Error bars represent SD. BMI, body mass index; CHF, congestive heart failure; HTN, hypertension; S-TOFHLA, short-test of functional health literacy in adults.