Abdominal aortic calcification (AAC) and ankle-brachial index (ABI) predict health care costs and utilization in older men, independent of prevalent clinical cardiovascular disease and each other
School of Medical and Health Sciences
National Health and Medical Research Council.
NHMRC Number : 1107474
Background and aims: Abdominal aortic calcification (AAC) and low ankle-brachial index (ABI) are markers of multisite atherosclerosis. We sought to estimate their associations in older men with health care costs and utilization adjusted for each other, and after accounting for CVD risk factors and prevalent CVD diagnoses.
Methods: This was an observational cohort study of 2393 community-dwelling men (mean age 73.6 years) enrolled in the Osteoporotic Fractures in Men (MrOS) study and U.S. Medicare Fee for Service (FFS). AAC was scored on baseline lateral lumbar spine X-rays using a 24-point scale. ABI was measured as the lowest ratio of arm to right or left ankle blood pressure. Health care costs, hospital stays, and SNF stays were identified from Medicare FFS claims over 36 months following the baseline visit.
Results: Men with AAC score ≥9 (n = 519 [21.7% of analytic cohort]) had higher annualized total health care costs of $1473 (95% C.I. 293, 2654, 2017 U S. dollars) compared to those with AAC score 0–1, after multivariable adjustment. Men with ABI <0.90 (n = 154 [6.4% of analytic cohort]) had higher annualized total health care costs of $2705 (95% CI 634, 4776) compared to men with normal ABI (≥0.9 and < 1.4), after multivariable adjustment.
Conclusions: High levels of AAC and low ABI in older men are associated with higher subsequent health care costs, after accounting for clinical CVD risk factors, prevalent CVD diagnoses, and each other. Further investigations of whether preventing progression of peripheral vascular disease and calcification reduces subsequent health care costs are warranted.