Background: Multimorbidity (the presence of multiple chronic conditions) is associated with high levels of healthcare utilization and associated costs. We investigated the association between number of chronic conditions and costs of care for nonelderly and elderly Veterans Affairs (VA) patients, and estimated mean VA healthcare costs for the most prevalent and most costly combinations of 3 conditions (triads).
Methods: We identified a cohort of 5,233,994 patients who received care within the VA system in fiscal year 2010. We estimated the costs of VA care for each patient using established methods and aggregated costs for inpatient care, outpatient care, prescription drugs, and contract care. Using ICD-9 diagnosis fields from all inpatient and outpatient records, we determined the prevalence of 28 chronic conditions and all condition triads. We then compared the condition-cost gradient, most prevalent triads, and most costly triads among nonelderly (below 65 y) and elderly (65 y and above) patients.
Results: Almost one third of nonelderly and slightly more than a third of elderly VA patients had ≥3 conditions, but these patients accounted for 65% and 67% of total VA healthcare costs, respectively. The most common triad of chronic conditions for both nonelderly and elderly patients was diabetes, hyperlipidemia, and hypertension (24% and 29%, respectively). Conditions that were present in the most costly triads included spinal cord injury, heart failure, renal failure, ischemic heart disease, peripheral vascular disease, stroke, and depression. Although patients with the most costly triads had average costs that were 3 times higher than average costs among patients with ≥3 conditions, the prevalence of these costly triads was extremely low (0.1%-0.4%).
Conclusions: Patients with multiple chronic conditions account for a disproportionate share of VA healthcare expenditures. Interventions that aim to optimize care and contain costs for multimorbid patients need to incorporate strategies specific to the most prevalent and the most costly combinations of conditions.