A 3-year study of high-cost users of health care

Background:

Characterizing high-cost users of health care resources is essential for the development of appropriate interventions to improve the management of these patients. We sought to determine the concentration of health care spending, characterize demographic characteristics and clinical diagnoses of high-cost users and examine the consistency of their health care consumption over time.

Methods:

We conducted a retrospective analysis of all residents of Ontario, Canada, who were eligible for publicly funded health care between 2009 and 2011. We estimated the total attributable government health care spending for every individual in all health care sectors.

Results:

More than $30 billion in annual health expenditures, representing 75% of total government health care spending, was attributed to individual costs. One-third of high-cost users (individuals with the highest 5% of costs) in 2009 remained in this category in the subsequent 2 years. Most spending among high-cost users was for institutional care, in contrast to lower-cost users, among whom spending was predominantly for ambulatory care services. Costs were far more concentrated among children than among older adults. The most common reasons for hospital admissions among high-cost users were chronic diseases, infections, acute events and palliative care.

Interpretation:

Although high health care costs were concentrated in a small minority of the population, these related to a diverse set of patient health care needs and were incurred in a wide array of health care settings. Improving the sustainability of the health care system through better management of high-cost users will require different tactics for different high-cost populations.Health care spending per person in any given year is highly uneven. The concentration of health care utilization among small numbers of patients is well established. In the United States, the Agency for Healthcare Research and Quality reported that 1% of users in 2008 accounted for 20% of expenditures and that 5% of users accounted for nearly 50% of expenditures.¹ Data from Canada in 1972 and 1996, and again in 2009, showed that high-cost users (individuals with the highest 5% of costs) consumed 65% of combined hospital and nursing home costs, 64% of acute care days and 84% of combined acute and post-acute home care resources, respectively.^2–4Each year, a few people have major health events that must be addressed, often with expensive treatments. The relative rarity and unpredictability of these events for any individual underlies the need for health care insurance. However, improved life expectancy, resulting in part from effective treatments of cardiovascular and respiratory disease, HIV infection and some cancers,⁵ as well as the chronic debilitating effects of conditions, such as severe stroke or heart failure, are contributing to rising numbers of chronically high users of health care resources. Yet, little is known about the sustained use of health care services among high-cost users.Previous studies of high-cost users in the US have been limited by the use of survey respondents as a source population¹ or included only patients in private insurance systems who were less than 65 years of age.^6,7 Studies in Canada have examined spending on acute hospital, physician or nursing home care only, representing less than half of all health care expenditures.^2,3 Age-related patterns have not been compared.We conducted a study to make a system-wide assessment of the concentration and persistence of costs in a comprehensive health care system. We had several objectives: to measure total expenditures of publicly insured care for every individual, and by health care sector, in the province of Ontario between 2009 and 2011; to track expenditure patterns for individuals over a 3-year period; to describe the concentration of health care spending among different age groups; and to identify the main diagnoses among high-cost users.