Blog post: What do utilization increases actually mean?

Single-payer cost estimates are in the news this week.  A key issue in estimating the cost of single-payer is how it will increase healthcare utilization.  Increased utilization, it’s worth pointing out, is basically the only way that single-payer adds to overall healthcare spending.  Now some increase is clearly expected and desirable – after all, we’re providing insurance to the uninsured and eliminating copays and deductibles for the rest.  However, as David Himmelstein and Steffie Woolhandler and others have argued, there are supply limits – the system can only provide so much care.

In any event, utilization increases are typically presented as abstract figures.  For instance, the recently released Mercatus Center study estimates an 11.3% increase in utilization (for 2019), whereas the Urban Institute estimates a 16.9% increase (averaged over 2017-2026).

It’s helpful to put those percentages in the context of actual services provided, as Himmelstein and Woolhandler sometimes do, because they translate into a concrete increase in the number of doctors’ visits, nights in the hospital, ER visits, etc.  I offer some rough estimates of these changes below, with the assumption that the average increase in utilization affects all services equally.  So, for instance, using Urban Institute estimates, 16.6% more utilization translates into 185 million more visits to the doctor and nearly 4 million more therapeutic surgeries a year.

Current utilization (millions) Change in utilization


Urban Institute Mercatus Center



(AHA, 2016)

35.0 5.8 4.0
Doctor visits

(NAMCS, 2015)*

1117.0 185.4 126.2
ER visits

(NAMCS, 2015)

137.0 22.7 15.5
Therapeutic surgical procedures

(HCUP, 2014)

21.8 3.6 2.5

Are those numbers realistic?  For the moment I won’t editorialize on this, but it’s worth keeping these figures in mind as cost estimates of single-payer are released and debated in coming days.


* There were 990,808 doctor office visits in 2015 per NAMCS.  However, data on visits to hospital outpatient departments (OPD) has not been released by NAMCS since 2011.  In that year, OPD visits were 12.7% office visits.  I inflated the office visits figure by this percentage, assuming that the proportion had not changed.