Impact of Cost Display on Ordering Patterns for Hospital Laboratory and Imaging Services

Abstract

Background: Physicians "purchase" many health care services on behalf of patients yet remain largely unaware of the costs of these services. Electronic health record (EHR) cost displays may facilitate cost-conscious ordering of health services.

Objective: To determine whether displaying hospital lab and imaging order costs is associated with changes in the number and costs of orders placed.

Design: Quasi-experimental study.

Participants: All patients with inpatient or observation encounters across a multi-site health system from April 2013 to October 2015.

Intervention: Display of order costs, based on Medicare fee schedules, in the EHR for 1032 lab tests and 1329 imaging tests.

Main measures: Outcomes for both lab and imaging orders were (1) whether an order was placed during a hospital encounter, (2) whether an order was placed on a given patient-day, (3) number of orders placed per patient-day, and (4) cost of orders placed per patient-day.

Key results: During the lab and imaging study periods, there were 248,214 and 258,267 encounters, respectively. Cost display implementation was associated with a decreased odds of any lab or imaging being ordered during the encounter (lab adjusted odds ratio [AOR] = 0.97, p = .01; imaging AOR = 0.97, p < .001), a decreased odds of any lab or imaging being ordered on a given patient-day (lab AOR = 0.95, p < .001; imaging AOR = 0.97, p < .001), a decreased number of lab or imaging orders on patient-days with orders (lab adjusted count ratio = 0.93, p < .001; imaging adjusted count ratio = 0.98, p < .001), and a decreased cost of lab orders and increased cost of imaging orders on patient-days with orders (lab adjusted cost ratio = 0.93, p < .001; imaging adjusted cost ratio = 1.02, p = .003). Overall, the intervention was associated with an 8.5 and 1.7% reduction in lab and imaging costs per patient-day, respectively.

Conclusions: Displaying costs within EHR ordering screens was associated with decreases in the number and costs of lab and imaging orders.

Keywords: cost display; electronic health record; physician ordering patterns.

Fig. 1

Cost display in electronic health record order screens. a Order search screen. b Order set screen.

Fig. 2

Changes in lab and imaging ordering associated with cost display. a Lab ordering. b Imaging ordering.

Fig. 3

Costs per patient hospital day relative to cost display intervention. a Lab costs. b Imaging costs. Red lines are predicted costs based on model parameters and covariates. Dashed purple lines after the cost display intervention are counterfactual costs, which represent predicted costs without the cost display intervention. The post-intervention time period for imaging costs was slightly shorter because data collection was stopped 3 weeks early to avoid a potential confounding effect of the switch to International Classification of Diseases (ICD) 10 coding.