Nudging Teams toward Cost-Effective Health Care: Evidence from a Field Experiment in Surgery

Last registered on June 19, 2022


Trial Information

General Information

Nudging Teams toward Cost-Effective Health Care: Evidence from a Field Experiment in Surgery
Initial registration date
March 28, 2022

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
March 28, 2022, 7:17 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Last updated
June 19, 2022, 9:21 AM EDT

Last updated is the most recent time when changes to the trial's registration were published.



Primary Investigator

Hebrew University of Jerusalem

Other Primary Investigator(s)

PI Affiliation
Bar Ilan University
PI Affiliation
University of Pennsylvania
PI Affiliation
Bar Ilan University

Additional Trial Information

In development
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Can non-financial incentives promote cost-effective health care in contexts where worker incentives cannot be fully aligned with those of their employers? If so, given that healthcare is provided in teams of specialized workers, to whom should such incentives be directed? We implement a field experiment in the leading public hospital in Israel to investigate whether nudges can motivate surgical teams to reduce wasteful spending without sacrificing quality of care. Our intervention consists of text messages containing encouragement as well as procedure-specific information on the median usage of disposable items. We randomly vary whether the surgeon, the circulating nurse, or both receive the message. We outline the mechanisms that might cause effects to differ depending on which combination of team members are treated. We exploit rich data on input use and patient outcomes to estimate treatment effects on both the cost and quality of care.
External Link(s)

Registration Citation

Ale-Chilet, Jorge et al. 2022. "Nudging Teams toward Cost-Effective Health Care: Evidence from a Field Experiment in Surgery." AEA RCT Registry. June 19.
Sponsors & Partners

There is information in this trial unavailable to the public. Use the button below to request access.

Request Information
Experimental Details


The treatment for both surgeons and nurses consists of three components.

First, at the beginning of each OR shift, treated individuals who are scheduled to work the shift will receive a personally customized message to their mobile phone. The message comprises a general nudge as well as a set of input recommendations for each upcoming procedure. The nudge reads “Dear Dr./Nurse X, For the surgeries this morning we remind you to avoid unnecessarily opening disposable equipment”. Then, for each upcoming procedure, we provide the recommended input use for three randomly chosen candidate inputs. We ensure that only 1 of the three items is inexpensive in order to weigh our treatment toward higher value items.

Second, treated individuals have access to a website that includes a table of thresholds for all candidate inputs. Staff can use this website to check thresholds for inputs that are not included in the message and for unscheduled surgeries (due to emergency or last minute schedule changes).

Third, treated surgeons and nurses will receive a bi-weekly feedback message containing a figure that summarizes the actual usage of candidate inputs during the surgeries they conducted over the last 14 days, compared to the recommended amounts.

For details on how we chose candidate inputs, please see the pre-analysis plan.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
input use (deviations from the recommendation), quality of care
Primary Outcomes (explanation)
Our main indicator of input use is deviations from the recommendation. Specifically, in addition to computing the median use of each input at the procedure level using baseline data, we also compute the standard deviation. Then, for each operation and input during the experiment, we compute how many standard deviations above (or below) the median input use was.

We use four indicators of quality of care: an indicator for surgery complication, re-surgery in the same department within 7 days, readmission to the same department of the hospital within 7 days, and death within 7 days. The indicator for surgery complication turns on if any of the following seven variables turns on: actual surgery time, transfer to cardiology department or ICU within 24 hours, imaging order after surgery, excess time in recovery ward, blood loss (hemoglobin levels after versus before surgery), kidney failure (creatinine levels after versus before surgery), and surgical site specific infection

Secondary Outcomes

Secondary Outcomes (end points)
See pre-analysis plan
Secondary Outcomes (explanation)
See pre-analysis plan

Experimental Design

Experimental Design
All nurses and all surgeons in the Operating Rooms department will be invited to participate in the study via individual “introductory meetings” with the Study Coordinators in the months prior to the start of the study. During the meeting, the Study Coordinator will administer a short baseline survey to all participating nurses and doctors. After the baseline surveys are complete, we conduct the randomization. Half of surgeons and half of nurses are randomly assigned to the treatment group. This generates four types of teams, with different combinations of untreated and treated nurses and surgeons. The treatment period is planned to last for 9000 scheduled operations, which we estimate will take roughly 6 months. At the end of the treatment period, we conduct an endline survey with nurses and surgeons.
Experimental Design Details
Randomization Method
The randomization will be done in the office by a computer. Details are specified in the pre-analysis plan.
Randomization Unit
Doctor and nurse level
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
95 nurses and 156 surgeons.
Sample size: planned number of observations
9,000 scheduled operations plus any unscheduled operations that occurred during the time frame. (In case of additional waves of Covid-19, we might need to increase the the volume of surgeries to achieve balance across surgery types.)
Sample size (or number of clusters) by treatment arms
Nurses: 47 treated, 48 untreated
Surgeons: 79 treated, 77 untreated
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Chaim Sheba Medical Center, Helsinki Committee
IRB Approval Date
IRB Approval Number
Analysis Plan

There is information in this trial unavailable to the public. Use the button below to request access.

Request Information


Post Trial Information

Study Withdrawal

There is information in this trial unavailable to the public. Use the button below to request access.

Request Information


Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials