Working Papers

What Passed Is Past? The Role of Recent Adverse Events in Physician Treatment Decisions [UNDER REVIEW]

In many areas of medical care, physician treatment decisions are made under substantial uncertainty. In the context of obstetrics, this uncertainty may predispose physicians to use decision-making heuristics when choosing between a cesarean or a vaginal mode of delivery. In this study, I examine whether obstetricians overreact to a prior patient’s adverse obstetric events when making subsequent delivery-mode choices, and if so, its effect on patient welfare. Using electronic health record data from a large academic hospital, I find that experiencing adverse obstetric events in one delivery-mode makes the physician more likely to switch to the other – and likely inappropriate–delivery-mode on the next patient, regardless of patient indication. This physician switching response to prior adverse events also results in worse patient outcomes and greater resource use for the subsequent patient. Informed by a simple model of Bayesian updating, I formally test and reject the hypothesis that observed physician switching behavior is consistent with Bayesian learning, and conclude that it is likely an overreaction to salient, negative events. These results highlight a clinical decision that is susceptible to cognitive bias, which may inform future efforts to improve the quality of obstetric decision-making through increased awareness or policy interventions.

MEDIA MENTIONS: New York Times, LA Times

Strained and Constrained: How ICU Capacity Affects Physician Decisions (with David Howard and Thomas Valley)

Limited ICU capacity has been said to exacerbate several consequences of COVID-19, such as mortality, misallocation of resources by physicians, and harmful spillovers on nonCOVID patients. However, whether greater ICU capacity would have avoided these pitfalls is not clear. The goal of this paper is to shed light on how ICU capacity affects physician decision-making and patient welfare when the healthcare system is strained. We use two sources of variation in ICU capacity to estimate its causal effect on physician thresholds for admitting patients to the ICU: i) ICU “expansions”, resulting from increases in hospital number of ICU beds, and ii) ICU “strain”, resulting from random fluctuations in ICU bed availability. Our analysis uses 100% inpatient EHR data from two hospitals (150K encounters. 2015-18) both of which expanded their ICUs separately. Importantly, we use lab test results to assign patients an objective and validated measure of ICU-need, called the eSOFA score. We motivate our empirical analyses using a model of physicians’ dynamic admission decisions when there is uncertainty about a patient’s ICU-need. Results show that increases in capacity cause physicians to lower their thresholds for ICU admission, with mixed effects on patient welfare. Patients are 1.8 pp more likely to be admitted to the ICU post-expansion (even when ICU strain is at pre-expansion levels), but there is significant heterogeneity in likelihood of admission and in-hospital mortality by ICU strain and ICU-need. Expanding ICU capacity does not always help the patients who need it most, and at times harms patients who need it least. Finally, the greatest benefits of ICU expansions accrue to patients in the general wards by allowing physicians to better allocate non-ICU resources, especially when the hospital is operating at capacity.

Who Benefits from Feedback? Evidence from MTurkers and Surgeons (with Jacob Zureich)

Performance feedback is considered critical for employee learning. Yet, research finds that feedback interventions often have meager, or even negative, effects on performance. We believe these lackluster results occur because feedback has heterogeneous effects based on individual learning type. However, the direction of these effects is unclear ex ante: while Laggers (slower learners) may benefit more because they are in greater need of additional feedback, Learners (faster learners) may benefit more because they use the feedback better. Our results support the latter. Both experimental data with MTurkers and clinical data linked to a surgeon report card show that feedback increases performance for Learners but decreases performance for Laggers. Further analyses show that Laggers (i) pay less attention to feedback, (ii) face particular struggles with negative feedback, and (iii) ineffectively adapt their explore-exploit strategies. Thus, feedback interventions may have small effects on average performance, but substantial effects on performance dispersion - widening the gap between Learners and Laggers. Dispersion can be beneficial when trying to distinguish amongst individuals (e.g., promotions) but detrimental when trying to maintain equity (e.g., in education and healthcare).

Published Papers

Druss, B. G., Singh, M., et al. (2018). Peer-led self-management of general medical conditions for patients with serious mental illnesses: A randomized trial. Psychiatric Services, 69(5), 529-535.

Rudolf, V. H., & Singh, M. (2013). Disentangling climate change effects on species interactions: effects of temperature, phenological shifts, and body size. Oecologia, 173(3), 1043-1052.