SGEM#316: What A Difference An A.P.P. Makes? Diagnostic Testing Differences Between A.P.P.s and Physicians

Podcast: Play in new window | Download

Subscribe: RSS

Date: January 20th, 2021

Guest Skeptic: Dr. Lauren Westafer an Assistant Professor in the Department of Emergency Medicine at the University of Massachusetts Medical School – Baystate. She is the cofounder of FOAMcast and a pulmonary embolism and implementation science researcher. Dr. Westafer serves as the Social Media Editor and  research methodology editor for Annals of Emergency Medicine and as an Associate Editor for the NEJM Journal Watch Emergency Medicine.

Background: We covered the use of advanced practice providers (APPs) on the SGEM#308. That SGEMHOP episode asked how the productivity of APPs compare to emergency physicians and what is its impact on ED operations? The key result from that study of 13 million ED visits across 94 states was that physicians were more productive than PAs and NPs. The SGEM bottom line was that increasing APP coverage has minimal effect on ED flow and safety outcomes based on the data.

Over the past two decades, the use of APPs has increased. APPs have a significantly truncated medical training (about 2 years of training) and practice experience compared with the traditional 4 years of medical school and 3-4 years of residency for emergency physicians.

There has been a concern about post-graduate training of NPs and PAs in the ED. A joint statement on the issue was published in 2020 by AAEM/RSA, ACEP, ACOEP/RSO, CORD, EMRA, and SAEM/RAMS. The American Academy of Emergency Medicine (AAEM) has a position statement on what they refer to as non-physician practitioners that was recently updated. The American College of Emergency Physicians (ACEP) also has a number of documents discussing APPs in the ED.

The difference in training between and emergency medicine physician and APPs is well recognized. A concern is that some APPs may compensate for this training gap by increased testing.

---

Clinical Question: Is ED evaluation by an APP associated with higher test utilization and hospitalization compared with evaluation by a physician?

---

Reference: Pines et al. Emergency Physician and Advanced Practice Provider Diagnostic Testing and Admission Decisions in Chest Pain and Abdominal Pain. AEM January 2021

• Population: All ED patients with a chief complaint of chest pain or abdominal pain triaged as an Emergency Severity Index (ESI) 2,3, or 4 who were seen independently by either an APP or emergency physician
  • Excluded: Patients who left without treatment or against medical advice, those who were dead on arrival or died in the ED. They also excluded those with a triage level ESI 1 or 5, as these are less common, as well as those with a final diagnosis of injury or poisoning – as in those cases the diagnosis would generally be apparent.
• Intervention: Evaluated by an APP
• Comparison: Evaluated a physicial
• Outcome:
  • Primary Outcomes: Laboratory tests, ECGs, imaging studies as well as hospital admissions (including transfer to other hospitals and observation admissions)
  • Secondary Outcomes: Testing based on evidence-based practice

This is an SGEMHOP episode which means we have the lead author on the show. Jesse Pines MD is the National Director for Clinical Innovation at US Acute Care Solutions and a Professor of Emergency Medicine at Drexel University. In this role, he focuses on developing and implementing new care models including telemedicine, alternative payment models, and also leads the USACS opioid programs.

Authors’ Conclusions: “We demonstrate that the care delivered in the ED by advanced practice providers and emergency physicians for patients matched on complexity and acuity presenting with chest pain or abdominal pain chief complaints is largely similar with respect to diagnostic test utilization and admission decisions. Future research should continue to explore the optimal use of advanced practice providers in the ED and the best ways to deploy this expanding part of the U.S. ED workforce”.

Quality Checklist for Observational Study:

1. Did the study address a clearly focused issue? Yes
2. Did the authors use an appropriate method to answer their question? Yes
3. Was the cohort recruited in an acceptable way? Unsure
4. Was the exposure accurately measured to minimize bias? Unsure
5. Was the outcome accurately measured to minimize bias? Yes
6. Have the authors identified all-important confounding factors? No
7. Was the follow up of subjects complete enough? Yes
8. How precise are the results? Fairly precise
9. Do you believe the results? Yes
10. Can the results be applied to the local population? Unsure
11. Do the results of this study fit with other available evidence? Unsure

Key Results: The data was collected over three years (2016-19) from around 90 facilities with over a thousand APPs and more than 1,500 emergency physicians. There were 663,599 patient visits for chest pain (12.8% seen by APPs and 87.2% seen by physicians). There were 946,042 patient visits for abdominal pain (21.3% seen by APPs and 78.7% seen by physicians).

---

There was not much difference between APPs and physicians for laboratory, imaging studies or admissions with APPs being slightly lower for all outcomes.

---

Physicians tended to see older patients, those with more comorbidities, and had a higher admission rate. In contrast, APPs tended to see younger patients, with less comorbidities and lower admission rates.

However, once IPW-adjusted average treatment effects showed that being seen by an

APP either reduced the probability or did not have a statistically significant impact the probability of having a laboratory test or imaging test ordered in comparison to physicians. This was consistent overall and among discharged ED visits, including models that contained past medical history.

1) Observational Study: One of the main limitations is this is an observational study. Although they stratified by age and did inverse propensity score weighting (IPW) there could have been confounding factors impacting the results.

2) Accuracy of Exposure Measurement:  Big datasets allow us to look at massive amounts of information. One problem, however, can be the granularity of the data. It’s not entirely clear in the manuscript how the exposure, which was whether an APP saw the patient or not, was determined. Was it that an APP was involved in any aspect of care? Was it that they saw the patient first? Last before disposition? In some EDs, while APPs may see patients primarily, physicians also see, evaluate, and help disposition the patient. In other EDs (or even the same ED but with different APP-attending physician combinations), the APP may truly independently see and manage the patient. These combinations make the exposure a little more opaque in this case.

3) Protocolized: Most of the patients (>90%) presenting with chest pain were adults. Often, they are being worked up for rule out ACS or rule out PE.  These tend to be very protocolized workups. There is also a zero-miss culture when it comes to MIs and PEs. It is not surprising that you did not find much variability in practice for patients presenting with chest pain.

4) Supervision: It says in the publication that all APPs had some degree of physician supervision and none were practicing independently. This is another reason why we would not expect to find much difference between APPs and physicians.

5) Patient-Oriented Outcome:  It could be argued that number of tests are not patient oriented outcomes depending on insurance status. A stronger case could be made about admission to hospital. Why not look at things like safety defined as mortality and morbidity?

We were correctly called out after SGEM#308 for not having an APP on the SGEM episode that reviewed a paper on APPs. Demonstrating that we listen to feedback and take action, Martha Roberts was invited to provide her comments on the paper. She is a critical and emergency care, triple-certified nurse practitioner currently living and working in Sacramento, California. She is the host of EM Bootcamp in Las Vegas, as well as a usual speaker and faculty member for The Center for Continuing Medical Education (CCME). She writes a blog called The Proceduralist and has started her own podcast with PA Mike Sharma called The 2-View podcast.

Comment on Authors’ Conclusion Compared to SGEM Conclusion: We generally agree with the authors conclusions.

---

SGEM Bottom Line: In patients presenting to the ED with chest pain and abdominal pain, physicians and APPs had similar practice patterns with test ordering and admissions rates.

---

Case Resolution: The patient has a work-up for his abdominal pain, including labs and CT abdomen-pelvis, and is diagnosed with uncomplicated diverticulitis. He is discharged home with a prescription for appropriate antibiotics.

Clinical Application: Unsure. We do not have high-quality data to inform us about the impact of APPs on the emergency department. This data comes from one large emergency department group and may lack external validity to other practice environments.

What Do I Tell My Patient? It probably will not matter whether you see the APP or the physician. Both have similar practice styles, and the APP will be supervised by an attending physician.

Keener Kontest: Last weeks’ winner was Kalmen Barkin an EMT from Somersworth, New Hampshire. They knew the term “blinding” came from an investigation into the practice of Dr. Franz Mesmer. The trials conducted included blind folding participants.

Listen to the SGEM podcast to hear this weeks’ question. Send your answer to TheSGEM@gmail.com with “keener” in the subject line. The first correct answer will receive a cool skeptical prize.

SGEMHOP: Now it is your turn SGEMers. What do you think of this episode on APPs in the ED? Tweet your comments using #SGEMHOP.  What questions do you have for Jesse and his team? Ask them on the SGEM blog. The best social media feedback will be published in AEM.

Also, don’t forget that those of you who are subscribers to Academic Emergency Medicine can head over to the AEM home page to get CME credits for this podcast and article. We will put the process on the SGEM blog:

• Go to the Wiley Health Learning website
• Register and create a log in
• Search for Academic Emergency Medicine – “January”
• Complete the five questions and submit your answers
• Please email Corey (coreyheitzmd@gmail.com) with any questions or difficulties.

You can now earn CME credits for all SGEM episodes. Just click on the LINK to find out more about this opportunity.

---

Remember to be skeptical of anything you learn, even if you heard it on the Skeptics’ Guide to Emergency Medicine.

---