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At a time when medical researchers are under pressure to increase diversity in clinical trials, a Johns Hopkins study is sparking outrage among some physicians because of its large number of Black patients.

The controversy has stoked concerns that the institution infamous for its role in the Henrietta Lacks story may have once again exploited marginalized people for medical research. The university denies any wrongdoing and instead said it was simply providing a service to its local community, which has a mostly Black population.

The paper was published last fall without much notice but caused a stir on social media in recent weeks. It was a retrospective study analyzing the abilities of three specially trained nurse practitioners to perform colonoscopies, an invasive and potentially lifesaving cancer screening procedure normally done by gastroenterologists. Of the more than 1,000 patients who received screening colonoscopies from the nurse practitioners between 2010 and 2016, nearly 75% were Black.


“That is a huge red flag because that could not have happened randomly,” said Fola May, a gastroenterologist at the University of California, Los Angeles. “Did they preferentially pick Black patients to be in the study and to get the NP colonoscopies?”

African Americans make up about 63% of Baltimore’s population and 88% of the Middle East Baltimore neighborhood where Johns Hopkins Hospital is located. But Black people account for only about 25% to 31% of the patients treated in the Hopkins hospital system, according to annual reports from 2015-2016 and 2017. Johns Hopkins did not provide racial demographics of the patients who undergo colonoscopies, but said it provides the procedure to people living in the local community and outside the community.


Amid projections that demand for colonoscopies will soar as the population ages and as colorectal cancers rise among younger people, the researchers wanted to find out whether nurse practitioners who completed a yearlong gastrointestinal training fellowship could perform colonoscopies up to the same standards as doctors. For comparison, a gastroenterologist typically completes three years of internal medicine residency and three years of a gastroenterology fellowship.

Critics of the study questioned whether the patients were adequately informed that nurses don’t commonly do the procedure in the U.S., and whether they were given a choice to have their exam done by a doctor.

“When I saw the paper, my immediate concerns were around informed patient consent,” said Rachel Issaka, a gastroenterologist at the Fred Hutchinson Cancer Research Center in Seattle. “I really wanted to know, were those patients told up front that their colonoscopy was being done by a nurse practitioner, because that’s not the standard of care in the United States.”

Anne Marie Lennon, who is director of the Johns Hopkins division of gastroenterology and hepatology and was not involved in the research, said the data from the study show that the nurse practitioners met the same national metrics for safety and effectiveness set for gastroenterologists performing screening colonoscopies.

“This is a service where it was offered to the community, and the community happened to be people of color,” Lennon told STAT. “The concept that … people think this is Hopkins sort of looking at and doing something that is incorrect or immoral — that is simply just not true.” She said patients could choose a nurse practitioner or a gastroenterologist when they called to make an appointment, and some may have opted for NPs because they typically had shorter waits.

The study was spearheaded by Anthony Kalloo, a gastroenterologist who preceded Lennon as director of gastroenterology and hepatology before his recent appointment as chair of the department of medicine at Maimonides Medical Center in Brooklyn, N.Y.

Kalloo told STAT the patients were informed that their procedure was being done by a nurse practitioner and that they did have the option to have it done by a doctor. None of the patients refused treatment by a nurse practitioner in favor of a gastroenterologist, he added. He said patients signed a standard consent form to undergo the colonoscopy and were not asked to explicitly acknowledge they understood their procedure was being done by a nurse practitioner as opposed to a doctor who would have had more training.

Kalloo started training nurse practitioners at Johns Hopkins Hospital to perform colonoscopies, he said, as a way to save money and give back to the community, as well as meet the rising demand for the procedure, especially in underserved areas and rural places where access to a gastroenterologist might be limited.

“My God, it’s such a no-brainer to me almost. Why wouldn’t you want to save costs, especially when you have demands for a procedure that’s increasing and increasing,” he said. “So the logical thing, in terms of supply and demand, would be to train nurse practitioners to do this.”

He chalked up the criticism from gastroenterologists to longstanding tensions between physicians and nurse practitioners over the growing scope of medical procedures that non-physicians are allowed to do. “It has a lot to do with the perceived conception that it’s a threat to their livelihood,” said Kalloo. “I expected a little bit of pushback, but I did not expect this degree of pushback.”

He compares it to complaints that emerged when certified registered nurse anesthetists began administering anesthesia to patients, and noted that nurse practitioners regularly perform colonoscopies in the United Kingdom. He said he was simply duplicating a procedure that happens elsewhere in the world, though in the U.S., the American Society of Gastrointestinal Endoscopy had published guidelines in 2009 that stated “there are insufficient data to support nonphysician endoscopists to perform colonoscopy. …”

“It’s flabbergasting that this is such an issue … this is nothing new,” he said. “Except we for the first time in this paper showed that we could do this in the U.S. and the implication of that is cost savings.”

On Twitter, May, at UCLA, suggested the Hopkins study was exploitative. She responded to a fellow gastroenterologist’s tweet by saying the paper was “fueling the woes and fears of experimentation and exploitation in the Black community yet again!”

She was not alone in her worries, as doctors from various specialties, health professionals, and others also voiced their concerns on social media.

“Feels a lot like medical experimentation (*cough* racism) to me,” wrote Jazmyn Shaw, an emergency room nurse and medical student.

“Trying to wrap my head around how they managed to get ~750 Black people to sign up for this. I can’t even convince family to get vaccinated,” tweeted Kerry Mitchell, a plastic surgeon at Ohio State University Wexner Medical Center.

“Two-tiered medical system here we come. ‘MD for me but not for thee,’” wrote Daniel Choi, an orthopedic surgeon at Spine Medicine and Surgery of Long Island.

Adding to the critics’ concerns was a 2015 study published by Kalloo and two colleagues that evaluated colonoscopies performed independently by a single nurse practitioner between 2010 and 2012. Of the 300 people in that study, nearly 85% were African American.

“What happened to all of the white patients that normally walk into Hopkins to get a colonoscopy?” May said in an interview. If the researchers wanted to ethically demonstrate that nurse practitioners can do high-quality colonoscopies, she said, they should have instead conducted a trial on a randomly selected group of patients. “You should start with all types of patients. You shouldn’t be targeting Black patients,” she said.

The patient makeup of the studies is particularly concerning to some because African Americans are disproportionately affected by colorectal cancer. They are 20% more likely to get colorectal cancer than white people and 40% more likely to die from it, according to the American Cancer Society. The American Society for Gastrointestinal Endoscopy says African Americans are also more likely to have advanced colon cancer when it is diagnosed, and to have polyps — abnormal tissue growths that could potentially become cancerous — deeper in the colon, where they can be harder to spot with a colonoscopy.

“Because their care is so complex, they need the gold standard,” said Ruqaiijah Yearby, a bioethicist at Saint Louis University. “They don’t just need somebody who was able to do it, they actually need somebody who can catch all of the problems that they may suffer because they’re at increased risk of a higher rate of disease, cancer, and death,” she said.

Kalloo defended his work against claims of racial exploitation, asserting the study would lead to better care and more access for patients of color seeking colonoscopies.

“I found those comments to be amusing,” said Kalloo. “Obviously, they saw that I was the lead author from Hopkins, but they obviously didn’t know what I look like,” he said. Kalloo is a Black man who was born in Trinidad.

“There was not a selective intent to seek out patients of minority [groups],” he added. “And as I said, I am a minority.”

The three nurse practitioners in the study performed at least 140 colonoscopies while supervised by a gastroenterologist during a fellowship program at Hopkins before they could perform the procedure independently. That amount was the minimum number of colonoscopies necessary to demonstrate competency, according to recommendations at that time from the American Society for Gastrointestinal Endoscopy. They also underwent a performance evaluation before being credentialed to perform the procedure on their own.

The paper noted that the nurse practitioners were women between the ages of 18 and 36. Two were white and one was Asian, and two held a master’s as their highest degree and one a doctorate. (STAT reached out to one of the nurse practitioners who was also the study’s lead author, but was referred by Johns Hopkins to speak with Lennon instead.)

Sophie Balzora, a gastroenterologist at NYU Langone Health, said 140 colonoscopies seemed very low to develop competency, and estimated that by the end of her three-year clinical fellowship at NYU, she had completed more than 800 colonoscopies.

“By the end of first year, you would have several hundred under your belt, and you still wouldn’t be comfortable performing procedure after procedure on your own without any supervision,” she said.

Some studies have suggested that colonoscopy competency comes after around 250-300 procedures and others around 500 procedures. In 2017, after the time frame of the Hopkins study, the American Society for Gastrointestinal Endoscopy raised its recommended minimum to 270 procedures for competency assessment.

A look at the Johns Hopkins gastroenterology and hepatology webpages from 2013 to 2016 suggests there were typically about 40 to 50 gastroenterologists and about 15 gastroenterology medical fellows on staff each year.

“You’re in a highly populated urban area where there are physicians who perform thousands of colonoscopies throughout their career, but then you’re having a colonoscopy done by an NP who has done only at least 140 procedures. Why is that?” Balzora said. “It’s a perfect example of systemic racism in my mind.”

Yearby, the Saint Louis University bioethicist, agreed that the study raises ethical issues. She said she doesn’t think the researchers targeted Black patients in the same way they were targeted in the Tuskegee syphilis study, or in a Hopkins HIV study in Ethiopia in which researchers cancelled plans to give pregnant women a placebo instead of the drug AZT to prevent HIV transmission to their babies, or the Hopkins Krieger study that evaluated interventions to reduce lead poisoning in children. But she called the procedures problematic for other reasons.

“They used a population because they were in an urban area at an academic medical center, and they had lots of people coming in who needed colonoscopies, and so they used that as an opportunity to try this out,” she said. “That is undue influence and targeting of particular populations.”

The nurse practitioners were permitted to work only at the hospital, according to Lennon. While they were performing on their own, there was always a gastroenterologist “on the floor,” Kalloo noted.

During the study period, the three nurse practitioners conducted a total of 1,425 colonoscopies. About 400 were excluded from the study because the patients either did not have clean enough bowels or they came in for screening and it was found they had a disease like inflammatory bowel disease, which led to a doctor taking over. The nurses detected adenomatous polyps in about 36% of cases, which exceeded the standard for detection of more than 25% of cases as set by the ASGE and the American College of Gastroenterology. The NPs also achieved cecal intubation, which is at the end of the colon, 98.5% of the time, which also met the national standards of higher than 95%. They did not cause any perforations of the colon.

“They can tout their results, but when they started the study they didn’t know what the results were going to be,” said May. She also took issue with the paper’s lack of follow-up. “They finished these colonoscopies over five years ago. Why not tell us how many of those patients have developed cancer in the interim?”

The study had several limitations. The use of only three nurse practitioners limits how much the results can be generalized to other nurse practitioners. It also did not say how many of the colonoscopies required the assistance of a physician to reach cecal intubation.

Kalloo said he struggled to get the work published in one of the more established GI journals, and ultimately published it in the journal Endoscopy International Open.

Johns Hopkins is no longer training nurse practitioners through its gastrointestinal fellowship to perform colonoscopies, Lennon said. Two of the three NPs involved in the study are now at different institutions, and the one still at Hopkins no longer does colonoscopies, she said. But Lennon asserted the program wasn’t stopped because of any concerns with it.

“There’s no insidious [reason], there’s nothing unusual about this. This is simply people have moved on,” she said. “It’s an interesting thing the prior division director did, but we’re not running this at the moment.”

Another factor in the Hopkins decision, Kalloo said, was the fact that Medicare and Medicaid don’t reimburse for nurse practitioners who perform colonoscopies. Still, he said he would be interested in starting up a similar gastrointestinal fellowship at his new medical center in Brooklyn to continue training nurse practitioners to conduct colonoscopies.

“I just got here at Maimonides four weeks ago, so I’m trying to get my feet wet,” Kalloo said. “It is something I would love to reinstate here. It’s just not going to happen tomorrow.”

  • If this is a retrospective chart review, as described in the manuscript and this article, why is this being portrayed as racist science? The entire point of a retrospective study is to examine standard of care results for something of interest. In this case it was to examine if the NPs were sufficient at performing colonoscopies. That’s why there was no research informed consent. It’s also why no patient whose data were included ” knew” they were in a study, because there was no study at the time. The patients were experiencing the hospital’s SOC at the time.

    The racism is not in the science, it’s in the scheduling of appointments, which absolutely needs to be addressed. The science unwittingly brought that issue to light. Please don’t paint this as a science issue. It only serves to lower the participation rates of POC in research.

    A counterpoint is that Kalloo should have brought this up when asked about this study. It’s clearly not exploitive science if it was retrospective in nature. The lack of making that point might indicate it was planned prospectively, which would clearly be a case of bad science.

  • whoa, that hurts to the GI MD or DO specialists community. NP get less reimbursement and now days are dominating the medical industry. we have less doctors and they are getting older and older. I am a pediatrician and I see 99% of Mexican-American children. I just published a couple of papers on them. Am I to blame? All of our primary doctors here in Laredo have nurse practitioners or PA’s . Where else you are going to get doctors to practice here in Laredo. When you die here you don’t go to hell because you have been already here at 100-110 degrees.

  • Disgusting practice on a vulnerable community. However, the doctor is not the only one to blame. Why is a nurse practicing medicine and surgery on top of that? Why did they willingly go through with it? Nurse practitioners buy their degrees online from diploma mills. A patient wouldn’t be comfortable with the lack of training. Shame on nurse practitioners for performing this on a vulnerable community and doing something that is so clearly from the scope of their minimal nursing knowledge. If I was a patient I would sue the board of nursing for racist medical practice. Leave the job the professional and be ethical.

  • To claim that the Nurse Practitioners “conformed with national metrics” means nothing. The claimed perforation rate varies between .03% and .5%. That is a variability factor of over 16, and I suspect from personal experience that the rate in many cases is much higher than that. Gastroenterologists have long played fast and loose with the suffering and risks (before and after) associated with this procedure, almost like a propaganda machine, and they are among the wealthiest specialists around – mainly from performing colonoscopies. They fought hard and, in some cases, dishonestly against ColoSure and then Cologuard, which they feared might reduce business. Make no mistake, this is a valuable and lifesaving procedure when used properly and judiciously. Unfortunately, it tends to be thrown around by GE’s like it’s little more than a blood test.

  • I’m really surprised at the individuals in this thread who are so dismissive of these actions. Maybe you will be guinea pigs one day.

    I am also offended by Dr. Kalloo’s laissez faire attitude in being questioned about this study.
    -Did the patients understand the difference between a nurse practitioner and gastroenterologist? There are no NP specific gastroenterology curriculums approved by the CCNE or ACEN, the bodies who approve nursing educational programs. This was a program set up by a physician for NPs that was not approved by any nursing body. What objective data was used to declare their competency? Because physicians are not nurses, how could Dr. Kalloo determine what was standard for nurses? He could only use the medical standard. We know the standard for gastroenterology training; how exactly does that transition to NP standards? Does that not matter?
    – Standardized procedures(SPs) allow NPs to perform functions that would otherwise be considered the practice of medicine. These have to be approved by a state’s board of nursing(BOM) and then signed off as an agreement between the medical facility and the BON. Was this done?
    -Was any of this approved by an IRB? If it wasn’t, then how can anyone assume the patients were properly consented? Because Dr. Kalloo said so? Common sense dictates that if a patient is asked if they want a physician or nurse practitioner for a procedure performed in which they will be sedated, they will most likely want a physician. But 75% of Black patients, who already have an underlying distrust of the medical establishment, agreed to have these procedures done by NPs. Pardon me for being skeptical.
    -I have a problem with NPs who may not have gone through a legitimate process to be trained being permitted to perform colonoscopies unsupervised in that facility. Who was responsible for overseeing the conscious sedation? Or was the colonoscopy performed without? Having a doctor “around” is not sufficient.

    The scientists and doctors who were involved in the Tuskegee experiments thought it was a good idea to follow the progression of syphilis and that they were performing something good for mankind. The comments in here smack of that mentality–because they ask no questions or they don’t have the right questions. The respondents presume everything was above board because it’s Johns Hopkins and the study involves a Black Chief of GI. It was not acceptable because Tuskegee, AL had a primarily Black population to use local men as lab rats. Convenience is not an excuse to violate ethical standards. It took a Public Health Service investigator to go to the press for that 40 year experiment to end, despite others voicing concerns about the immorality along the way. Being Black and exploiting Black people are not mutually exclusive. There were Black nurses involved in the Tuskegee experiment, Black medical students who rotated through and the study had the support of the local NMA.

  • Were these patients all pay patients or were these being done pro bono? I think the outcome data speak for themselves. It is funny the Chief who proposed this should be accused of racism when he is a person of color. You go Tony!

  • The drum beat of racism never ends; while in some instances, there may be issues, in others it feels like people go out of their way to twist circumstances to fit a narrative. If the participants agreed to a proper informed consent, what is the issue? There are frequent stories about the black community being underserved medically. Now, they have had an opportunity for a life-saving procedure at a top institute with the NPs no doubt being supervised by MDs and still people are finding fault. It may be a question of insurance or otherwise. I find it not at all believable that this was targeted racism.

    • No doubt being supervised….. they pretty clearly were not…. specialist “on the floor” at all times. “On the floor”?
      What is the meaning of significance of this?

  • The critics are just nitpicking. The only goal of the study was to show NPs can do safe and effective colonoscopies. You don’t need a diverse patient population for that, so running the study AND serving the local (minority) residents is a win-win.
    As a Respiratory Therapist, I remember when we took over drawing of arterial blood gas samples from the doctors, way back in the late 1970s. A small group of well trained therapist wound up doing a much better job than a rotating cast of interns and residents.

    • The issue here is that hopkins selected a population that was overwhelmingly black to be experimented on. This is ethically hugely problematic. This is not reflective of their normal colonoscopy population. It seems that they were approaching a vulnerable cohort of patients. This fits our concern that these patients were not adequately consented to understand the difference in training and education of the nurse practitioners and gastroenterologists.

      From a results standpoint, sure it probably is true that their results are valid – in this small cohort of patients there were no major bad short term outcomes and intubation of the cecum was successful at an adequate rate. However this study is unlikely to be powered to detect differences in rare, but significant bad outcomes and the authors do not address cancer rates in these patients in the following years. There is likely a good reason no well established GI journals were willing to publish this study.

      Finally, in regard to your point about ABGS — There is a huge difference between the invasiveness of ABGs and colonoscopy. Additionally, the stakes of the outcomes are dramatically different. Resticking the radial artery is not a big deal — missing cancer on a colonoscopy is a huge deal. Recognizing cancer or precancerous lesions especially in subtle presentations requires seeing far more than the abbreviated number of patients that these NPs practiced on.

    • Bob, I object to the premise that this was an experiment. If so, my training as a therapist and yours as a doctor were also experiments. We both know that the care we provided as students was not as good as that of more experience practitioners, but we were supervised – just like this study.

    • I said nothing bad about NPs. I said that their education and training are not to be compared to the gold standard – colonoscopy performed by a gastroenterologist. We do not allow third year GI fellows who have completed far more colonoscopies and far more complicated endoscopic procedures (EGD,ERCP, etc) to do these procedures without attending oversight. We cannot pretend that the current crop of near 100% online NP programs with only 500 unregulated clinical hours is remotely close to the training received by physicians. So ethically it is vital information to know if these patients were expressly told (Not in the fine print) that their procedure was being done by an NP and how their training differed. If the consent was “this is Joe they are the NP who will do your scope” that is not adequate information for the patient to decide if they are comfortable with that person doing the procedure.
      This is experimental because it departs from the standard of training. Residents and fellows performing these procedures UNDER ATTENDING SUPERVISION is not experimentation because that is the standard of medical training/education. There is a standardized curriculum and training process with aggressive auditing and review of training quality. NPs performing colonoscopies is not the standard of care and their training did not meet the standard of training, therefore it is experimental with a research question being “can someone who has less education and shorter training than a GI fellowship intubate the cecum >95% of the time without major complications?”

      And to the people who have had bad experiences with physicans being rude, I am sorry. However, I guarantee that there are plenty of people with bad experiences of non-physicians being rude. In fact the most malignant interactions I had in residency and med school were from nurse practitioners and PAs. Does that mean that all nonphysicians are rude and bad team players? No not at all and I don’t pretend that is the case.

    • Isn’t fee for service the way the economy usually runs, including health care for many decades? (Until massive government and employer provided insurance involvement). With incentives for seeking lower cost quality providers.
      e.g two or three quotes before getting your house painted, your kitchen renovated or your auto transmission rebuilt?

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