Medical error—the third leading cause of death in the US

Drs. Makary and Daniel in their British Medical Journal (BMJ) paper entitled “Medical error – the third leading cause of death in the US” have drawn additional attention to the extensive problem of lethal medical errors. (1) They rightly emphasize that these errors are not captured in death certificates. The purpose of my letter is to comment on their core calculation that declared 251,454 deaths result from medical errors in U. S. hospitals each year. This will be accomplished in light of a paper published in the Journal of Patient Safety (JPS) in 2013. (2)

Base year 2013 or 2007? The studies Drs. Makary and Daniel used were precisely those used in the JPS paper except that they did not use results from a pilot study that predated the 2010 study from the U.S. Office of Inspector General. When any estimate is made, there are no absolute rights and wrongs; however, there may be better ways of making an estimate. The BMJ and JPS analyses were both performed on data from 2002 to 2008. The JPS study employed a base year of 2007 in which there were 34.4 million hospital admissions because that year is within the bounds of the records studied. That is a better choice than the BMJ choice of 2013, which is well outside the years of the medical records reviewed. If the BMJ study had used 2007 as its base-year, then the result would have been 34.4 X 251,000/37 = 233,000. It is reasonable to suppose that there may have been substantial changes in the rate of medical errors from 2007 to 2013. One must hope that there was a decline. For example, the US Centers for Disease Control reports substantial reductions in many types of hospital acquired infections over that period. (3)

Combining the results of studies: After applying the respective preventability factors, which ranged from 44 to roughly 100%, the BMJ paper in table 1 employed a simple average. There is a better way to make the estimate. The number of medical records examined in the North Carolina study is 3-fold higher than in the other two. (4) The better way is to use a weighted average by adding up the total patient admissions and total number of deaths due to adverse events, and then applying the average of the preventability factors (69%). This is the approach used in the JPS paper. If, however, one were to use a weighted average of three BMJ estimates, applying a factor of 3 to the North Carolina study and 1 to the other two smaller studies, then the core estimate drops from 251, 000 to 205,000.

How large is the underestimate? Drs. Makary and Daniel opine that their estimate of 251,000 deaths per year is an underestimate “because the studies cited rely on errors extractable in documented health records.” How large is that underestimate? When the JPS paper was written I knew this was a problem for three reasons: 1) the Global Trigger Tool, which was the primary adverse-event finder in all three studies, misses many errors of omission, communication and context; 2) obviously it also misses errors that are not evident in the medical records; and 3) it does not detect many diagnostic errors. It’s a challenge to get a scientific handle on what is not found; however, a study by Weissman, et al. provides insight into the magnitude of underestimate. (5) He and his colleagues, studying medical records of 1000 hospitalized cardiac patients, found that patient reports of serious preventable harm, which were verified by the research team, were three-fold higher than discovered by physician review of the medical records. The JPS paper used a factor of only 2 to deal with all the missed adverse events except diagnostic errors. From the literature estimating that 40,000 to 80,000 die from missed diagnoses each year, the addition of 20,000 deaths from diagnostic errors in hospitals each year seemed reasonable. (6) If anything, these adjustments on the core estimate of 210,000 were probably low. The published final estimate was 210,000 x 2 + 20,000 = 440,000 preventable adverse events that contribute to patient death due to preventable adverse events each year.

What actually causes death? It's important to point out that many of the deaths resulting from non-evidence-based care in hospitals, do not occur while hospitalized. The adverse event that shortens life may occur long after discharge and go unrecognized. A classic example of this a few years before the time frame of the medical records of the studies showed that many were dying prematurely of heart failure because they were not receiving beta-blockers after a myocardial infarction. It seems that at last in 2007, nearly all patients that needed beta blockers were finally getting them. (7) The seminal study on the value of beta blockers was published in 1982 in the JAMA, yet as late as the early 2000s, tens of thousands of people with heart failure were dying prematurely each year, presumably many outside hospitals that could have given the life-prolonging drug, if only they had. (8) Such patients did die of heart failure, but they died earlier than they would have if they had been prescribed a beta blocker. A medical error of omission contributed to their death.

It may be misleading, once medical errors are acknowledged, to present causes of death as independent events as the BMJ paper suggests in table 2. One can speculate with much certainty that medical errors contributed a premature death to many of those who died of heart disease or cancer. A more appropriate way to express the national impact of medical errors is to note that about 2.4 million Americans die each year; roughly 1/6th of those deaths (400,000) are hastened by preventable mistakes originating in hospitals. Of course, one has to contend with the debate about what constitutes a “hastened” death.

Conclusion. The study by Drs. Makary and Daniel has drawn valuable, additional attention to the problem of medical error as the third leading cause of death in the US. Refining their numbers, as I suggest here, has not changed that. Three things are clear: 1) analyses of the limited data we have now must be performed with careful attention to optimizing the analytical approach, 2) the conclusions from those analyses must reflect the reality that people often die of more than one cause, and 3) there must be a national consensus on what constitutes a preventable adverse event, or medical error, if you will. Once there is a consensus definition, we can begin to count these errors with more certainty and hopefully track their decline.

References
1) Makary MA, Daniel M. Medical error – the third leading cause of death in the US. BMJ 2016;353:i2139 doi: 10.1136/bmj.i2139
2) James JT. A new, evidence-based estimate of patient harms associated with hospital care. J Pat Saf 2013; 9: 122-128
3) Centers for Disease Control and Prevention. Healthcare Associated Infections – Progress Report. March 3, 2016. http://www.cdc.gov/hai/surveillance/progress-report/index.html
4) Landrigan CP, Parry GJ, Bones CB, Hackbarth AD, Goldmann DA, Sharek PJ. Temporal trends in rates of patient harm resulting from medical care. N Engl J Med 2010; 363:2124-2134
5) Weissman JS, Schneider EC, Weingart SN, Epstein AM, David-Kasdan J, Feibelmann S, Annas CL, Ridley N, Kirle L, Gatsonis C. Comparing Patient-reported hospital adverse events with medical records review: Do patients know something that hospitals do not? Ann Intern Med 2008; 149:100-108
6) Leape L, Berwick D, Bates D. Counting deaths from medical errors. JAMA 2002; 288:2405
7) Lee TH. Eulogy for a quality measure. N Engl J Med 2007; 357:1175-1177
A randomized trial of propranolol in patients with acute myocardial infarction - 1. Mortality results. JAMA 1982; 247:1707-1714
8) Gheorghiade M, Gattis WA, O’Conner CM. Treatment gaps in the pharmacologic management pf heart failure. Review Cardiovascular Medicine 2002; 3:S11-S19

A couple of quick points. 1. True cause of death often isn't known. No one does autopsies anymore because of lack of funding. I remember how many times we ended up being surprised at the findings!
2. The cheapest, simplest, and likely most reliable way to reduce the number of errors is to appropriately staff hospitals! How can the poor nurses and techs etc. keep up the quality when they are stretched so thin and then have to do all the meaningless EMR data entry.
3. Don't get me started on EMR's and errors.

There is real value in the article by Makary, and unfortunately it is not the first time this alarm bell has been rung. While awareness of the problem has increased over the years, it is clear that the efforts so far have not achieved all that we may have hoped.

After 16 years of existence, VA National Center for Patient Safety (NCPS) data shows that the vast majority of errors are caused by failures in the system – or system vulnerabilities that contribute to the failures. Most investigations of adverse events and close calls reveal multiple causes and contributing factors that line up in perfect storm conditions. In order to address patient safety issues fairly, assume that clinicians are smart and they come to work to help people recover health. They often behave in heroic ways to prevent harm from reaching their patients. They worry, too. And they suffer when their patients don’t do well.

The healthcare delivery work environment is far from safe. A highly reliable and resilient system is precisely the opposite of what we have. However, there is evidence that there is progress in that direction. To bring reliability and resilience about, painful lessons need to be shared. In the VA, Patient Safety Managers at each hospital consult with each other and with analysts for database searches so that interventions that have proved successful are replicated. NCPS educators create high fidelity simulation and incorporate usability testing in order to spread lessons learned, allow the practice of teamwork and communication, and hone skills.

The FDA makes its MAUDE (https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/search.cfm) database available for both reporting and searching. The existence of this database, though it is much easier to enter data than to retrieve information, gives hope that a future version of a Consumer Reports style website will allow healthcare organizations the ability to make informed purchase decisions; avoiding devices with error provoking designs no matter how appealing the price; and finding devices with safe interoperability.

Soon after its inception, NCPS began receiving patient safety reports of adverse events, close calls, and the intended interventions aimed at preventing a recurrence. In return for receiving this gold mine of information, the VA promised confidentiality and legal protection for patient safety information. The issues identified are shared in a number of ways across VA healthcare systems.

Many significant changes to healthcare delivery systems have occurred as a result. These lessons are freely shared with FDA, ECRI, and others; and published on the NCPS website: http://www.patientsafety.va.gov/professionals/alerts/index.asp. NCPS staffers also research, write, and publish findings; and NCPS funds research at 10 Patient Safety Centers of Inquiry: http://www.patientsafety.va.gov/docs/VHA_NCPSPSCI_FY16to18_Summary.pdf.

In an effort to create a future workforce armed with competencies in patient safety, NCPS has developed advanced training programs. The VA’s Office of Academic Affiliations (OAA) then funds these Chief Residents in Quality and Safety who devote a year to solving problems and reducing risk at VA and university hospitals nationwide. In the 6 years of its existence the program has grown from one Chief Resident in Indianapolis to 80 nationwide. Because they work to accomplish safety and quality improvements and teach their junior colleagues, the work grows in strength as well as in numbers. OAA also funds Patient Safety Fellows who are a professionally diverse group well-prepared to lead hospital patient safety efforts.

National interest is also clearly seen through the work of the Accreditation Council for Graduate Medical Education (ACGME). ACGME revised the way that residency training programs are evaluated for accreditation; moving away from threats of loss towards creating a Clinical Learning Environment Review (CLER) that is heavily focused on improving safety and quality. [Nasca, et.al.; 2012]

There are now a myriad of meetings and conferences with focus on safety, improvements in informatics, human factors engineering and others. These conferences could not exist if there wasn’t a huge interest and also funding for the efforts to improve patient safety.

This is a challenging time in healthcare as attempts are made to balance financial constraints with a desire to create more patient centered care. Seeds have been sown in many areas across the continuum of healthcare. These efforts need greater support, and a recognition that clear focus and prioritization of a patient safety agenda, as done in many other industries, can help further advance these efforts.

Nasca TJ, Philibert I, Brigham T, Flynn TC. The next GME accreditation system – rational and benefits. N Engl J Med 2012:366:1051-1056. DOI: 10.1056/NEJMsr1200117

Using data to extrapolate the proportion of deaths due to human error, Makery and Daniel (Analysis 7 May 2016) estimate that in the USA medical error is the third highest cause of death beaten only by heart disease and cancer. This is a terrifying statistic: we as doctors may be the greatest threat to our patients.

The focus of the article was the limitation of current data sources to capture medical error as a cause of death. I agree in principle that accurate “assessment of the problem is critical to approaching any health threat”. However, I do not think that we can wait until such a data collection system is developed.

I think we need to act now; research and tools from other high risk industries illustrate the relevance of human factors. I believe the limited understanding of human factors amongst the medical community affects the application of the tools available. For example, the WHO checklist is a briefing, a process to create shared situational awareness. It has little value if performed as a tick box exercise. It should be used for “threat and error management” to highlight threats to patient safety (e.g. prone position, list changes, bleeding risk, fatigue, ASA 3 and above…). It aught to open communication between anaesthetic and surgical teams enabling them to share contingency plans.

We audit compliance with guidelines but how often do we assess the usability and accessibility of protocols, the system, team and organisational factors that contribute to error? High reliability organisations seek learning opportunities, they report incidents to learn not to sanction and they learn from other industries. We delivered an inter-agency human factors course for the fire service and healthcare. Discussion around standard operating procedures (SOP) generated new insight - medical personnel were impressed by the risk and safety awareness of the fire service personnel through their use of SOPs. The inter-agency aspect was key to gaining this new insight into error. It was so well received that Aviation Safety week at Manchester Airport will include a two day Inter-agency Human Factors conference, open to aviation, health care and fire service. We need to use what is available to the best of our ability while trying to devise a system of data collection.