Friday, October 9, 2015

On Not Being a Surgical Statistic

When I used to motor the 400 miles from my home in Tennessee to Duke Medical School, my mother would say to me,”Richard, don’t be a statistic.” She was referring to road death statistics.

A single death is a tragedy, multiple deaths are a statistic. This is particularly true with surgical deaths. Surgery is designed to save lives, not end in death.

But how to avoid surgical deaths?

One answer may lie in statistics, or the law of large numbers. This law, according to my dictionary, is “The theorem in probability theory that the number of successes increases as the number of experiments increases and approximates the probability that the number of experiments for a large number of experiments.”

So much for statistical jargon. Translated this means the more surgeries you perform the better the results are likely to be.
This, in turn, means that big hospitals what perform large numbers of surgical procedures are the place to go, especially is have a condition that requires complicated surgery.

I thought of large numbers theorem, when I read two articles in the October 8 New England Journal of Medicine.

The first, “Scoring No Goal – Further Advances in Transparency,’ by Lisa Rosenbaum , MD, medical correspondent for the Journal, explains that the surgical score developed by ProPublica, an organization devoted to identifying quality of care as delivered by individual surgeons, may not achieve its goal . ProPublica studied outcomes of 17,000 surgeons performing 8 elective procedures, and concluded the higher the volume of procedures by an individual surgeon, the better the results. It assumed such a scorecard would root out doctors who performed too few operations to be good at them. The author concludes such a scorecard is deeply flawed and can destroy the careers and reputations of excellent surgeons. Besides, the data isn’t statistically meaningful doesn’t capture the expertise of individual surgeons who are not in the position to cherry-pick low risk candidate to make their statistics look good.

The second, “Pledge to Eliminate Low-Volume Surgery,” by David Urbach, MD, of the University of Toronto, describes the campaign by leaders of 3 large hospital systems – Dartmouth and Hitchcock Medical Center, the Johns Hopkins, and University of Michigan Health Center. The campaign is called “Take the Volume Pledge” and is dedicated to the proposition that complicated surgeries should be referred to high volume institutions if surgeons have not performed the requisite number of operations to be competent at them. The volumes recommended are” bariatric surgery 20 to 40, esophagus 5 to 20, lung 20 to 40, pancreas 5 to 20, rectum 5 to 20, carotid stents 5 to 10, complex aortic surgeries 7 to 20, mitral valve repair 10 to 20, and hip and knee replacements, 20 to 50. The idea is to redirect complex procedures to high volume hospitals. The author comments that most surgeries will continue to be done as smaller hospitals, and a more important goal should be to improve structures and processes at these small hospitals.

Volume alone will not improve surgical results, and statistical results alone can’t be used to judge surgical quality. Bigger is not necessarily better in all cases. Besides, not surgeon wants to be considered a mere statistic. But no patient wants to become a statistic, and for certain surgical problem, the patient may fare better at large institutions who have wide experience with complicated problems.

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