Humans not yet obsolete
Stuff has a story on robot-assisted surgeries, claiming
Patients who have robot-assisted surgeries on their kidneys or prostate have shorter hospital stays and a lower risk of having a blood transfusion or dying – but the bill is significantly higher, a study found.
That’s not quite what the study found. The abstract says
While robotic assisted and laparoscopic surgery are associated with fewer deaths, complications, transfusions and shorter length of hospital stay compared to open surgery, robotic assisted laparoscopic surgery is more costly than laparoscopic and open surgery.
The researchers used the Nationwide Inpatient Sample, a random subset of US hospital admissions, to compare three approaches to prostate and kidney surgery: laparoscopic (‘keyhole’) surgery by hand, robot-assisted laparoscopic surgery, and open (non-keyhole) surgery. They found that laparoscopic surgery, whether robot-assisted or not, was safer than open surgery, but they didn’t report an advantage of robot over non-robot keyhole surgery, just an increase in cost.
Now, you might well be muttering about causation and correlation, and asking “How do we know the open surgeries weren’t just more difficult cases?” If you aren’t, then you can start now and I’ll let you pretend you were doing it all along. Since surgeon experience makes a big difference, we should also worry whether it’s the most experienced surgeons who get the expensive and shiny new robots.
The researchers did try to cope with this problem using a technique called propensity scores. Essentially, they tried to classify patients according to how likely they were to have an open surgery vs manual laparoscopic surgery vs a robot surgery, and match the patients so comparisons were done only between similar cases. However, the researchers did say in the main body of the paper “Results from unadjusted and propensity adjusted analyses were largely similar”, ie, the attempt to remove bias didn’t actually remove any bias. The optimistic view is that this means there wasn’t any bias; the pessimistic realistic view is that it means the adjustment probably failed.
Surgical robots have been a bit of a disappointment. It’s not that they don’t work, but they were supposed to have huge and dramatic advantages (over and above “ooh, shiny”) and these huge advantages don’t seem to have materialized.
Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »
Just finished Atul Gawande’s The Checklist Manifesto, which has some interesting discussion of how doctors like to use fancy/expensive machinery (e.g. robots) even when the benefits are small, rather than less fancy things (e.g. checklists) that are low cost and appear to have significant benefits.
It was pleasing to note that Auckland Hospital participated in his checklist trials and NZ is mentioned as a country implementing them, although I don’t know how that has gone.
12 years ago
The checklist is at least recommended for general use in NZ. Here’s the Minister for Health launching it in 2009, and here’s a recent evaluation of its use at what I presume is Auckland hospital, and the 2009/2010 Health Quality and Safety Commission report on serious/sentinel events said “The uptake of the World Health Organization’s Safe Surgery Checklist is very gratifying: events related to the wrong patient, site or procedure are substantially lower this year than in previous reports.”
12 years ago