In the book “How We Decide” by Jonah Lehrer, a section describes the history of diagnosing and treating back pain. The early treatment, based on little information of the root cause, was bed rest. It was 90% effective after 7 weeks of bed rest. Then came X-rays followed by MRIs. Experiments were done to determine if more detailed information in the form of MRIs compared to X-rays improved patient outcomes.
The result was that patients were roughly as likely to get better in each diagnostic treatment, but those who received MRIs were twice as likely to have surgery for spinal disc abnormalities and generally had more doctors’ visits. Yet about 1/3 of normal patients scanned with MRIs were diagnosed with spinal disc abnormalities though there was nothing wrong with them. In “How We Decide”, the conclusion is that much more detailed information leads to the identification of more things that could be wrong and a greater tendency to act in an effort to fix the perceived problems.
What do industrial engineers already know that the doctors did not?
- More reports equate to more time spent reviewing reports. Ideally, reports should be optimized to be sent in intervals short enough to allow quick action when a problem arises but otherwise rare enough to avoid using up resources like reviewer’s time and bandwidth.
- Know the norm for your system and the acceptable boundaries in system behavior or user behavior.
- Track your trends.
- Log the exceptions.
What can industrial engineers learn from this story?
- More detailed information can increase the odds of a false diagnosis of a problem.
- Provide sufficient granularity in the reported information for administrators or experts to recognize when a problem has occurred. Include links or reports with more detail available upon request when sending the report so that someone can troubleshoot in depth the moment they deem it necessary.
- Set guidelines of when to maintain watch and when to act. As with the case of MRIs and back surgery, just because something is abnormal does not mean it requires action.
- If action is required, look for the less invasive solutions that can be used before wielding a knife or taking other drastic actions.