We all like to complain about how defensive medical testing leads to constantly rising insurance premium costs until the person seeking the peace of mind or the early diagnosis a test can produce is you and I or a member of our family.

FORBES: Physician Organizations Voluntarily Heal Themselves To Save Healthcare Dollars

Reams of research point to the same finding: physicians looking at the same thing will disagree with each other, or even with themselves, from 10 percent to 50 percent of the time during virtually every aspect of the medical-care process from taking a medical history to doing a physical examination, reading a laboratory test, performing a pathological diagnosis and recommending a treatment.

FORBES: Are Medical Treatments Keeping Up With Science?

The diagnosis triggered a sort of "Typhoid Mary" scramble to find and test everyone who might have been in close contact with Ms. Skipper.

WSJ: TB's Global Resurgence Amplifies U.S. Risk

Last year it said it would scale up its treatment of drug-resistant TB and eventually test all TB patients for resistance at their initial diagnosis.

WSJ: TB Fight Hits a Wall in India

Dr. Singh and other researchers are studying how to better define and measure errors and what strategies best prevent them, such as using electronic health records to track patient test results and helping doctors with software that suggests an alternative diagnosis based on symptoms.

WSJ: Adding Up Diagnosis Errors

One of the things that's most shocking about diagnosis of Type 1 diabetes is that in some cases parents do identify the symptoms and ask for a test but are told by their GP that it is probably just a virus or infection and that they should come back in a week if symptoms persist.

BBC: Child diabetes 'is being missed'