At least I'd expect something like 99.9% accuracy (1/1000 chance of an error) when someone gives me my own heart diagnosis.
For example, the algorithm in implantable cardioverter defibrillators generates unnecessary shocks in 1 in 6 patients. Its accuracy is getting worse over time: http://www.reuters.com/article/us-untimely-jolts-idUSTRE70O7...
At least I'd expect something like 99.9% accuracy (1/1000 chance of an error) when someone gives me my own heart diagnosis.