Ghana’s hospitals are adopting AI, but the machines were never trained on Ghanaian patients

An algorithm that reads chest X-rays learns by looking at tens of thousands of them. It learns what a normal lung looks like, what tuberculosis looks like, what a tumour looks like, by being shown examples until the pattern sticks. The question nobody asks at the point of purchase is whose lungs it was shown. If the answer is Boston and Berlin and Seoul, and the lung now in front of it belongs to a farmer in Bolgatanga, the machine is working from a reference population that does not include him. It will still return an answer. It will return it with the same confident interface and the same clean percentage it would give a patient in Massachusetts. It just has a higher chance of being wrong, and nothing on the screen will tell the clinician which case this is.