200M+
people affected by the algorithm
What the research found
A landmark study found a risk-prediction algorithm applied to more than 200 million people a year systematically under-referred Black patients, because it used healthcare cost as a proxy for need. Correcting the bias would have raised the share of Black patients flagged for extra care from 17.7% to 46.5%.
Why it matters for providers
A 'neutral' metric baked in racial bias at national scale — the canonical warning that every deployed model needs auditing for who it leaves behind.
Original source
Science (Obermeyer et al.)
Peer-reviewed or official source — the most reliable tier.