Case Study: Eleven Hospitals in a Single Health System achieves 100% audit coverage and sustained IRR with Carta Healthcare’s Lighthouse AI-assisted abstraction

Eleven Hospitals keep NSQIP IRR above 99% with Carta Healthcare

A group of eleven hospitals in a single health system, which was already achieving high inter-rater reliability scores for its NSQIP surgical registry submissions, faced the challenge of mitigating risk while expanding its use of AI-assisted abstraction. The existing manual audit process was limited to small samples due to budget constraints, leaving the vast majority of cases unchecked and preventing the identification of systematic error patterns. The hospitals partnered with Carta Healthcare to implement its Lighthouse AI-assisted abstraction platform.

Carta Healthcare's solution shifted from a manual spot-check of 5% of cases to a 100% AI-assisted review of every case each cycle, which was fast enough to be cost-effective. The audit posture changed from enforcement to education, allowing abstractors to review and correct their own flagged cases. The results proved that AI-assisted abstraction was equivalent to manual methods, with reliability scores holding steady at over 99% for all eleven hospitals. This shift provided a new category of assurance through complete, consistent measurement instead of statistical estimation.