An increase in the lung allocation score (LAS) greater than 5 units between the 30 days before and the time of transplantation correlates with worse survival rates after transplantation, according to new research.

LAS, rated on a scale from 0 to 100, is a lung allocation system that prioritizes patients to receive an organ based on medical urgency and chance for survival after transplantation.

Unrelated research shows an individual’s LAS may change between listing and surgery. For this study, investigators reviewed hospital records for 5,749 lung recipients. They discovered that patients with an increase of greater than 5 units within the 30 days before transplantation had a 31% increased hazard of death after lung transplantation.

Researchers believe this information should be assessed when weighing the net benefit of lung transplantation. The LAS system is administered by the United Network for Organ Sharing (UNOS).