Doctors in Massachusetts with the least experience incurred 13.2% greater costs for treating patients than their most senior counterparts, shows an analysis by the RAND Corporation that appeared in Health Affairs.1 The findings applied across diseases and medical specialties.

The study looked at anonymised insurance claims records for 1.13 million patients aged 18-65 years who were enrolled in one of four commercial health plans in Massachusetts in 2004-5, before the implementation of major healthcare changes in the state. It matched the records with 12 116 doctors, who were stratified into five groups according to …