These are the most frequent medical errors in Massachusetts

1. Pressure ulcer (14,369 claims in 2013)

2. Postoperative infection (4,625)

3. Infection and inflammatory reaction due to internal prosthetic device implant and graft (1,919)

4. Bleeding or blood loss complicating a procedure (1,628)

5. Chronic pain after back surgery (1,606)

6. Accidental puncture or laceration during a procedure (1,511)

7. Abnormally low blood pressure induced by medical treatment (1,367)

8. Certain adverse drug reactions (1,238)

9. Abnormal bruising or contusion complicating a procedure (1,224)

10. Abdominal wall hernia related to a procedure (948)

SOURCE: Betsy Lehman Center for Patient Safety. Data based on 2013 Massachusetts insurance claims data.

Liz Kowalczyk can be reached at