Some readers have noted that, although many prostate surgeries are performed at cancer centers, several, such as Memorial Sloan Kettering, seemed to be missing from our new Surgeon Scorecard database.

We investigated and discovered the cause, which related to the eternal mysteries of Medicare bureaucracy. Although the data for cancer centers was included in our analysis and we’ve calculated adjusted complication rates for the surgeons who work there, the database we were using to match hospital names to our data didn’t include the name of five cancer centers. This is because they are reimbursed differently by Medicare than other hospitals.

Because of the missing hospital names, some surgeon pages in the database showed an error message when readers clicked on them.

We have identified the missing hospital names. This fixes the bug in the interactive database, and it means we now have profiles for the following cancer centers:

Correction, July 22, 2015: An earlier version of this article imprecisely described one of the eight elective procedures in Surgeon Scorecard. What we identified as “Lumbar Spinal Fusion, Anterior Technique” is an operation in which a surgeon attaches a bone graft to the front of the patient’s spinal column, what doctors call anterior placement. The operation is done through an incision in the patient’s back, known as posterior approach. We are publishing the medical codes for each procedure including this one, which is IDC-9-CM code 81.08. We have revised the language for clarity.