Adherence to Hydroxychloroquine Dosing Guidelines by Rheumatologists: An Electronic Medical Record-Based Study in an Integrated Health Care System.

Purpose: To study the adherence of rheumatologists to the hydroxychloroquine (HCQ) dosing guidelines established by the American Academy of Ophthalmology in 2011 and 2016.

Design: Retrospective review of electronic medical records (EMRs) in an integrated health care system.

Participants: All rheumatology patients started on HCQ who were seen by a NorthShore ophthalmologist between the years 2009 and 2016.

Methods: Data on patient weights, height, gender, and HCQ dosage were extracted from the EMR. The recommended maximum starting dose was determined using 2 formulas based on ideal or actual body weight.

Main Outcome Measures: The percentage of patients whose dose exceeded the recommended maximum.

Results: A total of 554 patients on HCQ were identified. Some 50% of the patients had been placed on excess initial doses according to the 2011 guidelines, and 47% of the patients had been placed on excess initial doses according to the 2016 guidelines. The introduction of the guidelines had no appreciable effect on HCQ dosing. A separate analysis of all patients currently receiving maintenance HCQ therapy demonstrated excess dosing in 297 of 527 (56%), according to the 2016 guidelines.

Conclusions: Approximately one half of all patients started on HCQ by NorthShore rheumatologists received doses in excess of the recommended maximum, and slightly more than one-half of all patients currently on treatment continue to receive excess doses. Our data suggest that the publication of the consensus guidelines in 2011 had no appreciable effect on HCQ dosing and that transitioning to the 2016 dosing modification is unlikely to change this outcome unless additional steps are taken to improve adherence.