Only one-third of lupus patients on Medicaid had a baseline retinal exam before initiating treatment with hydroxychloroquine in an analysis of a claims database, despite the exam being recommended as the standard in multiple clinical guidelines.
The analysis of 12,755 patients with systemic lupus erythematosus (SLE) on Medicaid from 29 of the most populated U.S. states between 2001 and 2010 found that 32.5% received a baseline dilated eye exam 30 days before, and up to 1 year after, starting treatment with the anchor drug hydroxychloroquine (HCQ). This figure rose to 40% when Humphrey visual field tests and other “optional” eye exams were included, Tzu-Chieh Lin, PhD, of Brigham and Women’s Hospital, Boston, and his colleagues reported in.
HCQ is known to cause retinal damage in some patients, binding to and accumulating in the retinal pigment epithelium melanin. If undetected, patients may gradually lose central vision. There is particular risk for HCQ-induced retinal damage in patients on higher doses (5 mg/kg or greater of actual weight), HCQ exposure over 5 years, or renal, hepatic, or retinal disease, the research team explained.
Baseline retinal examinations for first-time HCQ users were first recommended by American Academy of Ophthalmology guidelines in 2002, and in 2009 the American College of Rheumatology developed guidelines specifically for SLE that also recommended a funduscopic exam within 1 year of starting HCQ.
The proportion of patients beginning treatment with HCQ who received a retinal exam only slightly increased from 31% in 2001 to 34.4% in 2009 (P value for linear trend over time = .12).
Women were significantly more likely to have a baseline retinal exam (odds ratio, 1.30; 95% confidence interval, 1.08-1.55), and certain sociodemographic factors also predicted who received a baseline exam, likely reflecting problems with adherence and access to health care.
For example, the likelihood of having a baseline exam proved significantly lower for blacks and American Indian/Alaska natives (OR, 0.85; 95% CI, 0.77-0.93; and OR, 0.69; 95% CI, 0.47-1.02) than for whites, whereas Asian Americans had greater odds than whites (OR, 1.30; 95% CI, 1.06-1.60).
“We have previously observed that these sociodemographic factors have been associated with differences in both access to care and adherence in the SLE Medicaid population for indicated care, including infection prevention, adherence to indicated medications including HCQ, treatments for lupus nephritis, and choices in renal replacement therapies and use of erythropoietin-stimulating agents among SLE end-stage renal disease patients,” they wrote.
Patients who had received multiple SLE-related laboratory tests (OR, 1.33; 95% CI, 1.16-1.52) and liver function tests (OR, 1.16; 95% CI, 1.04-1.29) were also more likely to have an eye exam before commencing HCQ.
The researchers said both patient and physician factors likely played a role in adherence to preventive medical care.
“While adherence to daily dosing, by the latest recommendations less than 5 mg/kg actual weight, is a more important factor determining renal toxicity risk, baseline examinations are necessary to avoid treating patients with preexisting retinal disease and to allow early detection of changes from baseline,” the research team concluded.
The work was supported by grant awards from the Rheumatology Research Foundation and the National Institutes of Health. No disclosures were made.
SOURCE: Lin T et al. Arthritis Care Res. 2018 Feb 6. .