Accuracy of Billing Codes Used in the Therapeutic Care of Diabetic Retinopathy

Question  Do codes in administrative billing claims data accurately represent the medical record for procedures, therapies, and diagnostic testing used in the care of diabetic retinopathy?

Findings  Among 146 patients included in this medical record review, nearly all codes used in the care of diabetic retinopathy had high positive and negative predictive values as well as high sensitivity and specificity.

Meaning  These data suggest diagnostic, procedure, and therapeutic codes derived from insurance billing claims accurately reflect the medical record for patients with diabetic retinopathy.

Importance  Insurance billing claim databases represent a growing field of scientific inquiry within ophthalmology. Validating the accuracy of billing claim codes used during the care of diabetic retinopathy is a necessary precursor to fully understanding the underlying data and subsequent results of these types of studies.

Objective  To determine the accuracy of diagnostic, procedural, and therapeutic billing codes used in the treatment of diabetic retinopathy.

Design, Setting, and Participants  This retrospective medical record review was conducted at 3 clinical practices (1 academic and 2 private). Insured patients with diabetic retinopathy were seen by the practices between 2011 and 2013. Each patient then had every visit for 2 years reviewed twice, once for billing data and the second for data from the medical record. Data were collected and analyzed from October 2015 to July 2016.

Main Outcomes and Measures  The positive predictive value (PPV) and negative predictive value (NPV) for each code of interest. Sensitivity and specificity were secondary outcomes.

Results  A total of 146 patients (mean [SD] age, 60.3 [12.5] years) from 11 physicians had 1072 encounters reviewed over 2 calendar years. Among the included patients, 49.3% were female (n = 72), 48.6% were white (n = 71), 37.0% were black (n = 54), and 18.5% had type 1 diabetes and a mean (SD) hemoglobin A_1C level of 7.7% (1.8) (n = 27). Nearly all codes of interest that were used frequently also had a high PPV (range, 89.5%-100%) and NPV (88.6%-100%) including billing codes for intravitreal injection, focal laser, panretinal photocoagulation, laterality of procedure, ranibizumab, bevacizumab, fundus photographs, fluorescein angiography, and optical coherence tomography. Codes that were used infrequently (<20 instances) but still had a high PPV (all 100%) and NPV (99.7%-100%) were codes for aflibercept, triamcinolone, and the dexamethasone implant. Only the codes for infrequently used B-scan ultrasonography (PPV, 69.6%) and subtenon injection (PPV, 100%; NPV, 99.7%, but sensitivity of only 40%) were found to be of questionable accuracy. Other than subtenon injection (40%), all codes were also found to have a high sensitivity (range, 87.6%-100%) and a high specificity (range, 97.2%-100%).

Conclusions and Relevance  These data suggest diagnostic, procedure, and therapeutic codes derived from insurance billing claims accurately reflect the medical record for patients with diabetic retinopathy.