Abstract
Purpose :
The epidemiology of herpes simplex virus keratitis (HSVK) is not well understood. We sought to determine the incidence of HSVK and explore how HSVK varies by demographic and temporal factors for enrollees in a large US managed care network.
Methods :
We analyzed health claims data for 21 million patients enrolled in a large nationwide managed care plan from 2001-2016. To be eligible, enrollees must have been continuously enrolled in the health plan for 3 years with no record of HSVK during that timeframe (to exclude persons with pre-existing disease). After this lookback period, patients were followed longitudinally over time and observed for incident HSVK. Patients were censored at the time they were first diagnosed with HSVK, when they left the plan, or at the end of follow-up (2016). Incident cases were defined as persons coded with ICD-9 or ICD-10 codes for HSVK (ICD-9 054.40-44 &/or 054.49; ICD-10 B00.50-53 &/or B00.59) followed by at least one subsequent record of HSVK on a different date to confirm presence of this condition. Incidence rates per 100,000 person-years of observation were calculated yearly and also compared by age at beginning of follow-up, birth year, sex, and race. Differences across groups were assessed via incidence rate ratio tests.
Results :
Incidence rates of HSVK increased by 1.7-fold from 9.0 cases/100,000 person-years in 2004 to 15.3/100,000 person-years in 2016 (p <0.05; Figure 1). Patients age <15 years had the lowest incidence rate (12.2/100,000 person-years) while age groups >15 years old exhibited modest increases in incidence rates with older age (36.6-42.3/100,000 person-years, p<0.05 for all comparisons). Females had slightly higher incidence rates than males (35.1/100,000 person-years vs. 33.9/100,000 person-years) but this difference was not significant (p>0.05). Incidence rates per 100,000 person-years were highest among whites (32.9) and lower among blacks (29.9), Latinos (22.9), and Asians (21.7, p<0.05 for all comparisons; Table 1).
Conclusions :
Nationwide incidence of HSVK has substantially increased over the past decade, possibly due to the aging US population. White patients and older age groups have greater incidence of HSVK, which may indicate underlying differences in community exposure and immunologic response across demographic groups.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.