Location – Four location types exist in the VEHSS application:

  • All available locations – users can explore data for all locations at the same time, such as state maps
  • National – users can view a single data point or estimate for the entire United States
  • Individual states, territories, and District of Columbia – users can explore data for each individual location
  • Missing Location – users can view data for which a location was not reported

Type – Three data types exist in the current VEHSS application:

  • Claims data come from four different sources:
    • Medicare
    • Medicaid (MAX)
    • Managed Vision Care (VSP)
    • Market Scan – Commercial Medical Insurance (MSCANCC)
  • Electronic Health Records (EHR) data:
    • IRIS® Registry
  • Survey data come from five national surveys:
    • American Community Survey (ACS)
    • Behavioral Risk Factors Surveillance System (BRFSS)
    • National Health Interview Survey (NHIS)
    • National Health and Nutrition Examination Survey (NHANES)
    • National Survey of Children’s Health (NSCH)

Topics – In VEHSS, Topics are the highest level of organization of case definitions, or outcomes tracked by the surveillance system. Each Topic is designed to allow similar concepts to be measured in different types of data. The topics included in VEHSS data include: 1) Eye Health Conditions; 2) Service Utilization; and 3) Visual Function. In subsequent VEHSS revisions, topics may expand to include costs and other outcomes.

Categories – VEHSS Categories are the second level of organization of VEHSS indicators. Categories are unique to each Topic area:

  1. Categories in the Eye Health Conditions topic: VEHSS reports the prevalence of Eye Health Condition indicators based on survey self-reported diagnosis history, ophthalmologic examination in surveys or published studies, or diagnosis codes in administrative claims and electronic medical registry data.
  2. Categories in the Service Utilization topic: VEHSS reports the utilization of eye care services as the percentage of persons or patients within each dataset who had a record of at least one instance of an eye care service per calendar year of data.
  3. Categories in the Visual Function topic: VEHSS reports the prevalence of Visual Function indicators such as the proportion or persons or patients in each dataset with each visual function category or response value, based on survey-self reported vision or function, objectively measured visual acuity, or diagnosed low vision.

Indicator – An indicator refers to the specific measure of report, such as specific survey question. Some indicators are unique to a single data set, while others are found in more than one VEHSS dataset (such as the same survey question existing in multiple surveys).

Responses – Responses are specific response values for survey questions. For scaled response indicators, VEHSS includes all possible responses. For binary response questions (Yes/No), VEHSS reports only the result of the ‘Yes’ response. The data may contain other response values such as “Refused” or “Missing”.

Subgroups – Claims and EHR data include a variety of eye health condition categories, each of which can separated into more specific sub-categories or subgroups. For example, within the Glaucoma category, subgroups include:

  • All Glaucoma
  • Open-angle glaucoma
  • Low-tension glaucoma
  • Glaucoma suspect
  • Primary angle-closure glaucoma
  • Congenital glaucoma
  • Other/unspecified glaucoma
  • Secondary glaucoma

Risk Factors – Filtering VEHSS data by Risk Factor allows the user to explore data for the subset of participants or patients who report having that specific risk factor. The risk factors currently included in the VEHSS survey analyses are diabetes, hypertension, and smoking. Each risk factor is analyzed independently of the others. If Risk Factor equals ‘All participants’ or ‘All patients’, this indicates that the user is exploring VEHSS data for all participants (for survey data) or patients (for Claims and EHR data), regardless of the presence of any risk factors.

Risk Factor Responses – All Risk Factors have one or more corresponding Risk Factor Responses associated with them. If Risk Factor Response equals ‘Total’, this indicates that the user is exploring VEHSS data for all persons regardless of the presence of any risk factors.

Data Type – All datasets in the data visualization application display crude prevalence rates. BRFSS data display both ‘crude prevalence’ and ‘age adjusted prevalence’ rates.

Confidence Interval – The 95% confidence interval expresses the uncertainty associated with the provided estimates. With repeated estimates, the computed 95% confidence intervals would contain the true estimate 95% of the time.

Sample Size (N or n) – Sample size “N”, is the denominator of rates. For surveys, “N” is the number of respondents in the survey data for the year of observation. For claims, “N” includes all patients in the data for the year of observation, rounded to the nearest 100.

Variable –Each drop-down menu in the application represents a variable (i.e., Gender, Race/Ethnicity, Indicator, Subgroup, etc. are all variables).

Compare Variable – Each variable in the application can be compared to a different variable in the application. This allows the user to explore data that is singly stratified when looking at data for all locations or cross-stratified when looking at state- or territory-specific data. For example, the user can explore Visual Acuity data for a state by each Subgroup and each Age Group.