Prevalence of Cataract
VEHSS reports on the prevalence of cataract for the following categories based on the method of identification:
Examination-Based Cataract
The prevalence of cataract based on examination-based studies is not available in the VEHSS data explorer, but VEHSS does include a literature review summarizing published estimates of cataract prevalence from population-based examination studies.
Self-Reported Cataract
The National Health Interview Survey (NHIS) includes a self-report question on whether a doctor ever told the respondent that they had cataracts.
| Dataset | Description | Question Text | Variable name(s) | Sample | Response options |
|---|---|---|---|---|---|
| NHIS – Adult module | Percentage of adults ever told by a doctor or other health professional they had cataracts | Have you EVER been told by a doctor or other health professional that you had cataracts? | VIM_CAEV, CATAREV, AVISCAT | Ages 18+ | 1 Yes 2 No 7 Refused 8 Not ascertained 9 Don’t know |
The data source available for this category include NHIS. See data source documentation.
VEHSS reports the annual prevalence of diagnosed cataract based on the presence of International Classification of Diseases ICD-9 and ICD-10 codes in patient claims or electronic health record (EHR) systems. Patients with one or more diagnosis codes associated with a VEHSS subgroup are assigned to that subgroup. Diagnosis codes may be primary or secondary. Only one instance of a diagnosis code is required for assignment to the subgroup. Note that diagnosis codes in claims data are intended for billing purposes and may underestimate the true prevalence of cataracts. Codes may not be present in cases where diagnosis codes are not required to justify payment. Diagnosed prevalence will also not identify any undiagnosed conditions, will not include patients not covered by the insurer, and will not identify prevalence among patients without a visit in the calendar year of data.
Cataract, Clinical Subgroups
VEHSS defines the following clinical subgroups. Clinical subgroups are not mutually exclusive. A patient may be assigned to multiple clinical subgroups.
| Subgroup | Indicated conditions |
|---|---|
| Diagnosed cataract – any stage | Category total – includes any clinical stage below. |
| Age-related cataract | Age-related cataract indicates the presence of diagnosis codes for age-related incipient, polar, cortical, nuclear, morgagnian, other, or unspecified cataract. |
| Other or unspecified cataract | Other or unspecified cataract includes diagnosis codes for various cataracts not specified as age-related or congenital, including traumatic cataract, drug-induced cataract, cataract with neovascularization, cataract secondary to ocular disorders, or unspecified cataracts. |
| Congenital cataract | Congenital cataract includes diagnosis codes indicating congenital cataract, congenital aphakia, coloboma of lens, spherophakia, congenital lens malformations, or infantile or juvenile cataracts of any type. |
| Posterior capsular opacity | Posterior capsular opacity includes diagnosis codes indicating posterior capsular opacity, Soemmering’s ring, or other secondary cataract. |
| Pseudophakia | Pseudophakia includes diagnosis codes indicating the presence of intraocular lens or aphakia. |
The data sources available for this category include Medicare (default), IRIS Registry, Medicaid, Managed Vision Care, and MarketScan commercial insurance claims. See data source documentation.
VEHSS defines the following summary subgroups indicating whether there is evidence that a patient with diagnosed cataract also had a diagnosis of previous cataract treatment. These summary subgroups are mutually exclusive and sum to equal the category total of all patients with diagnosed cataract of any stage.
Note that treated and untreated cataract summary states rely on the presence of diagnosis codes for pseudophakia to identify treated cataract, which may not always be included in claims. In addition, patients may have had treatment in only one eye, in which case they would be classified as treated. VEHSS separately includes annual prevalence of cataract treatment based on procedure codes.
| Subgroup | Indicated conditions |
|---|---|
| Treated cataract | Treated cataract includes diagnosed cataract at any stage AND diagnosed pseudophakia. |
| Untreated cataract | Untreated cataract includes diagnosed cataract at any stage AND NOT diagnosed pseudophakia. |
The data sources available for this category include Medicare (default), IRIS Registry, Medicaid, Managed Vision Care, and MarketScan commercial insurance claims. See data source documentation.