Medicaid

The Medicaid Analytic eXtract (MAX)

Medicare Claims at a Glance
Medicaid MAX
Data type 100% Medicaid Analytic eXtract (MAX), including Fee for Service and managed medical claims
Sample Universe of Medicaid beneficiaries in State Reporting Data
VEHSS Topics Included Service Utilization
Medical Diagnoses
Years Analyzed 2013, 2014
Approximate Size 70 million persons per year

Medicaid Analytic eXtract (MAX) data are a set of de-identified person-level data files with information on Medicaid eligibility, service utilization, diagnoses, and payments. Derived from the Medicaid Statistical Information System (MSIS), the Medicaid MAX data contain one person summary (PS) file and four claims files. Claims files include Inpatient (IP), Long Long-Term Care (LTC), Other Services (OT), and Prescription Drug (RX). These claims data include fee for service (FFS) claims as well as managed care encounter and premium payments. Owned by the Centers for Medicare and Medicaid (CMS), Medicaid data cover everyone enrolled in Medicaid and Children’s Health Insurance Program (CHIP) from states and DC. However, Medicaid MAX data generally has a multiple year delay, and not all states are available, with fewer states represented in later data. As of September 2019, data were available for 28 states in 2013, and 17 states in 2014.

sample data map
Medicaid Claims
sample data spreadsheet
Medicaid Claims
Analysis Overview

VEHSS analyzed the 2013 and 2014 Medicaid MAX claims databases to estimate the annual prevalence rate of treated diagnoses and the rate of clinical procedures.  NORC’s subcontractor KPMG analyzed the data and generated summary reports of frequencies and rates, summarized by state and by age group, race/ethnicity, and sex.  A detailed description of the analytical steps is described in the report “VEHSS Claims & Registry Analysis Plan.” NORC further analyzed the summary data files, mapping outcomes to VEHSS-defined categories, calculating confidence intervals, and cleaning data. Results were suppressed if the denominator was <11, or if the numerator was <3 and the denominator was <30.

Study Population and Denominator used to Calculate Prevalence Rates

The study population includes FFS and managed care beneficiaries who are enrolled in the Medicaid program for any portion of the year. In 2013 data, 28 states are available while 17 states are available in 2014 data.

  • Arkansas
  • Arizona
  • California
  • Connecticut
  • Georgia
  • Hawaii
  • Iowa
  • Idaho
  • Indiana
  • Louisiana
  • Massachusetts
  • Michigan
  • Minnesota
  • Missouri
  • Mississippi
  • New Jersey
  • New York
  • Ohio
  • Oklahoma
  • Oregon
  • Pennsylvania
  • South Dakota
  • Tennessee
  • Utah
  • Vermont
  • Washington
  • West Virginia
  • Wyoming
  • California
  • Georgia
  • Iowa
  • Idaho
  • Louisiana
  • Michigan
  • Minnesota
  • Missouri
  • Mississippi
  • New Jersey
  • Pennsylvania
  • South Dakota
  • Tennessee
  • Utah
  • Vermont
  • West Virginia
  • Wyoming

The population information (e.g., enrollment, beneficiary characteristics) is included in the person summary files under the MAX library. Each beneficiary is uniquely identified by MSIS_ID, which is used to cross-reference data for each beneficiary across all MAX data files. Demographic characteristics, such as state, age, sex and race, are also available in person summary files for analysis. This population is the basis for calculating rates, and also serves as the sample denominator when calculating prevalence rates.

Below we describe the analytic steps for defining the study population:

  1. Using the MAXDATA_PS _201X dataset, group the beneficiaries by MSIS_ID.
  2. For each month, obtain active (i.e., living) beneficiaries that had FFS or MC coverage.
    For example, for January 201X,
    • Select beneficiaries who have FFS coverage (MAX_ELG_CD_MO_01 in “16”) or have MC (MAX_ELG_CD_MO_01 in “01”-“15”);
    • Excluded beneficiaries who are not enrolled in Dental Plan or Behavioral Plan (MAX_ELG_CD_MO_01 in “02”, “03”, “14”)
  3. Using the twelve monthly enrollment information from previous step, combine beneficiaries into three groups:
    1. FFS only: have FFS enrollment for at least one month without MC enrollment
    2. MC only: have MC enrollment for at least one month without FFS enrollment
    3. FFS & MC: have combined MC and FFS enrollment (for at least two months)
  4. Create a new variable “enrollment_type” to indicate the length of enrollment and split the groups by length of enrollment and: If enrolled in a given calendar year, then set enrollment_type = “full” , else set enrollment_type = “partial”

We found that most Medicaid patients have unknown race or ethnicity. Because we cannot control for any bias associated with race information being present in MAX data, we do not publicly release Medicaid MAX summary results by race or ethnicity.

A detailed description of the analytical steps is described in the report “VEHSS Claims & Registry Data Analysis Plan pdf icon[PDF – 579 KB]external icon.” Full analysis documentation is included in the “VEHSS Medicare Data Report pdf icon[PDF – 1.5 MB]external icon.”

Service Utilization

VEHSS analyzes the proportion of Medicaid enrollees who had at least one Medicaid claim indicating a specified service, as listed below in Table 1.

Table 1. Service Utilization Indicators Analyzed in VEHSS
Category Subgroup
AMD treatment, among diagnosed AMD patients​ Any AMD procedure
Intravitreal injections (including anti-VEGF)
Laser surgery
Photodynamic therapy
Cataract surgery, among diagnosed cataract patients Any Cataract treatment
Cataract surgery
Diabetic retinopathy Treatment, among diagnosed diabetic retinopathy patients Any DR treatment
Intravitreal injections (including anti-VEGF)
Laser/photocoagulation
Retinal detachment repair
Victrectomy
Eye exams By any provider type
By an ophthalmologist or other physician
By an optometrist or optician
Glaucoma treatment, among diagnosed glaucoma patients Any glaucoma treatment
Drain
Glaucoma surgery
Laser surgery
Imaging or diagnostic test Any diagnostic eye test
Flourescein angiography
Gonioscopy
Optical coherence tomography
Stereo fundus exam
Tonometry test
Visual field testing
Screening Any eye or vision screening
Glaucoma screening
Vision screening
Diabetic Retinopathy Telemedicine Screening
Vision correction Any vision correction
Contact lens or fitting
Eyeglasses

Medical Diagnoses

VEHSS categorizes diagnosis codes into medical diagnosis categories and subgroups. Individual Medicare beneficiaries were assigned to diagnosis categories and subgroups based on International Classification of Diseases (ICD) 9 (permissible in 2014) or ICD10 diagnosis codes on any patient claim during the year of observation. As reported in the “VEHSS Diagnosis Code Categories and Crosswalk,” we identified all eye and vision related ICD10 diagnosis codes, and organized them into a two-level categorization structure, including 17 categories and 78 subgroups, as listed in Table 2.

Eye Condition Included subgroups Subgroup description
Table 2. Medical Diagnosis Indicators Analyzed in VEHSS
Retinal Detachment and Defects​ Retinal Detachment and Defects Retinal detachment and retinal breaks without detachment.
Diabetic eye diseases Early/mild diabetic retinopathy Early/Mild Diabetic Retinopathy includes diagnosis codes for background diabetic retinopathy, nonproliferative diabetic retinopathy, or mild nonproliferative diabetic retinopathy.
Moderate /severe non-proliferative diabetic retinopathy Moderate /Severe Non-proliferative Diabetic Retinopathy includes diagnosis codes indicating moderate or severe nonproliferative diabetic retinopathy, without macular edema.
Proliferative diabetic retinopathy Proliferative Diabetic Retinopathy includes diagnosis codes indicating proliferative diabetic retinopathy, without macular edema.
Diabetic macular edema (DME) Diabetic Macular Edema (DME, CSDME) includes diagnosis codes indicating diabetic retinopathy of any type with the presence of macular edema (DME), including clinically significant diabetic macular edema (CSDME).
Other/unspecified diabetes related eye conditions Other/unspecified diabetes related eye conditions includes diagnosis codes indicating diabetic retinopathy of unspecified type, other ophthalmic complications of diabetes including diabetic cataract, or diabetes mellitus with ophthalmic complication resolved after treatment.
Age related macular degeneration (AMD) AMD, unspecified Unspecified macular degeneration includes diagnosis codes indicating degeneration of macula and/or posterior pole, but does not specify stage.
Early AMD Early AMD includes diagnosis codes indicating the presence of drusen (degenerative) of the macula.
Dry-form AMD Dry-form AMD indicates the presence of diagnosis codes for nonexudative age-related macular degeneration.
Geographic atrophy AMD Geographic atrophy AMD indicates the presence of ICD10 codes indicating advanced atrophic stage of dry-form AMD.
Wet-form AMD Wet-form AMD indicates the presence of diagnosis codes for exudative age-related macular degeneration.
Choroidal neovascularization AMD Choroidal neovascularization AMD indicates the presence of ICD10 codes specifying active choroidal neovascularization; advanced wet-form AMD.
Other Retinal Disorders Retina vascular disease, Occlusive (arterial, venous) Retina vascular disease, Occlusive (arterial, venous) includes diagnosis codes indicating unspecified or transient retinal vascular occlusion.
Other/unspecified retinal disorders Other/unspecified retinal disorders include diagnosis codes indicating age-related choroidal atrophy, diffuse secondary atrophy of choroid, retinoschisis, retinal cysts, cyst of ora serrata, retinopathy of prematurity, non-diabetic proliferative retinopathy, unspecified separation of retinal layers, central serous chorioretinopathy, detachment of retinal pigment epithelium, macular cyst, hole, or pseudohole, toxic maculopathy, puckering of macula, various forms of retinal degeneration, retinal hemorrhage, and other or unspecified retinal disorders.
Central retinal vein occlusion Central retinal vein occlusion indicates diagnosis codes for central retinal vein occlusion, with or without macular edema or retinal neovascularization.
Branch retinal vein occlusion Branch retinal vein occlusion indicates diagnosis codes for tributary (branch) retinal vein occlusion, with or without macular edema or retinal neovascularization, or venous engorgement.
Central retinal arterial occlusion Central retinal arterial occlusion indicates diagnosis codes for central retinal arterial occlusion, with or without macular edema or retinal neovascularization.
Branch retinal artery occlusion Branch retinal artery occlusion indicates diagnosis codes for tributary (branch) retinal arterial occlusion.
Retina vascular disease, Non-Occlusive Retina vascular disease, Non-Occlusive includes diagnosis codes indicating hypertensive or exudative retinopathy, changes in retinal vascular appearance, retinal micro-aneurysms, retinal telangiectasis, neovascularization, or vasculitis, intraretinal microvascular abnormalities, or unspecified background retinopathy.
Macular edema (Cystoid or non-diabetic) Macular edema (Cystoid or non-diabetic) indicates diagnosis codes for cystoid macular degeneration.
Hereditary chorioretinal dystrophy Hereditary chorioretinal dystrophy includes diagnosis codes indicating various types of chiorioretinal dystrophy, including circumpapillary, central choroidal atrophy, and choroideremia.
Myopic degeneration Myopic degeneration includes diagnosis codes indicating progressive high (degenerative) myopia.
Glaucoma Open-angle glaucoma Open-angle glaucoma includes diagnosis codes indicating unspecified open-angle glaucoma, pigmentary glaucoma, or capsular glaucoma with pseudoexfoliation of lens.
Primary open-angle glaucoma Primary open-angle glaucoma includes diagnosis codes for primary open-angle glaucoma of any stage.
Low-tension glaucoma Low-tension glaucoma includes diagnosis codes for low-tension glaucoma of any stage.
Glaucoma suspect Glaucoma suspect indicates diagnosis codes for pre-glaucoma, open-angle with borderline findings, ocular hypertension, steroid responder, or primary angle closure without damage.
Primary angle-closure glaucoma Primary angle-closure glaucoma includes diagnosis codes indicating primary, acute, chronic, intermittent or unspecified angle-closure glaucoma.
Narrow-angle glaucoma Narrow-angle glaucoma includes diagnosis codes indicating narrow angle glaucoma, anatomical or secondary to eye trauma.
Congenital glaucoma Congenital glaucoma includes diagnosis codes for congenital glaucoma or buphthalmos (enlargement of the eye in children).
Neovascular glaucoma Neovascular glaucoma includes diagnosis codes indicating glaucoma associated with vascular disorders, phacolytic or other specified glaucoma.
Other/unspecified glaucoma Other/unspecified glaucoma includes diagnosis codes indicating unspecified glaucoma, glaucoma secondary to drugs, other eye disorders or inflammation, hypersecretion glaucoma, increased episcleral venous pressure, or aqueous misdirection.
Cataracts 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, aphakia
Aphakia and other disorders of lens Aphakia and other disorders of lens includes diagnosis codes indicating aphakia, subluxation of lens, anterior dislocation of lens, posterior dislocation of lens, or other disorders of lens
Refraction and accommodation Myopia Myopia includes diagnosis codes indicating myopia in one or both eyes.
Hypermetropia Hypermetropia includes diagnosis codes indicating hypermetropia in one or both eyes.
Astigmatism Astigmatism includes diagnosis codes indicating regular, irregular, or unspecified astigmatism in one or both eyes.
Presbyopia Presbyopia includes diagnosis codes indicating presbyopia in one or both eyes.
Other disorder of refraction and accommodation Other disorder of refraction and accommodation includes diagnosis codes indicating anisometropia and aniseikonia, disorders of accommodation, internal ophthalmoplegia, paresis of accommodation, or spasm of accommodation.
Diagnosed Blindness and low vision Unqualified visual loss, both eyes Unqualified vision loss, both eyes includes a diagnosis code indicating unqualified visual loss in both eyes.
Unqualified vision loss in one eye, or unspecified visual loss Unqualified vision loss in one eye or unspecified vision loss includes diagnosis codes indicating unqualified vision loss in one eye, unspecified visual loss, or problems with sight.
Low vision or blindness, one eye Low vision or blindness in one eye includes diagnosis codes indicating low vision or blindness in one eye, normal vision in the other eye.
Blindness one eye, low vision other eye Blindness in one eye, low vision in other eye includes diagnosis codes indicating blindness in one eye, low vision in other eye.
Low vision, both eyes Low vision, both eyes includes diagnosis codes indicating low vision in both eyes.
Blindness, both eyes, including legal blindness Blindness, both eyes, including legal blindness includes diagnosis codes indicating blindness in both eyes, legal blindness, or cortical blindness.
Strabismus and amblyopia Strabismus Strabismus includes diagnosis codes indicating monocular or binocular strabismus, including esotropia, exotropia, heterophoria and other types, nerve palsy of the eye, ophthalmoplegia, Brown’s sheath syndrome, disorders of convergence or binocular movement, or other unspecified disorders of binocular vision.
Amblyopia Amblyopia includes diagnosis codes indicating amblyopia, including deprivation, strabismic, refractive, or unspecified amblyopia type, or ablyopia suspect.
Injury, burns and surgical complications of the eye Injury Injury includes diagnosis codes indicating injury to the eye or ocular adnexa, due to trauma, foreign bodies, penetrating wounds, bites, abrasions or other causes, or injury secondary to other ocular disorders.
Burn Burn includes diagnosis codes indicating any type of burn or corrosion of the eye or ocular adnexa.
Surgical complication Surgical complication includes diagnosis codes indicating or typically associated with surgical complications, including postprocedural inflammation or infection, mechanical complications, cataract fragments, and other conditions usually associated with procedures.
Disorders of optic nerve and visual pathways Optic nerve disorders Optic nerve disorders includes diagnosis codes indicating optic neuritis and other disorders of the optic nerve.
Disorders of the visual pathway and visual cortex Disorders of the visual pathway and visual cortex includes diagnosis codes indicating disorders of visual pathways and visual cortex.
Other visual disturbances Visual field defect Visual field defect includes diagnosis codes indicating defects of the visual field, including scotoma, sector or arcuate defects, localized visual field defects, homonymous bilateral field defects or contraction of the visual field.
Color blindness Color blindness included diagnosis codes indicating color vision deficiencies.
Night blindness Night blindness includes diagnosis codes indicating night blindness, abnormal dark adaptation and glare sensitivity.
Other/unspecified visual disturbances Other/unspecified visual disturbances includes other disturbances or defects of sight including subjective visual disturbances, diplopia, other and unspecified disorders of binocular vision, and vision sensitivity deficiencies.
All Infectious and inflammatory diseases Infectious diseases Infectious diseases includes diagnosis codes indicating an infection of the eye or ocular adnexa.
Keratitis Keratitis includes diagnosis codes indicating keratitis, including corneal ulcer, other and unspecified superficial keratitis without conjunctivitis, keratoconjunctivitis, corneal neovascularization, or other or unspecified forms of keratitis.
Conjunctivitis Conjunctivitis includes diagnosis codes indicating most forms of conjunctivitis, including mucopurulent, acute, chronic, blepharoconjunctivitis, or other disorders of conjunctiva, including pterygium, conjunctival degenerations and deposits, or conjunctival scars, hemorrhage, vascular disorders, or cysts.
Eyelid disorders Eyelid disorders includes diagnosis codes indicating hordeolum and chalazion or other inflammation of the eyelid, including Blepharitis, noninfectious dermatosis or other inflammation of the eyelid.
Other inflammatory conditions Other inflammatory conditions includes diagnosis codes indicating inflammation of the eye or ocular adnexa not otherwise classified.
Lacrimal system and orbit inflammation Lacrimal system and orbit inflammation includes diagnosis codes indicating disorders of the lacrimal system and inflammatory disorders of the orbit.
Endophthalmitis Endophthalmitis includes diagnosis codes indicating enophthalmitis and disorders of the globe including degenerative myopia and uveitis.
Orbital and external disease Congenital anomalies Congenital anomalies includes diagnosis codes indicating congenital malformations of the eye and ocular adnexa.
Other/unspecified orbital or external disease Other/unspecified orbital or external disease includes diagnosis codes indicating non-inflammatory disorders of the orbit.
Lacrimal diseases Lacrimal diseases includes diagnosis codes indicating disorders of the lacrimal system, including dacryoadenitis, epiphora, stenosis and insufficiency of lacrimal passages, or other changes or disorders of the lacrimal system.
Eyelid disorders Eyelid disorders includes diagnosis codes indicating non-inflammatory disorders of the eyelid, including entropion, ectropion, lagophthalmos, ptosis, blepharochalasis, xanthelasma disorders of the eyelid, or other non-specified, non-inflammatory eyelid disorders.
Dry eye syndrome Dry eye syndrome includes diagnosis codes indicating dry eye syndrome.
Disorders of the globe Disorders of the globe includes diagnosis codes indicating disorders of the globe, excluding endoophthalmitis, degenerative myopia, and hypotony of the eye.
Cancer and neoplasms of the eye diseases Malignant neoplasm of the eye Malignant neoplasm of the eye includes diagnosis codes indicating malignant neoplasm of the eye, or carcinoma in situ of the eye.
Benign neoplasm of the eye Benign neoplasm of the eye includes diagnosis codes indicating benign neoplasm of the eye.
Cornea disorders Keratoconus Keratoconus includes diagnosis codes indicating keratoconus or conical cornea conditions.
Endothelial dystrophy (inc Fuchs) Endothelial dystrophy includes diagnosis codes indicating Endothelial or Fuchs dystrophy.
Other Corneal disorders Other Corneal disorders includes diagnosis codes indicating corneal scars, opacities and other disorders of the cornea.
All Other eye disorders Other eye disorders Other eye disorders includes diagnosis codes related to vision, the eye and ocular adnexa that are not otherwise classified.
Potential Limitations

The VEHSS analysis of Medicaid MAX data is subject to a number of potential limitations:

  • Medicaid claims are intended for billing purposes only. Diagnosis information included on claims is intended to justify payment. Therefore, diagnosis data on claims may suffer from bias or limited detail.
  • Medicaid does not cover all healthcare services and coverage differs by patient, plan and state. Medicaid patients may utilize these services using a different payer, and thus these services are not captured in Medicaid MAX data.
  • Patients may be insured by multiple insurers. Thus, even normally covered ophthalmology services may not be indicated in Medicaid MAX data if services were reimbursed by another plan.
  • A large proportion of Medicaid beneficiaries are enrolled for only part of the year. Unlike other administrative claims databases included in VEHSS, we did not require full annual coverage because this would have excluded the majority of patients and services. We therefore allow Medicaid beneficiaries who have at least 1 month of enrollment.
  • While Medicaid Max claims represent the universe of persons enrolled in Medicaid, the data are only representative of persons in the Medicaid program.  Because the Medicaid population differs substantially from the general population, users should not attempt to infer results from Medicaid data to all persons in the general population.