Resource Utilization and Costs of Age-Related
`Macular Degeneration
`Michael T. Halpern, M.D., Ph.D., Jordana K. Schmier, M.A., David Covert, M.B.A., and
`Krithika Venkataraman, Ph.D.
`
`Data were analyzed from the 1999-2001
`Medicare Beneficiary Encrypted Files for
`patients with age-related macular degen-
`eration (AMD), an ophthalmic condi-
`tion characterized by central vision loss.
`Classifying AMD subtype by International
`Classification of Diseases, Ninth Revision,
`Clinical Modifications (ICD-9-CM) (Centers
`for Disease Control and Prevention, 2003)
`code, resource utilization rates increased
`with disease progression. Individuals with
`more severe disease (wet only or wet and
`dry AMD) had greater costs than did those
`with less severe disease (drusen only or dry
`only). Costs among patients with wet disease
`increased yearly at rates exceeding infla-
`tion, possibly due in part to increased rates
`of treatment with photodynamic therapy
`among these individuals and the aging of the
`population.
`
`INTRODUCTION
`
`AMD is an ophthalmic condition charac-
`terized by acquired lesions of the macula
`region. These pathologic changes usually
`appear in individuals age 50 or over and
`result in alteration of central visual func-
`tion. Lesions are associated with abnor-
`malities of the retinal pigment epithelium
`and/or the sensory retina (cone and rod
`photoreceptors), and may be related to the
`appearance of drusen (hyaline deposits
`beneath the retinal pigment epithelium).
`The appearance of drusen alone does not
`Michael T. Halpern and Jordana K. Schmier are with Exponent Inc.
`David Covert is with Alcon Research Ltd. Krithika Venkataraman
`is with AstraZeneca, LP. The statements expressed in this article
`are those of the authors and do not necessarily reflect the views
`or policies of Exponent Inc., Alcon Research Ltd., or the Centers
`for Medicare & Medicaid Services (CMS).
`
`cause vision loss, although change in dru-
`sen size or number is associated with
`increased risk for development of AMD.
`There are two basic forms of AMD: atro-
`phic (dry) and exudative (wet). Dry AMD,
`the more common form of the disease,
`occurs in approximately 85 to 90 percent of
`patients with AMD and is generally slow to
`progress. An advanced form of dry AMD,
`geographic atrophy, occurs in about 5 per-
`cent of patients and may be characterized
`by a gradual loss of visual function. Wet
`AMD, which is characterized by choroidal
`neovascularization (CNV), is usually more
`severe and is responsible for 90 percent of
`vision loss attributed to AMD. It occurs in
`only about 10 percent of patients with AMD
`(Macular Degeneration Partnership, 2005).
`A recent report from the Age-Related Eye
`Disease Study (AREDS) indicated that
`approximately 8 million persons in the U.S.
`age 55 or over have some form of interme-
`diate or advanced AMD (Clemons et al.,
`2003).
`is commonly associated
`Wet AMD
`with clinically significant loss of vision,
`regardless of either the original location
`or characteristics of the CNV. Treatment
`options for AMD are limited. Currently,
`three approved treatment options exist
`for patients with exudative AMD: (1) laser
`photocoagulation, (2) ophthalmic photo-
`dynamic therapy (PDT) with verteporfin,
`and (3) pegaptanib sodium injection. Many
`AMD patients do not meet the criteria for
`treatment, i.e., they have early or inter-
`mediate AMD without CNV (American
`Academy of Ophthalmology, 2005). For
`those who do meet the criteria and are
`
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`
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`treated, patients may still experience high
`rates of recurrence in treated vessels,
`the need for repeat procedures, and/or
`clinically significant vision loss (Fine et
`al., 2000; O’Neill et al., 2001). In addition
`to these currently used therapies, other
`therapies are being investigated.
`In addition to increasing morbidity and
`decreasing patient quality of life, AMD is
`likely associated with substantial medi-
`cal care costs. However, much of the lit-
`erature on the costs of visual impairment
`has focused on glaucoma, cataracts, and
`diabetic retinopathy. These conditions are
`more prevalent than AMD in the U.S.
`population age 50 or over. Prevalence of
`glaucoma is 8 percent among individu-
`als with diabetes and 4 percent in people
`without diabetes; prevalence of cataracts
`is 34 versus 20 percent in individuals with
`and without diabetes, respectively; and
`prevalence of diabetic retinopathy is 10
`percent (Centers for Disease Control and
`Prevention, 2004). In contrast, the preva-
`lence of AMD is approximately 3 percent
`in older Americans, regardless of diabetes
`status (Centers for Disease Control and
`Prevention, 2004). In a review of cost of ill-
`ness issues in AMD, O’Neill and colleagues
`(2001) reported that few data are available
`on the direct costs of AMD. Given the age
`distribution of AMD, most patients in the
`U.S. receive coverage of medical services
`from Medicare; thus, Medicare data could
`be considered the most appropriate source
`of information on resource utilization and
`costs of AMD. The objective of this study
`was to evaluate resource utilization, treat-
`ment patterns, and medical care costs for
`AMD patients using Medicare claims data
`and to compare results for patients with
`dry versus wet disease.
`
`MeTHODS
`
`Data were analyzed from the 1999, 2000,
`and 2001 Medicare Beneficiary Encrypted
`Files (BEF). The BEF represents a random
`5-percent sample of all Medicare enrollees
`and is representative of all U.S. citizens
`age 65 or over. The random sample used
`for this claims data set is selected based on
`the same algorithm each year. Thus, the
`same patients are included in the BEF data
`each year (unless they die) as well as new
`patients entering each year; therefore, longi-
`tudinal treatment patterns can be evaluated.
`The BEF data consist of seven claims com-
`ponents: (1) Inpatient; (2) Outpatient; (3)
`Durable Medical Equipment; (4) Hospice;
`(5) Home Health Agency; (6) Skilled
`Nursing Facility (nursing home); and (7)
`Physician/Supplier (Part B) claims.
`For this study, data from the Outpatient
`and Part B (Physician/Supplier) files from
`all patients with two or more claims for
`AMD (ICD-9-CM 362.5) were included.
`Two separate claims with an AMD diagno-
`sis code were required as patients with a
`single claim for this diagnosis may be relat-
`ed to a rule-out visit for AMD. Furthermore,
`patients were included in the analysis only
`if they had one or more claims with ICD-9-
`CM diagnosis codes for specific subtypes
`of AMD, namely dry (ICD-9-CM 362.51),
`wet (362.52), or drusen (362.57). Based on
`these diagnosis codes, patients were clas-
`sified as having dry AMD, wet AMD, both
`dry and wet AMD, or drusen only. Patients
`were classified in the drusen only group if
`they did not have claims specific for either
`wet or dry AMD. This group was included
`in the analysis because of the increased
`risk for development of AMD compared
`to a general population. Any AMD patient
`may have also had a concomitant diagnosis
`
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`of drusen; however, patients with a con-
`comitant drusen diagnosis comprised less
`than 8 percent of each group.
`Resource utilization for AMD patients
`was determined from Outpatient and Part B
`claims. Costs were derived from Medicare
`payments. All data analysis was performed
`using SAS® Version 8.1 (SAS Institute Inc.,
`2002).
`
`ReSUlTS
`
`Table 1 presents demographic charac-
`teristics of the Medicare BEF patients by
`AMD subtype and study year (1999, 2000,
`or 2001). With the exception of drusen-
`only patients, the proportion of patients
`with AMD generally increased with age.
`The greatest proportion of patients in the
`drusen only category (the earliest stage of
`AMD) occurred in the 75 to 79 age group.
`Approximately two-thirds of patients were
`female and the overwhelming majority
`(>90 percent) was white.
`Table 2 presents resource utilization
`data from 1999 for the included AMD
`patients. Resource utilization is presented
`for all four AMD subtypes. Further, for
`patients classified as wet only or wet and
`dry who received PDT, resource utilization
`is presented separately. In most instanc-
`es, drusen only patients had the highest
`rates of resource utilization for diagnos-
`tic services. These diagnostic services
`per patient included retinal ultrasound
`(0.069) for drusen only, visual refraction
`(0.56), and visual field examinations (0.13).
`However, drusen only patients had lower
`rates of indocyanine-green angiography
`(0.0024), a procedure used in detecting
`occult neovascularizations, compared to
`wet only (0.065) or wet and dry (0.091)
`AMD patients. Drusen only patients also
`had lower rates of ophthalmologist visits
`(1.4), generalist physician visits (0.80), and
`
`specialist consultations (0.15) compared
`to the other specified subgroups. Patients
`with dry only had similar rates of resource
`utilization to drusen only patients.
`In 1999, both wet only and wet and
`dry AMD patients had similar rates of
`resource utilization for certain diagnostic
`tests, including retinal ultrasound and visu-
`al field examinations. However, wet only
`patients had lower rates than wet and dry
`patients for visual refraction (0.25 versus
`0.37) and indocyanine-green angiography
`(0.065 versus 0.091). Similarly, wet only
`AMD patients had lower average annual
`numbers of ophthalmoscopy (0.82) and of
`fundus photographs (0.91) compared to val-
`ues for wet and dry patients (1.39 and 1.43,
`respectively). With respect to therapeutic
`procedures, both groups had similar rates
`of photocoagulation (0.10 versus 0.11) and
`similar annual number of PDT procedures
`(0.12 versus 0.16). Wet and dry patients
`had higher annual numbers of ophthal-
`mologist visits (1.97), generalist physician
`visits (2.28), and specialist consultations
`(0.64) compared to all other groups.
`Striking differences were seen among
`wet only and wet and dry patients who
`received one or more PDT procedures
`during the year versus those that did not
`receive any PDT. Patients receiving at least
`one PDT procedure were also more likely
`to undergo photocoagulation, fluorescein
`angiography, indocyanine-green angiogra-
`phy, ophthalmoscopy, and fundus photog-
`raphy. In contrast, patients who did not
`receive any PDT procedures were more
`likely to receive retinal ultrasound or visual
`field examination.
`Annual costs reflect these differences
`in resource utilization. Costs for drusen
`only and dry only AMD patients for 1999
`are similar ($204 to $206). Wet only AMD
`patients had annual costs two and one-half
`times those of dry only AMD patients
`
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`
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`

`Table 1
`Demographic Characteristics of Medicare Beneficiary Encrypted File Patients, by Age-Related
`Macular Degeneration Subtype and Year: 1999-2001
`
`Demographic
`
`All Patients
`
`Drusen Only
`
`1999
`Age
`<65 Years
`65-69 Years
`70-74 Years
`75-79 Years
`80-84 Years
`>84 Years
`Sex
`Male
`Female
`Race
`White
`Black
`Other
`
`2000
`Age
`<65 Years
`65-69 Years
`70-74 Years
`75-79 Years
`80-84 Years
`>84 Years
`Sex
`Male
`Female
`Race
`White
`Black
`Other
`
`2001
`Age
`<65 Years
`65-69 Years
`70-74 Years
`75-79 Years
`80-84 Years
`>84 Years
`Sex
`Male
`Female
`Race
`White
`Black
`Other
`
`N=58,594
`
`1.1
`7.6
`16.3
`23.8
`24.2
`27.0
`
`32.7
`67.4
`
`94.7
`2.3
`3.0
`
`N=61,977
`
`1.0
`7.1
`15.8
`23.6
`24.5
`28.0
`
`32.5
`66.5
`
`94.8
`2.1
`3.1
`
`N=60,896
`
`1.0
`6.2
`15.0
`23.0
`25.4
`29.4
`
`32.5
`67.5
`
`95.6
`2.1
`2.3
`
`N=7,788
`
`2.2
`13.0
`23.4
`26.4
`20.0
`15.0
`
`31.8
`68.2
`
`92.4
`3.8
`3.8
`
`N=7,788
`
`1.8
`12.4
`22.4
`26.2
`21.5
`15.7
`
`31.6
`68.4
`
`92.4
`3.6
`4.0
`
`N=6,942
`
`2.1
`10.7
`21.8
`25.4
`22.6
`17.5
`
`30.9
`69.1
`
`93.1
`3.8
`3.1
`
`Dry Only1
`
`N=38,376
`Percent
`1.0
`7.0
`15.4
`23.3
`24.4
`28.9
`
`32.5
`67.5
`
`94.9
`2.2
`2.9
`
`N=40,301
`
`1.0
`6.6
`15.1
`23.3
`24.5
`29.6
`
`32.2
`67.8
`
`94.8
`2.1
`3.1
`
`N=39,162
`
`0.9
`5.7
`14.5
`22.6
`25.3
`31.0
`
`32.2
`67.8
`
`95.5
`2.2
`2.3
`
`Wet Only2
`
`Dry and Wet3
`
`N=7,441
`
`1.2
`6.5
`15.2
`22.7
`26.0
`28.6
`
`34.2
`65.8
`
`94.7
`2.0
`3.3
`
`N=8,070
`
`1.1
`6.2
`14.6
`23.2
`25.7
`29.3
`
`34.3
`65.7
`
`95.3
`1.6
`3.1
`
`N=8,290
`
`1.0
`5.9
`12.8
`22.7
`26.4
`31.2
`
`35.0
`65.0
`
`96.0
`1.5
`2.5
`
`N=4,989
`
`0.5
`5.1
`13.3
`25.5
`26.5
`29.0
`
`33.0
`67.0
`
`96.9
`0.8
`2.3
`
`N=5,793
`
`0.4
`4.7
`13.3
`23.0
`27.0
`31.6
`
`33.6
`66.4
`
`97.0
`0.7
`1.8
`
`N=6,502
`
`0.5
`4.8
`12.9
`23.4
`28.2
`30.3
`
`32.9
`67.1
`
`97.9
`0.9
`1.2
`
`1 The proportion of dry only patients who also have a diagnosis of drusen is 4.1 percent in 1999, 4.5 percent in 2000, and 4.9 percent in 2001.
`2 The proportion of wet only patients who also have a diagnosis of drusen is 4.6 percent in 1999, 5.2 percent in 2000, and 5.5 percent in 2001.
`3 The proportion of wet and dry patients who also have a diagnosis of drusen is 7.2 percent in 1999, 7.5 percent in 2000, and 8.2 percent in 2001.
`SOURCE: Halpern, M.T., Schmier, J.K., Exponent Inc., Covert, D., Alcon Research Ltd. and Venkataraman, K., AstraZeneca, LP, 2006.
`
`($513), while wet and dry patients had
`annual costs almost four times those of dry
`only AMD patients($767).
`Resource utilization patterns for 2000
`(Table 3) and 2001 (Table 4) are similar
`to those from 1999. Patients with drusen
`only and dry only AMD had similar rates of
`resource utilization, and had higher rates of
`
`most diagnostic tests compared those with
`wet only or wet and dry AMD. Conversely,
`drusen only and dry only AMD patients
`had lower rates of indocyanine-green angi-
`ography and photocoagulation procedures,
`fewer generalist physician visits, and fewer
`specialist consultations compared to the
`other specified subgroups. Comparing wet
`
`40
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`

`$2,430.30
`
`$612.95
`
`$767.03
`
`$2,233.74
`
`$392.25
`
`SOURCE: Halpern, M.T., Schmier, J.K., Exponent Inc., Covert, D., Alcon Research Ltd. and Venkataraman, K., AstraZeneca, LP, 2006.
`2 Annual cost per patient.
`1 Annual rate of resource utilization per patient.
`Total Reimbursement2
`
`$512.52
`
`$204.43
`
`$205.93
`
`0.97
`2.65
`2.19
`
`1.84
`0.15
`
`0.33
`0.082
`0.023
`2.26
`0.35
`4.02
`4.79
`
`0.61
`2.25
`1.95
`
`
`
`0
`0.11
`
`
`
`0.38
`0.12
`0.066
`1.31
`0.067
`1.19
`1.41
`
`Wet and Dry, Wet and Dry,
`Wet and Dry
`
`N=423
`PDT
`
`N=4,566
`No PDT
`
`
`
`0.64
`2.28
`1.97
`
`
`
`0.16
`0.11
`
`
`
`0.37
`0.12
`0.062
`1.39
`0.091
`1.43
`1.7
`
`0.81
`1.99
`1.53
`
`
`
`1.85
`0.2
`
`
`
`
`
`0.24
`0.054
`0.023
`1.5
`0.29
`3.6
`4.51
`
`
`
`0.33
`1.28
`1.37
`
`
`
`0
`0.097
`
`
`
`0.25
`0.11
`0.053
`0.77
`0.049
`0.73
`0.84
`
`
`
`0.36
`1.32
`1.38
`
`
`
`0.12
`0.1
`
`
`
`0.25
`0.1
`0.051
`0.82
`0.065
`0.91
`1.08
`
`
`
`0.17
`0.89
`1.31
`
`
`
`0
`0.0084
`
`
`
`0.46
`0.1
`0.069
`0.41
`0.0016
`0.24
`0.2
`
`N=4,989
`
`All
`
`
`
`Wet Only,
`
`N=486
`PDT
`
`N=6,955
`No PDT
`Wet Only,
`Wet Only
`
`N=7,441
`
`All
`
`
`
`N=38,376
`Dry Only
`
`
`
`
`
`
`
`0.15
`0.8
`1.4
`
`
`
`0
`0.012
`
`
`
`0.56
`0.13
`0.069
`0.54
`0.0024
`0.21
`0.14
`
`
`
`N=7,788
`
`Drusen Only
`
`
`
`
`
`Consultations
`Generalist Visits
`Ophthalmologist Visits
`Physician Interactions1
`
`Photodynamic Therapy (PDT)
`Photocoagulation
`Therapeutic Procedures1
`
`Visual Refraction
`Visual Field Exam
`Retinal Ultrasound
`Ophthalmoscopy
`Indocyanine-Green Angiography
`Fundus Photography
`Fluorescein Angiography
`Diagnostic Procedures1
`AMD Subtype
`
`
`
`
`
`
`Medicare Age-Related Macular Degeneration (AMD) Resource Utilization and Costs, by AMD Subtype: 1999
`
`Table 2
`
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`
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`

`1.1
`2.69
`2.25
`
`1.87
`0.063
`
`0.34
`0.1
`0.053
`2.2
`0.29
`3.69
`4.96
`
`0.71
`1.94
`2.14
`
`
`
`0
`0.061
`
`
`
`0.36
`0.1
`0.08
`1.34
`0.058
`1.25
`1.54
`
`
`
`666
`
`PDT
`
`5,127
`
`No PDT
`
`Wet and Dry, Wet and Dry,
`Wet and Dry
`
`0.75
`2.03
`2.16
`
`
`
`0.22
`0.061
`
`
`
`0.36
`0.1
`0.077
`1.43
`0.085
`1.53
`1.94
`
`
`
`5,793
`
`All
`
`
`
`0.8
`1.8
`1.71
`
`
`
`1.8
`0.067
`
`
`
`0.19
`0.05
`0.02
`1.6
`0.31
`2.87
`4.19
`
`
`
`777
`
`PDT
`
`Wet Only,
`
`0.39
`1.17
`1.44
`
`
`
`0
`0.063
`
`
`
`0.26
`0.08
`0.052
`0.78
`0.036
`0.75
`0.93
`
`
`
`7,293
`
`No PDT
`Wet Only,
`Wet Only
`
`0.43
`1.23
`1.46
`
`
`
`0.17
`0.063
`
`
`
`0.25
`0.078
`0.049
`0.86
`0.063
`0.96
`1.25
`
`
`
`8,070
`
`All
`
`
`
`0.2
`0.81
`1.4
`
`
`
`0
`0.0087
`
`
`
`0.47
`0.11
`0.073
`0.42
`0.0007
`0.25
`0.22
`
`
`
`0.17
`0.74
`1.48
`
`
`
`0
`0.013
`
`
`
`0.58
`0.13
`0.085
`0.55
`0.0013
`0.24
`0.15
`
`
`
`40,301
`
`Dry Only
`
`
`
`
`
`7,813
`
`Drusen Only
`
`
`
`
`
`Consultations
`Generalist Visits
`Ophthalmologist Visits
`Physician Interactions1
`
`Photodynamic Therapy (PDT)
`Photocoagulation
`Therapeutic Procedures1
`
`Visual Refraction
`Visual Field Exam
`Retinal Ultrasound
`Ophthalmoscopy
`Indocyanine-Green Angiography
`Fundus Photography
`Fluorescein Angiography
`Diagnostic Procedures1
`
`Number of Patients
`
`AMD Subtype
`
`Medicare Age-Related Macular Degeneration (AMD) Resource Utilization and Costs, by AMD Subtype: 2000
`
`Table 3
`
`
`
`
`
`42
`
`$2,744.22
`
`$773.43
`
`$1,000.00
`
`$2,353.77
`
`$485.09
`
`SOURCE: Halpern, M.T., Schmier, J.K., Exponent Inc., Covert, D., Alcon Research Ltd. and Venkataraman, K., AstraZeneca, LP, 2006.
`2 Annual cost per patient.
`1 Annual rate of resource utilization per patient.
`Total Reimbursement2
`
`$665.01
`
`$258.83
`
`$264.36
`
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`

`$4,030.23
`
`$913.59
`
`$1,592.33
`
`$3,549.69
`
`$567.35
`
`SOURCE: Halpern, M.T., Schmier, J.K., Exponent Inc., Covert, D., Alcon Research Ltd. and Venkataraman, K., AstraZeneca, LP, 2006.
`2 Annual cost per patient.
`1 Annual rate of resource utilization per patient.
`Total Reimbursement2
`
`$1,190.44
`
`$346.89
`
`$334.16
`
`1.15
`2.53
`3.23
`
`2.45
`0.046
`
`0.33
`0.095
`0.041
`2.5
`0.23
`3.73
`5.06
`
`0.73
`1.87
`2.68
`
`
`
`0
`0.042
`
`
`
`0.4
`0.13
`0.074
`1.56
`0.072
`1.22
`1.54
`
`
`
`0.82
`2.01
`2.8
`
`
`
`0.53
`0.043
`
`
`
`0.39
`0.12
`0.067
`1.76
`0.11
`1.76
`2.31
`
`
`
`0.74
`1.74
`2.39
`
`
`
`2.63
`0.03
`
`
`
`0.18
`0.045
`0.035
`1.55
`0.24
`2.95
`4.31
`
`
`
`0.38
`1.16
`1.86
`
`
`
`0
`0.057
`
`
`
`0.3
`0.084
`0.051
`0.94
`0.036
`0.74
`0.89
`
`
`
`1,416
`
`PDT
`
`5,086
`
`No PDT
`
`Wet and Dry, Wet and Dry,
`Wet and Dry
`
`6,502
`
`All
`
`
`
`1,732
`
`PDT
`
`Wet Only,
`
`6,558
`
`No PDT
`Wet Only,
`Wet Only
`
`0.46
`1.28
`1.97
`
`
`
`0.55
`0.051
`
`
`
`0.28
`0.076
`0.048
`1.07
`0.078
`1.2
`1.61
`
`
`
`8,290
`
`All
`
`
`
`0.24
`0.86
`1.79
`
`
`
`0
`0.0097
`
`
`
`0.57
`0.13
`0.091
`0.53
`0.0008
`0.32
`0.25
`
`
`
`0.17
`0.74
`1.95
`
`
`
`0
`0.01
`
`
`
`0.73
`0.16
`0.096
`0.67
`0
`0.27
`0.15
`
`
`
`Consultations
`Generalist Visits
`Ophthalmologist Visits
`Physician Interactions1
`
`Photodynamic Therapy (PDT)
`Photocoagulation
`Therapeutic Procedures1
`
`Visual Refraction
`Visual Field Exam
`Retinal Ultrasound
`Ophthalmoscopy
`Indocyanine-Green Angiography
`Fundus Photography
`Fluorescein Angiography
`Diagnostic Procedures1
`
`39,162
`
`Dry Only
`
`
`
`
`
`6,942
`
`Drusen Only
`
`
`
`
`
`Number of Patients
`
`AMD Subtype
`
`
`
`
`
`Medicare Age-Related Macular Degeneration (AMD) Resource Utilization and Costs, by AMD Subtype: 2001
`
`Table 4
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`

`only and wet and dry AMD patients in
`2000 and 2001, wet only patients had lower
`rates of most diagnostic procedures (visual
`refraction, indocyanine-green angiography,
`ophthalmoscopy, and fundus photographs).
`Wet only AMD patients also had lower
`annual numbers of ophthalmologist visits,
`generalist physician visits, and specialist
`consultations. Despite these lower levels of
`resource utilization among wet only AMD
`patients, therapeutic procedures (photoco-
`agulation and PDT) were similar between
`wet only and wet and dry patients. Total
`costs reflect these differences in resource
`utilization in a similar manner to that seen
`in Table 2.
`The proportion of wet only patients
`receiving PDT increased over this 3-year
`period, reflecting the increasing accep-
`tance of PDT into general practice. The
`proportion of wet only patients receiving
`one or more PDT treatments increased
`from 7.3 percent in 1999 to 10.4 percent in
`2000 and 21.2 percent in 2001. In contrast,
`rates of photocoagulation among wet only
`AMD patients decreased from over 11 per-
`cent of patients in 1999 to approximately
`6 percent in 2000 and 4 percent in 2001.
`Among patients who received any PDT
`treatments, the number of annual treat-
`ments remained fairly constant between
`1999 (1.84) and 2000 (1.87), but increased
`substantially in 2001 (2.45). The rates of
`diagnostic procedures also increased over
`this 3-year period. For example, among
`drusen only and dry only AMD patients,
`retinal ultrasound increased from less than
`7 percent in 1999 to over 9 percent in 2001;
`fundus photography also increased in these
`groups. Rates of fluorescein angiography
`increased annually among wet only AMD
`patients. Further, the annual number of
`ophthalmologist visits and specialist con-
`sultations increased for each group each
`year, while the annual number of generalist
`physician visits tended to decrease. This
`
`suggests that over this 3-year period, as
`specialists performed more of the medical
`care for AMD patients, use of specialized
`techniques (both diagnostic and therapeu-
`tic procedures) became more common.
`Costs for care of AMD increased each
`year for each subgroup. However, the
`increase in costs was greater than that
`attributable to inflation using the medical
`care services component of the consumer
`price index (CPI). For example, average
`annual costs for patients with wet only
`AMD increased by approximately 30 per-
`cent from 1999 to 2000 and by almost 79
`percent from 2000 to 2001. In contrast, the
`increase in the medical care services CPI
`was 4.3 percent from 1999 to 2000 and 4.8
`percent from 2000 to 2001. This increase
`reflects both greater numbers of patients
`receiving expensive services (e.g., PDT)
`and more frequent use of these services.
`
`DISCUSSION
`
`This study evaluated rates of resource
`utilization and costs for individuals with
`AMD. In general, rates of resource uti-
`lization increased with disease progres-
`sion. Patients with drusen or dry AMD
`generally experienced the lowest rates of
`resource utilization, while those with wet
`AMD or mixed wet and dry experienced
`the greatest. For certain diagnostic proce-
`dures associated with defining AMD type
`or monitoring AMD progression, resource
`utilization rates were higher among the
`earlier stage patients. However, for all
`therapeutic procedures, rates were greater
`among those with more advanced disease.
`In all cases, individuals with wet or wet
`and dry AMD had greater costs than did
`drusen or dry AMD patients.
`Results in this study are based on clas-
`sification of patients using ICD-9-CM codes
`for AMD subtypes. A large proportion
`of the total Medicare AMD population
`
`44
`
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`

`did not have claims with diagnosis codes
`specifying subtype (i.e., they had claims
`with diagnosis codes only for unspecified
`AMD). These individuals were therefore
`not included in the analysis. If patients with
`Medicare claims for only unspecified AMD
`are substantially different from those with
`specified AMD subtypes, our results may
`have limited generalizability. However,
`our results are still generalizable to the
`Medicare population with AMD subtype(s)
`specified.
`In this study, we were able to present
`results only in terms of cost per patient,
`not per eye. There are no ICD-9-CM diag-
`nosis codes that separate binocular from
`monocular AMD. Further, while physi-
`cians can report on the eye receiving treat-
`ment as part of the Medicare billing pro-
`cess (as a Healthcare Common Procedure
`Coding System modifier code) (Centers
`for Medicare & Medicaid Services, 2005),
`specifying the eye or eyes involved is not
`required to receive payment. Thus, few of
`the claims in the Medicare data included
`specification of left or right eye. Among
`the subgroup of patients who did have
`one or more claims specifying left versus
`right eye, approximately one-half of the
`patients had binocular disease (i.e., they
`had separate claims for the left and right
`eyes) while the other one-half had claims
`associated with only one eye. This does not
`mean that one-half of the Medicare AMD
`population had monocular disease; rather,
`among one-half of the AMD patients, we
`are unable to determine whether they had
`monocular or binocular disease.
`Little information is available regarding
`the incidence of monocular versus binocu-
`lar AMD and the risk of progression from
`monocular to binocular disease. A number
`of studies have indicated that approxi-
`mately 50 percent of patients with AMD
`have binocular disease (Vinding, 1990).
`However, in a small study from Japan (17
`
`patients with diagnosed unilateral AMD),
`drusen were found in 15 (88 percent) of
`the 17 undiagnosed fellow eyes (Ishiko
`et al., 2002). This suggests a risk for
`development of binocular disease among
`AMD patients with diagnosed monocular
`disease. Drusen have been reported to
`represent a risk factor or preliminary stage
`of AMD (Wang et al., 2003). In the present
`study, a small proportion of patients (4 to 8
`percent) in the dry only, wet only, and wet
`and dry categories also had diagnoses for
`drusen. These patients may be a greater
`risk for progression to binocular AMD.
`A number of previous studies have eval-
`uated ophthalmologic services covered by
`Medicare. In 1983, ophthalmology was sec-
`ond only to internal medicine in the total
`volume of approved charges in Medicare
`(Frenkel, 1986). An analysis of the 1991
`Medicare 5-percent sample found that the
`mean number of visits per eye care ben-
`eficiary is 2.7, although the mode was
`one visit (Ellwein et al., 1996). Males and
`females had almost the same number of
`visits per year (2.72 versus 2.73), and there
`was an increase in visits by age group. In
`addition, black beneficiaries received more
`visits (3.09 per year) than white beneficia-
`ries (2.71 per year). Macular degeneration
`was the primary diagnosis code listed for
`4.9 percent of ophthalmologist visits and
`4.8 percent of optometrist visits. Cataracts
`and glaucoma were the only more common
`diagnoses listed for visits to eye care pro-
`fessionals than macular degeneration.
`In our study, rates of AMD-related
`resource utilization increased from 1999
`to 2001. Ellwein and Urato (2002) also
`reported that the proportion of Medicare
`beneficiaries receiving eye care through
`fee-for-service providers increased over
`an 8-year period. Over two-thirds of eye
`care visits and charges were for ophthal-
`mologist care, but the proportion of visits
`with optometrists increased from 10.8 to
`
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`

`

`14.3 percent during the study period. The
`proportion of Medicare patients having
`one or more claims for macular degenera-
`tion increased each year from 1991-1998,
`from 3.52 to 4.53 percent. This may reflect
`increasing incidence of AMD over time or
`changes in the detection and diagnosis of
`AMD.
`In a study of Medicare recipients, Javitt
`et al. (2003) reported the 3-year incidence
`of wet AMD as being between 9.4 and 11.4
`per 1,000 Americans age 65 or over. The
`results from their study may not be direct-
`ly comparable to our study, as these inves-
`tigators included patients with serous/
`exudative detachment of retinal pigment
`epithelium (ICD-9-CM 362.42) and hemor-
`rhagic detachment of retinal pigment epi-
`thelium (362.43), while we excluded these
`patient groups. Further, they excluded
`patients with dry AMD (ICD-9-CM 362.51)
`or drusen (362.57); we included these
`patients to assess differences in resource
`utilization rates and costs associated with
`different types of AMD. They also used cri-
`teria separating ophthalmologists broadly
`from retinal specialists (based on propor-
`tion of all surgery performed that was
`retinal surgery) in patient ascertainment.
`Despite these differences in patient selec-
`tion, their results combined with ours illus-
`trate important trends in AMD treatment
`over time. The 3-year incidence of AMD
`treated with laser photocoagulation was 2.3
`per 1,000 in 1996-1998 (Javitt et al., 2003),
`corresponding to photocoagulation being
`used as a treatment among 20 to 25 percent
`of all Medicare AMD patients over this
`period. Among the Medicare population in
`our study, photocoagulation was received
`by approximately 10.6 percent of wet AMD
`patients in 1999, 6.2 percent in 2000, and
`5.0 percent in 2001. This decrease was
`accompanied by an increase in rates of
`PDT over our 3-year study period.
`
`Costs of inpatient care may also be high-
`er for patients with visual impairment, as
`was shown using New York State hospital
`discharge data (Morse et al., 1999). The
`average length of stay among patients with
`visual impairment was 2.4 days longer than
`that for patients without visual impairment.
`The increased length of stay for patients
`with visual impairment could be due to lack
`of discharge planning, which may be more
`complicated for those with low vision. This
`suggests that the visual impairment associ-
`ated with AMD can have substantial costs,
`in addition to treatment for AMD.
`In summary, these results indicate sub-
`stantial rates of resource utilization and
`associated Medicare reimbursements for
`individuals with AMD. Further research in
`the prevention, treatment, and outcomes
`associated with AMD is needed to quantify
`the burden of this condition to Medicare
`enrollees as well as to develop appropriate
`guidelines for its treatment. Results from
`AREDS, evaluating the impacts of nutri-
`tional supplements on AMD progression,
`indicated that use of nutritional supple-
`ments could prevent more than 300,000
`cases of advanced AMD over the next 5
`years (Bressler et al., 2003). The results of
`the present study, demonstrating increas-
`es in resource utilization rates and costs
`by AMD type, suggest that interventions
`preventing progression of AMD at earlier
`stages could produce considerable cost
`savings in addition to beneficial patient
`outcomes. Policies associated with funding
`of AMD services, in particular second-
`ary prevention services to prevent dis-
`ease progression among individuals diag-
`nosed with AMD, should be reviewed and
`strengthened. Treatments that prevent or
`delay progression of AMD are likely have
`substantial benefits in terms of improving
`patient well-being, maintaining vision, and
`decreasing medical care costs.
`
`46
`
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`
`

`

`ReFeReNCeS
`
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`gov/summar y/summar y.aspx?view_id=1&doc_
`id=4349 (Accessed 2005.)
`Bressler, N.M., Bressler, S.B., Congdon, N.G., et
`al.: Potential Public Health Impact of Age-Related
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`MMWR Morbidity and Mortality Weekly Report
`53(45):1069-1071, November 19, 2004.
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`(HCPCS). Internet address: http://www.cms.hhs.
`gov/medicare/hcpcs/default.asp (Accessed 2005.)
`Clemons, T.E., Chew, E.Y., Bressler, S.B., et
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`Questionnaire in the Age-Related Eye Disease Study
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`of Eye Care Services Among the 1991 Medicare
`Population. Ophthalmology 103(11):1732-1743,
`November 1996.
`Ellwein, L.B. and Urato, C.J.: Use of Eye Care
`and Associated Charges Among the Medicare
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`Fine, S.L., Berger, J.W., Maguire, M.G., et al.:
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