The relative value of provider work for maxillofacial prosthetic services

The relative services Thomas

value of provider

R. Cowper,

work for maxillofacial

prosthetic

DDSa

The Cleveland Clinic Foundation, Cleveland, Ohio The results of a national survey of members of the American Academy of Maxillofacial Prosthetics who estimated the relative value of provider work for nine existing and two proposed coded maxillofacial prosthetic services is reported. The work estimates are a necessary component of a larger effort by the Health Care Financing Administration to establish a resource-based relative value scale for reimbursement for all Medicare services. Analysis of the survey data reveals agreement regarding the relative value of work for maxillofacial services compared with other established medical procedures and that the median values for each service are acceptable initial estimates. (J PROSTHETDENT 199~75Bl4-301.)

F

or the past three years the American Academy of Maxillofacial Prosthetics (AAMP) has worked toward the establishment of accurate relative work values (RVUw,,rk) for maxillofacial prosthetic services. At the direction of the Health Care Financing Administration (HCFA) ofthe U.S. Department of Health and Human Services a subcommittee of the American Medical Association (AMA)/Specialty Society Relative Values Scale (RVS) Update Committee (RUC) also actively participated in this endeavor. The intent of these efforts, previously lacking, has been to institute reasonable and consistent reimbursement for these “medical services” throughout the United States. This article summarizes the results of a membership survey for RVUwOrk values for all existing maxillofacial services assigned Current Procedural Terminology (CPT) codes of the AMA and two proposed new codes.

BACKGROUND In 1985, in an attempt to stabilize the burgeoning costs of Medicare and other entitlement programs, Congress passed the Consolidated Omnibus Budget Reconciliatory Act,l which, among other actions, mandated that the Secretary of Health and Human Services develop a resourcebased RVS (RBRVS) for establishing a definitive national Medicare fee schedule. RBRVS in its purest form is suggested to avoid the abuses and inconsistencies of a charge-based reimbursement method that had previously been the mainstay of Medicare payment schedules. The HCFA contracted with the Harvard University Department of Public Health, under the direction of William Hsiao, to develop a cross-specialty RVS for all medical and surgical services to construct a single national Medicare

aHead, Section of Maxillofacial Prosthetics, Department of Dentistry, The Cleveland Clinic Foundation, and Assistant Clinical Professor, Department of Prosthodontics, School of Dentistry, Case Western Reserve University. Copyright 63 1996 by The Editorial Council of THE JOURNAL OF PROSTHETIC DENTISTRY.

0022-3913/96/$5.00

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fee schedule.2 The subsequent introduction of 11 CPT codes for maxillofacial services ultimately ensured the eventual incorporation of maxillofacial prosthetic treatment into this reimbursement system. In July 1993 HCFA gave public notice of its intent to establish relative values for low-volume procedures, which included maxillofacial prosthetic services3 The AAMP Board of Directors designated a task force to construct and carry out determinations for the 11 coded maxillofacial services. The AAMP had previously conducted two openpanel workshops (November 1992, February 1993) to identify and formulate initial parameters and policy. The detailed results of these workshops and a preliminary analysis outlining RBRVS methods applied to maxillofacial prosthetics were published.4 A national survey of all AAMP members was conducted in November and December of 1993. The resultant data were collated, analyzed, and presented to the Specialty RVS Refinement Panel of HCFA in May 1994.5

RBRVS

methods

A general comprehension of RVS methods is a prerequisite to understanding the survey results.4~g In summary, when constructing a relative value scale the relative value of the work of a discrete service is estimated by comparing it with services whose work values have in turn been previousIy determined. This process, formally called “magnitude estimation,” has been used extensively in medical and industrial research for the last several decades,10-13Although they may seem initially nebulous, such methods have been implemented by all specialties in medicine. In addition,

RBRVS

methods

are

now

increasingly

applied

by

many other public and private agencies.14 The RBRVS definition of work value for a service is formally given as: Workser+. = (Tirnesetice) x (Intensityser& Work is not solely the time required to perform that service, but also a function of its intensity. Thus two proce-

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Fig.

1. Parameters established by HCFA to determine relative intensity of service.

ReferenceSet Work Values ~ ~ ~

El

El AMA RVS Update Committee WJC

12.0 13.5 24.3

4

2. Schematic diagram of process used in developing RVS. Respondents compare unvalued services with established reference values (Table I). Data are collected and analyzed by RVS committee, which in turn recommends final values to RVS RUC of American Medical Association. RUC can mandate further study or transmit values to HCFA.

Fig.

dures that take the same amount of time but having unequal intensities will have different work values. The intensity of a given unit of work is formally defined by the established parameters in Fig. 1. The goal of a specialty relative value scale survey is to invite the respondents to relate the work of their particular specialty services to those of the known reference set, nameIy, to assign relative comparison work values to them. An extensive set of ‘
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estimates for the various services. Additionally, the respondent has the opportunity to object to the clinical vignette offered. The survey also included a selected set of reference procedures familiar to the potential respondents (Table I). A committee appointed by the specialty society carrying out the RVS is responsible for constructing the final questionnaire, selecting the reference set, and analyzing the collected data. The information gathered from the open-panel workshops was used to aid in this process.

Survey

methods

The survey questionnaire was adapted from the standard RVS Survey Instrument provided to specialty societies by the MSpecialty Society RVS Update Panel. Appropriate modifications to the instructions, service definitions, and reference set services were made by the subcommittee of the AAMP. The questionnaire sheet for Service Code 21079, Interim Obturator Prosthesis is a typical example (Fig. 3). Eleven questionnaire sheets consisting of nine existing services and two uncoded but commonly performed services were included in the survey. The survey of all active members of the AAMP was conducted in November 1993. A more detailed description of the survey methods has been previously published.5 Responses were forwarded to the committee, entered in a database, collated, and documented. Appropriate statistical analysis of the data was performed.

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1. The list of selected established reference procedures distributed (RVLJW,& are basis of comparison for new services Table

CF’T code

Description of service

99214

Office or other outpatient visit for evaluation and management of established patient, which requires at least two of these three key components, physicians typically spend 25 minutes face-to-face with patient or family Excision, other benign lesion (unless listed elsewhere), face ears, eyelids, nose, lips, mucous membrane; lesion diameter 0.6 to 1.0 cm Interdental fixation-application of interdental fixation device for conditions other than fracture or dislocation, including removal Open treatment of mandibular fracture; with interdental fEation Graft, bone; mandible (includes obtaining graft) Open treatment of complicated mandibular fracture by multiple surgical approaches including internal fixation, interdental fmation, or wiring of dentures or splints Maxillectomy; without orbital exenteration Reconstruction of mandibular condyle with bone and cartilage autografts (including obtaining grafts) (e.g., for hemifacial microsomia) Open treatment of craniofacial separation (Lefort III type); with wiring or internal fKation; complicated

11411

21110

21462 21215 21470

31225 21247

21433

*Numeric values from Fedad tGloba1 periods are maximum

Regish-, November 25, 1992. time in days in which all work

is considered

RESULTS A total of 72 out of 190 questionnaires were tabulated for a response rate of 38%. The response rate is considered well within statistical significance by the HCFA. The percent regional response distribution was similar for five of the eight regions surveyed (Fig. 4). The greatest percentage of responses was reported from the southwest region, whereas the lowest came from the mid-Atlantic region. Private practitioners provided the greatest response rate, followed by hospital-based providers, and those in “combination” practices were third. “Combination” practices were defined as those not devoted entirely to one of the other three categories. University-based practitioners were least represented in the survey (Fig. 5). Nine established reference services were provided in the survey (Table I). The work values for these services ranged from a low of 0.98 relative value units to a high of 24.27. All members were comfortable with at least one of these services to aid in estimating the relative provider work for the maxillofacial prosthetic services in question. A majority of the respondents consistently used the established reference service, “Maxillectomy, without orbital ation,” as a key reference comparison procedure.

296

exenter-

with

national

survey;

these reference

1993 RVU*

pa-t

of total

values

Global period7

0.98

xxx

1.60

010

5.16

090

9.37

090

10.31 14.54

090 090

15.56 21.67

090 090

24.27

090

service.

Members were also questioned on the adequacy of the clinical vignettes in describing the maxillofacial prosthetic services. Thirty-one objections were recorded of 749 responses, for an overall approval rate of 96% for these vignettes. The response rate per service varied because the survey instructions specifically discouraged those unfamiliar with a given service from guessing its value. In all instances at

least 50 responses were recorded; therefore statistical analysis was possible. A detailed descriptive analysis of all surveyed procedures is beyond the intent of this article.16 However, the service Interim Obturator Prosthesis (CPT 21079) serves as a representative example. This service is well-known and was performed an average of 10 times per respondent during the 12 months before the survey.

The interim

obturator

prosthesis

Fifty-nine returns were analyzed for this service. Some respondents had performed the service more than 30 times per year whereas others had provided the service infrequently (fewer than five times per year). Total time estimates for this service varied from a minimum of 0.75

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OUESTIONNAIRE Is sue: Musculoskeletal C PT Descriptor:Impression T, ypical

CPT

System

Code:

and custom

Global

21079

preparation;

interim

Period:

obturator

090

prosthesis

Service/Patient:

A 68 year old partially edentulous male presents 10 days after a left maxillectomy for a squamous cell carcinoma of the al mum. A surgical obturator prosthesis is in place. Several teeth in both arches have been extracted at the time of the definitive 01aeration, however the restorative status of the remainiig teeth is stabile. A full course of post operative radiation therapy is lo be in stitmed in the near future. An interim obturator prosthesis will be fabricated and the necessary adjustments made to maintain the Piitient’s oral and deglutory functioning.

Sltep 1

Estimate

S tep 2

List, in priority order, those services that were important reference services (Table estimating physician work for the new or revised code (CPT code number only):

S tep 3

If m typical patient differs from the one described above, please describe the typical patient you wonId expect to treat using the code and/or the nature of the services you would expect to provide:

s tep 4

Estimate Time Length

S tep 5

the Relative

Value

the folIowing in Minutes

of Physician

service

(RVW): 1) in

characteristics:

PreService:

of Stay:

Work

IntraService: Number

and Level

-

PostService:

of PostHospital

Visits:

How many times in the last 12 months have you provided this service? If zero, how many times have you provided the service in your career?

~

F‘inal assignments of codes and code descriptors are subject to change by the CPT Editorial Panelprior to publication of CPT 1995. 1?ze information contained in this questionnaire is confidential and oromietaq and should only be wed pursuant to participation in the A.MA/Specialty Socieo RVS Update Process. A,ssociation.

CPT@vedigit codes, twodigit mod$ers,

and descriptions

only are 0 American Medicc

Fig. 3. Standard RVS survey questionnaire form for “Interim Obturator,” adapted and modified with permission from AMA. “Typical Service/Patient” description near top of form is referred to as “clinical vignette” for service. Similar form with appropriate vignettes were constructed for each of other 10 services.

hours to a maximum of 21.50 hours. The mean total time for the service was 12.27 hours and the median was 11.50 hours with an SD of 4.65 hours. The reference service “Maxillectomy, without orbital exenteration” (RWwork = 15.56) was selected by most respondents as the comparison service on which the RWw,,rk for this service was based, as was the case for most of the survey services. Estimates of RWwork varied from a low of 6.06 to a high of 116.0 relative value units. The mean RWwO,.k for the service was calculated at 25.39 relative value units, and the median value was determined to be 17.20 relative value units. Comparative sorting and frequency arrays were constructed and graphically plotted for the data (Figs. 6 through 8), Similar calculations and arrays were performed for all 11 maxillofacial services. Table II represents

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the final median RWwork estimates for these procedures ranked in ascending order.

DISCUSSION The use of RVSs to rank the value of services is not new to medicine. The first such scale was developed by the California Medical Association in 1956, and experimentation and implementation of RVSs has been continuing in the medical and insurance communities until congressional involvement in the 1980’s.6 The rank ordering of relative work values for specialty services by the survey respondents demonstrated typical data and statistical trends. Immediately apparent, and typical of most RVS surveys, is the wide variation in response estimates for work for the services in question. This represents a reflection of broad differences in experience.

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UndeterminedQ%)

Middle Atlantic(l%)

North Cenfral(l3’7

Northeast(lL%)

South Central@%) Northwest Fig.

4. Regional

distribution

ospital Based(31%)

University

Based(lB%)

Private Practice(BB%)

Fig.

5. Distribution

of responses

by practice

type.

For example, Fig. 6 overlays individual respondent estimates of total time for the service Interim Obturator Prosthesis on their corresponding work estimates, which have in turn been distributed in an ascending array. Note that the time estimates exhibit less variation than the corresponding work values. It is apparent that a range of interpretation for intensity (Intensity = WorMTime) exists for this service. Fig. 7 depicts the same data with an ascending array of the number of procedures performed (over the last 12 months) per respondent superimposed over the corresponding work estimates. A wide range of experience is reported in Fig. ‘7. Of interest is the observation that some individuals report almost no experience and estimate the high work values whereas others report comparatively great experience and yet assign relatively low work value estimates. This observation could be explained by the fact that those who perform the service infrequently are less familiar and have a greater degree of difficulty in performing it, whereas those who render the service routinely con-

298

of survey

responses.

sider it easier because of familiarity and hence assign a lower work value. Analysis of the extremes of the distributions can lead to confusing and contradictory conclusions. A consideration of the central values of the range is more profitable. Care, however, must be taken not to allow undue influence from the extreme values to skew these middle values. More precisely, use of the median, the measure of central tendency unaffected by the outlying values for these data, is a more accurate method in analysis. Thus initial estimates of work values should always begin with a consideration of median values. Fig. 8, which is a frequency histogram of work estimates for the service Interim Obturator Prosthesis, provides a visual representation of the overall distribution of the survey work estimates. A polynomial curve has been fit over the histogram to further accentuate the nature of the overall distribution. This graph suggests that the majority of estimates clusters around a relatively narrow range. Similar distributions were found for all the surveyed services with the exception of CPT code 21088, Facial Prosthesis, which demonstrated multimodal distribution. (This code was subsequently discarded). Data evaluation with these methods supports median values as good representative initial estimates of work and, in fact, this has been the tact taken by most specialty societies and HCFA. The preceding analyses were applied to all 11 maxillofacial prosthetic services surveyed, and they provide the basis for the median work values in the summary table. Providers responses from all venues of practice and regions of the United States are included in the data, and the likelihood is that the majority of providers for maxillofacial prosthetic services engaged in the survey. Consequently, we feel that these values are the best initial estimates of provider work for these services. Other deliberations, nevertheless, are important in the

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Fig. 6. Comparison of respondents’ estimates of total time for service “Interim Obturator” compared with corresponding estimates of provider work (RVQ&. Work values are distributed in ascending &ray.

Comparison ofNumber of Procedures to Estimates ofRVUwork

,.’

.

Survey Responses Fig. 7. Comparison of number of times service “Interim Obturator” was performed over last 12 months compared with corresponding estimates of RVI&,& final recommendations of work values submitted to the HCFA. For example, bimodal or multimodal distributions (as in the case of facial prosthesis) that may indicate significant membership differences of opinion with regard to values may occur and must be reconciled. Another common problem is confusion or disagreement about what entails work for a service. Such difficulties can cloud interpretation of the data. For example the definition of direct provider work is somewhat obscured in maxillofacial prosthetic practices where artists, laboratory technicians, or other “extenders” are used by some and not by others. The interpretation, resolution, and justification of these questions fall to the RVS specialty society committee members before final values are recommended. These survey final values, even after such deliberations, were not far from the median survey values. These values are subsequently submitted to the RUC of

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1996

the AMA for evaluation and comment by any other interested parties. The RUC may refine the values or refer them to the specialty society for further revision. Ultimately the final recommended values are submitted to the HCFA, where another similar review process is conducted. CONCLUSIONS Although the numeric results of such surveys may seem abstract and even irrelevant to general practitioners, they serve as a foundation for establishing reimbursement for services. The actual reimbursement values are derived from a complex formula that relates regional variations and other resources (practice and malpractice expense relative values1.5 The final calculations comprise the total relative values of the services (RV&,&, which are subsequently converted to dollars by use of a monetary conversion factor. The current recommendations, which are

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I

Work Units

Fig. 8. Frequency histogram of distribution of estimates of provider work (RVQ,,& for service “Interim Obturator.” Polynomial curve was fit over distribution to accentuate modal distribution. Outliers are clearly differentiated in such distribution. Table II. Survey estimates of provider work (RV&,&

CFI’

code

for maxillofacial prosthetic services

Service

210xX1-t 210% 21079 21082

Surgical obturator Surgical Splint Interim obturator PalataI augmentation Palatal lift prosthesis Auricular prosthesis Speech aid prosthesis Nasal prosthesis Mandibular resection Definitive obturator OrbitaI prosthesis Facial prosthesis

21083 21086 21084 21087 21081 21080

210xX-2? 21088*

Number of respondents

Average value estimate (~~w,rk)

Median value estimate (rework)

62 61

8.42 14.44 25.34 24.57

7.00 10.00 17.20 19.00

61 57 62

25.74 28.88 28.64

20.50 22.00 23.25

56 62 62 54 55

28.68

23.70 24.30 24.75 30.25 36.50

64

59

29.88 32.29 44.10 50.51

*Subsequently deleted TProposed codes.

based on the results of this survey together with practice and malpractice expense estimates, are currently being evaluated by the HCFA to establish a national “maxillofacial prosthetic” fee schedule. The RVS process has been used by more than 65 medical specialty

societies.

Currently

more than 6000 medical

codes have been assigned relative values, including many from speech pathology, psychology, social work, oral and maxillofacial surgery, osteopathy, and other allied health specialties. Although there has been resistance to what some feel is unjustified quantification of these services, the fact remains that the process has been unrelenting in the public and now the private sectors. Advocates of RBRVS contend that more consistent and

300

equitable

national

fees result

from these efforts

because

historic charges are ignored in the calculations. The relative values of the resources used in the services form the basis for the final determination of their monetary worth. The estimation of provider work serves as the foundation for such calculations, and its estimate is crucial to the validity of the result. This survey provides a logical foundation by offering national estimates by the relative values for provider

work in maxillofacial

prosthetics.

The author would like to acknowledge the invaluable assistance of the following individuals who donated many hours of their time and expertise in these endeavors: Drs. Jonathan Wiens, Clifford VanBlarcom, Steven Eckert, Terry Kelly, and AIan Hickey.

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REFERENCES 1. Consolidated Omnibus Budget Reconciliatory Act, Pub L 99-272. 2. Hsiao WC, Brawn P, Becker E, et al. A national s’cudy of resource-based relative value scales for physician services: final report. Boston: Harvard School of Public Health, 1988. 3. Proposed rules. Federal Register 1993;58:38006-7. 4. Wiens JP, Cowper TR, Eckert SE, Kelly TM. Maxillofacial prosthetics: a preliminary analysis of resource based relative value scale. J PROSTHET DENT 1994;72:159-63. 5. Wiens JP, Cowper TR. Practice and malpractice expenses in maxillofacial prosthetics. J PROSTHET DENT 1995;73:5638. 6. American Medical Association. Medicare RBRVS: the physicians’ guide Chicago: American Medical Association, 1994. 7. Hsiao WC, Stason WB. Toward developing a relative value scale for medicine and surgical services. Health Care Financing Review 1979;1:23-8. 8. Hsiao WC, Brawn P, Becker ER, Thomas SR. The resource-based relative value scale: toward the development of an alternative physician payment system. JAMA 1987;258:799-502. 9. Jensen AD. Are relative value scales the answer? Health Affairs 1988;7:157-8. 10. Stevens SS. Psychodynamics. New York: John Wiley, 1975.

The Glossay

of Prosthodontic

OF PROSTHETIC

DENTISTRY

of delinquency. New York: 11. Sellin T, Wolfgang M. The measurement John Wiley, 1964. GW. A quick method for determining the reliability and 12. Bohrnstedy validity of multiple items scales. Am Sociology Rev 1969;34:542-8. 13. Cronbach LJ. Coef&ient alpha and internal structure tests. Psychometrika 1951;16:297-302. 14. Swerm TR, How and why private payers are using the RBRVS, RBRVS physician paymenti choice, fee-for-service and health system reform. In: Proceedings of the second annual national conference of the American Medical Association, Chicago: Plenary Session III, May 5-6,1994. 15. Final rule, Federal Register 156FR595021, November 25, 1991. recommendations and practice and 16. Cowper TR, Final report-RBRVS malpractice expenses for maxillofacial prosthetic procedures. Chicago: American Academy of Maxillofacial Prosthetics, 1994.

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Terms, Sixth Edition

2%~ Glossary of Prosthodordic T~s is the ultimate resource for the professional. This document, a collection of words/terms and their special connotation in the art and science of prosthodontics, was created to provide a standard lexicon for the profession. The sixth edition of the GlossaT (printed in the January 1994 issue of Z’he]ou~l is now available from Mosby in your choice of formats:

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