Recent Trends in Mammography Utilization in the Medicare Population: Is There a Cause for Concern?

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1 Recent Trends in Mammography Utilization in the Medicare Population: Is There a Cause for Concern? Vijay M. Rao, MD a, David C. Levin, MD a,b, Laurence Parker, PhD a, Andrea J. Frangos, MS a Context: Recent published reports have shown a decline in the mammography screening rate in women over age 40, but it is not known whether this trend is a reason for concern in the Medicare population. Objective: To study recent trends in mammography utilization in the Medicare population and determine how the newer digital mammography may be affecting mammography utilization. Design and Setting: The Centers for Medicare & Medicaid Services Physician/Supplier Procedure Summary Master Files for 1996 through 2005 were examined to determine overall trends in mammography utilization, as well as trends in screening vs diagnostic and conventional screen-film vs newer digital examinations. Medicare Limited Datasets for 2002 to 2004 were used to determine 2-year mammography and multiple imaging rates in individual patients. Main Outcome Measure: Mammography utilization. Results: Overall, the mammography utilization rate increased from 26,646 per 100,000 in 1996 to 39,363 per 100,000 in 2005, a 48% increase. The diagnostic mammography rate decreased by 39% (from 15,314 to 9,301), whereas the rate for screening mammography increased by 166% (from 11,332 to 30,062). Digital mammography increased from 2.2% of all mammography in 2002 to 10.4% in In both digital and film mammography, screening increased more rapidly than diagnostic mammography. Conclusions: The utilization rate of all mammography showed a substantial 48% increase between 1996 and 2005, and an 11% increase in screening mammography was seen between 2000 and Although the increase in mammography utilization is encouraging, the 2005 rate of 39,363 per 100,000 female Medicare beneficiaries seems to be well below American Cancer Society recommendations. Key Words: Mammography, breast imaging, mammography utilization J Am Coll Radiol 2008;5: Copyright 2008 American College of Radiology Mammography is the mainstay of efforts to screen women for breast cancer [1-3]. Large-scale public education campaigns have been conducted in efforts to raise awareness among women of the importance of breast cancer screening. The American Cancer Society continues to recommend that women over age 40 with average risk undergo annual screening mammography [3]. It is therefore of concern that a recent survey study by Breen et al [4] suggested that the use of mammography may be decreasing. Using interviews of a nationwide sample of more than 10,000 women, they calculated the number of women who had received at least one mammogram over every 2-year period and determined that there had been a nearly 4% decline in mammography use between 2000 and They pointed out that a reduction in screening rates could result in an apparent short-term decrease in the incidence of breast cancer. Although carefully constructed surveys are very good at providing population estimates, they are subject to recall and information biases. An alternative approach is to conduct secondary analyses of administrative data sets. This approach avoids both biases and provides a wealth of information, including utilization, types of examinaa Department of Radiology, Thomas Jefferson University Hospital and Jefferson Medical College, Philadelphia, Pennsylvania. b HealthHelp, Inc., Houston, Texas. Corresponding author and reprints: Vijay M. Rao, MD, Thomas Jefferson University Hospital, Department of Radiology, 132 S 10th Street, 1087 Main Building, Philadelphia, PA 19107; vijay.rao@jefferson.edu. This study was supported in part by a grant from the American College of Radiology, Reston, Virginia American College of Radiology /08/$34.00 DOI /j.jacr

2 Rao et al/trends in Mammography Utilization 653 tions, and providers of services. Using the nationwide Medicare billing records, a more precise measure of mammography utilization can be obtained. We can determine the utilization of diagnostic and screening mammography and conventional screen-film and newer digital mammography, as well as obtain information on the utilization of other breast imaging modalities such as ultrasound and magnetic resonance imaging (MRI). Diagnostic mammography is utilized in the surveillance of previous breast cancer or other abnormal findings, whereas screening mammography is used in asymptomatic women. The two have separate billing procedure codes and are reimbursed differently. Surveys that assess the mammography rate do not distinguish between screening and diagnostic mammography. One recent innovation that might be influencing mammography utilization is the introduction of full-field digital mammography. As this technology came into use over the past decade, there was hope that it would offer substantial improvement in accuracy over conventional screen-film mammography. However, several early studies suggested that the two techniques were comparable in performance, without any major demonstrable advantage for digital mammography [5,6]. As the technology has continued to evolve, more recent studies have shown some advantages for digital mammography, particularly in women under age 50 and those with dense breasts [7,8]. With this as background, the purposes of our study were twofold. First, we wanted to study recent trends in mammography utilization to see if the findings of Breen et al [4] could be validated in the Medicare population. Second, we wished to determine how rapidly digital mammography was diffusing into clinical practice and how it might be affecting mammography utilization. MATERIALS AND METHODS The primary data sets for the study were the Centers for Medicare & Medicaid Services (CMS) Physician/Supplier Procedure Summary Master Files (PSPSMFs) for 1996 through These files are the summary tables for the nationwide Part B data sets for all beneficiaries in the Medicare fee-for-service program (about 85% of the total Medicare population). The PSPSMFs provide data on each code in the Current Procedural Terminology, Fourth Edition (CPT-4), manual, including procedure volume. Denominators were derived from CMS Medicare Managed Care Market Penetration for All Medicare Plan Contractors Quarterly State/County Data Files, which were used to calculate the rate per 1,000 or 100,000 female Medicare beneficiaries per year. The PSPSMF rate allows us to look at overall trends but does not take into account women who had multiple mammograms. Therefore, we also used the CMS Limited Datasets (LDS) for 2002 to 2004, a 5% random sample of fee-for-service Medicare beneficiaries. These files have encrypted beneficiary identifiers, which permit the tracking of all procedures a given patient undergoes, allowing us to account for multiple imaging in a single patient. A 2-year LDS mammography rate was calculated by counting the number of women who had one or more mammograms in a 2-year period and dividing by the appropriate denominator. This rate was calculated to determine whether our data agreed with the findings of Breen et al [4]. Because the PSPSMF is a complete count for a population rather than a sample, confidence intervals need not be calculated. The LDS, which represent a 5% sample of the Medicare population, are very large, including almost 1 million women, and confidence intervals are very small (about 0.1%). The PSPSMFs and LDS files are public-use files available from CMS. The PSPSMFs contain nonidentifiable person-specific information, and the LDS files contain beneficiary-level health information but exclude specified direct identifiers, as outlined in the Health Insurance Portability and Accountability Act privacy rule. Therefore, secondary analyses of these data are exempt from institutional review board review. Table 1 shows the codes that were studied and their descriptors. Three were Level I Healthcare Common Procedure Coding System (HCPCS) codes for screenfilm mammography. Level I HCPCS codes are the codes that are listed in the CPT-4 manual. The other 3 were Level III HCPCS codes for digital mammography. Level Table 1. Mammography codes studied and their descriptors CPT -4 or HCPCS Code Descriptor Film diagnostic mammography; unilateral Film diagnostic mammography; Film screening mammography; G0202 Digital screening mammography; G0204 Digital diagnostic mammography; G0206 Digital diagnostic mammography; unilateral Note: CPT-4 Current Procedural Terminology, Fourth Edition; HCPCS Healthcare Common Procedure Coding System. Three additional HCPCS codes appeared only in 2001: G0203 (digital screening), G0205 (digital diagnostic), and G0207 (film diagnostic).

3 654 Journal of the American College of Radiology/Vol. 5 No. 5 May 2008 Fig. 1. Trends in the utilization of mammography (mammo) among female Medicare beneficiaries, 1996 through Dx diagnostic; scr screening. III HCPCS codes are alphanumeric codes that are typically used to collect data on the utilization of new procedures before those procedures are assigned Level I codes in the CPT-4 manual. For digital mammography, the Level III HCPCS codes began to be used in 2001, and the first full year of their use was Trends in the utilization rates of screen-film and digital mammography were analyzed separately and in combination. Although the primary focus of this study was an analysis of mammography utilization trends, for the sake of completeness, we also noted trends in breast ultrasound (CPT code 76645) and breast MRI (CPT codes and 76094) from 1996 through RESULTS Figure 1 shows separate trend lines from 1996 through 2005 for all mammography, screening mammography, and diagnostic mammography. Overall, the mammography utilization rate increased from 26,646 per 100,000 in 1996 to 39,363 per 100,000 in 2005, a 48% increase. The rate for diagnostic mammography decreased by 39% (from 15,314 to 9,301) during the study period, whereas the rate for screening mammography increased by 166% (from 11,332 to 30,062). By 2005, the screening rate was more than triple the diagnostic rate. Two distinct phases can be noted in Figure 1. In the late 1990s, there was a sharp increase in the screening mammography rate, while at the same time, there was a more moderate decrease in the diagnostic mammography rate. From 2000, the trend lines flattened, with a slow increase in the screening mammography rate and a slower decrease in the diagnostic rate. Table 2 shows the overall PSPSMF mammography utilization rates for 2000 to 2005, as well as diagnostic vs screening mammography and digital vs film mammography. In 2005, a total of 7.7 million mammograms of all types were performed in the fee-for-service Medicare female population. The overall utilization rate from 2000 through 2005 showed an increase from 37,329 to 39,363 per 100,000, a 5.4% increase. During 2002, the first full year in which HCPCS codes were available to track the use of digital mammography, a total of 157,862 of these studies were performed. In 2005, a total of 797,123 digital mammographic studies were performed. This translates to a rate per 100,000 of 830 in 2002, compared with 4,093 in 2005, a 393% increase. Digital mamography increased from 2.2% of all mammography in 2002 to 10.4% in In both digital and film mammography, screening increased more rapidly than diagnostic mammography. The LDS 2-year mammography rate for 2003 to 2004, in which each beneficiary was counted only once regardless of the number of mammograms she had during that period, was %. The percentage of women who had more than one mammogram in a given year was examined in the LDS for 2002 to 2004, and it remained consistent at 15% each year. Figure 2 shows the PSPSMF utilization rate for breast ultrasound and MRI for 1996 through During these years, both breast ultrasound and MRI were used primarily for diagnostic purposes rather than screening. The rate of breast ultrasound increased from approximately 1,538 per 100,000 in 2000 to 3,525 per 100,000 in 2005 (a 129% increase). The utilization of breast MRI was far lower. It went from 6 per 100,000 in 2000 to 138 per 100,000 in 2005 (a 2,200% increase). Table 2. Utilization rates of mammography per 100,000 female Medicare beneficiaries Type of Mammography % Change Screening 27,088 28,778 28,247 28,298 29,124 30, Film 27,088 27,892 27,629 27,229 27,283 26, Digital ,069 1,841 3,074 Diagnostic 10,241 9,969 9,810 9,438 9,333 9, Film 10,241 9,856 9,598 9,073 8,725 8, Digital ,019 Total 37,329 38,747 38,057 37,736 38,457 39,

4 Rao et al/trends in Mammography Utilization 655 Fig. 2. Trends in utilization rates per 100,000 for breast ultrasound (US) and breast magnetic resonance imaging (MRI) among female Medicare beneficiaries. DISCUSSION In the late 1990s, there was an increase in mammography utilization in the Medicare fee-for-service population. This appears to have been driven by a sharp increase in the utilization of screening mammography, whereas during the same years, there was a modest decline in the utilization of diagnostic mammography. The sharp increase in screening may have been due to many public health and education initiatives that were aimed at increasing the awareness among women of the importance of being screened for breast cancer. The decrease in diagnostic mammography may have been due to a clarification of the guidelines that defined the differences in coding for diagnostic vs screening studies. This increase in screening and small decrease in diagnostic studies may also reflect lower recall rates. The trend lines flattened considerably from 2000 on. From that year through 2005, our study demonstrated a small decrease in the utilization rate of diagnostic mammography and a somewhat larger increase in the utilization rate of screening mammography in the Medicare fee-for-service population. Overall, there was a 5.4% increase in mammography utilization from 2000 to Breen et al [4] found that during the same time interval, there was a 3.7% decrease in the utilization of mammography among all women in the United States and a 1% increase in their Medicare fee-for-service subpopulation. Their study was based on interviews conducted by the US Census Bureau as part of the National Health Interview Survey; women were asked if they had undergone mammography within the past 2 years. The 2-year mammography rate they reported for 2005, which corresponds to whether a woman had at least one mammogram in the 2 years before being interviewed, was 57.1% (confidence interval, ). The 2-year rate calculated in the present study for 2003 to 2004, which corresponds to whether a woman had at least one mammogram in 2003 and 2004, was 58.2% (confidence interval, 0.1%). Our 2-year rate corresponds well with those of Breen et al [4]. A concern with the results showing a 5.4% utilization increase compared with the study of Breen et al [4] is that the nationwide PSPSMFs provide an overall number of examinations performed. Therefore, the rates may be inflated if women are getting multiple mammograms in one year. Our examination of the LDS for 2002 to 2004 showed that the percentage of women who got multiple mammograms in one year remained consistently at 15% over those years. We can therefore assume that multiple imaging did not account for our larger percentage increase over the 6-year period. The survey population from Breen et al [4] consisted of more than 10,000 women, including 539 Medicare fee-for-service beneficiaries, and had fairly large confidence intervals (about 1% for the entire population and 4.5% for the Medicare fee-for-service subsample). Our data, based on all actual claims submitted to Medicare Part B for all Medicare fee-for-service beneficiaries, represent a better estimate of mammography utilization in this subset of the nationwide population. We found a 5.4% increase from 2000 through The present study also shows a more encouraging 11% increase in screening mammography during these recent years. Other modalities that are being used as diagnostic rather than screening tests in the detection of breast cancer are breast ultrasound and MRI. Although diagnostic mammography utilization has decreased, breast ultrasound utilization has continued to grow steadily, as shown in Figure 2. By 2005, approximately 1 breast ultrasound examination was performed for every 3 diagnostic mammograms. Magnetic resonance imaging of the breast is as yet only a small contributor to overall breast imaging, but its use is also growing rapidly. This may further accelerate in view of recent observations that in women with newly diagnosed breast cancer, MRI can detect cancer in the contralateral breast that is missed by mammography and clinical examination [9]. It is possible that some of the decrease in the utilization of diagnostic mammography could be due to substitution by breast ultrasound and MRI. A limitation of our study is that it covered only the Medicare fee-for-service population, and it is therefore not clear if these findings would also pertain to younger women with commercial health care insurance. Additionally, secondary analyses of administrative data are subject to coding inaccuracies and the inability to assess appropriateness. The 2005 figure of 39,363 studies per 100,000 (see Table 2) seems to be well below what it should be if most women in the Medicare population are following the

5 656 Journal of the American College of Radiology/Vol. 5 No. 5 May 2008 American Cancer Society s [3] recommendation for annual mammography for women over age 40. One important reason was summarized in a report of the US Government Accountability Office [10] to Congress in July The Government Accountability Office found that between 2001 and 2004, the number of mammography facilities nationwide decreased by 6%, the number of radiologists interpreting mammograms decreased by 5%, and the number of technologists performing mammograms decreased by 3%. Experts cited low reimbursement and difficulties recruiting personnel as the main reasons for the closure of facilities. Another possible reason may be fewer educational efforts and public health initiatives aimed at increasing mammography use among women in recent years. Other possible reasons could be reports that mammography may not be fully effective in lowering breast cancer mortality, an increase in the number of uninsured women, and higher copayments for outpatient visits [4]. However, the latter two explanations seem unlikely, considering that the utilization of other types of imaging has risen rapidly in recent years. An additional possible explanation could be the decrease in the incidence of breast cancer that occurred in women over age 50 from 2002 to 2003 [4,11]. This was felt to be due to a sharp decline in the use of hormone-replacement therapy. If women perceived a lower risk for breast cancer, this could have caused them to be less diligent in obtaining their annual breast screening. Despite the high cost of digital machines, their introduction into clinical practice seems to be proceeding fairly rapidly. This may have been facilitated by the ongoing conversion to electronic image records throughout the radiology practice. In 2005, 10.4% of all mammograms were digital studies, and it will be interesting to see if rapid growth of this technology continues in the future. The growth in the use of digital mammography may account for the small increase in screening mammography utilization rates seen in Figure 1 between 2003 and Because digital mammography is now perceived as new and better technology, it is possible that the further diffusion of this technology will encourage more women to undergo screening. REFERENCES 1. Koomen M, Pisano ED, Kuzmiak C, Pavic D, McLelland R. Future directions in breast imaging. J Clin Oncol 2005;23: Elmore JG, Armstrong K, Lehman CD, Fletcher SW. Screening for breast cancer. JAMA 2005;293: Smith RA, Saslow D, Sawyer KA, et al. American Cancer Society guidelines for breast cancer screening: update CA Cancer J Clin 2003; 53: Breen N, Cronin KA, Meissner HI, et al. Reported drop in mammography. Is this cause for concern? Cancer 2007;109: Lewin JM, D Orsi CJ, Hendrick RE, et al. Clinical comparison of fullfield digital mammography and screen-film mammography for detection of breast cancer. AJR Am J Roentgenol 2002;179: Skaane P, Young K, Skjennald A. Population based mammography screening: comparison of screen-film and full-field digital mammography with soft-copy reading Oslo I study. Radiology 2003;229: Fischmann A, Siegmann KC, Wersebe A, Claussen CD, Muller- Schimpfle M. Comparison of full-field digital mammography and screenfilm mammography: image quality and lesion detection. Br J Radiol 2005;78: Pisano ED, Gatsonis C, Hendrick E, et al. Diagnostic performance of digital versus film mammography for breast-cancer screening. N Engl J Med 2005;353: Lehman CD, Gatsonis C, Kuhl CK, et al. MRI evaluation of the contralateral breast in women with recently diagnosed breast cancer. N Engl J Med 2007;356: US Government Accountability Office. Mammography current nationwide capacity is adequate, but access problems may exist in certain locations. Available at: documents/gao mammoaccess.pdf. Accessed June 20, Ravdin PM, Cronin KA, Howlader N, et al. The decrease in breast cancer incidence in 2003 in the United States. N Engl J Med 2007;356: