Mammography: Capacity Generally Exists to Deliver Services
Released: 2002-04-26T00:00:00

Letter

Background

Research studies, including eight large randomized clinical trials with 11- 20 years of followup, indicated that widespread use of mammography could reduce breast cancer mortality. The benefit of mammography has recently been challenged by two Danish researchers and an NCI advisory panel made up of independent experts; they cite serious flaws in six of the eight clinical trials that showed benefits. However, subsequent to the Danish report and the NCI panel’s statement, both NCI and the U.S Preventive Services Task Force reiterated their recommendations for regular mammography screening. While acknowledging the methodological limitations in these trials, the U.S. Preventive Services Task Force concluded that the flaws in these studies were unlikely to negate the reasonable consistent and significant mortality reductions observed in these trials.

The effectiveness of mammography as a cancer detection technique is directly tied to the quality of mammography procedures. Concerned about the quality of mammography procedures provided by the nation’s mammography facilities, the Congress enacted the Mammography Quality Standards Act (MQSA) of 1992, which imposed standards effective October 1, 1994.

FDA has major oversight responsibilities, including establishing quality standards for mammography equipment and personnel and certifying and inspecting each facility to ensure it provides quality services. For mammography personnel, such as radiologic technologists and interpreting physicians, FDA specifies detailed qualifications and continuing training requirements. Mammography technologists are required to be licensed by a state or certified by the American Registry of Radiologic Technologists in general radiography, and meet additional mammography-specific training and continuing education and experience requirements. Similarly, FDA specifies that all interpreting physicians be licensed in a state and certified in the specialty by an appropriate board, such as the American Board of Radiology, and meet certain mammography-specific medical training, as well as continuing education and experience requirements.

FDA collects detailed information about each facility when a facility is initially certified. FDA has established a database that incorporates data from the certification process and from its annual inspection program. Besides facility identification information, the database contains information on the number of machines, personnel, and whether the facility is active or no longer certified.

Medicare, the federal government’s health insurance program for people age 65 and above, is the nation’s largest purchaser of health services. Beginning in 1991, Medicare provided coverage of annual mammography screening for women beneficiaries. Medicare is administered by CMS. As a part of its health care improvement program, since 1999, CMS and a set of contractors, called peer review organizations, have been involved in monitoring and improving the quality of care, including increasing mammography screening rates among women Medicare beneficiaries.

National Capacity for Mammography Services Is Generally Adequate

The nation’s overall capacity to meet the growing demand for mammography services is generally adequate. Between 1998 and 2000, the use of services, as measured by the number of mammograms provided to women age 40 and older, increased nearly 15 percent. The most recent data on capacity show that the total number of machines and radiologic technologists available to perform mammography services increased 11 percent and 21 percent respectively from October 1998 to October 2001. During this same period, the total number of mammography facilities decreased about 5 percent, indicating that facilities were consolidating or becoming somewhat larger. The average number of mammograms performed per machine increased slightly but was considerably below estimates of full capacity. The one potentially negative development is in personnel, where the number of new entrants into the field—as measured by the number of persons who sit for mammography technologist or diagnostic radiology examinations for the first time—has dropped each year since 1997.

Utilization of Mammography Services Continues to Grow

The use of mammography as a tool for detecting early cancer continues to increase. Data from CDC’s Behavioral Risk Factor Surveillance System indicate a continuing increase in national mammography screening rates. The proportion of women age 40 and over who had received a mammogram within the past year increased from 58 percent in 1998 to about 64 percent in 2000. These screening rate increases, coupled with the growth of this population, have resulted in significant increases in the number of mammograms provided each year. Based on CDC’s data on screening rates and Bureau of Census population data, we estimate that the total number of mammograms received by women 40 and above nationwide has increased nearly 15 percent, from about 35 million in 1998 to more than 40 million in 2000.

These increases in mammography utilization extended across nearly every state. Using the screening rates and the Bureau of Census population data, we computed the number of mammograms received by women age 40 and above on a state-by-state basis. Between 1998 and 2000, screening rates for women in this age group increased in all but one state (i.e., Oklahoma) and the District of Columbia, and 39 states had an increase of more than 10 percent in the total number of women age 40 and above who had received a mammogram within the past year.

Capacity to Provide Mammography Services Has Also Increased

The nation’s capacity to provide mammography services, as measured by the numbers of machines and radiologic technologists available to perform mammography services, has also increased. FDA’s data show that between October 1998 and October 2001, the total number of mammography machines and radiologic technologists available nationwide to perform mammography services increased 11 percent and 21 percent respectively (see table 1). While FDA’s data showed that the total number of certified facilities has decreased about 5 percent between 1998 and 2001, the average number of machines per facility increased from 1.22 in 1998 to 1.42 in 2001. Overall, the 5 percent decrease in facilities has been offset by the 16 percent increase in the number of machines per facility and the increase in personnel.

Utilization Does Not Appear To Be Straining Capacity

The current average number of mammograms actually being performed per machine appears to be well below estimates of how many mammograms could be performed, if equipment is operating at full capacity. While there is no uniform standard on the number of mammograms that a mammography machine can do in a day, FDA officials estimated that one machine and one full-time technologist can potentially perform between 16 and 20 mammograms in an 8-hour work day, or between 4,000 to 5,000 mammograms a year (assuming 5 days a week and 50 weeks a year). Using CDC’s data on mammography screening rates, Bureau of Census data on the population of women age 40 and older, and FDA’s data on the number of machines, we computed the average number of mammograms performed per machine. At the national level, the average number of mammograms per machine was 2,759 in 1998. While this average number of mammograms per machine had increased to 2,840 in 2001, it was still well under 4,000, the lower end range of estimated full capacity. At the state level, the average number of mammograms per machine in 2001 ranged from a low of 1,790 in Alaska to a high of 3,720 in Maryland.

While the number of radiologic technologists has increased in the past in general proportion with the increase in mammography utilization, certain trends bear monitoring. According to an American Hospital Association survey, the job vacancy rate for radiologic technologists was 18 percent in 2001, and 63 percent of hospitals reported that they had more difficulty recruiting radiologic technologists than the previous year. Data from ARRT show the rate of increase for certified mammography technologists through 2000 has slowed down substantially in recent years. Similarly, the number of new entrants to the field, as represented by the number of first- time examinees for the mammography certificate, declined substantially each year from 1996 through 2000 (see table 2).

In addition, while comprehensive data are not available on the total number of radiologists available to interpret mammograms, the limited data available also indicate that the availability of radiologists may bear watching. For example, data from the employment placement service of the American College of Radiology show an increasing ratio of job listings per job seeker for radiologists –from 1.3 in 1998 to 3.8 in 2000. Also, data from the American Board of Radiology show that the number of first-time candidates who sit for diagnostic radiology examination has declined each year from 1997 through 2001 (see table 3).

Capacity Has Decreased in Some Locations, Causing Scattered Problems

Because of local factors such as a shortage of personnel or closure of certain facilities, waiting times for routine mammograms could be several months in certain locations. Nationwide, 241 counties had a net loss of mammography machines between October 1998 and October 2001, with 121 of them losing more than 25 percent. Our follow-up at 55 rural and metropolitan counties where reductions occurred indicated that lengthy appointment waiting times for mammography services were primarily in metropolitan locations.

Small Proportion of Counties Nationwide Lost Capacity

Our county-by-county analysis of data on equipment shows that overall, 241 counties had a net loss in the number of mammography machines between October 1998 and October 2001. Of these counties, 121 lost more than 25 percent of their machines. This number represents counties spread throughout the nation. These counties together contained less than 1.9 percent of the total U.S. population in the 2000 census.

We conducted an analysis to determine what had occurred in those counties close to the 121 counties that lost more than 25 percent of their machines. In general, the adjacent counties showed an increase in the number of machines, with nearly all of the 121 counties being within 50 miles of a county that gained machines. Thus, residents in most of the counties that lost services appear to be able to draw on increased resources nearby.

Counties with Largest Losses Are Mostly Rural; Most Reported No Significant Problems

Because data are not available to measure the effect of capacity loss on the mammography utilization rates at the county level, we randomly selected 37 of the 121 counties that lost more than 25 percent of their machines for in-depth analysis at the local level. These 37 counties are located in 19 states (see appendix I for a list of these 37 counties). Over three quarters of these counties are in nonmetropolitan areas. Eighteen of the counties we selected had one facility and 11 had no facility at all in 2001. We interviewed state and local officials familiar with conditions in these counties, asking them to assess the impact of the loss of facilities.

With two exceptions, officials generally reported no significant problems. They said existing facilities in the county or neighboring counties were able to provide needed services, and the longest appointment waiting time reported for routine screening mammograms was 1 month or less, which they considered to be reasonable. In most counties where women had to travel to neighboring counties for services, the travel distance was less than 40 miles, which officials considered common in rural areas. Several officials also said that some counties were served by mobile facilities that travel to their areas.

Largest Service Dislocation Appears to Be Occurring in Some Metropolitan Areas

In metropolitan counties, the picture was more mixed than for rural counties. To examine the extent of problems in metropolitan areas, we selected 18 additional counties (including the District of Columbia) from a list of counties that lost the largest number of machines. All of these counties are classified as metropolitan counties (see appendix I for a list of these counties). As we did for the rural counties, we contacted state and local officials and asked them to assess the impact of the loss of machines on women’s access to services. These officials reported wide variations in availability of services. While no problems were reported in nine counties, officials in the other nine counties reported a variety of problems. The nine counties with problems are concentrated in five metropolitan areas— Baltimore, Boston, the District of Columbia, and San Antonio and Wichita Falls, Texas. For example, officials in three counties surrounding the Baltimore metropolitan area reported an average waiting time of up to 3 months for screening mammograms and 2 to 3 weeks for follow-up diagnostic mammograms. Similarly, a survey conducted by Massachusetts officials in April 2001 found that, in the Boston metropolitan area, appointment waiting time for screening mammograms ranged from 1 to 20 weeks, depending on facilities. In the District of Columbia, officials reported that the only facility available in one part of the city had up to an 8-week backlog of appointments, while the rest of the city generally did not have significant problems.

In addition to contacting these 18 counties, we also contacted state and local officials to inquire about six other urban areas—Buffalo, Chicago, Houston, Los Angeles, New York, and Tallahassee—where no significant number of machines was lost but problems were cited by state and local officials or media reports. Officials familiar with situations in these cities reported that most of the problems were limited to certain facilities. For example, an official in Buffalo said that one well-known facility there had a 3-month waiting list for appointments while others could accommodate appointments within 2 weeks. In Chicago, Houston, and Los Angeles, long waiting time problems were concentrated in public health facilities that served low income populations. In New York and Tallahassee, long waiting times of 5 to 6 months were reported in 2000, but our recent interviews with officials found no significant problem. In almost all cases where some problems were reported, officials said that women who needed a diagnostic mammogram generally were able to get appointments within 1 to 3 weeks.

Several factors have contributed to the waiting time problems in the nine metropolitan counties and the six urban areas that we identified. Among the reasons provided by state and local officials were the following: Demand for services grew while capacity declined. In the Baltimore area, for example, officials said that a shortage of technologists and financial difficulty caused many facilities to consolidate or shut down, resulting in a net decrease in capacity, while the demand for services continued to grow.

High demand for services at some facilities. In cities such as Buffalo, Boston, Houston, and Los Angeles, where variation was more on a facility- by-facility basis, officials provided various reasons for the high demand at some facilities. For example, such factors as facilities’ reputations, physicians’ referral patterns, and large patient workload from public assistance programs cause some facilities to have a large backlog of appointments. Some women may experience waiting time problems because they are restricted by insurance coverage as to where they can go for services.

Inability to meet FDA’s quality requirements. Several officials told us that many small facilities with old machines had shut down because they could not meet FDA quality requirements. For example, an official from Los Angeles said that one provider had shut down three mobile units during the last 2 years because of quality problems.

Temporary interruptions in availability. The waiting time problems may also be caused by the closure of one or more large facilities—a temporary problem that often resolves itself when new facilities open or existing facilities expand in the area. For example, lengthy waiting problems in Tallahassee in 2000 were largely generated by the closure of one large mammography facility but a local public assistance program official told us in March 2002 that women in her program could get appointments within 2 weeks as the result of a recent opening of one new facility.

In addition to these factors, state and local officials also frequently raised concerns about the adequacy of the Medicare reimbursement rate, particularly in the high cost metropolitan areas. However, during the course of our work, CMS implemented a statutory change to the method for determining the Medicare reimbursement rate for screening mammography. The new method includes geographic adjustments for cost differences among areas and resulted in significant rate increases for high cost areas.

Concluding Observations

In general, the increase in mammography equipment and personnel has been sufficient to meet the steady increase in demand for mammography services. However, while the general buildup of personnel has been in line with the growth in the use of services, the last few years show a substantial decline in the number of new entrants to the fields, which could result in a reversal in this trend. If this reversal occurs, more personnel shortage problems could arise in the future.

Some instances of long waiting times for services are occurring. Consolidation of facilities and increases in demand can create a strain on service availability in specific communities. However, appointment delays are primarily for screening mammograms rather than for follow-up diagnostic mammograms. These conditions, which can be temporary, may be exacerbated by local physicians’ referral patterns, patients’ insurance coverage, or local shortages in available personnel.

Agency Comments

We provided FDA with a draft of the report for review and comment. FDA responded that it found the report to be accurate and it had no other general comments. In addition, FDA provided technical comments, which we incorporated as appropriate. Appendix II contains FDA’s written response.

As arranged with your offices, unless you release its contents earlier, we plan no further distribution of this report until 10 days after its issue date. At that time, we will send copies to the secretary of health and human services, the commissioner of FDA, the director of NCI, the director of CDC, the administrator of CMS, appropriate congressional committees, and other interested parties.

If you or your staff have any questions about this report, please contact me at (202) 512-7250. Other contacts and major contributors are included in appendix III.

Appendix I: Scope and Methodology

To compare recent trends in the use of mammography services with changes in facilities, equipment, and personnel available to deliver these services, we did the following.

We used data from CDC’s Behavioral Risk Factor Surveillance System for calendar years 1998 and 2000 (the most recent year available) to estimate mammography screening rates for women age 40 and older on a state-by- state basis. To estimate the number of mammograms provided to these women in 1998 and 2000, we then multiplied these screening rates by the population of women age 40 and over, using Census’ population estimates for 1998 and the 2000 Census population.

We used FDA’s national database on mammography facilities to assess the change in the total numbers of certified facilities, machines, and radiological technologists at national, state, and county levels. We compared the characteristics of facilities operating on October 1, 1998, with those operating 3 years later on October 1, 2001. FDA estimated an error rate of less than 1 percent for the data on mammography facilities. We excluded facilities in Puerto Rico, other U.S. territories, and federal facilities operated by the Department of Defense and the Department of Veteran Affairs from the analysis.

To identify geographical areas where the capacity to perform mammography services had decreased, and to assess the effect of these decreases on access to services, we used FDA’s national database to identify counties that lost mammography machines and focused on those that lost more than 25 percent of their machines from October 1, 1998, to October 1, 2001. To determine if machines became more available in areas close to these counties, we analyzed what had happened to the number of machines in nearby counties. Because data were not available to measure the effect of changes in capacity on mammography utilization rates at the county level, we carried out follow-up interviews with state and local officials in a random sample of 37 counties that lost more than 25 percent of their machines (see table 4).

Because over three quarters of these counties are in nonmetropolitan areas, we selected an additional 18 counties (including the District of Columbia) from a list of counties that lost the largest number of machines (though not enough to reduce the number by more than 25 percent). All of these 18 counties are in metropolitan areas. We also made additional inquiries about six other urban areas—Buffalo, Chicago, Houston, Los Angeles, New York, and Tallahassee—where problems had been cited by state and local officials or media reports. Table 5 lists the 18 counties and their metropolitan areas.

Because no systematic data were available on waiting times and travel distances for mammography services, we relied on observations of state and local officials about the situations at each location. For each selected location, both rural and metropolitan, we interviewed officials familiar with the availability of mammography services in these areas to obtain their views on whether women in their areas were experiencing problems with long waiting times for appointments and/or long travel distance to obtain services. These officials generally included state radiation control personnel contracted by FDA to conduct annual onsite inspections of mammography facilities; state and local public health officials involved in CDC’s Breast and Cervical Cancer Early Detection Program, which contracts with mammography facilities in each state to provide screening and diagnostic mammograms to underserved women; and in some locations, officials of Medicare peer review organizations contracted by CMS to monitor and improve the quality of care, including increasing statewide mammography screening rates for Medicare beneficiaries.

While most of these officials have not conducted any formal studies to gather this type of information, some have conducted informal surveys about waiting times and others were able to provide estimates of waiting times and travel distances through their involvement and frequent contacts with mammography facilities.

In addition, we interviewed representatives from several professional organizations, such as the American College of Radiology, the American Cancer Society, and ARRT, along with officials of FDA, CDC, NCI, and CMS. We performed our work from June 2001 through March 2002 in accordance with generally accepted government auditing standards.

Appendix II: Comments from the Food and Drug Administration

Appendix III: GAO Contacts and Staff Acknowledgments

GAO Contacts

Acknowledgments

In addition to those named above, Jennifer Cohen and Stan Stenersen made key contributions to this report.