- Email: [email protected]
Trends in on-call workload in an academic medical center radiology department 1998–20021
Departmental Administration
Trends in On-call Workload in an Academic Medical Center Radiology Department 1998 –20021 Timothy J. Carroll, MD, PhD2
Rationale and Objectives. The workload in radiology departments is increasing rapidly. This study was designed to determine whether and to what extent the workload is being generated outside of traditional working hours (defined as 08001700 Monday thru Friday, excluding holidays). Materials and Methods. Exam statistics were derived from the radiology department’s automated examination scheduling and reporting system for four successive fiscal years. The distribution of the number of studies completed throughout the 24-hour day and the 7-day week was charted. Results. A large proportion of studies are being completed outside of traditional working hours. Moreover, as the overall workload of the department increased, the proportion of studies being completed during nontraditional working hours was increasing at an even faster pace, particularly in the cross-sectional imaging modalities. Computed tomography, magnetic resonance imaging, and ultrasound have increased by 59%, 51%, and 30%, respectively, over 4 years. The on-call proportions have increased from 34% to 40% and 13% to 18% for computed tomography and ultrasound, respectively, over 4 years and from 44% to 50% for magnetic resonance imaging over 3 years. Conclusion. These trends have implications for radiologist and radiology technologist staffing. The department has already modified the scheduling of technologist staffing to provide in-house extended-hours coverage in most modalities. As the number of studies conducted outside of traditional working hours continues to expand and the demand for contemporaneous readings increases, radiologist staffing may need to be adjusted as well. Traditional on-call coverage may be insufficient to competently handle the growing workload. This may have particular implications for radiology residency programs. Key Words. Workload; call; residency; trends; staffing. ©
AUR, 2003
The volume of radiologic examinations is growing at a rapid rate across the United States in all practice settings (1–5). This is plainly apparent to everyone in the radiology department, from staff radiologists to radiologic technologists to film librarians, as the pace of the work in-
Acad Radiol 2003; 10:1312–1320 1 From the Department of Radiology, Fletcher Allen Health Care/University of Vermont, Burlington, VT. Received May 27, 2003; revision requested July 12; received in revised form July 26; accepted 28 July 2003. Address correspondence to T.J.C. 2Current address: Department of Radiology, Children’s Hospital, 300 Longwood Ave., Boston, MA 02115.
©
AUR, 2003 doi:10.1016/S1076-6332(03)00381-7
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creases. It may be less apparent in general, but radiologist “night hawks,” on-call radiologists, and radiology residents are acutely aware that the pace of work outside traditional working hours is also growing. Does this represent a shift of work away from traditional 9 AM to 5 PM radiology practice toward a uniform demand for radiology services 24 hours a day, 7 days a week (commonly referred to as 24/7) (6), or is this perception simply a reflection of the general increase in demand for radiology services? The demands on the radiology workforce will be very different, depending on the answer to this question. This article presents an analysis of radiology workload that quantifies the trends in the temporal distribution of work throughout the day and week by enumerating the
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number of examinations completed outside of traditional working hours in an academic medical center. These hours have historically been covered by a reduced staff of on-call personnel; consequently, these hours will be referred to throughout this article as on-call hours. MATERIALS AND METHODS Fletcher Allen Health Care located in Burlington, VT is a nonprofit academic medical center affiliated with the University of Vermont School of Medicine. In addition to the 562-bed main hospital that is a level I trauma center, there are two radiologist-staffed outpatient settings that perform ultrasound, mammography, and computed tomography (CT) examinations (at one site) during traditional working hours. Multiple primary care sites have plain radiograph capabilities, but the films are hand delivered to the Department of Radiology for interpretation. The Department of Radiology has used an automated scheduling and reporting system known as IDXrad (IDX Systems Corporation, South Burlington, VT) since October 1998. IDXrad includes many statistics reporting functions, one of which is a record of the completion time of all studies conducted by the department. The “exam statistics” function can compile counts of each type of study completed during any time period of interest. For this article, that function was used to generate counts of studies completed during normal working hours (defined as 0800-1700 Monday thru Friday, excluding holidays) and those completed during other hours. This was performed for four successive fiscal years (10/1/98 –9/30/99, 10/1/ 99 –9/30/00, 10/1/00 –9/30/01, 10/1/01–9/30/02) to discern temporal trends. Studies are recorded as completed at the time that the technologist ends the examination in the IDXrad system, not when it is interpreted. In practice, this almost always occurs at the time an examination was confirmed as technically complete by an approving radiologist or, for routine examinations, at the physical completion of the study. Reading may or may not take place soon thereafter. There are several potential limitations of this method, which include: There is an ongoing revision of the numbers of examinations recorded in IDXrad as studies are deleted or combined for billing and other administrative purposes. As a proportion of the total number of examinations, this has proven to be an insignificant amount that does not change the total examinations
in any particular modality overall more than a fraction of 1%. A related concern arises from an evolution in examination coding over the study period. For example, in the first year, a CT of the chest, abdomen, and pelvis required three requisition numbers and was counted as three studies. More recently, this common combination used for cancer staging and follow-up has been combined into a single requisition code. IDXrad accounts for these changes, however, through the implementation of an examination dictionary that includes an assigned study count for each examination code that can be greater than one. The combined chest/abdomen/ pelvis code is counted as three studies in that dictionary, thereby preserving the internal consistency of the examination number accounting. Other examples have been handled in a similar fashion. There is a lack of weighting of the individual examination counts for the amount of effort involved. Relative value units have been used to measure workload in other studies (7,8), which are based on a composite estimate of the total resources used. Relative value unit analysis was contemplated but impractical for this study because the relative value unit database in our IDXrad system is locally defined for technologist scheduling purposes and therefore is not comparable to the Medicare definitions used in other studies. The exam number is a satisfactory measure for the purposes of this study when establishing trends because it makes no difference what units are chosen, as long as same is compared with same. Random variation has been considered, but proves to be unimportant. Confidence intervals have been estimated assuming Poisson counting statistics for the absolute numbers of examinations and a binomial distribution for the proportions (9). With the large numbers involved, the confidence intervals are small, and random variation can be seen to change the trends not at all. A lack of overlap of 95% confidence intervals is equivalent to a probability less than 0.003 that the results are the same. For the few cases where confidence intervals do overlap, confidence intervals for the differences are computed and stated. RESULTS Table 1 and Figures 1–5 present the data in graphical bar chart form. The 95% confidence intervals are included.
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Table 1 Trends in Total Number of Departmental Radiologic Studies Completed Overall and During On-Call Hours for Four Successive Fiscal Years (95% Confidence Intervals are Included) Fiscal Year
10/98–09/99
10/99–09/00
10/00–09/01
10/01–09/02
Total cases Total call cases
179,876 ⫾ 831 51,279 ⫾ 444
188,035 ⫾ 850 53,667 ⫾ 454
192,483 ⫾ 860 56,286 ⫾ 465
211,743 ⫾ 902 62,627 ⫾ 490
Figure 1.
Total number of examinations by modality 2001–2002.
Table 1 shows both the absolute number of total examinations completed by the department in each of the four years studied, as well as similar data for the examinations completed outside traditional working hours (on-call examinations) over the same 4-year period. This shows a monotonic increase in the number of studies completed both in total and during on-call hours. The number of examinations is not evenly distributed across the different modalities. Figure 1 illustrates the distribution of radiology examinations among various modalities including CT, ultrasound (excluding breast), fluoroscopy, plain radiography (excluding mammography), magnetic resonance imaging (MRI), angiography/interventional and the mammography department for the most recent fiscal year 2001–2002. To demonstrate the distribution of examinations throughout the day, Figure 2 plots the ratio of the number of examinations completed on-call to those completed during traditional working hours for both the total exami-
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nations as well as the ratio broken down by modalities for the most recent year 2001–2002. This figure clearly illustrates that a large proportion of examinations are being completed on-call and that particular modalities are heavily utilized during on-call hours including CT, MRI, ultrasound, and plain radiography. Figure 3 presents the same data as Table 1 in a different way by normalizing the number of examinations to the number in 1998 –1999. A selected group of the most heavily used modalities is also included. Figure 4 does the same for the number of on-call examinations. Comparison of Figures 3 and 4 clearly shows that the proportional increase in the number of on-call studies is greater than for the total number of studies, particularly in the body imaging modalities. The most striking example is for ultrasound, where the annual total number has actually steadily declined while the number completed on-call has continued to rise. The drop in total ultrasound examinations is partly attributable to a shift in the bulk of the obstetrics and a
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Figure 2.
Fraction of cases completed on-call, 2001–2002.
significant proportion of the gynecologic ultrasounds to a new maternal/fetal medicine service in the obstetrics and gynecology department during 2001, studies that had been routinely performed in the radiology department before that time. On-call studies are still the responsibility of the radiology department. A similar situation exists for vascular ultrasound studies that are conducted by a vascular laboratory in the surgery department during the day, but on-call examinations are conducted by radiology. The vascular ultrasound arrangement existed before 1998, the earliest year included in this study, so it does not cause a similar discontinuity in the statistical trends. The dramatic jump in total MRI examinations from fiscal year 1998 – 1999 to year 1999 –2000 corresponds with the installation of a second MRI machine in July 1999. While these particular circumstances may be unique to our hospital, they also provide evidence that expansion of daytime imaging capacity (by additional equipment or transfer of duties to other departments) has not prevented continuing growth in on-call examinations. To discern any shift in the distribution of work into on-call hours, Figure 5 plots the trend in the fraction of examinations completed on-call as a percentage of the department annual totals for the each of the years studied for the selected group of modalities most heavily utilized after-hours. Figure 5 shows that the trend in the percent
of studies completed on-call is stable overall, but it is steadily upward in the cross-sectional imaging modalities.
DISCUSSION Where Are We Now? The radiology workday is lengthening. The data presented in the previous section concretely demonstrate and quantify the steadily increasing workload for the radiology department overall, but an even faster growth trend in the number of radiologic studies completed on-call as illustrated by Figures 3 and 4. This is most striking for ultrasound, where the total number of examinations has steadily declined while the on-call numbers have climbed by 30% over 4 years since 1998. CT and MRI utilization has also rapidly expanded during on-call hours, with the numbers increasing by 59% and 51%, respectively. Plain radiography has changed the least, but still has climbed 13%. Overall, the total examinations being completed during on-call hours has increased 22% over 4 years. Absolute numbers are growing both day and night, but there is also a perceptible trend toward shift of studies into on-call hours. This is most pronounced for the body imaging modalities CT, ultrasound, and MRI, with the percentage completed on-call increasing from 34% to 40% over 4 years, 13% to 18% over 4 years, and from
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Figure 3.
Normalized trends in total department studies (referenced to 1998 –1999).
44% to 50% over 3 years, respectively (Fig 5). The magnitude of the shift has been mitigated somewhat in our department by expansion of daytime imaging capacity by the installation of a second MRI machine (explaining the drop in on-call percentage from 1998 –1999 to 1999 –2000 from 56% to 44%) and faster multi-detector CT scanners. The overall proportion of studies conducted on-call has barely changed from 29% to 30% (difference ⫽ 1.1 ⫾ 0.3, 95% confidence interval), but this reflects growth in routine examinations during the day such as mammography (up 28% over 4 years), and, most importantly, the minimal shift in the most common modality by far, plain radiography, that changed only from 37% to 38% (difference ⫽ 0.7 ⫾ 0.4). Although small in percentage, this represents a large additional absolute number of radiographic studies on-call as noted above. If mammography is excluded, then the shift toward on-call hours is more pronounced, with the total examination on-call proportion increasing from 32% to 34% (difference ⫽ 1.9 ⫾ 0.7) over 4 years. This disproportionate rise in on-call examinations has several contributing causes. Not only has the demand for emergent and in-patient services increased (5,10), imaging volume for the emergency department and inpatient ser-
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vices has increased even faster (5). It should not be surprising that the completion of scheduled studies has also spilled over into on-call hours because there are systemic limitations to the number of scheduled exams that can be completed during the day (eg, number of scanners, technologists, workstations, interpreting radiologists). Technologists are required to be physically present to perform the studies, but it has traditionally been true that examination completion does not necessarily equal contemporaneous interpretation by a radiologist. Many routine examinations are conducted in the evening for reading the next day, and radiologists prefer it that way. Our department performs evening mammograms, and the bulk of on-call hours MRI examinations are routine musculoskeletal and neuroradiology examinations. Many radiology practices provide on-call wet readings by residents, teleradiology, or “night-hawk” contractors, depending on the practice setting, leaving the final interpretation for normal work hours. This does not belie the observation that examinations are being performed increasingly during on-call hours, and that some proportion of these demand an urgent and accurate interpretation. Indirect evidence for this demand is provided by the volume of pages (calls) received by our on-call in-house pager. For the
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Figure 4.
Normalized trends in number of on-call studies (referenced to 1998 –1999).
time period 5/15/01 – 11/2/01, the on-call in-house pager received an average of 367 pages per week, or an average of three pages per on-call hour. This is a pace impossible to cover except by being physically present in the department at all hours. The increasing proportion of on-call examinations is in contrast to a traditional gross disproportion in staffing. Our department has 21 full-time equivalent attending radiologist slots during the day, with an additional 10 –12 residents and fellows, plus ancillary staff such as schedulers, clerks, transporters, nurses, and nurse practitioners on duty as well. During call hours, there are four attending radiologists covering interventional, neuroradiology, general, and body imaging from home, and a single in-house resident. Where Are We Going? The demand for radiology services will continue to grow. By design or not, the radiology department has become central to diagnosis, patient management planning, and, increasingly, treatment. The specialty of radiology has been extraordinarily successful in developing numerous
technically elegant and convenient imaging studies that can often clear up any clinical ambiguities. Conversely, imaging often raises other questions that require additional imaging either for follow-up or complementary modalities for clarification. Because imaging can be so sensitive and specific, it is tempting to use it as a screening tool to rule out a rare but critical diagnosis, rather than to confirm a clinical diagnosis. These factors may explain the paradoxical observation that, despite greater sophistication in diagnostic imaging, radiology use has risen faster than the hospital and emergency department caseload (5). Contributing also to the on-call workload is the continuing evolution of radiology practice. CT-guided abscess drainages are standard of care and routinely requested on evenings, weekends, and holidays. CT- and ultrasound-guided biopsies consume large blocks of scheduled time during the day. New radiologic approaches to problems also contribute: our department has shifted the preponderance of its pulmonary embolus evaluation to CT arteriograms and away from ventilationperfusion nuclear medicine scanning. Ventilation-perfusion scans have decreased in frequency by 48% over the
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Figure 5.
Trends in percentage of on-call cases.
past 3 years. Conventional pulmonary arteriograms are now rare. Advances in medical care will also contribute: treatment of emergent stroke with thrombolysis now requires urgent CT and will likely require urgent MRI interpretation before intervention. Lung cancer screening (11) and even routine whole body CT may take place in the future (12). An inevitable force for growth in radiologic workload will be demographic. The age distribution for the United States population from the 2000 US Census (13) coupled with the current life expectancy of approximately 79 years implies that there will be a steep increase in the number of older citizens demanding health care and radiology services with aging of the population. Clearly, there will be a lot more work to do. Increasing demand for radiology services will have the greatest effects on the radiologist if it is accompanied by increasing demand for real-time interpretation of imaging studies, the venerable “wet-reading.” Emergency physicians have long agitated for this (14), but busy primary care and subspecialty physicians expect timely reports as well, often to coincide with an office visit. Many primary care sites now have evening and weekend office hours. With the definition of normal radiology working hours as
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0800 –1700 Monday through Friday excluding holidays, on-call hours comprise fully 74% of the hospital and emergency department operating hours during a year, hours during which patient care decisions are being made. With growing awareness of and national concern for medical errors (15), it may become increasingly difficult to argue that radiologist input after patient management decisions have been made is appropriate. It is the American College of Radiology standard that each examination represents an individual consultation with a requesting clinical physician, and the examination is not officially complete until results have been communicated to that clinician (16). The newer, more sophisticated, and technically complex modalities (eg, CT, ultrasound, MRI) are the ones seeing the greatest shift in utilization on-call. These are also the ones that most demand the skills of a radiologist for confident interpretation. An emergency room physician may comfortably evaluate a chest or ankle radiograph, but he or she typically has neither the time nor the training to evaluate a CT or MRI examination. Although ultrasound is present in many emergency departments, the official examination is left to the radiology department. It is the American College of Radiology position that all
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imaging studies, including radiographs, are best interpreted by a radiologist (6). How Will We Get There? If the daytime schedule is full and all equipment is being fully utilized, then the growing volume of studies can only be accommodated in three ways: by extending the waiting list backlog and waiting times, by increasing the number of scanners and support personnel to increase throughput during the day, or by staffing the available equipment for more hours during each day and for more days each week. The first option is unacceptable for customer service reasons, and the second is unacceptable because of cost. This article provides evidence that the third solution has already been implementing by default. The general increase in the utilization of radiology services coincides with an explosion in the demand for on-call radiology services. The conventional practice of covering on-call hours with a single on-call radiologist, or a single resident in academic settings, and on-call technologists appears unsustainable if current trends continue. A change in staff scheduling will likely be required sooner or later to handle the workload. Our department has recently changed its technologist staffing to meet the growing demands. CT technologists are in-house 24 hours a day 7 days a week, as plain film technologists have been for many years. An ultrasound technologist is now scheduled until midnight on weekdays and 0800 –1600 on weekend days. MRI schedules patients until 11 PM every weekday night. Scheduled outpatient MRI on weekends is not uncommon. In response to the increased radiologist workload, our department has recently undergone an aggressive hiring phase for new attending radiologists, as have many other groups. Despite retirements and part-time transfers, the number of full-time equivalent radiologists on duty has increased during the day. The number of radiologists covering outside of “normal” working hours has not. This has most direct implications for the on-call radiologist. In an academic medical institution this is a resident with anywhere from 6 months to 3.5 years experience who has first call for interpretation of on-call studies and, furthermore, handles calls to schedule these and to report results, adjunctive duty not required during the day. Obtaining procedural consents and resolving complications for interventional radiology patients, including the occasional emergent admission, are also routine on-call duties. Our institution has attending radiologist coverage for emergency room radiographs on weekday evenings, which still
leaves 62% of operating hospital hours covered by a single resident only. A second resident has recently been added on weekend days to staff the plain film and fluoroscopy examinations. Even residents are a limited resource, however, and there are practical and statutory limitations to how many can be assigned to call duties (17). With no foreseeable increase in the number of radiology residency slots or in the number of practicing radiologists, as well as the shortage of radiologic technologists in all modalities, radiology departments will be challenged to meet future expectations. There may even be a liability issue lurking (18,19). For an academic medical center, tertiary referral center, and Level I trauma center, radiology services are in demand 24 hours a day, 7 days a week. Full radiology staffing only during traditional working hours is not sustainable in the long run if current trends in the growing demand for services at other times continue as routine studies spill over into nights and weekends, and emergency department and inpatient examinations proliferate. Although this article examines the experience of only a single academic radiology department, the findings are expected to be generalizable to other radiology practices that are sure to be grappling with these issues in their own way (20). REFERENCES 1. Sunshine JH, Cypel YS, Schepps B. Diagnostic radiologists in 2000: basic characteristics, practices, and issues related to the radiologist shortage. AJR Am J Roentgenol 2002; 178:291–301. 2. Bhargavan M, Sunshine JH. Workload of radiologists in the United States in 1998 –1999 and trends since 1995-1996. AJR Am J Roentgenol 2002; 179:1123–1128. 3. Sunshine JH, Bushee GR, Mallick R. U.S. radiologists’ workload in 1995-1996 and trends since 1991-1992. Radiology 1998; 208:19 –24. 4. Taylor GA. Impact of clinical volume on scholarly activity in an academic children’s hospital: trends, implications, and possible solutions. Pediatr Radiol 2001; 31:786 –789. 5. Henley MB, Mann FA, Holt S, Marotta J. Trends in case-mix-adjusted use of radiology resources at an urban level 1 trauma center. AJR Am J Roentgenol 2001; 176:851– 854. 6. American College of Radiology. ACR standard for radiologist coverage of imaging performed in hospital emergency departments. In: Standards, 2000-2001. Reston, VA: American College of Radiology, 2001; 7–9. 7. Sunshine JH, Burkhardt JH. Radiology groups’ workload in relative value units and factors affecting it. Radiology 2000; 214:815– 822. 8. Conoley PM. Productivity of radiologists in 1997: estimates based on analysis of resource-based relative value units. AJR Am J Roentgenol 2000; 175:591–595. 9. Altman DG. Practical Statistics for medical research. London, UK: Chapman and Hall/CRC, 1991, 160 –164. 10. Burt CW, McCaig LF. Trends in hospital emergency department utilization: United States, 1992-99. Vital Health Stat 13 2001; 150:1– 34. 11. Garg K, Keith RL, Byers T, et al. Randomized controlled trial with low-
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12. 13. 14.
15.
dose spiral CT for lung cancer screening: feasibility study and preliminary results. Radiology 2002; 225:506 –510. Brant-Zawadzki MN. CT Screening: Why I Do It. AJR Am J Roentgenol 2002; 179:319 –326. US Census 2000. Population Age distribution. Available at: http:// www.census.gov. Accessed May 25, 2003. Rapp, MT. President American College of Emergency Physicians Address to American College of Radiology, ACR Bulletin 2000; November: 44 – 46. Kohn LT, Corrigan JM, Donaldson MS. Committee on Quality Health Care in America, Institute of Medicine. To err is human. Washington, DC: National Academies Press, 2000.
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16. American College of Radiology. ACR standard for communication: diagnostic radiology. In: Standards, 2000-2001. Reston, VA: American College of Radiology, 2001: 3–5. 17. Patient and Physician Safety and Protection Act of 2001, HR 3236, 107th Congress (2001). 18. Berlin L. Liability of interpreting too many radiographs. AJR Am J Roentgenol 2000; 175:17–22. 19. Berlin L. Liability of attending physicians when supervising residents. AJR Am J Roentgenol 1998; 171:295–299. 20. Mueller CF, Yu JS. The concept of a dedicated emergency radiology section: justification and blueprint. AJR Am J Roentgenol 2002; 179: 1129 –1131.
Trends in On-call Workload in an Academic Medical Center Radiology Department 1998 –20021 Timothy J. Carroll, MD, PhD2
Rationale and Objectives. The workload in radiology departments is increasing rapidly. This study was designed to determine whether and to what extent the workload is being generated outside of traditional working hours (defined as 08001700 Monday thru Friday, excluding holidays). Materials and Methods. Exam statistics were derived from the radiology department’s automated examination scheduling and reporting system for four successive fiscal years. The distribution of the number of studies completed throughout the 24-hour day and the 7-day week was charted. Results. A large proportion of studies are being completed outside of traditional working hours. Moreover, as the overall workload of the department increased, the proportion of studies being completed during nontraditional working hours was increasing at an even faster pace, particularly in the cross-sectional imaging modalities. Computed tomography, magnetic resonance imaging, and ultrasound have increased by 59%, 51%, and 30%, respectively, over 4 years. The on-call proportions have increased from 34% to 40% and 13% to 18% for computed tomography and ultrasound, respectively, over 4 years and from 44% to 50% for magnetic resonance imaging over 3 years. Conclusion. These trends have implications for radiologist and radiology technologist staffing. The department has already modified the scheduling of technologist staffing to provide in-house extended-hours coverage in most modalities. As the number of studies conducted outside of traditional working hours continues to expand and the demand for contemporaneous readings increases, radiologist staffing may need to be adjusted as well. Traditional on-call coverage may be insufficient to competently handle the growing workload. This may have particular implications for radiology residency programs. Key Words. Workload; call; residency; trends; staffing. ©
AUR, 2003
The volume of radiologic examinations is growing at a rapid rate across the United States in all practice settings (1–5). This is plainly apparent to everyone in the radiology department, from staff radiologists to radiologic technologists to film librarians, as the pace of the work in-
Acad Radiol 2003; 10:1312–1320 1 From the Department of Radiology, Fletcher Allen Health Care/University of Vermont, Burlington, VT. Received May 27, 2003; revision requested July 12; received in revised form July 26; accepted 28 July 2003. Address correspondence to T.J.C. 2Current address: Department of Radiology, Children’s Hospital, 300 Longwood Ave., Boston, MA 02115.
©
AUR, 2003 doi:10.1016/S1076-6332(03)00381-7
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creases. It may be less apparent in general, but radiologist “night hawks,” on-call radiologists, and radiology residents are acutely aware that the pace of work outside traditional working hours is also growing. Does this represent a shift of work away from traditional 9 AM to 5 PM radiology practice toward a uniform demand for radiology services 24 hours a day, 7 days a week (commonly referred to as 24/7) (6), or is this perception simply a reflection of the general increase in demand for radiology services? The demands on the radiology workforce will be very different, depending on the answer to this question. This article presents an analysis of radiology workload that quantifies the trends in the temporal distribution of work throughout the day and week by enumerating the
TRENDS IN ON-CALL WORKLOAD
Academic Radiology, Vol 10, No 11, November 2003
number of examinations completed outside of traditional working hours in an academic medical center. These hours have historically been covered by a reduced staff of on-call personnel; consequently, these hours will be referred to throughout this article as on-call hours. MATERIALS AND METHODS Fletcher Allen Health Care located in Burlington, VT is a nonprofit academic medical center affiliated with the University of Vermont School of Medicine. In addition to the 562-bed main hospital that is a level I trauma center, there are two radiologist-staffed outpatient settings that perform ultrasound, mammography, and computed tomography (CT) examinations (at one site) during traditional working hours. Multiple primary care sites have plain radiograph capabilities, but the films are hand delivered to the Department of Radiology for interpretation. The Department of Radiology has used an automated scheduling and reporting system known as IDXrad (IDX Systems Corporation, South Burlington, VT) since October 1998. IDXrad includes many statistics reporting functions, one of which is a record of the completion time of all studies conducted by the department. The “exam statistics” function can compile counts of each type of study completed during any time period of interest. For this article, that function was used to generate counts of studies completed during normal working hours (defined as 0800-1700 Monday thru Friday, excluding holidays) and those completed during other hours. This was performed for four successive fiscal years (10/1/98 –9/30/99, 10/1/ 99 –9/30/00, 10/1/00 –9/30/01, 10/1/01–9/30/02) to discern temporal trends. Studies are recorded as completed at the time that the technologist ends the examination in the IDXrad system, not when it is interpreted. In practice, this almost always occurs at the time an examination was confirmed as technically complete by an approving radiologist or, for routine examinations, at the physical completion of the study. Reading may or may not take place soon thereafter. There are several potential limitations of this method, which include: There is an ongoing revision of the numbers of examinations recorded in IDXrad as studies are deleted or combined for billing and other administrative purposes. As a proportion of the total number of examinations, this has proven to be an insignificant amount that does not change the total examinations
in any particular modality overall more than a fraction of 1%. A related concern arises from an evolution in examination coding over the study period. For example, in the first year, a CT of the chest, abdomen, and pelvis required three requisition numbers and was counted as three studies. More recently, this common combination used for cancer staging and follow-up has been combined into a single requisition code. IDXrad accounts for these changes, however, through the implementation of an examination dictionary that includes an assigned study count for each examination code that can be greater than one. The combined chest/abdomen/ pelvis code is counted as three studies in that dictionary, thereby preserving the internal consistency of the examination number accounting. Other examples have been handled in a similar fashion. There is a lack of weighting of the individual examination counts for the amount of effort involved. Relative value units have been used to measure workload in other studies (7,8), which are based on a composite estimate of the total resources used. Relative value unit analysis was contemplated but impractical for this study because the relative value unit database in our IDXrad system is locally defined for technologist scheduling purposes and therefore is not comparable to the Medicare definitions used in other studies. The exam number is a satisfactory measure for the purposes of this study when establishing trends because it makes no difference what units are chosen, as long as same is compared with same. Random variation has been considered, but proves to be unimportant. Confidence intervals have been estimated assuming Poisson counting statistics for the absolute numbers of examinations and a binomial distribution for the proportions (9). With the large numbers involved, the confidence intervals are small, and random variation can be seen to change the trends not at all. A lack of overlap of 95% confidence intervals is equivalent to a probability less than 0.003 that the results are the same. For the few cases where confidence intervals do overlap, confidence intervals for the differences are computed and stated. RESULTS Table 1 and Figures 1–5 present the data in graphical bar chart form. The 95% confidence intervals are included.
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Table 1 Trends in Total Number of Departmental Radiologic Studies Completed Overall and During On-Call Hours for Four Successive Fiscal Years (95% Confidence Intervals are Included) Fiscal Year
10/98–09/99
10/99–09/00
10/00–09/01
10/01–09/02
Total cases Total call cases
179,876 ⫾ 831 51,279 ⫾ 444
188,035 ⫾ 850 53,667 ⫾ 454
192,483 ⫾ 860 56,286 ⫾ 465
211,743 ⫾ 902 62,627 ⫾ 490
Figure 1.
Total number of examinations by modality 2001–2002.
Table 1 shows both the absolute number of total examinations completed by the department in each of the four years studied, as well as similar data for the examinations completed outside traditional working hours (on-call examinations) over the same 4-year period. This shows a monotonic increase in the number of studies completed both in total and during on-call hours. The number of examinations is not evenly distributed across the different modalities. Figure 1 illustrates the distribution of radiology examinations among various modalities including CT, ultrasound (excluding breast), fluoroscopy, plain radiography (excluding mammography), magnetic resonance imaging (MRI), angiography/interventional and the mammography department for the most recent fiscal year 2001–2002. To demonstrate the distribution of examinations throughout the day, Figure 2 plots the ratio of the number of examinations completed on-call to those completed during traditional working hours for both the total exami-
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nations as well as the ratio broken down by modalities for the most recent year 2001–2002. This figure clearly illustrates that a large proportion of examinations are being completed on-call and that particular modalities are heavily utilized during on-call hours including CT, MRI, ultrasound, and plain radiography. Figure 3 presents the same data as Table 1 in a different way by normalizing the number of examinations to the number in 1998 –1999. A selected group of the most heavily used modalities is also included. Figure 4 does the same for the number of on-call examinations. Comparison of Figures 3 and 4 clearly shows that the proportional increase in the number of on-call studies is greater than for the total number of studies, particularly in the body imaging modalities. The most striking example is for ultrasound, where the annual total number has actually steadily declined while the number completed on-call has continued to rise. The drop in total ultrasound examinations is partly attributable to a shift in the bulk of the obstetrics and a
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Figure 2.
Fraction of cases completed on-call, 2001–2002.
significant proportion of the gynecologic ultrasounds to a new maternal/fetal medicine service in the obstetrics and gynecology department during 2001, studies that had been routinely performed in the radiology department before that time. On-call studies are still the responsibility of the radiology department. A similar situation exists for vascular ultrasound studies that are conducted by a vascular laboratory in the surgery department during the day, but on-call examinations are conducted by radiology. The vascular ultrasound arrangement existed before 1998, the earliest year included in this study, so it does not cause a similar discontinuity in the statistical trends. The dramatic jump in total MRI examinations from fiscal year 1998 – 1999 to year 1999 –2000 corresponds with the installation of a second MRI machine in July 1999. While these particular circumstances may be unique to our hospital, they also provide evidence that expansion of daytime imaging capacity (by additional equipment or transfer of duties to other departments) has not prevented continuing growth in on-call examinations. To discern any shift in the distribution of work into on-call hours, Figure 5 plots the trend in the fraction of examinations completed on-call as a percentage of the department annual totals for the each of the years studied for the selected group of modalities most heavily utilized after-hours. Figure 5 shows that the trend in the percent
of studies completed on-call is stable overall, but it is steadily upward in the cross-sectional imaging modalities.
DISCUSSION Where Are We Now? The radiology workday is lengthening. The data presented in the previous section concretely demonstrate and quantify the steadily increasing workload for the radiology department overall, but an even faster growth trend in the number of radiologic studies completed on-call as illustrated by Figures 3 and 4. This is most striking for ultrasound, where the total number of examinations has steadily declined while the on-call numbers have climbed by 30% over 4 years since 1998. CT and MRI utilization has also rapidly expanded during on-call hours, with the numbers increasing by 59% and 51%, respectively. Plain radiography has changed the least, but still has climbed 13%. Overall, the total examinations being completed during on-call hours has increased 22% over 4 years. Absolute numbers are growing both day and night, but there is also a perceptible trend toward shift of studies into on-call hours. This is most pronounced for the body imaging modalities CT, ultrasound, and MRI, with the percentage completed on-call increasing from 34% to 40% over 4 years, 13% to 18% over 4 years, and from
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Figure 3.
Normalized trends in total department studies (referenced to 1998 –1999).
44% to 50% over 3 years, respectively (Fig 5). The magnitude of the shift has been mitigated somewhat in our department by expansion of daytime imaging capacity by the installation of a second MRI machine (explaining the drop in on-call percentage from 1998 –1999 to 1999 –2000 from 56% to 44%) and faster multi-detector CT scanners. The overall proportion of studies conducted on-call has barely changed from 29% to 30% (difference ⫽ 1.1 ⫾ 0.3, 95% confidence interval), but this reflects growth in routine examinations during the day such as mammography (up 28% over 4 years), and, most importantly, the minimal shift in the most common modality by far, plain radiography, that changed only from 37% to 38% (difference ⫽ 0.7 ⫾ 0.4). Although small in percentage, this represents a large additional absolute number of radiographic studies on-call as noted above. If mammography is excluded, then the shift toward on-call hours is more pronounced, with the total examination on-call proportion increasing from 32% to 34% (difference ⫽ 1.9 ⫾ 0.7) over 4 years. This disproportionate rise in on-call examinations has several contributing causes. Not only has the demand for emergent and in-patient services increased (5,10), imaging volume for the emergency department and inpatient ser-
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vices has increased even faster (5). It should not be surprising that the completion of scheduled studies has also spilled over into on-call hours because there are systemic limitations to the number of scheduled exams that can be completed during the day (eg, number of scanners, technologists, workstations, interpreting radiologists). Technologists are required to be physically present to perform the studies, but it has traditionally been true that examination completion does not necessarily equal contemporaneous interpretation by a radiologist. Many routine examinations are conducted in the evening for reading the next day, and radiologists prefer it that way. Our department performs evening mammograms, and the bulk of on-call hours MRI examinations are routine musculoskeletal and neuroradiology examinations. Many radiology practices provide on-call wet readings by residents, teleradiology, or “night-hawk” contractors, depending on the practice setting, leaving the final interpretation for normal work hours. This does not belie the observation that examinations are being performed increasingly during on-call hours, and that some proportion of these demand an urgent and accurate interpretation. Indirect evidence for this demand is provided by the volume of pages (calls) received by our on-call in-house pager. For the
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Figure 4.
Normalized trends in number of on-call studies (referenced to 1998 –1999).
time period 5/15/01 – 11/2/01, the on-call in-house pager received an average of 367 pages per week, or an average of three pages per on-call hour. This is a pace impossible to cover except by being physically present in the department at all hours. The increasing proportion of on-call examinations is in contrast to a traditional gross disproportion in staffing. Our department has 21 full-time equivalent attending radiologist slots during the day, with an additional 10 –12 residents and fellows, plus ancillary staff such as schedulers, clerks, transporters, nurses, and nurse practitioners on duty as well. During call hours, there are four attending radiologists covering interventional, neuroradiology, general, and body imaging from home, and a single in-house resident. Where Are We Going? The demand for radiology services will continue to grow. By design or not, the radiology department has become central to diagnosis, patient management planning, and, increasingly, treatment. The specialty of radiology has been extraordinarily successful in developing numerous
technically elegant and convenient imaging studies that can often clear up any clinical ambiguities. Conversely, imaging often raises other questions that require additional imaging either for follow-up or complementary modalities for clarification. Because imaging can be so sensitive and specific, it is tempting to use it as a screening tool to rule out a rare but critical diagnosis, rather than to confirm a clinical diagnosis. These factors may explain the paradoxical observation that, despite greater sophistication in diagnostic imaging, radiology use has risen faster than the hospital and emergency department caseload (5). Contributing also to the on-call workload is the continuing evolution of radiology practice. CT-guided abscess drainages are standard of care and routinely requested on evenings, weekends, and holidays. CT- and ultrasound-guided biopsies consume large blocks of scheduled time during the day. New radiologic approaches to problems also contribute: our department has shifted the preponderance of its pulmonary embolus evaluation to CT arteriograms and away from ventilationperfusion nuclear medicine scanning. Ventilation-perfusion scans have decreased in frequency by 48% over the
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Figure 5.
Trends in percentage of on-call cases.
past 3 years. Conventional pulmonary arteriograms are now rare. Advances in medical care will also contribute: treatment of emergent stroke with thrombolysis now requires urgent CT and will likely require urgent MRI interpretation before intervention. Lung cancer screening (11) and even routine whole body CT may take place in the future (12). An inevitable force for growth in radiologic workload will be demographic. The age distribution for the United States population from the 2000 US Census (13) coupled with the current life expectancy of approximately 79 years implies that there will be a steep increase in the number of older citizens demanding health care and radiology services with aging of the population. Clearly, there will be a lot more work to do. Increasing demand for radiology services will have the greatest effects on the radiologist if it is accompanied by increasing demand for real-time interpretation of imaging studies, the venerable “wet-reading.” Emergency physicians have long agitated for this (14), but busy primary care and subspecialty physicians expect timely reports as well, often to coincide with an office visit. Many primary care sites now have evening and weekend office hours. With the definition of normal radiology working hours as
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0800 –1700 Monday through Friday excluding holidays, on-call hours comprise fully 74% of the hospital and emergency department operating hours during a year, hours during which patient care decisions are being made. With growing awareness of and national concern for medical errors (15), it may become increasingly difficult to argue that radiologist input after patient management decisions have been made is appropriate. It is the American College of Radiology standard that each examination represents an individual consultation with a requesting clinical physician, and the examination is not officially complete until results have been communicated to that clinician (16). The newer, more sophisticated, and technically complex modalities (eg, CT, ultrasound, MRI) are the ones seeing the greatest shift in utilization on-call. These are also the ones that most demand the skills of a radiologist for confident interpretation. An emergency room physician may comfortably evaluate a chest or ankle radiograph, but he or she typically has neither the time nor the training to evaluate a CT or MRI examination. Although ultrasound is present in many emergency departments, the official examination is left to the radiology department. It is the American College of Radiology position that all
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imaging studies, including radiographs, are best interpreted by a radiologist (6). How Will We Get There? If the daytime schedule is full and all equipment is being fully utilized, then the growing volume of studies can only be accommodated in three ways: by extending the waiting list backlog and waiting times, by increasing the number of scanners and support personnel to increase throughput during the day, or by staffing the available equipment for more hours during each day and for more days each week. The first option is unacceptable for customer service reasons, and the second is unacceptable because of cost. This article provides evidence that the third solution has already been implementing by default. The general increase in the utilization of radiology services coincides with an explosion in the demand for on-call radiology services. The conventional practice of covering on-call hours with a single on-call radiologist, or a single resident in academic settings, and on-call technologists appears unsustainable if current trends continue. A change in staff scheduling will likely be required sooner or later to handle the workload. Our department has recently changed its technologist staffing to meet the growing demands. CT technologists are in-house 24 hours a day 7 days a week, as plain film technologists have been for many years. An ultrasound technologist is now scheduled until midnight on weekdays and 0800 –1600 on weekend days. MRI schedules patients until 11 PM every weekday night. Scheduled outpatient MRI on weekends is not uncommon. In response to the increased radiologist workload, our department has recently undergone an aggressive hiring phase for new attending radiologists, as have many other groups. Despite retirements and part-time transfers, the number of full-time equivalent radiologists on duty has increased during the day. The number of radiologists covering outside of “normal” working hours has not. This has most direct implications for the on-call radiologist. In an academic medical institution this is a resident with anywhere from 6 months to 3.5 years experience who has first call for interpretation of on-call studies and, furthermore, handles calls to schedule these and to report results, adjunctive duty not required during the day. Obtaining procedural consents and resolving complications for interventional radiology patients, including the occasional emergent admission, are also routine on-call duties. Our institution has attending radiologist coverage for emergency room radiographs on weekday evenings, which still
leaves 62% of operating hospital hours covered by a single resident only. A second resident has recently been added on weekend days to staff the plain film and fluoroscopy examinations. Even residents are a limited resource, however, and there are practical and statutory limitations to how many can be assigned to call duties (17). With no foreseeable increase in the number of radiology residency slots or in the number of practicing radiologists, as well as the shortage of radiologic technologists in all modalities, radiology departments will be challenged to meet future expectations. There may even be a liability issue lurking (18,19). For an academic medical center, tertiary referral center, and Level I trauma center, radiology services are in demand 24 hours a day, 7 days a week. Full radiology staffing only during traditional working hours is not sustainable in the long run if current trends in the growing demand for services at other times continue as routine studies spill over into nights and weekends, and emergency department and inpatient examinations proliferate. Although this article examines the experience of only a single academic radiology department, the findings are expected to be generalizable to other radiology practices that are sure to be grappling with these issues in their own way (20). REFERENCES 1. Sunshine JH, Cypel YS, Schepps B. Diagnostic radiologists in 2000: basic characteristics, practices, and issues related to the radiologist shortage. AJR Am J Roentgenol 2002; 178:291–301. 2. Bhargavan M, Sunshine JH. Workload of radiologists in the United States in 1998 –1999 and trends since 1995-1996. AJR Am J Roentgenol 2002; 179:1123–1128. 3. Sunshine JH, Bushee GR, Mallick R. U.S. radiologists’ workload in 1995-1996 and trends since 1991-1992. Radiology 1998; 208:19 –24. 4. Taylor GA. Impact of clinical volume on scholarly activity in an academic children’s hospital: trends, implications, and possible solutions. Pediatr Radiol 2001; 31:786 –789. 5. Henley MB, Mann FA, Holt S, Marotta J. Trends in case-mix-adjusted use of radiology resources at an urban level 1 trauma center. AJR Am J Roentgenol 2001; 176:851– 854. 6. American College of Radiology. ACR standard for radiologist coverage of imaging performed in hospital emergency departments. In: Standards, 2000-2001. Reston, VA: American College of Radiology, 2001; 7–9. 7. Sunshine JH, Burkhardt JH. Radiology groups’ workload in relative value units and factors affecting it. Radiology 2000; 214:815– 822. 8. Conoley PM. Productivity of radiologists in 1997: estimates based on analysis of resource-based relative value units. AJR Am J Roentgenol 2000; 175:591–595. 9. Altman DG. Practical Statistics for medical research. London, UK: Chapman and Hall/CRC, 1991, 160 –164. 10. Burt CW, McCaig LF. Trends in hospital emergency department utilization: United States, 1992-99. Vital Health Stat 13 2001; 150:1– 34. 11. Garg K, Keith RL, Byers T, et al. Randomized controlled trial with low-
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12. 13. 14.
15.
dose spiral CT for lung cancer screening: feasibility study and preliminary results. Radiology 2002; 225:506 –510. Brant-Zawadzki MN. CT Screening: Why I Do It. AJR Am J Roentgenol 2002; 179:319 –326. US Census 2000. Population Age distribution. Available at: http:// www.census.gov. Accessed May 25, 2003. Rapp, MT. President American College of Emergency Physicians Address to American College of Radiology, ACR Bulletin 2000; November: 44 – 46. Kohn LT, Corrigan JM, Donaldson MS. Committee on Quality Health Care in America, Institute of Medicine. To err is human. Washington, DC: National Academies Press, 2000.
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16. American College of Radiology. ACR standard for communication: diagnostic radiology. In: Standards, 2000-2001. Reston, VA: American College of Radiology, 2001: 3–5. 17. Patient and Physician Safety and Protection Act of 2001, HR 3236, 107th Congress (2001). 18. Berlin L. Liability of interpreting too many radiographs. AJR Am J Roentgenol 2000; 175:17–22. 19. Berlin L. Liability of attending physicians when supervising residents. AJR Am J Roentgenol 1998; 171:295–299. 20. Mueller CF, Yu JS. The concept of a dedicated emergency radiology section: justification and blueprint. AJR Am J Roentgenol 2002; 179: 1129 –1131.