|Gerald R. Kolb, JD|
The digital revolution in radiology is well under way, with many full-digital departments in operation across the United States. While the focus of digital radiology has largely been on the acquisition technologies, the interpretive environment of the radiologist also has undergone radical change.
The ability to electronically present a stream of digital images to an interpreting physician creates new opportunities for radiologists, but raises new challenges for those physicians and the departments in which they work. The opportunities include both greater radiologist and department productivity. The challenges are physical and mental fatigue, including the potential to interrupt or prematurely end the physician’s career. This article will discuss how the digital environment is affecting radiologist workflow; the dangers inherent in the new work paradigm; and how to optimize the interpretive environment to improve both productivity and the well-being of the interpreting physician.
In the film-based practice environment, physicians utilize a wide variety of light boxes and viewing systems, up to and including complex motorized viewers, to provide the appropriate backlighting necessary to review x-ray and other images. These systems are invariably fixed in their relationship to the interpreting physician, and the physician utilizes a number of tools (eg, magnifying lenses, scales, masking materials or systems) to aid in the interpretive process.
With film images, the physician, a technologist, or a film technician is required to periodically remove films that have been reviewed by the radiologist and to hang new films for review. In busy practices or departments, the typical radiologist will need to move from “board to board,” reviewing images in order to keep up with department volume, and to view different types of images. Use of soft-copy review workstations that are specific to certain modalities (eg, MRI, CT) exacerbate this situation in the film-based practice.
One of the great productivity enhancements cited by PACS advocates is the elimination of the wasted motion and interruption illustrated in the preceding paragraphs. A good PACS, quite literally, allows the radiologist to interpret successive images with little movement other than that required to open and close cases from the worklist, utilize digital tools driven by a handy key pad, and dictate findings. The potential—and often the expectation—is for dramatic increases in productivity from the reduction in “noise” in the interpretive process caused by interruptions.
Unfortunately, unless we redesign the interpretive environment, the potential productivity increases cannot be realized except at substantial and very expensive human cost. In the simplest of terms, the radiologist is a human being, not a robot, and the interpretive environment in which he or she is expected to function must be defined in human terms. Humans cannot sit in one place all day performing repetitive tasks without becoming fatigued. This is not simply a comfort issue. Physical fatigue leads to mental fatigue, and mental fatigue increases the potential for interpretive error.
It is interesting, if somewhat disconcerting, to note that the literature reflects the study of workstation ergonomics for nurses 1 and dental offices, 2 but there have been few studies of the radiologists’ work environment, 3,4 despite the fact that the majority of a diagnostic radiologist’s time is spent in front of either a film viewing system, monitors for use with either a specific modality (eg, CT, MRI), or a PACS workstation. In fact, when researching this subject, one finds that the references to ergonomics in the radiology literature are primarily to subjects like productivity, 5 monitor light conditions, 6 room architecture, 7,8 and the way tools and features are presented on PACS workstations. 9
ADAPTING GENERAL ERGONOMICS
Fortunately, there has been significant study of computer workers, and this information can be considered as a general analog of the workstation experience for radiologists. Individuals working at computer workstations 4 or more hours per day have been defined as being at risk for cumulative trauma disorders (CTDs), 10 and radiologists in PACS environments certainly fit that criteria. OSHA has taken the position that while it is difficult, if not impossible, to determine a specific length of time in front of a computer that creates a risk of injury, workers maintaining static posture and who use repetitive motions will have problems if work variation and breaks are not used, and if the work environment has not been appropriately designed. 11 The Ruess study, 4 though small, identified the ergonomic issues in radiology as the same as in other computer-intensive endeavors.
Ergonomics research over many years has established the need for incorporation of several basic elements to build a work environment for the pursuit of high-order mental activity involving visual interpretation. 11 Those elements include:
- The viewing angle between the head/neck and the image being reviewed;
- Proper support for the lower arms and wrists;
- Maintaining a 90-degree relationship of the lower and upper arm;
- A chair that supports the buttocks and the entire spinal column, including the head and neck, without creating any pressure points;
- Proper seat height, allowing the feet to rest firmly on the floor or a support;
- Elimination of extraneous noise/interruption; and
- Proper ambient light levels for the output of the monitors being used.
With these criteria, we could build a special reading room for a single radiologist incorporating the correct lighting level, with monitors located at the correct height and a lower shelf for input devices; also purchasing a specialized chair that is adjustable for height and angle, and provides support for the spinal column, buttocks, and upper leg. Unfortunately, not all radiologists are built alike, and to expect several different radiologists to use such a room would be akin to expecting several people of differing heights and builds to drive the same car without adjusting the seat, steering wheel, or mirrors. Clearly, in the PACS interpretive environment, much more than just the chair needs to be adjustable.
Assuming that we could solve the monitor and input device height adjustability issues, the study of ergonomics has one more lesson to throw at us:
In order to minimize fatigue and create a sustainable environment for visual interpretation, the individual should vary his or her position every 20 minutes—while continuing to maintain the proper relationship of the head/neck to the image, and the rest of the ergonomic parameters set out above. 12
This rule helps to explain why film-based viewing environments, though clearly not optimal, have worked as well as they have. Simply put, the radiologist is in almost constant motion while he or she is reviewing films, moving toward the image to allow a magnifying glass to be used, and scanning across a series of images with the head, neck, and torso when more complex studies are reviewed. In addition, the radiologist must periodically leave the viewer entirely to allow it to be rehung with images. This continuum of movement tends to mitigate the poor static viewing position vis-à-vis the images.
PROPER INTERPRETIVE PROTOCOLS
In the digital/PACS world, however, there is no procedural need to move around, and we must be careful to develop and incorporate interpretive solutions that facilitate the appropriate reading posture, and enable varying positions while retaining the correct posture. While the former requirement can be met by hand-operated mechanical systems, the latter requires electrical assistance, or it becomes too difficult to accomplish on a regular basis during an interpretive session. There are studies, in fact, that have established that small breaks (less than 2 minutes) to adjust position and change the focus of the eyes away from the computer every 20 minutes reduce the complaints of musculoskeletal distress without adversely affecting productivity. 12,13
Tables are just now becoming available that meet all of the criteria for an ergonomic platform, are electrically operated, create a micro environment by controlling both sound and lighting, and allow the radiologist to stand for periods of time while maintaining all of the correct relationships.
These tables also are expensive, as much as $7,000 and more. In the fight for scarce capital, how can this kind of purchase be financially justified? For a radiology practice, the financial justification should be simple. If a radiologist is lost due to injury, the cost is about $4,500 per day in chargeable revenue. 14 Carpal tunnel injuries alone result in significant losses of productive time (3-6 week recovery time from surgery), and the financial consequences of an extended absence due to injury is not one that is comfortable for a radiology administrator to contemplate.
In a hospital-based department, the argument may be more difficult, but clearly the hospital as well as the radiology group require sustained radiology coverage. With the current shortage of radiologists, the difference of one radiologist in a department may be critical to meeting JCAHO standards as well as patient needs for timely interpretation of images. Even in outpatient operations (eg, breast imaging), the loss of the radiologist may curtail the ability of the center or program to accept patients or deliver services within an acceptable time period.
Of focal importance—other than concern for human health conditions—is that the practice or hospital has made a very substantial investment in PACS. There are many reasons to invest in PACS, but one of the most important of these reasons is to improve and optimize the overall cost-effectiveness of the delivery of medical imaging.
CALCULATING VALUE IN ERGONOMICS
How can improvement of the ergonomic environment in a reading room be valued? There is no direct reimbursement, and it would be very difficult to construct a prospective study that could differentiate between the productivity value of the PACS components and the ergonomic influence. To a certain extent, the valuation process becomes intuitive, but there is a way that we can come to some more concrete comparisons. One of these is to compare the value of a given procedure with the cost of the equipment.
Table 1 looks at reimbursement for three typical procedures selected because they do not have extraordinary variable costs (eg, contrast agents). The payments for each (Medicare Outpatient Prospective Payment System, 2005 15 ) are then developed, and the cost of $7,000 is divided by the procedure reimbursement, yielding the approximate number of additional procedures that would be required to amortize the cost of a purchase of one ergonomic table. Notice that an additional volume of 19 MRI brain studies will pay for one table. On an annual basis, this is less than one additional procedure every other week. Viewed in this manner, it should be evident that the additional productivity required to pay for this significant improvement is relatively small. Even though the hospital department might not directly recognize revenue from increased radiologist productivity, increases in radiologist productivity indirectly create additional revenue by allowing the department to operate at maximum efficiency.
|Table 1. Cost of PACS Work Table in Procedure Equivalents.|
Proper attention to ergonomics in the radiology interpretive environment is a good human investment and it is also a good economic investment. As radiology moves toward the digital PACS environment, it is important that we reinvent our old interpretive environments to optimize the capabilities of the new tools. It is equally important that we consider the health of radiologists, as we put more and new physical demands on them, and that we prioritize ergonomic solutions in our PACS implementation plans.
Gerald R. Kolb, JD, is president, Breast Health Management, a consulting service headquartered in Bend, Ore.
- Nielsen K, Trinkoff A. Applying ergonomics to nursing computer workstations. CIN: Computers, Informatics, Nursing. 2003;21(3):150-157.
- Andrews N, Vigoren G. Ergonomics: muscle fatigue, posture, magnification, and illumination. Compend Contin Educ Dent. 2002;23(3):261-6, 268, 270 passim; quiz 274.
- Rumreich LL, Johnson AJ. From traditional reading rooms to a soft copy environment: radiologist satisfaction survey. J Digit Imaging. 2003;16(3):262-269.
- Ruess L, O’Conner SC, Cho KH, et al. Carpal tunnel syndrome and cubital tunnel syndrome: work-related musculoskeletal disorders in four symptomatic radiologists. AJR Am J Roentgenol. 2003;181:37-42.
- Redfern RO, Horii SC, Feingold E, et al. Radiology workflow and patient volume: effect of picture archiving and communication systems on technologists and radiologists. J Digit Imaging. 2000;13(2 suppl 1):97-100.
- Wade C, Brennan PC. Assessment of monitor conditions for the display of radiological diagnostic images and ambient lighting. Br J Radiol. 2004;77(918):465-71.
- Horii SC, Horii HN, Mun SK, et al. Environmental designs for reading from imaging work stations: ergonomic and architectural features. J Digit Imaging. 1989;2(3):156-162.
- Badano A. AAPM/RSNA tutorial on equipment selection: PACS equipment overview: display systems. Radiographics. 2004;24(3):879-889.
- Moise A, Atkins MS. Design requirements for radiology workstations. J Digit Imaging. 2004;17(2):92-9.
- Hess D. Employee perceived stress: relationship to the development of repetitive strain injury symptoms. AAOHN J. 1997;45(3):115-23.
- Working Safely with Video Data Terminals. Washington, DC: US Department of Labor, Occupational Safety and Health Administration; 1997. 3072 (revised).
- Henning RA, Jacques P, Kissel GV, et al. Frequent short rest breaks from computer work: effects on productivity and well being at two field sites. Ergonomics. 1997;40:78-91.
- Dababneh AJ, Swanson N, Shell RL. Impact of added rest breaks on the productivity and well being of workers. Ergonomics. 2001;44:164-174.
- Murphey SL. PACS: refining the human-machine interface. AuntMinnie.com, October 29, 2004. Available at: www.auntminnie.com/index.asp?Sec=sup&Sub=pac&Pag=dis&ItemId=63368 . Accessed December 3, 2004.
- Department of Health and Human Resources, Centers for Medicare and Medicaid Services, Medicare Program; Revisions to Payment Policies Under the Physician Fee Schedule for Calendar Year 2005. Federal Register. November 15, 2004; 69(219):66235-66916. Available at: www.cms.hhs.gov/providers/pufdownload/#pfspayment . Accessed December 14, 2004.