Radiology (Position Paper)
Diagnostic radiography is an integral part of the evaluation and management of acute and chronic illnesses. Offering radiography in the family medicine practice reduces access issues and decreases the time to diagnosis and treatment. Specific radiologic services provided are at the discretion of an individual practice. According to the American Academy of Family Physicians (AAFP) Member Census (as of June 30, 2015), 26.1 percent of AAFP members offer x-ray services in their practices, 7.4 percent offer obstetric (OB) ultrasound imaging, 5.6 percent offer non-OB ultrasound imaging, and 4.3 percent offer echocardiography.1 Family medicine practices that offer in-office radiography typically do not have a radiologist on staff, particularly in rural settings. Because family physicians receive the necessary training in residency to interpret radiographs, it is common for them to order and read radiographs in their practices. A family physician is uniquely positioned to make a diagnosis and develop a treatment plan by integrating his or her interpretation of a patient’s radiograph with knowledge and understanding of the patient’s complete history, physical examination, and laboratory testing. In some cases, the family physician may choose to have a radiograph over-read by a radiologist. The patient’s care may be modified if there is a clinically significant discrepancy between the readings.
The PCMH model promotes increased patient access and same-day services; in-office diagnostic radiography supports these goals. It is a valuable service for patients, providing care at a local level and giving needed access to patients who would have difficulty traveling to another facility, especially patients who are elderly or have a disability. Diagnostic radiography provided in the family physician’s office reduces transitions of care, allowing patients to remain in their medical home for diagnosis and treatment (e.g., splinting or definitive care of fractures or sprains). It saves the health care system money because patients are not seen in the emergency department (ED) or an urgent care center. This also avoids the fragmentation of care that can occur when an urgent care or ED physician refers a patient out of the PCMH to another specialist following radiography.
Physicians billing for in-office radiography may bill for the technical component (taking the pictures) or the professional component (reading the images) or both. A family physician with on-site radiography equipment will typically bill for the technical component of the imaging service. In addition, if the family physician reads a radiograph and generates a separate written report, then the professional component would also be billed. If a radiograph is initially read by the family physician and then over-read by a radiologist who generates the written report, the radiologist would bill for the professional component. A 2015 study estimated that 53.8 percent of Medicare Physician Fee Schedule (MPFS) payments for medical imaging services in 2011 were made to nonradiologists.2 Nonradiologists received the following percentages of specific payment types for medical imaging:
- Professional-only payments: 20.6 percent
- Technical-only payments: 84.9 percent
- Global (both professional and technical) payments: 70.1 percent
MPFS medical imaging payments to nonradiologists differed from state to state, with percentages ranging from a low of 32 percent (Minnesota) to a high of 69.5 percent (South Carolina). In nearly 60 percent of states, the percentage of MPFS payments for medical imaging to nonradiologists exceeded payments to radiologists.
Between 2000 and 2005, medical imaging was one of the fastest growing categories of Medicare spending, with the number of imaging studies paid for under the MPFS (excluding imaging studies performed in hospital outpatient departments) growing more rapidly (61 percent growth) than the sum of all physician services (31 percent growth).3 In response to this rapid growth, Congress and the Centers for Medicare & Medicaid Services (CMS) took action to systematically reduce reimbursement for medical imaging, primarily focusing on reductions to the unit cost. One major action was the 2005 Deficit Reduction Act (DRA), which took effect on January 1, 2007; it reduced global and technical-only payments for in-office imaging to the outpatient hospital payment level.4 Other initiatives to address medical imaging costs included changes to payment methods for practice expense and equipment utilization, bundling of CPT codes, and discounting of Multiple Procedure Payment Reduction (MPPR).5,6
Aggregate Medicare payments to physicians for diagnostic imaging began to decline in 2007; in 2010, these payments were 21 percent lower than they had been in 2006.6 The volume of medical imaging also declined during this time period.5 According to a report from the American College of Radiology (ACR), data from private payers on medical imaging use reflect the same general trends as Medicare data.6 In addition to the DRA and other payment-reduction initiatives, factors that have contributed to slowing the growth of medical imaging include changes in imaging technology and clinical practice, such as technological maturation; initiatives to reduce radiation exposure; increased use and promotion of evidence-based medicine, appropriateness criteria, and clinical utilization guidelines; increased attention to cost-effective care; and better electronic access to reports and images from previous examinations.4-6
It is the position of the AAFP that clinical privileges should be granted on the basis of each individual physician’s documented training and/or experience, demonstrated abilities, and current competence, not on specialty designation alone.7 This general policy applies to ordering and interpreting radiographs in the family medicine practice. Patient care is improved when a family physician is able to fully integrate the patient’s history and physical examination with contemporaneous interpretation of diagnostic imaging and other diagnostic studies. Patient convenience and satisfaction also are improved by the availability of on-site radiography.
The AAFP believes that family physicians—like other physicians who use diagnostic radiography to evaluate patients—are entitled to appropriate compensation for their services. This position is in keeping with the positions of other specialty organizations that represent physicians who are not radiologists but use diagnostic radiography to evaluate patients, such as orthopedic specialists and ED physicians. For example, according to a position statement of the American Academy of Orthopaedic Surgeons (AAOS) that was revised in February 2012, “The AAOS believes that orthopaedists are entitled to adequate compensation for the cost and work involved in providing [musculoskeletal radiographic studies] in their offices. Any policy that prohibits orthopaedists from performing and interpreting diagnostic imaging studies in their offices interferes with the patient’s ability to receive optimal care.”8 In February 2013, the American College of Emergency Physicians (ACEP) reaffirmed a policy statement that endorses the following principle: “The emergency physician providing contemporaneous interpretation of a diagnostic study is entitled to reimbursement for such interpretation even if the study is reviewed subsequently as part of the quality control process of the institution in which the physician practices.”9
The American Medical Association’s (AMA’s) approved policy Freedom of Practice in Medical Imaging states that the AMA will:
- “Encourage and support collaborative specialty development and review of any appropriateness criteria, practice guidelines, technical standards, and accreditation programs, particularly as Congress, federal agencies and third-party payers consider their use as a condition of payment, and [use] the AMA Code of Ethics as the guiding code of ethics in the development of such policy;
- Actively oppose efforts by private payers, hospitals, Congress, state legislatures, and the Administration to impose policies designed to control utilization and costs of medical services unless those policies can be proven to achieve cost savings and improve quality while not curtailing appropriate growth and without compromising patient access or quality of care;
- Actively oppose efforts to require patients to receive imaging services at imaging centers that are mandated to require specific medical specialty supervision and support patients receiving imaging services at facilities where appropriately trained medical specialists can perform and interpret imaging services regardless of medical specialty; and
- Actively oppose any attempts by federal and state legislators, regulatory bodies, hospitals, private and government payers, and others to restrict reimbursement for imaging procedures based on physician specialty, and continue to support the reimbursement of imaging procedures being performed and interpreted by physicians based on the proper indications for the procedure and the qualifications and training of the imaging specialists in that specific imaging technique regardless of their medical specialty.”10
The CMS policy on Medicare Part B payment for the professional component of diagnostic radiography does not discriminate on the basis of specialty. Chapter 13, Section 20.1 of the Medicare Claims Processing Manual states that Medicare administrative contractors (MACs) that process Medicare Part A and Medicare Part B claims for a defined geographic area or jurisdiction (A/B MACs) “must pay for the [professional component] of radiology services furnished by a physician to an individual patient in all settings under the fee schedule for physician services regardless of the specialty of the physician who performs the service.”11 CMS also notes that the interpretation of a diagnostic procedure includes a written report. Regarding payment for the technical component of diagnostic radiography, Chapter 13, Section 20.2.2 of the Medicare Claims Processing Manual states that A/B MACs “must pay under the fee schedule for the [technical component] of radiology services furnished to beneficiaries who are not patients of any hospital, and who receive services in a physician’s office, a freestanding imaging or radiation oncology center, or other setting that is not part of a hospital.”11
Diagnostic radiography is part of the evaluation of many clinical conditions that present in a family medicine practice. For example, well-accepted criteria for diagnostic radiography have been reported in the literature for acute knee and ankle injuries that are commonly evaluated and treated by family physicians.12-17 Initial radiologic evaluation of a variety of acute and chronic conditions is appropriately performed in the family physician’s office, with referral to another facility for more extensive imaging, if necessary.
Physicians should be mindful of the risks of medical imaging (e.g., radiation exposure, overuse) and make judicious use of diagnostic radiography to reduce these risks.18,19 Diagnostic radiography should be performed when indicated after careful consideration of the patient’s clinical presentation and the evidence related to various imaging modalities. For example, under the Choosing Wisely campaign—a national effort to reduce waste in the health care system and avoid unnecessary or harmful tests and treatment—the AAFP recommends that physicians should not do imaging for low back pain within the first six weeks unless red flags are present because “imaging of the lower spine before six weeks does not improve outcomes, but does increase costs.”20 There is also a Healthcare Effectiveness Data and Information Set (HEDIS) measure for the use of imaging studies for low back pain; it measures performance based on the percentage of adults 18 to 50 years of age with a primary diagnosis of low back pain who did not have a plain x-ray, magnetic resonance imaging (MRI), or computed tomography (CT) scan within 28 days of the diagnosis.21
The use of evidence-based appropriateness criteria for various clinical scenarios may help physicians weigh risk versus benefit so that they use diagnostic radiography judiciously and avoid overuse. The ACR Committee on Appropriateness Criteria and its expert panels use literature review and a modified Delphi method to develop practice guidelines based on clinical indications for a large number of diagnostic imaging modalities.22 The criteria include recommendations and a summary of relevant literature, as well as a relative radiation level designation for each rated procedure. Representatives from 23 specialty organizations participate in the development of the ACR Appropriateness Criteria®, although no representatives from a family medicine organization are currently involved in this process.23 The criteria address a large variety of clinical conditions using a nine-point scale, with a rating of seven, eight, or nine indicating that a radiologic procedure is considered “usually appropriate” by expert consensus panels. Many indications for plain radiographs are acute and chronic conditions that frequently present in the family physician’s office.
Training in diagnostic radiography interpretation begins during clinical training in medical school, although the amount and intensity of the training experience at various medical schools can vary widely. The Accreditation Council for Graduate Medical Education’s (ACGME’s) Residency Review Committee, which accredits family medicine residency programs, developed a set of requirements that became effective July 1, 2014. The requirements state, “The curriculum should include diagnostic imaging interpretation and nuclear medicine therapy pertinent to family medicine.”24
Extensive individualized training also occurs during acute and chronic patient care in the hospital, ED, and continuity practice experience during residency training. This training occurs during consultation with family physician and emergency medicine preceptors, and during formal and informal consultation with interpreting radiologists. Additional training occurs when patient care decisions based on a resident’s provisional reading are either reinforced or adjusted following review of a radiologist’s written report. For family physicians who use diagnostic radiography in their practices, training and feedback continue throughout their careers as they consult with practice colleagues and radiologists.
To advance through their training, residents are expected to have an appropriate level of competence in ordering and interpreting diagnostic radiographs. Competence is judged by the supervising faculty. Deficiencies are addressed by more intense remedial training, as in any other educational category for family medicine.
Testing knowledge of indications for and interpretation of diagnostic radiographs is a part of the general testing for certification by the American Board of Family Medicine. Certification examinations include questions about diagnostic radiography and some radiographic images. Radiography is considered one of many general areas of medical knowledge tested. There are no specific rules for the number of interpretations of radiographs or questions about radiography on each primary certification or recertification examination.25
Medicare covers imaging services that are “performed or supervised by a physician who is certified or eligible to be certified by the American Board of Radiology or for whom radiology services account for at least 50 percent of the total amount of charges made under Medicare.”26 Effective January 1, 2012, the Medicare Improvements for Patients and Providers Act of 2008 (MIPPA) required suppliers of the technical component of advanced diagnostic imaging (ADI) procedures to be accredited by a CMS-approved accrediting organization in order to receive Medicare reimbursement. The MIPPA defines ADI procedures as diagnostic MRI, CT, and nuclear medicine imaging procedures (e.g., positron emission tomography [PET]).27 X-ray, ultrasound, and fluoroscopy procedures are not included in this definition. Diagnostic and screening mammography, which is subject to oversight by the U.S. Food and Drug Administration (FDA), also are not included in the MIPPA's definition of ADI procedures.28 CMS allows ADI accrediting organizations to establish their own individual quality standards, but states, “At a minimum, these standards must address, but are not limited to, the following areas: staff qualifications; equipment standards and safety; safety of patients, family and staff; medical records; and patient privacy.”28
The issue of hospital privileges is not relevant to outpatient radiograph interpretation. Managed care and health insurance organizations may request that participating physicians go through a credentialing process, either to meet internal standards or as a part of an application for National Committee for Quality Assurance (NCQA) accreditation. However, specific procedures or skills are not usually considered in the credentialing process.
A. Competence for interpretation of diagnostic radiographs
The literature on interpretation of diagnostic radiographs suggests that the error rates of family physicians are similar to the error rates of radiologists. A primary care physician is likely to have a more complete clinical history for the patient than a radiologist has, which may give the primary care physician an advantage in interpreting radiographs accurately. One systematic review reported that the majority of studies showed higher accuracy of radiograph readings when clinical information was provided, and none of the studies showed a decrease in accuracy.29
Several studies have evaluated the frequency of agreement between primary care physicians’ readings of office radiographs and radiologists’ readings. Concordance between readings by family physicians and radiologists was found in 72.5 percent to 92.4 percent of all radiographs.30-33 In addition, concordance between readings by internists and radiologists was found in 92 percent of all radiographs.34 Concordance rates for extremity films were higher, ranging from 79 percent to 96 percent.31-33,35 Concordance rates were lower for chest radiographs, ranging from 41.9 percent to 89.5 percent, which likely reflects a greater level of complexity.30-37 Results from different studies are not directly comparable because different criteria for concordance were used.
B. Over-reading of radiographs
A variety of studies have addressed the issue of whether over-reading by a radiologist improves clinical care. For example, a 2004 study evaluated 1,393 pairs of radiograph readings, with an initial reading performed by one of 86 primary care clinicians in nine ambulatory practices and an over-reading performed by one of 42 radiologists.30 In a subgroup of 553 pairs of radiographic readings—instances in which the primary care clinician would not have requested an over-read if it had not been required—researchers found that clinical care would only have been different without the second reading for 2.5 percent of the 553 cases. Moreover, they found “zero substantial changes in care or episodes of averted patient harm.”30 Similarly, a 1989 study reported clinically significant discordance in only four of 508 radiographs and zero substantial changes in care.36
Family physicians refer patients for specialty consultation for numerous reasons and are usually able to determine independently when such consultation is needed. Review of the literature does not support mandatory over-reading of all radiographs performed in family physicians’ offices. Instead, studies suggest that over-reading by a radiologist is not always necessary and that selective request for radiology consultation is appropriate. Allowing family physicians to decide which radiographs to send for consultation and over-reading frees radiologists’ time for interpretation of more complex radiographs and radiological interventions.
C. Formal relationships with other organizations
Cooperation should be encouraged between the AAFP, the ACR, the Intersocietal Accreditation Commission, and other relevant organizations in the development of quality improvement programs, radiography use guidelines, and CMS standards for in-office imaging.
D. Broader dissemination of ACR Appropriateness Criteria®
Broader use of the ACR Appropriateness Criteria® may have some beneficial impact by encouraging appropriate outpatient radiography use and discouraging unnecessary or inappropriate use. Studies of radiograph guideline dissemination methods have had mixed results.38-42 Studies reporting a decrease in inappropriate radiographs have shown only modest improvements.40,41
E. Research agenda
The research agenda for interpretation of outpatient radiographs should focus on the following:
- Quantifying whether a shift in billing for the professional component of radiology services, or in CMS standards for performing and interpreting outpatient radiographs would affect the financial model of the PCMH
- Developing effective quality improvement programs that ensure acceptable image quality, reduce interpretation error rates, ensure patient safety, and provide guidance regarding which radiographs should be referred for consultation
- Identifying effective methods to encourage appropriate outpatient radiography use and discourage unnecessary or inappropriate use
- Defining the effect of on-site performance and interpretation of diagnostic radiographs by family physicians on patient-oriented clinical outcomes compared with the effect of referral to a radiologist for off-site imaging and interpretation, with particular attention to outcomes in rural areas and other underserved areas.
- American Academy of Family Physicians. AAFP Member Census, June 30, 2015. Table 13: Clinical Procedures Performed by Physicians at their Practice. http://www.aafp.org/about/the-aafp/family-medicine-facts/table-13.html. Accessed June 1, 2016.
- Rosman DA, Nsiah E, Hughes DR, Duszak R Jr. Regional variation in Medicare payments for medical imaging: radiologists versus nonradiologists. AJR Am J Roentgenol. 2015;204(5):1042-1048.
- Winter A, Ray N. Paying accurately for imaging services in Medicare. Health Aff (Millwood). 2008;27(6):1479-1490. content.healthaffairs.org/content/27/6/1479.full.(content.healthaffairs.org) Accessed June 1, 2016.
- Kennedy S, Forman HP. Deficit Reduction Act: effects on utilization of noninvasive musculoskeletal imaging. Radiology. 2012;264(1):146-153.
- Lee DW, Duszak R Jr, Hughes DR. Comparative analysis of Medicare spending for medical imaging: sustained dramatic slowdown compared with other services. AJR Am J Roentgenol. 2013;201(6):1277-1282.
- Duszak R. Medical imaging: is the growth boom over? The Neiman Report, No. 1, October 2012. Reston, Va.: Harvey L. Neiman Health Policy Institute; 2012.
- American Academy of Family Physicians. Privileges (revised and approved 2013). http://www.aafp.org/about/policies/all/privileges.html. Accessed June 1, 2016.
- American Academy of Orthopaedic Surgeons. Position statement. In-office diagnostic imaging studies by orthopaedic surgeons (revised February 2012). http://www.aaos.org/uploadedFiles/PreProduction/About/Opinion_Statements/position/1132 In-Office Diagnostic Imaging Studies by Orthopaedic Surgeons.pdf(www.aaos.org). Accessed June 1, 2016.
- American College of Emergency Physicians. Interpretation of Imaging Diagnostic Studies (revised and approved February 2013). https://www.acep.org/Content.aspx?id=32874(www.acep.org). Accessed June 1, 2016.
- American Medical Association. Freedom of practice in medical imaging D-385.974 (reaffirmed 2015). https://searchpf.ama-assn.org/SearchML/searchDetails.action?uri=%2FAMADoc%2Fdirectives.xml-0-1292.xml#(searchpf.ama-assn.org). Accessed June 1, 2016.
- Centers for Medicare & Medicaid Services. Chapter 13: Radiology services and other diagnostic procedures. https://www.cms.gov/Regulations-and-Guidance/Guidance/Manuals/Downloads/clm104c13.pdf(www.cms.gov). Access June 1, 2016.
- Stiell IG, Greenberg GH, McKnight RD, Nair RC, McDowell I, Worthington JR. A study to develop clinical decision rules for the use of radiography in acute ankle injuries. Ann Emerg Med. 1992;21(4):384-390.
- Pigman EC, Klug RK, Sanford S, Jolly BT. Evaluation of the Ottawa clinical decision rules for the use of radiography in acute ankle and midfoot injuries in the emergency department: an independent site assessment. Ann Emerg Med. 1994;24(1):41-45.
- Stiell IG, Greenberg GH, Wells GA, et al. Derivation of a decision rule for the use of radiography in acute knee injuries. Ann Emerg Med. 1995;26(4):405-413.
- Stiell IG, Wells GA, Hoag RH, et al. Implementation of the Ottawa Knee Rule for the use of radiography in acute knee injuries. JAMA. 1997;278(23):2075-2079.
- Nugent PJ. Ottawa Ankle Rules accurately assess injuries and reduce reliance on radiographs. J Fam Pract. 2004;53(10):785-788.
- Seaberg DC, Yealy DM, Lukens T, Auble T, Mathias S. Multicenter comparison of two clinical decision rules for the use of radiography in acute, high-risk knee injuries. Ann Emerg Med. 1998;32:8-13.
- Crownover BK, Bepko JL. Appropriate and safe use of diagnostic imaging. Am Fam Physician. 2013;87(7):494-501.
- Lin EC. Radiation risk from medical imaging. Mayo Clin Proc. 2010;85(12):1142-1146.
- Choosing Wisely®. Imaging for low back pain. http://www.aafp.org/patient-care/clinical-recommendations/all/cw-back-pain.html. Accessed June 1, 2016.
- National Committee for Quality Assurance. Use of imaging studies for low back pain. http://www.ncqa.org/report-cards/health-plans/state-of-health-care-quality/2015-table-of-contents/low-back-pain(www.ncqa.org). Accessed June 1, 2016.
- American College of Radiology. ACR Appropriateness Criteria®. http://www.acr.org/Quality-Safety/Appropriateness-Criteria(www.acr.org). Accessed June 1, 2016.
- American College of Radiology. Medical specialty organizations with representatives on the ACR Appropriateness Criteria® Expert Panels (listed by society). October 2015. http://www.acr.org/~/media/ACR/Documents/AppCriteria/MedicalSpecialtyOrgRep.pdf(www.acr.org). Accessed June 1, 2016.
- Accreditation Council for Graduate Medical Education. ACGME program requirements for graduate medical education in family medicine (revised 2016). http://www.acgme.org/portals/0/pfassets/programrequirements/120_family_medicine_2016.pdf(www.acgme.org). Accessed June 1, 2016.
- Fain R. American Board of Family Medicine, Senior Editor. Personal communication, April 2016.
- Centers for Medicare & Medicaid Services. Medicare coverage of imaging services. https://www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNProducts/downloads/Radiology_FactSheet_ICN907164.pdf(www.cms.gov). Accessed June 1, 2016.
- Centers for Medicare & Medicaid Services. Important reminders about advanced diagnostic imaging (ADI) accreditation requirements. July 31, 2012. https://www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNMattersArticles/Downloads/SE1122.pdf(www.cms.gov). Accessed June 1, 2016.
- Centers for Medicare & Medicaid Services. Accreditation of advanced diagnostic imaging suppliers. https://www.cms.gov/Medicare/Provider-Enrollment-and-Certification/SurveyCertificationGenInfo/Accreditation-of-Advanced-Diagnostic-Imaging-Suppliers.html(www.cms.gov). Accessed June 1, 2016.
- Loy CT, Irwig L. Accuracy of diagnostic tests read with and without clinical information: a systematic review. JAMA. 2004;292(13):1602-1609.
- Smith PD, Temte J, Beasley JW, Mundt M. Radiographs in the office: is a second reading always needed? J Am Board Fam Pract. 2004;17(4):256-263.
- Knollmann BC, Corson AP, Twigg HL, Schulman KA. Assessment of joint review of radiologic studies by a primary care physician and a radiologist. J Gen Intern Med. 1996;11(10):608-612.
- Hopper KD, Rosetti GF, Edmiston RB, et al. Diagnostic radiology peer review: a method inclusive of all interpreters of radiographic examinations regardless of specialty. Radiology. 1991;180(2):557-561.
- Strasser RP, Bass MJ, Brennan M. The effect of an on-site radiology facility on radiologic utilization in family practice. J Fam Pract. 1987;24(6):619-623.
- Kuritzky L, Haddy RI, Curry RW Sr. Interpretation of chest roentgenograms by primary care physicians. South Med J. 1987;80(11):1347-1351.
- Bergus GR, Franken EA Jr, Koch TJ, Smith WL, Evans ER, Berbaum KS. Radiologic interpretation by family physicians in an office practice setting. J Fam Pract. 1995;41(4):352-356.
- Halvorsen JG, Kunian A, Gjerdingen D, et al. The interpretation of office radiographs by family physicians. J Fam Pract. 1989;28(4):426-432.
- Franken EA Jr, Bergus GR, Koch TJ, Berbaum KS, Smith WL. Added value of radiologist consultation to family practitioners in the outpatient setting. Radiology. 1995;197(3):759-762.
- Matowe L, Ramsay CR, Grimshaw JM, Gilbert FJ, Macleod MJ, Needham G. Effects of mailed dissemination of the Royal College of Radiologists’ guidelines on general practitioner referrals for radiography: a time series analysis. Clin Radiol. 2002;57(7):575-578.
- Kerry S, Oakeshott P, Dundas D, Williams J. Influence of postal distribution of the Royal College of Radiologists’ guidelines, together with feedback on radiological referral rates, on x-ray referrals from general practice: a randomized controlled trial. Fam Pract. 2000;17(1):46-52.
- Eccles M, Steen N, Grimshaw J, et al. Effect of audit and feedback, and reminder messages on primary-care radiology referrals: a randomised trial. Lancet. 2001;357(9266):1406-1409.
- Oakeshott P, Kerry SM, Williams JE. Randomized controlled trial of the effect of the Royal College of Radiologists’ guidelines on general practitioners’ referrals for radiographic examination. Br J Gen Pract. 1994;44(382):197-200.
- Cameron C, Naylor CD. No impact from active dissemination of the Ottawa Ankle Rules: further evidence of the need for local implementation of practice guidelines. CMAJ. 1999;160(8):1165-1168.
(B1999) (2017 COD)