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The Pittsburgh Decision Rule: Triage nurse versus physician utilization in the emergency department
The Journal of Emergency Medicine, Vol. 31, No. 3, pp. 247–250, 2006 Copyright © 2006 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/06 $–see front matter
doi:10.1016/j.jemermed.2005.12.020
Original Contributions
THE PITTSBURGH DECISION RULE: TRIAGE NURSE VERSUS PHYSICIAN UTILIZATION IN THE EMERGENCY DEPARTMENT Leslie V. Simon,
DO,*
Michael J. Matteucci, MD,* David A. Tanen, Robert H. Riffenburgh, PhD‡
MD,*
Joel A. Roos,
MD,†
and
*Department of Emergency Medicine, Naval Medical Center San Diego, San Diego, California, †Department of Emergency Medicine, Naval Medical Center Portsmouth, Portsmouth, Virginia, and ‡Department of Clinical Investigations, Naval Medical Center San Diego, San Diego, California Reprint Address: Michael J. Matteucci, MD, Department of Emergency Medicine, Naval Medical Center, 34800 Bob Wilson Dr., San Diego, CA 92134
e Abstract—The Pittsburgh Decision Rule (PDR) is a rule for ordering knee radiographs in patients with acute knee injuries. This study was designed to compare the utilization of the PDR between triage nurses and physicians. Consecutive patients presenting to the Emergency Department were enrolled. Nurses and physicians were blinded to each other’s examinations. Of 182 subjects approached, 30 were excluded for incomplete data or refusal to obtain radiographs, leaving 152 subjects enrolled. Thirteen fractures (8.6%) were identified. Kappa scores were high for each component of the rule: mechanism of injury (fall or blunt trauma) ⴝ 0.67, age ( < 12 or > 50 years) ⴝ 1, inability to ambulate ⴝ 0.67 and overall ⴝ 0.83. Four of 13 fractures (31%) would have been missed using the PDR, resulting in a sensitivity of 77% for both physicians and nurses, and a specificity of 57% for physicians and 58% for nurses. Triage nurses and physicians were able to apply the PDR to patients who presented with acute knee injuries with a high level of agreement. However, the PDR demonstrated poor sensitivity in this patient population. © 2006 Elsevier Inc.
INTRODUCTION Every year, acute knee injuries account for about 1.3 million Emergency Department (ED) visits in the United States (1). Acute knee trauma results in a fracture in only about 6% of cases, leading to many unnecessary radiographs (2,3). The overuse of radiographs prolongs ED waiting times, drives up health care costs, and exposes patients to unnecessary radiation (4). Moreover, many Emergency Physicians (EPs) order radiographs on patients even when their clinical judgment excludes fracture, due to patient expectations and fear of lawsuits (5,6). To combat these problems, clinical decision rules for ordering diagnostic radiographs for traumatic knee injuries have been developed in Pittsburgh, Pennsylvania and Ottawa, Ontario, Canada. The Pittsburgh Decision Rule (PDR) was developed in 1994 and has been reported to reduce the number of patients who require X-rays by 78% without missing a fracture (7,8). This clinical decision rule found that the combination of a fall or blunt trauma with either the inability to ambulate or age (younger than 12 or older than 50 years) was 100% sensitive and 79% specific for the detection of fractures (7). The PDR has been validated with good results when utilized by physicians, with sensitivities of 99 –100% and specificities of 24 –79% (7–9).
e Keywords— knee injury; clinical decision rule; nurses; Pittsburgh Decision Rule; knee radiographs The views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the Navy, Department of Defense, nor the U.S. government.
RECEIVED: 9 February 2005; FINAL ACCEPTED: 2 December 2005
SUBMISSION RECEIVED:
18 July 2005; 247
248
L. V. Simon et al.
However, in many EDs, patients presenting with acute knee trauma are initially evaluated by triage nurses who order radiographs when they deem it appropriate. These radiographs are often obtained before physician evaluation of the patient. Therefore, appropriate utilization of clinical decision rules for the ordering of knee radiographs by triage nurses may save money by avoiding unnecessary films. Two prior studies have compared the ability of triage nurses with Emergency physicians to utilize the Ottawa Knee Rules and demonstrated fair to good agreement (10,11). The agreement between triage nurses and EPs in utilizing the PDR has not yet been studied. This study was designed to compare physicians to triage nurses in the utilization of the Pittsburgh decision rule. Because the PDR is less complex than the Ottawa rule and requires no knowledge of anatomy, agreement was hypothesized to be greater between the two groups than with use of the Ottawa knee rule.
MATERIALS AND METHODS This was a prospective, observational study of consecutive patients with acute knee injuries who met PDR inclusion criteria presenting to the ED of a military tertiary care facility between August 2002 and May 2003. The ED has an annual census of approximately 55,000 patients and is staffed 24 h a day by Board Certified/Board Eligible Emergency Physicians and Emergency Medicine (EM) residents. The study population was composed of active duty military personnel, family members and retirees. This study was approved by the Institutional Review Board. Both pediatric and adult patients were included in the study. Included patients had acute knee injuries less than 8 days old, a normal mental status, and no prior visits for the same complaint. Exclusion criteria included injuries older than 1 week, pregnancy, history of prior surgery on the same knee, isolated superficial skin lesions, and paraplegia. Before the initiation of the study, all EPs, EM residents, and triage nurses underwent a 15-min training program provided by the primary investigator (LVS). Examination of the knee, the PDR and the data collection sheet were reviewed. Only the EPs had prior knowledge of the PDR but the rule was not being routinely utilized in the department. The majority of physician examiners were PGY 2– 4 EM residents. Triage nurses obtained their positions by a minimum of 6 months ED experience and one-on-one instruction by experienced triage nurses. A triage nurse and a physician independently evaluated each patient. Findings were documented on separate data collection sheets before radiographic evaluation. Physicians and nurses were blinded to each other’s re-
sponses. Examiners were to ask the following questions: Was the mechanism of injury a fall or blunt trauma? (MECH) Is the patient older than 50 or younger than 12 years of age? (AGE) Can the patient walk 4 weightbearing steps? (WALK) Standard radiographs (anteriorposterior, lateral and sunrise views) were ordered on all patients and were reviewed after all study forms were completed and submitted. All films were read by attending radiologists who were blinded to the clinical findings noted in the ED. Data points were entered into an Excel 2000 (Microsoft Corp., Redmond, WA) database then transferred into Stata Version 7.0 (Stata Corporation, College Station, TX) for statistical analysis. Kappa coefficients of inter-observer agreement were calculated for all three individual components of the PDR as well as for the overall need for radiographs as determined by the rule. Qualitative descriptions of agreement were as follows: 0.8 –1.0 ⫽ “almost perfect,” 0.6 – 0.8 ⫽ “substantial,” 0.4 – 0.6 ⫽ “moderate,” 0.2– 0.4 – “fair,” 0.0 – 0.2 ⫽ “slight” (12).
RESULTS There were a total of 182 patients approached for entry into the study; 28 were excluded due to incomplete or missing consent forms or data collection sheets and 2 for patient’s refusal to have radiographs performed; 152 patients completed the study (Figure 1). Patient’s ages ranged from 8 to 83 years with an average age of 37 years. Sixty-one percent of the patients were men. All patients had radiographs performed. Thirteen fractures (8.6%) were identified in the study population; 7 involved the patella, 4 were fractures of the tibial plateau, and 2 were avulsion fractures of the tibia (Table 1). One of the fractures, involving the tibial plateau, was not noted by the EP or the radiologist on the original radiographs but was found on a subsequent MRI (Table 1). Substantial agreement was found for both the mechanism (MECH) component of the rule ( ⫽ 0.67, substantial) and assessment of the patient’s ability to ambulate (WALK) ( ⫽ 0.67, substantial). There were no discrepancies between physicians and nurses as to the patient’s age ( ⫽ 1.0, almost perfect). The overall kappa score for all components of the rule to determine the need for radiographs was 0.83, indicating that physicians and triage nurses were able to utilize the PDR with “almost perfect” agreement. Interestingly, 4 of the 13 fractures (31%) found in this study would have been missed using the PDR. Because the study design mandated that all patients have radiographs, no fractures were actually missed, with the ex-
Nurse vs. EP
249
for both physicians and nurses. The specificity was 57% (95% CI 48%– 65%) for physicians and 58% (95% CI 50%– 67%) for nurses.
DISCUSSION
Figure 1. The CONSORT diagram showing the flow of participants through the study.
ception of an occult tibial plateau fracture later found on MRI. In contrast to prior studies that showed nearly 100% sensitivity for the PDR, sensitivity in our study was only 77% (95% confidence interval [CI] 46%–95%)
Frequently, triage nurses will order knee radiographs in patients who present to Emergency Departments for acute traumatic knee injuries in the belief that this may speed up the throughput of patients through the department, as the EP will have radiographs available at the time of patient evaluation. This practice, however, may increase the total number of radiographs that are obtained, increasing total health care costs and unneeded radiation exposure. Two prior studies have compared the ability of triage nurses to EPs to utilize the Ottawa Knee Rules. In one study, performed at our institution, agreement was only fair (10). Triage nurses were more likely than physicians to feel that radiographs were needed, reducing the cost effectiveness of the Ottawa Knee Rule. In that study, no fractures were missed, but the fracture rate was too low to calculate sensitivities or specificities. In the second study, triage nurses demonstrated fair to good ability to apply the Ottawa Knee Rule when compared with physicians. However, nurses failed to order radiographs in 3 out of 10 patients who had fractures and in 11 patients who met criteria for radiographs (11). The nurses’ use of the rule had 70% sensitivity and 33% specificity, whereas the physician use had 100% sensitivity and 25% specificity. We chose to study the PDR, as it seems to be simpler to use than the Ottawa Knee Rule, subsequently yielding
Table 1. Characteristics of Subjects with Fractures Subject number
Age (years)
Sex
Fracture location
Detected by PDR
Component
15 16 23 24 34 39 46 74 80
23 71 58 32 59 19 12 23 24
M M F M F F M F M
Femoral adductor avulsion Patella Patella Tibial plateau Tibial plateau Patella Tibial plateau Patella Tibial plateau
Yes Yes Yes Yes Yes Yes Yes Yes Yes by triage nurse; no by EP
WALK AGE & WALK AGE & WALK WALK AGE WALK WALK WALK WALK
85 86
21 25
M M
Tibial avulsion Patella
110 126
24 16
F M
Patella Patella
No No by triage nurse; yes by EP No Yes
Component ⫽ Component of PDR that tested positive and would have resulted in radiography.
WALK WALK
Comments
Fracture missed on standard radiographs; found on MRI
250
L. V. Simon et al.
higher agreement between EPs and triage nurses and a higher prognostic accuracy. Whereas the triage nurses were relatively inexperienced, the EM residents had had at least 2 years of independent medical duty before entering residency and were well practiced in orthopedic examinations, and yet, there was substantial agreement between the two groups. This may be due to a threecomponent rule and no need for anatomical knowledge vs. a five-component rule that requires anatomical knowledge. However, considering the rule would have not have mandated radiographs for 4 out of 13 patients who actually had fractures, its utility in our patient population was very limited. There are several potential hypotheses for the rule’s poor performance in this study. The fracture rate in our study was 1–2% higher than the expected rate of 6 –7%. Perhaps the nature of our population in a military hospital contributed to the increased incidence of fractures. This increased fracture rate, however, was not found in a prior study using this same population that found a rate of only 3% (10). The missed fractures in this study were in younger, healthy individuals who may have been able to compensate for their injuries and thus not demonstrate the findings needed for the PDR to trigger radiography. Also, digital radiography was fully instituted in our institution before this study and may have increased the sensitivity to detect fractures. Two of the 4 missed fractures were avulsion-type injuries or patellar fractures that likely would have a very limited clinical significance. However, any missed fracture in today’s litigious society can be argued to be significant. One of the missed fractures was in a 24-yearold Marine who walked into the ED after sustaining a tibial plateau fracture while skydiving. Despite the significant nature of his trauma, his age and ability to ambulate would have made radiographs unnecessary by strict utilization of the PDR.
STUDY LIMITATIONS Although this was a consecutive sample, 30 of 181 patients were excluded from the study for incomplete paperwork or radiographs. It is unclear whether this population suffered any fractures. Although we did not directly follow-up the patients in this study, any missed
fractures would have most likely come to our attention due to our closed, military health care system. Because all subjects in this study received radiographs, it is unclear how patient expectations could influence actual radiograph ordering characteristics. CONCLUSION Although this study of the Pittsburgh Decision Rule demonstrated substantial to almost perfect agreement between triage nurses and emergency physicians, the PDR had a low sensitivity of 77% and a high number of missed fractures. For this reason, we cannot recommend the use of the PDR in a similar patient population. Acknowledgment—Supported by a grant from the Clinical Investigation Department, Naval Medical Center, San Diego, CA.
REFERENCES 1. McCaig L. National Hospital Ambulatory Medical Care Survey. 1992 emergency department summary. Adv Data 1994;248:1–12. 2. Gratton MC, Salomone JA 3rd, Watson WA. Clinically significant radiograph misinterpretations at an emergency medicine residency program. Ann Emerg Med 1990;19:497–502. 3. Steill IG, Wells GA, McDowell I, et al. Use of radiography in acute knee injuries: need for clinical decision rules. Acad Emerg Med 1995;2:966 –73. 4. Abrams HL. The overutilization of X-rays. N Engl J Med 1979; 301:668. 5. Hall FM. Overutilization of radiological examinations. Radiology 1976;120:443– 8. 6. Long AE. Radiographic decision-making by the emergency physician. Emerg Med Clin North Am 1985;3:437– 46. 7. Seaberg DC, Jackson R. Clinical decision rule for knee radiographs. Am J Emerg Med 1994;12:541–3. 8. Seaberg DC, Yearly 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. 9. Weber JE, Jackson RE, Peacock WF, et al. Clinical decision rules discriminate between fractures and nonfractures in acute isolated knee trauma. Ann Emerg Med 1995;26:429 –33. 10. Matteucci MJ, Roos JA. Ottawa Knee Rule: a comparison of physician and triage-nurse utilization of a decision rule for knee radiography. J Emerg Med 2003;24:147–50. 11. Kec RM, Richman PB, Szucs PA, Mandell M, Eskin B. Can emergency department triage nurses appropriately use the Ottawa Knee Rules to order radiographs? An implementation trial. Acad Emerg Med 2003;10:146 –50. 12. Jekel JF, Elmore JG, Katz DL. Epidemiology, biostatistics, and preventative medicine. Philadelphia, PA: W. B. Saunders; 1996: 96 –7.
doi:10.1016/j.jemermed.2005.12.020
Original Contributions
THE PITTSBURGH DECISION RULE: TRIAGE NURSE VERSUS PHYSICIAN UTILIZATION IN THE EMERGENCY DEPARTMENT Leslie V. Simon,
DO,*
Michael J. Matteucci, MD,* David A. Tanen, Robert H. Riffenburgh, PhD‡
MD,*
Joel A. Roos,
MD,†
and
*Department of Emergency Medicine, Naval Medical Center San Diego, San Diego, California, †Department of Emergency Medicine, Naval Medical Center Portsmouth, Portsmouth, Virginia, and ‡Department of Clinical Investigations, Naval Medical Center San Diego, San Diego, California Reprint Address: Michael J. Matteucci, MD, Department of Emergency Medicine, Naval Medical Center, 34800 Bob Wilson Dr., San Diego, CA 92134
e Abstract—The Pittsburgh Decision Rule (PDR) is a rule for ordering knee radiographs in patients with acute knee injuries. This study was designed to compare the utilization of the PDR between triage nurses and physicians. Consecutive patients presenting to the Emergency Department were enrolled. Nurses and physicians were blinded to each other’s examinations. Of 182 subjects approached, 30 were excluded for incomplete data or refusal to obtain radiographs, leaving 152 subjects enrolled. Thirteen fractures (8.6%) were identified. Kappa scores were high for each component of the rule: mechanism of injury (fall or blunt trauma) ⴝ 0.67, age ( < 12 or > 50 years) ⴝ 1, inability to ambulate ⴝ 0.67 and overall ⴝ 0.83. Four of 13 fractures (31%) would have been missed using the PDR, resulting in a sensitivity of 77% for both physicians and nurses, and a specificity of 57% for physicians and 58% for nurses. Triage nurses and physicians were able to apply the PDR to patients who presented with acute knee injuries with a high level of agreement. However, the PDR demonstrated poor sensitivity in this patient population. © 2006 Elsevier Inc.
INTRODUCTION Every year, acute knee injuries account for about 1.3 million Emergency Department (ED) visits in the United States (1). Acute knee trauma results in a fracture in only about 6% of cases, leading to many unnecessary radiographs (2,3). The overuse of radiographs prolongs ED waiting times, drives up health care costs, and exposes patients to unnecessary radiation (4). Moreover, many Emergency Physicians (EPs) order radiographs on patients even when their clinical judgment excludes fracture, due to patient expectations and fear of lawsuits (5,6). To combat these problems, clinical decision rules for ordering diagnostic radiographs for traumatic knee injuries have been developed in Pittsburgh, Pennsylvania and Ottawa, Ontario, Canada. The Pittsburgh Decision Rule (PDR) was developed in 1994 and has been reported to reduce the number of patients who require X-rays by 78% without missing a fracture (7,8). This clinical decision rule found that the combination of a fall or blunt trauma with either the inability to ambulate or age (younger than 12 or older than 50 years) was 100% sensitive and 79% specific for the detection of fractures (7). The PDR has been validated with good results when utilized by physicians, with sensitivities of 99 –100% and specificities of 24 –79% (7–9).
e Keywords— knee injury; clinical decision rule; nurses; Pittsburgh Decision Rule; knee radiographs The views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the Navy, Department of Defense, nor the U.S. government.
RECEIVED: 9 February 2005; FINAL ACCEPTED: 2 December 2005
SUBMISSION RECEIVED:
18 July 2005; 247
248
L. V. Simon et al.
However, in many EDs, patients presenting with acute knee trauma are initially evaluated by triage nurses who order radiographs when they deem it appropriate. These radiographs are often obtained before physician evaluation of the patient. Therefore, appropriate utilization of clinical decision rules for the ordering of knee radiographs by triage nurses may save money by avoiding unnecessary films. Two prior studies have compared the ability of triage nurses with Emergency physicians to utilize the Ottawa Knee Rules and demonstrated fair to good agreement (10,11). The agreement between triage nurses and EPs in utilizing the PDR has not yet been studied. This study was designed to compare physicians to triage nurses in the utilization of the Pittsburgh decision rule. Because the PDR is less complex than the Ottawa rule and requires no knowledge of anatomy, agreement was hypothesized to be greater between the two groups than with use of the Ottawa knee rule.
MATERIALS AND METHODS This was a prospective, observational study of consecutive patients with acute knee injuries who met PDR inclusion criteria presenting to the ED of a military tertiary care facility between August 2002 and May 2003. The ED has an annual census of approximately 55,000 patients and is staffed 24 h a day by Board Certified/Board Eligible Emergency Physicians and Emergency Medicine (EM) residents. The study population was composed of active duty military personnel, family members and retirees. This study was approved by the Institutional Review Board. Both pediatric and adult patients were included in the study. Included patients had acute knee injuries less than 8 days old, a normal mental status, and no prior visits for the same complaint. Exclusion criteria included injuries older than 1 week, pregnancy, history of prior surgery on the same knee, isolated superficial skin lesions, and paraplegia. Before the initiation of the study, all EPs, EM residents, and triage nurses underwent a 15-min training program provided by the primary investigator (LVS). Examination of the knee, the PDR and the data collection sheet were reviewed. Only the EPs had prior knowledge of the PDR but the rule was not being routinely utilized in the department. The majority of physician examiners were PGY 2– 4 EM residents. Triage nurses obtained their positions by a minimum of 6 months ED experience and one-on-one instruction by experienced triage nurses. A triage nurse and a physician independently evaluated each patient. Findings were documented on separate data collection sheets before radiographic evaluation. Physicians and nurses were blinded to each other’s re-
sponses. Examiners were to ask the following questions: Was the mechanism of injury a fall or blunt trauma? (MECH) Is the patient older than 50 or younger than 12 years of age? (AGE) Can the patient walk 4 weightbearing steps? (WALK) Standard radiographs (anteriorposterior, lateral and sunrise views) were ordered on all patients and were reviewed after all study forms were completed and submitted. All films were read by attending radiologists who were blinded to the clinical findings noted in the ED. Data points were entered into an Excel 2000 (Microsoft Corp., Redmond, WA) database then transferred into Stata Version 7.0 (Stata Corporation, College Station, TX) for statistical analysis. Kappa coefficients of inter-observer agreement were calculated for all three individual components of the PDR as well as for the overall need for radiographs as determined by the rule. Qualitative descriptions of agreement were as follows: 0.8 –1.0 ⫽ “almost perfect,” 0.6 – 0.8 ⫽ “substantial,” 0.4 – 0.6 ⫽ “moderate,” 0.2– 0.4 – “fair,” 0.0 – 0.2 ⫽ “slight” (12).
RESULTS There were a total of 182 patients approached for entry into the study; 28 were excluded due to incomplete or missing consent forms or data collection sheets and 2 for patient’s refusal to have radiographs performed; 152 patients completed the study (Figure 1). Patient’s ages ranged from 8 to 83 years with an average age of 37 years. Sixty-one percent of the patients were men. All patients had radiographs performed. Thirteen fractures (8.6%) were identified in the study population; 7 involved the patella, 4 were fractures of the tibial plateau, and 2 were avulsion fractures of the tibia (Table 1). One of the fractures, involving the tibial plateau, was not noted by the EP or the radiologist on the original radiographs but was found on a subsequent MRI (Table 1). Substantial agreement was found for both the mechanism (MECH) component of the rule ( ⫽ 0.67, substantial) and assessment of the patient’s ability to ambulate (WALK) ( ⫽ 0.67, substantial). There were no discrepancies between physicians and nurses as to the patient’s age ( ⫽ 1.0, almost perfect). The overall kappa score for all components of the rule to determine the need for radiographs was 0.83, indicating that physicians and triage nurses were able to utilize the PDR with “almost perfect” agreement. Interestingly, 4 of the 13 fractures (31%) found in this study would have been missed using the PDR. Because the study design mandated that all patients have radiographs, no fractures were actually missed, with the ex-
Nurse vs. EP
249
for both physicians and nurses. The specificity was 57% (95% CI 48%– 65%) for physicians and 58% (95% CI 50%– 67%) for nurses.
DISCUSSION
Figure 1. The CONSORT diagram showing the flow of participants through the study.
ception of an occult tibial plateau fracture later found on MRI. In contrast to prior studies that showed nearly 100% sensitivity for the PDR, sensitivity in our study was only 77% (95% confidence interval [CI] 46%–95%)
Frequently, triage nurses will order knee radiographs in patients who present to Emergency Departments for acute traumatic knee injuries in the belief that this may speed up the throughput of patients through the department, as the EP will have radiographs available at the time of patient evaluation. This practice, however, may increase the total number of radiographs that are obtained, increasing total health care costs and unneeded radiation exposure. Two prior studies have compared the ability of triage nurses to EPs to utilize the Ottawa Knee Rules. In one study, performed at our institution, agreement was only fair (10). Triage nurses were more likely than physicians to feel that radiographs were needed, reducing the cost effectiveness of the Ottawa Knee Rule. In that study, no fractures were missed, but the fracture rate was too low to calculate sensitivities or specificities. In the second study, triage nurses demonstrated fair to good ability to apply the Ottawa Knee Rule when compared with physicians. However, nurses failed to order radiographs in 3 out of 10 patients who had fractures and in 11 patients who met criteria for radiographs (11). The nurses’ use of the rule had 70% sensitivity and 33% specificity, whereas the physician use had 100% sensitivity and 25% specificity. We chose to study the PDR, as it seems to be simpler to use than the Ottawa Knee Rule, subsequently yielding
Table 1. Characteristics of Subjects with Fractures Subject number
Age (years)
Sex
Fracture location
Detected by PDR
Component
15 16 23 24 34 39 46 74 80
23 71 58 32 59 19 12 23 24
M M F M F F M F M
Femoral adductor avulsion Patella Patella Tibial plateau Tibial plateau Patella Tibial plateau Patella Tibial plateau
Yes Yes Yes Yes Yes Yes Yes Yes Yes by triage nurse; no by EP
WALK AGE & WALK AGE & WALK WALK AGE WALK WALK WALK WALK
85 86
21 25
M M
Tibial avulsion Patella
110 126
24 16
F M
Patella Patella
No No by triage nurse; yes by EP No Yes
Component ⫽ Component of PDR that tested positive and would have resulted in radiography.
WALK WALK
Comments
Fracture missed on standard radiographs; found on MRI
250
L. V. Simon et al.
higher agreement between EPs and triage nurses and a higher prognostic accuracy. Whereas the triage nurses were relatively inexperienced, the EM residents had had at least 2 years of independent medical duty before entering residency and were well practiced in orthopedic examinations, and yet, there was substantial agreement between the two groups. This may be due to a threecomponent rule and no need for anatomical knowledge vs. a five-component rule that requires anatomical knowledge. However, considering the rule would have not have mandated radiographs for 4 out of 13 patients who actually had fractures, its utility in our patient population was very limited. There are several potential hypotheses for the rule’s poor performance in this study. The fracture rate in our study was 1–2% higher than the expected rate of 6 –7%. Perhaps the nature of our population in a military hospital contributed to the increased incidence of fractures. This increased fracture rate, however, was not found in a prior study using this same population that found a rate of only 3% (10). The missed fractures in this study were in younger, healthy individuals who may have been able to compensate for their injuries and thus not demonstrate the findings needed for the PDR to trigger radiography. Also, digital radiography was fully instituted in our institution before this study and may have increased the sensitivity to detect fractures. Two of the 4 missed fractures were avulsion-type injuries or patellar fractures that likely would have a very limited clinical significance. However, any missed fracture in today’s litigious society can be argued to be significant. One of the missed fractures was in a 24-yearold Marine who walked into the ED after sustaining a tibial plateau fracture while skydiving. Despite the significant nature of his trauma, his age and ability to ambulate would have made radiographs unnecessary by strict utilization of the PDR.
STUDY LIMITATIONS Although this was a consecutive sample, 30 of 181 patients were excluded from the study for incomplete paperwork or radiographs. It is unclear whether this population suffered any fractures. Although we did not directly follow-up the patients in this study, any missed
fractures would have most likely come to our attention due to our closed, military health care system. Because all subjects in this study received radiographs, it is unclear how patient expectations could influence actual radiograph ordering characteristics. CONCLUSION Although this study of the Pittsburgh Decision Rule demonstrated substantial to almost perfect agreement between triage nurses and emergency physicians, the PDR had a low sensitivity of 77% and a high number of missed fractures. For this reason, we cannot recommend the use of the PDR in a similar patient population. Acknowledgment—Supported by a grant from the Clinical Investigation Department, Naval Medical Center, San Diego, CA.
REFERENCES 1. McCaig L. National Hospital Ambulatory Medical Care Survey. 1992 emergency department summary. Adv Data 1994;248:1–12. 2. Gratton MC, Salomone JA 3rd, Watson WA. Clinically significant radiograph misinterpretations at an emergency medicine residency program. Ann Emerg Med 1990;19:497–502. 3. Steill IG, Wells GA, McDowell I, et al. Use of radiography in acute knee injuries: need for clinical decision rules. Acad Emerg Med 1995;2:966 –73. 4. Abrams HL. The overutilization of X-rays. N Engl J Med 1979; 301:668. 5. Hall FM. Overutilization of radiological examinations. Radiology 1976;120:443– 8. 6. Long AE. Radiographic decision-making by the emergency physician. Emerg Med Clin North Am 1985;3:437– 46. 7. Seaberg DC, Jackson R. Clinical decision rule for knee radiographs. Am J Emerg Med 1994;12:541–3. 8. Seaberg DC, Yearly 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. 9. Weber JE, Jackson RE, Peacock WF, et al. Clinical decision rules discriminate between fractures and nonfractures in acute isolated knee trauma. Ann Emerg Med 1995;26:429 –33. 10. Matteucci MJ, Roos JA. Ottawa Knee Rule: a comparison of physician and triage-nurse utilization of a decision rule for knee radiography. J Emerg Med 2003;24:147–50. 11. Kec RM, Richman PB, Szucs PA, Mandell M, Eskin B. Can emergency department triage nurses appropriately use the Ottawa Knee Rules to order radiographs? An implementation trial. Acad Emerg Med 2003;10:146 –50. 12. Jekel JF, Elmore JG, Katz DL. Epidemiology, biostatistics, and preventative medicine. Philadelphia, PA: W. B. Saunders; 1996: 96 –7.