Validation of the Ottawa Knee Rule in children: a multicenter study

STUDY OBJECTIVE: The main objective of this study was to determine the sensitivity and specificity of the Ottawa Knee Rules when they were applied to children. The secondary objective was to determine post hoc whether use of the rules would reduce the number of knee radiographs ordered. METHODS: This prospective, multicenter validation study included children aged 2 to 16 years who presented to the emergency department with a knee injury sustained in the preceding 7 days. Children were assessed for the variables comprising the Ottawa Knee Rules, and physicians ordered radiographs at their discretion. A positive outcome was defined as any fracture. A negative outcome was defined as children who did not have a fracture on radiograph or, if no radiograph was obtained, were asymptomatic after 14 days. RESULTS: A total of 750 children were enrolled. The mean age was 11.8+/-3.1 years, and 443 (58.7%) were male patients. Seventy children had fractures. Radiography was performed for 670 children, whereas 80 children had only a structured telephone interview. The Ottawa Knee Rules were 100% sensitive (95% confidence interval [CI] 94.9% to 100%), with a specificity of 42.8% (95% CI 39.1% to 46.5%). Only 460 children would have required a radiograph if radiographs had been performed according to the Ottawa Knee Rules, which would have resulted in an absolute reduction of 209 (31.2%) radiographs. CONCLUSION: The Ottawa Knee Rules are valid in children and have the potential to decrease the use of radiography in children with knee injuries.     

Awareness and use of the Ottawa ankle and knee rules in 5 countries: can publication alone be enough to change practice?

STUDY OBJECTIVES: We evaluate the international diffusion of the Ottawa Ankle and Knee Rules and determine emergency physicians' attitudes toward clinical decision rules in general. METHODS: We conducted a cross-sectional, self-administered mail survey of random samples of 500 members each of the American College of Emergency Physicians, Canadian Association of Emergency Physicians, British Association for Accident and Emergency Medicine, Spanish Society for Emergency Medicine, and all members (n=1,350) of the French Speaking Society of Emergency Physicians, France. Main outcome measures were awareness of the Ottawa Ankle and Knee Rules, reported use of these rules, and attitudes toward clinical decision rules in general. RESULTS: A total of 1,769 (57%) emergency physicians responded, with country-specific response rates between 49% (United States and France) and 79% (Canada). More than 69% of physicians in all countries, except Spain, were aware of the Ottawa Ankle Rules. Use of the Ottawa Ankle Rules differed by country with more than 70% of all responding Canadian and United Kingdom physicians reporting frequent use of the rules compared with fewer than one third of US, French, and Spanish physicians. The Ottawa Knee Rule was less well known and less used by physicians in all countries. Most physicians in all countries viewed decision rules as intended to improve the quality of health care (>78%), a convenient source of advice (>67%), and good educational tools (>61%). Of all physicians, those from the United States held the least positive attitudes toward decision rules. CONCLUSION: This constitutes the largest international survey of emergency physicians' attitudes toward and use of clinical decision rules. Striking differences were apparent among countries with regard to knowledge and use of decision rules. Despite similar awareness in the United States, Canada, and the United Kingdom, US physicians appeared much less likely to use the Ottawa Ankle Rules. Future research should investigate factors leading to differences in rates of diffusion among countries and address strategies to enhance dissemination and implementation of such rules in the emergency department.     

Validation of the Ottawa Knee Rules

STUDY OBJECTIVE: We sought to validate the Ottawa Knee Rules for determining the need for radiography in patients with acute knee injury. METHODS: A prospective cohort study was performed in emergency departments of 11 hospitals of the Osakidetza-Basque Country Health Service. The patient population was composed of a convenience sample of 1,522 eligible adults of 2,315 patients with acute knee injuries. The attending emergency physicians assessed each patient for standardized clinical variables and determined the need for radiography according to the decision rule. Radiography was performed in each patient, irrespective of the determination of the rule, after clinical evaluation findings were recorded. The rule was assessed for the ability to correctly identify fracture of the knee. RESULTS: The decision rule had a sensitivity of 1.0 (95% confidence interval [CI] 0.96 to 1.0), identifying 89 patients with clinically important fractures. The potential reduction in use of radiography was estimated to be 49%. The probability of fracture, if the decision rules were negative, is estimated to be 0% (95% CI 0% to 0.5%). CONCLUSION: Prospective validation has shown the Ottawa Knee Rules to be 100% sensitive for identifying fractures of the knee and to have the potential to allow physicians to reduce the use of radiography in patients with acute knee injuries.     

Safety and efficiency of the Ottawa Ankle Rule in a Swiss population with ankle sprains

OBJECTIVES: We examined the accuracy of the Ottawa Ankle Rule (OAR) to rule out ankle and mid-foot fractures in patients presenting with acute ankle sprain and differences of accuracy between surgeons and non-surgeons. DESIGN: Prospective cohort study. SETTING: Swiss urban secondary care centre. PARTICIPANTS: Between September 2001 and October 2002 359 patients presented with a case of ankle sprain. Of these, 251 patients both met recruitment criteria and provided data for this study. A group of surgeons and non-surgeons assessed the OAR and all patients underwent blinded radiographic assessment. MAIN OUTCOME MEASURES: Sensitivity, specificity of the OAR. RESULTS: Of the 251 patients with ankle sprains 33 had an ankle fracture (13%) and none had a mid-foot fracture. All cases with a fracture had a positive OAR result (sensitivity 100% 95% CI; 89-100) and of 218 patients without a fracture, the OAR was negative in 45 cases (specificity 21%; 16-27). In the subgroup of patients assessed by surgeons, sensitivity was 100% (77-100) and specificity was 32% (20-46). In the non-surgical group, sensitivity was also 100% (82-100) but specificity was lower (17% (11-23). CONCLUSIONS: This validation study of the OAR in a Swiss setting produced similar results than those published previously in various other settings. We found differences in the performance of the rule between surgical and non-surgical staff indicating that the OAR has its interpretation component which is more difficult to judge properly by well-instructed non-surgical assessors.     

A study to develop clinical decision rules for the use of radiography in acute ankle injuries.

STUDY OBJECTIVE: To develop decision rules that will predict fractures in patients with ankle injuries, thereby assisting clinicians in being more selective in their use of radiography. DESIGN: Prospective survey of emergency department patients over a five-month period. SETTING: Two university hospital EDs. PARTICIPANTS: One hundred fifty-five adults in a pilot stage and 750 in the main study; all presented with acute blunt ankle injuries. INTERVENTIONS: Thirty-two standardized clinical variables were assessed and recorded on data sheets by staff emergency physicians before radiography. MEASUREMENTS: Variables were assessed for reliability by the kappa coefficient and for association with significant fracture on both ankle and foot radiographic series by univariate analysis. The data then were analyzed by logistic regression and recursive partitioning techniques to develop decision rules for predicting fractures in each radiographic series. MAIN RESULTS: All 70 significant malleolar fractures found in the 689 ankle radiographic series performed were identified among people who had pain near the malleoli and were age 55 years or more, had localized bone tenderness of the posterior edge or tip of either malleolus, or were unable to bear weight both immediately after the injury and in the ED. This rule was 100% sensitive and 40.1% specific for detecting malleolar fractures and would allow a reduction of 36.0% of ankle radiographic series ordered. Similarly, all 32 significant midfoot fractures on the 230 foot radiographic series performed were found among patients with pain in the midfoot and bone tenderness at the base of the fifth metatarsal, the cuboid, or the navicular. CONCLUSION: Highly sensitive decision rules have been developed and will now be validated; these may permit clinicians to confidently reduce the number of radiographs ordered in patients with ankle injuries.     

Does ethanol affect the reliability of pelvic bone examination in blunt trauma?

STUDY OBJECTIVE: We sought to determine whether the reliability of clinical evaluation for pelvic bone fracture after trauma is compromised by a serum ethanol level of 100 mg/dL or greater. METHODS: This is a retrospective case control study of trauma registry patients presenting from October 1, 1995, to March 31, 1997, to an urban level I trauma center. Inclusion criteria were as follows: blunt trauma, age 13 years or older, and Glasgow Coma Scale score of 13 or greater. Exclusion criteria were as follows: isolated penetrating injury and suspected spinal injury. Patients were separated into 2 groups: those with an ethanol level of 100 mg/dL or greater, and those with an ethanol level of less than 100 mg/dL. Physician performance in clinical identification of pelvic bone fracture by using a complaint of pain, pelvic tenderness, with or without deformity, was compared between the 2 groups. RESULTS: Seven hundred sixty-three patients met inclusion criteria. Fifty-five (7. 2%) patients had a pelvic fracture, 75% of which were isolated acetabulum or pubic ramus fractures. Two hundred six control patients without pelvic fractures were randomly selected. The sensitivity and specificity of the complaint of pain and tenderness, deformity, or both for identification of a pelvic fracture was not significantly different between the ethanol groups. Five (9%) of 55 patients with pelvic fractures had neither a complaint of pain nor bony tenderness or deformity on examination. This was not statistically associated with an ethanol level of 100 mg/dL or greater (P =1.000). CONCLUSION: In our study, clinical evaluation for pelvic fracture in trauma patients with a Glasgow Coma Scale score of 13 or greater was not compromised by an ethanol level of 100 mg/dL or greater. The most common reason for clinically missed pelvic fractures was the presence of additional painful distracting injuries.     

Tuberculous ankle versus pyogenic septic ankle arthritis: a retrospective comparison

Ankle tuberculosis (TB) manifests with varying symptoms and is easily confused with pyogenic septic ankle arthritis. In this study, all patients with either ankle TB or pyogenic septic ankle arthritis who were admitted to a medical center in southern Taiwan between May 1986 and October 2006 were reviewed retrospectively to identify risk factors for ankle TB. Compared with the 42 patients with culture-confirmed pyogenic septic ankle arthritis, the 26 patients with ankle TB (12 definitive, 5 probable, and 9 possible) were significantly more likely to have evidence of TB on chest radiographs (50 versus 10%; P<0.01), a history of trauma (58 versus 17%; P<0.01), presentation with sinus discharge (50 versus 12%; P<0.01), duration of symptoms of more than 3 months (69 versus 12%; P<0.01), a leukocyte count of <10,000/μL (58 versus 29%; P=0.03), and C-reactive protein of <5 mg/dL (42 versus 17%; P=0.03). Evidence of TB on chest radiographs was identified as an independent risk factor for ankle TB (odds ratio=35.1; 95% confidence interval=1.6?779.8; P=0.02) by multiple logistic regression analysis. Awareness of these factors is essential for the accurate and timely diagnosis of ankle TB.     

Comparison of physician judgment and decision aids for ordering chest radiographs for pneumonia in outpatients

STUDY OBJECTIVES: To compare physician judgment in the use of chest radiographs for diagnosing pneumonia with decision rules developed by Diehr, Singal, Heckerling, and Gennis. DESIGN: Propsective observational investigation with preradiograph survey of physicians' intent to order chest radiographs for patients presenting with respiratory complaints. All patients had uniform clinical data collected, including chest radiographs and sufficient information to retrospectively apply the four clinical prediction rules. SETTING: The emergency department and medical outpatient clinic of a major urban teaching hospital. PARTICIPANTS: Adult patients presenting with recent history of acute cough or exacerbation of chronic cough plus either fever, sputum production, or hemoptysis. RESULTS: Of 290 patients, 21 (7%) had pneumonia. The sensitivity of physician judgment (0.86) exceeded that of all four decision rules. The specificity of the Diehr (0.67), Heckerling (0.67), and Gennis (0.76) rules exceeded that of physician judgment (0.58). The accuracy of the Gennis (0.76) and Heckerling (0.68) rules also exceeded that of the physicians (0.60). DISCUSSION: Physicians' diagnostic and therapeutic decisions were characterized by high sensitivity but lower specificity for ordering chest radiographs to diagnose pneumonia. The higher specificity and accuracy of two of the decision rules suggest that they may have a role in patient evaluation.     

Clinical Decision Rules Discriminate Between Fractures and Nonfractures in Acute Isolated Knee Trauma

Study objective: To develop criteria that optimize clinical decisionmaking in the use of radiography after isolated knee trauma in adults. Design: A prospective survey of emergency department patients over a 7-month period. Standardized data forms were completed by emergency physicians, residents, and certified physician assistants. Setting: A large suburban community teaching hospital. Participants: Two hundred forty-two patients older than 17 years with isolated knee injuries sustained less than 24 hours previously. Results: We constructed a clinical decision model, calculating sensitivity, specificity, and odds ratios. Twenty-eight patients (11.6%) had fractures, with the patella the most commonly fractured osseous structure. Patients able to walk without limping had not experienced a fracture, nor had patients with twist injuries without effusion. Sensitivity of this model for detecting fracture was 1.0 (99% confidence interval, .97 to 1.0), and specificity was .337 (99% confidence interval, .26 to .42). Conclusion: Clinical decision rules are effective in detecting knee fractures with 100% sensitivity and with sufficient specificity to eliminate 29% of knee radiographs in the ED. These findings require prospective validation. [Weber JE, Jackson RE, Peacock WF, Swor RA, Carley R, Larkin GL: Clinical decision rules discriminate between fractures and nonfractures in acute isolated knee trauma. Ann Emerg Med October 1995;26:429-433.]     

Rational ordering of cervical spine radiographs following trauma

A retrospective review of 312 hospitalized patients with cervical spine injuries was conducted to identify presenting signs, symptoms, and coexisting conditions, and to determine if any injuries were not diagnosed in the emergency department. Of the 257 (82%) patients who were alert on ED evaluation, 215 (84%) complained of neck pain or tenderness. Of the remaining 42 alert patients without neck pain, 34 had sensory or motor symptoms or signs suggestive of cervical spine injury, and eight had significantly painful other injuries. Of the 284 patients presenting within the first 48 hours after injury, 23 were not diagnosed initially, 21 because radiographs were initially read as negative and two because no radiographs were taken. A significant number of patients had more than one fracture of the spinal column. A stepwise approach to rational ordering of cervical spine radiographs in blunt trauma is proposed.     

THE CHERWELL SPLINT: AN ANKLE AND FOOT ORTHOSIS FOR RHEUMATOID ARTHRITIS

Rheumatoid arthritis often gives rise to painful collapse orpartial collapse of the foot into valgus under load-bearingconditions, limiting the subject's ability to walk. However,the ankle joint frequently remains unimpaired. Thus, in seriouscases a cosmetic splint is required which supports the footwhilst allowing the ankle to plantarflex and dorsiflex. TheCherwell ankle–foot orthosis has been designed and extensivelytested in Oxford and elsewhere during the last four years, andcan now be prescribed and supplied from three orthopaedic centresto meet this requirement. KEY WORDS: Rheumatoid arthritis, Orthotics, Ankle, Foot     

Vertebral Fracture Assessment by Dual X‐Ray Absorptiometry: A Valid Tool to Detect Vertebral Fractures in Community‐Dwelling Older Adults in a Population‐Based Survey

Objective

Vertebral fractures are associated with higher morbidity and mortality. Since 70% of vertebral fractures are clinically silent, a radiologic image of the spine has to be acquired for the diagnosis. The aim of this study was to compare the performance of Vertebral Fracture Assessment (VFA) by dual x‐ray absorptiometry (DXA) with radiographs to identify vertebral fractures in community‐dwelling older adults.

Methods

A total of 429 older adults (ages ≥65 years) were enrolled in this cohort. VFA by DXA measurements were evaluated by 2 expert rheumatologists by consensus, and spine radiographs were analyzed according to the semiquantitative method by an expert radiologist. The correlation between VFA and spine radiographs to identify vertebral fractures was analyzed by kappa scores.

Results

The prevalence of vertebral fractures in VFA and radiographs was 29.1% and 29.4%, respectively (P = 0.99). The frequency of unavailable vertebrae was significantly lower in spinal radiographs than in VFA (0.9% and 5.6%, respectively; P < 0.001), particularly in T4–T6. According to VFA, 5,013 vertebrae (96%) were identified as normal and 144 (2.7%) had grade 1, 58 (1.1%) had grade 2, and 12 (0.2%) had grade 3 fractures. The sensitivity of VFA was 72.9% and the specificity was 99.1% to identify vertebral fractures. The sensitivity increased to 92% and the specificity increased to 99.9% when excluding grade 1 deformities. A good correlation between VFA and radiographs (κ = 0.74) was observed, and the exclusion of grade 1 resulted in even better agreement (κ = 0.84).

Conclusion

In community‐dwelling older adults, VFA and radiographs had comparable performances in identifying vertebral fractures, particularly if mild deformities are excluded. Therefore, this methodology is a feasible and promising alternative to improve the management of patients with a high risk of osteoporotic fractures.     

EULAR report on the use of ultrasonography in painful knee osteoarthritis. Part 2: exploring decision rules for clinical utility

BACKGROUND: Synovial inflammation (as defined by hypertrophy and effusion) is common in osteoarthritis (OA) and may be important in both pain and structural progression. OBJECTIVE: To determine if decision rules can be devised from clinical findings and ultrasonography (US) to allow recognition of synovial inflammation in patients with painful knee OA. METHODS: A EULAR-ESCISIT cross sectional, multicentre study enrolled subjects with painful OA knee who had clinical, radiographic, and US evaluations. A classification and regression tree (CART) analysis was performed to find combinations of predictor variables that would provide high sensitivity and specificity for clinically detecting synovitis and effusion in individual subjects. A range of definitions for the two key US variables, synovitis and effusion (using different combinations of synovial thickness, depth, and appearance), were also included in exploratory analyses. RESULTS: 600 patients with knee OA were included in the analysis. For both knee synovitis and joint effusion, the sensitivity and specificity were poor, yielding unsatisfactory likelihood ratios (75% sensitivity, 45% specificity, and positive LR of 1.36 for knee synovitis; 71.6% sensitivity, 43.2% specificity, and positive LR of 1.26 for joint effusion). The exploratory analyses did not improve the sensitivity and specificity (demonstrating positive LRs of between 1.26 and 1.57). CONCLUSION: Although it is possible to determine clinical and radiological predictors of OA inflammation in populations, CART analysis could not be used to devise useful clinical decision rules for an individual subject. Thus sensitive imaging techniques such as US remain the most useful tool for demonstrating synovial inflammation of the knee at the individual level.     

Boehler's angle: a reappraisal

STUDY OBJECTIVES: To reappraise Boehler's angle and evaluate factors, including centering of the central beam, sex of subjects, and side of the body, that may affect angle measurement. DESIGN: Retrospective clinical review. SETTING: Emergency department, Level I trauma center. TYPE OF PARTICIPANTS: 120 consecutive patients radiographed for ankle injury who had normal bones on the ankle and/or foot radiographs. MEASUREMENTS AND MAIN RESULTS: The mean and SD of Boehler's angle were 30 degrees C +/- 6 degrees (range, 14 degrees to 50 degrees). There was no difference in Boehler's angle between male and female subjects (P greater than .05) or between left and right feet (P greater than .05). Slight variations in central beam location for ankle and foot radiographs had no significant effect on Boehler's angle. CONCLUSION: If 28 degrees is taken as the lower limit of normal for Boehler's angle, 37 cases (31%) would be false-positive "abnormal." The use of 20 degrees as the lower limit may decrease the number of false-positive to three cases (2.5%); using 18 degrees (mean -2 SD) reduces the false-positive rate to less than 1% (one case).     

The Canadian C-spine rule performs better than unstructured physician judgment

STUDY OBJECTIVES: We compare the predictive accuracy of emergency physicians' unstructured clinical judgment to the Canadian C-Spine rule. METHODS: This prospective multicenter cohort study was conducted at 10 Canadian urban academic emergency departments. Included in the study were alert, stable, adult patients with a Glasgow Coma Scale score of 15 and trauma to the head or neck. This was a substudy of the Canadian C-Spine and CT Head Study. Eligible patients were prospectively evaluated before radiography. Physicians estimated the probability of unstable cervical spine injury from 0% to 100% according to clinical judgment alone and filled out a data form. Interobserver assessments were done when feasible. Patients underwent cervical spine radiography or follow-up to determine clinically important cervical spine injuries. Analyses included comparison of areas under the receiver operating characteristic (ROC) curve with 95% confidence intervals (CIs) and the kappa coefficient. RESULTS: During 18 months, 6265 patients were enrolled. The mean age was 36.6 years (range 16 to 97 years), and 50.1% were men. Sixty-four (1%) patients had a clinically important injury. The physicians' kappa for a 0% predicted probability of injury was 0.46 (95% CI 0.28 to 0.65). The respective areas under the ROC curve for predicting cervical spine injury were 0.85 (95% CI 0.80 to 0.89) for physician judgment and 0.91 (95% CI 0.89 to 0.92) for the Canadian C-Spine rule (P <.05). With a threshold of 0% predicted probability of injury, the respective indices of accuracy for physicians and the Canadian C-Spine rule were sensitivity 92.2% versus 100% (P <.001) and specificity 53.9% versus 44.0% (P <.001). CONCLUSION: Interobserver agreement of unstructured clinical judgment for predicting clinically important cervical spine injury is only fair, and the sensitivity is unacceptably low. The Canadian C-Spine rule was better at detecting clinically important injuries with a sensitivity of 100%. Prospective validation has recently been completed and should permit widespread use of the Canadian C-Spine rule.     

Non-gouty arthritis in sickle cell disease: report of 37 consecutive cases.

Arthritis in association with sickle cell disease was seen in 37 patients in a 21/2-year period. Cases of gout and of avascular necrosis of the femoral head were excluded. In 12 patients a non-inflammatory effusion occurred during the course of a painful crisis, in 12 patients an ankle effusion occurred in association with spontaneous development or deterioration of leg ulceration, and in 13 patients there was a group of miscellaneous arthritides. Ankle arthritis with leg ulceration has not been previously recognised, and its association with spontaneous ulceration, which is presumed to have a vaso-occlusive origin, is compatible with ischaemic synovial damage. The aetiology may therefore be similar to that believed to account for effusions in association with the painful crisis.     

Radiographic change is common in new presenters in primary care with hip pain. PCR Hip Study Group

OBJECTIVE: To determine the prevalence of radiographic osteoarthritis in subjects with hip pain newly presenting to primary care. METHODS: The study was cross-sectional in design, set in 35 general practices across the UK. It included 195 men and women aged 40 yr and over (median 63 yr) presenting with a new episode of hip pain. Hip radiographs were scored for minimum joint space (MJS) and overall-Croft's modification of the Kellgren and Lawrence (Croft)-grade of osteoarthritis. RESULTS: In all, definite evidence of radiographic change in the painful joint was common: Croft grade > or =2 in 44%, > or =3 in 34%. MJS of 2.5 mm or less was seen in 30% of whom half were below 1.5 mm. There were no significant gender differences in radiographic severity. CONCLUSIONS: Radiographic change is common in patients newly presenting with hip pain and many already have advanced disease.     

Comparison of diagnostic accuracy between three different rules of interpreting high sensitivity troponin T results

With the introduction of high sensitivity troponin-T (hs-TnT) assay, clinicians face more patients with 'positive' results but without myocardial infarction. Repeated hs-TnT determinations are warranted to improve specificity. The aim of this study was to compare diagnostic accuracy of three different interpretation rules for two hs-TnT results taken 6 h apart. After adjusting for clinical differences, hs-TnT results were recoded according to the three rules. Rule1: hs-TnT >13 ng/L in at least one determination. Rule2: change of >20 % between the two measures. Rule3: change >50 % if baseline hs-TnT 14-53 ng/L and >20 % if baseline >54 ng/L. The sensitivity, specificity and ROC curves were compared. The sensitivity analysis was used to generate post-test probability for any test result. Primary outcome was the evidence of coronary critical stenosis (CCS) on coronary angiography in patients with high-risk chest pain. 183 patients were analyzed (38.3 %) among all patients presenting with chest pain during the study period. CCS was found in 80 (43.7 %) cases. The specificity was 0.62 (0.52-0.71), 0.76 (0.66-0.84) and 0.83 (0.74-0.89) for rules 1, 2 and 3, respectively (P < 0.01). Sensitivity decreased with increasing specificity (P < 0.01). Overall diagnostic accuracy did not differ among the three rules (AUC curves difference P = 0.12). Sensitivity analysis showed a 25 % relative gain in predicting CCS using rule 3 compared to rule 1. Changes between two determinations of hs-TnT 6 h apart effectively improved specificity for CCS presence in high-risk chest pain patients. There was a parallel loss in sensitivity that discouraged any use of such changes as a unique way to interpret the new hs-TnT results.     

Diagnostic utility of the two methods of ankle brachial index in the detection of peripheral arterial disease of lower extremities.

BACKGROUND: Peripheral arterial disease (PAD) is a common disease that is diagnosed with a screening test called the Ankle Brachial Index (ABI). Different methods of ABI have been described in the literature. We wanted to estimate and compare the sensitivity and specificity of an alternative method of calculating the ABI (LAP ABI, low ankle pressure ABI) with the current method (named high ankle pressure (HAP)), using digital subtraction angiography (DSA) as the gold standard. METHODS: We reviewed the records of all patients who had undergone DSA at a major academic center between August 2003 and October 2005.The study includes 107 patients/208 limbs. Inclusion criteria included patients with an ABI performed within 30 days prior to the DSA. Patients with non-compressible vessels and ABI >1.40 were excluded. Abnormal ABI was defined as < or = 0.9 for both methods. Disease on angiogram was defined as the presence of 50% or more stenosis of any lower extremity artery from the aorto-iliac bifurcation to the ankle arteries. RESULTS: The sensitivity of the HAP and LAP ABI for the diagnosis of PAD was 69 and 84%, respectively (P < 0.001). The specificity of the HAP and the LAP method was 83 and 64% respectively (P < 0.01). The overall accuracy of LAP ABI and HAP ABI was 80 and 72%, respectively. CONCLUSIONS: The LAP ABI has better sensitivity and overall accuracy in comparison to the HAP ABI to diagnose PAD.