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Biomedical subjects

I G Stiell

Publications and source records attributed to I G Stiell.

At least 19 recordsLinked to original sources
PubMed1998

Potential cost-effectiveness of public access defibrillation in the United States.

BACKGROUND: Approximately 360,000 Americans experience sudden cardiac arrest each year; current treatments are expensive and not very effective. Public access defibrillation (PAD) is a novel treatment for out-of-hospital sudden cardiac arrest that refers to use of automated external defibrillators by the lay public or by nonmedical personnel such as police. A clinical trial has been proposed to evaluate the effectiveness of public access defibrillation, but it is unclear whether such early defibrillation will offer sufficient value for money. Our objective was to estimate the potential cost-effectiveness of public access defibrillation by use of decision analysis. METHODS AND RESULTS: A decision model compared the potential cost-effectiveness of standard emergency medical services (EMS) systems with that of EMS supplemented by PAD. We considered defibrillation by lay responders or police, using an analysis with a US health-care perspective. Input data were derived from published data or fiscal databases. Future costs and effects were discounted at 3%. Monte Carlo simulation was performed to estimate the variability in the costs and effects of each program. Sensitivity analyses assessed the robustness of the results to changes in input data. A standard EMS system had a median cost of $5900 per cardiac arrest patient (interquartile range, IQR, $3200 to $10,900) and yielded a median of 0.25 quality-adjusted life years (IQR, 0.20 to 0.30). PAD by lay responders had a median incremental cost of $44,000 per additional quality-adjusted life year (IQR, $29,000 to $68,900). PAD by police had a median incremental cost of $27,200 per additional quality-adjusted life year (IQR, $15,700 to $47,800). The results were sensitive to changes in the cost and relative survival benefit of PAD. CONCLUSIONS: Although more expensive than standard EMS for sudden cardiac arrest, PAD may be economically attractive. The effectiveness and cost-effectiveness of PAD should be assessed in a randomized, controlled trial.

Cost-Benefit Analysis↗
PubMed1998

Emergency physicians' attitudes toward and use of clinical decision rules for radiography.

OBJECTIVES: 1) To assess Canadian emergency physicians' (EPs') use of and attitudes toward 2 radiographic clinical decision rules that have recently been developed and to identify physician characteristics associated with decision rule use; 2) to determine the use of CT head and cervical spine radiography by EPs and their beliefs about the appropriateness of expert recommendations supporting the routine use of these radiographic procedures; and 3) to determine the potential acceptance of clinical decision rules for CT scan in patients with minor head injury and cervical spine radiography in trauma patients. METHODS: A cross-sectional anonymous mail survey of a random sample of 300 members of the Canadian Association of Emergency Physicians using Dillman's Total Design Method for mail surveys. RESULTS: Of 288 eligible physicians, 232 (81%) responded. More than 95% of the respondents stated they currently used the Ottawa Ankle Rules and were willing to consider using the newly developed Ottawa Knee Rule. Physician characteristics related to frequent use of the Ottawa Ankle Rules were younger age, fewer years since graduating from medical school, part time or resident employment status, working in a hospital without a CT scanner, and believing that decision rules are not oversimplified cookbook medicine or too rigid to apply. Eighty-five percent did not agree that all patients with minor head injuries should receive a CT head scan and only 3.5% stated they always refer such patients for CT scan. Similarly, 78.5% of the respondents did not agree that all trauma patients should receive cervical spine radiography and only 13.2% said they always refer such patients for cervical spine radiography. Ninety-seven and 98% stated they would be willing to consider using well-validated decision rules for CT scan of the head and cervical spine radiography, respectively. Fifty-two percent and 67% of the respondents required the proposed CT and C-spine to be 100% sensitive for identifying serious injuries, respectively. CONCLUSIONS: Canadian EPs are generally supportive of clinical decision rules and, in particular, have very positive attitudes toward the Ottawa Ankle and Knee Rules. Furthermore, EPs disagree with recommendations for routine use of CT head and cervical spine radiography and strongly support the development of well-validated decision rules for the use of CT head and cervical spine radiography. Most EPs expected the latter rules to be 100% sensitive for acute clinically significant lesions.

Adult↗
PubMed1997

Implementation of the Ottawa Knee Rule for the use of radiography in acute knee injuries.

CONTEXT: The Ottawa Knee Rule is a previously validated clinical decision rule that was developed to allow physicians to be more selective and efficient in their use of plain radiography for patients with acute knee injuries. OBJECTIVE: To assess the impact on clinical practice of implementing the Ottawa Knee Rule. DESIGN: Controlled clinical trial with before-after and concurrent controls. SETTING: Emergency departments of 2 teaching and 2 community hospitals. PATIENTS: All 3907 consecutive eligible adults seen with acute knee injuries during two 12-month periods before and after the intervention. INTERVENTION: During the after period in the 2 intervention hospitals, the Ottawa Knee Rule was taught to all house staff and attending physicians who were encouraged to order knee radiography according to the rule. MAIN OUTCOME MEASURES: Referral for knee radiography, accuracy and reliability of the rule, mean time in emergency department, and mean charges. RESULTS: There was a relative reduction of 26.4% in the proportion of patients referred for knee radiography in the intervention group (77.6% vs 57.1 %; P<.001), but a relative reduction of only 1.3% in the control group (76.9% vs 75.9%; P=.60). These changes over time were significant when the intervention and control groups were compared (P<.001). The rule was found to have a sensitivity of 1.0 (95% confidence interval [CI], 0.94-1.0) for detecting 58 knee fractures. The K coefficient for interpretation of the rule was 0.91 (95% CI, 0.82-1.0). Compared with nonfracture patients who underwent radiography during the after-intervention period, those discharged without radiography spent less time in the emergency department (85.7 minutes vs 118.8 minutes) and incurred lower estimated total medical charges for physician visits and radiography (US $80 vs US $183). CONCLUSIONS: Implementation of the Ottawa Knee Rule led to a decrease in use of knee radiography without patient dissatisfaction or missed fractures and was associated with reduced waiting times and costs. Widespread use of the rule could lead to important health care savings without jeopardizing patient care.

Acute Disease↗
PubMed1997

Variation in emergency department use of cervical spine radiography for alert, stable trauma patients.

OBJECTIVE: To, assess the emergency department use of cervical spine radiography for alert, stable adult trauma patients in terms of utilization, yield for injury and variation in practices among hospitals and physicians. DESIGN: Retrospective survey of health records. SETTING: Emergency departments of 6 teaching and 2 community hospitals in Ontario and British Columbia. PATIENTS: Consecutive alert, stable adult trauma patients seen with potential cervical spine injury between July 1, 1994, and June 30, 1995. MAIN OUTCOME MEASURES: Total number of eligible patients, referral for cervical spine radiography (overall, by hospital and by physician), presence of cervical spine injury, patient characteristics and hospitals associated with use of radiography. RESULTS: Of 6855 eligible patients, cervical spine radiography was ordered for 3979 (58.0%). Only 60 (0.9%) patients were found to have an acute cervical spine injury (fracture, dislocation or ligamentous instability); 98.5% of the radiographic films were negative for any significant abnormality. The demographic and clinical characteristics of the patients were similar across the 8 hospitals, and no cervical spine injuries were missed. Significant variation was found among the 8 hospitals in the rate of ordering radiography (p < 0.0001), from a low of 37.0% to a high of 72.5%. After possible differences in case severity and patient characteristics at each hospital were controlled for, logistic regression analysis revealed that 6 of the hospitals were significantly associated with the use of radiography. At 7 hospitals, there was significant variation in the rate of ordering radiography among the attending emergency physicians (p < 0.05), from a low of 15.6% to a high of 91.5%. CONCLUSIONS: Despite considerable variation among institutions and individual physicians in the ordering of cervical spine radiography for alert, stable trauma patients with similar characteristics, no cervical spine injuries were missed. The number of radiographic films showing signs of abnormality was extremely low at all hospitals. The findings suggest that cervical spine radiography could be used more efficiently, possibly with the help of a clinical decision rule.

Adolescent↗
PubMed1997

Clinical prediction rules. A review and suggested modifications of methodological standards.

BACKGROUND: Clinical prediction rules are decision-making tools for clinicians, containing variables from the history, physical examination, or simple diagnostic tests. OBJECTIVE: To review the quality of recently published clinical prediction rules and to suggest methodological standards for their development and evaluation. DATA SOURCES: Four general medical journals were manually searched for clinical prediction rules published from 1991 through 1994. STUDY SELECTION: Four hundred sixty potentially eligible reports were identified, of which 30 were clinical prediction rules eligible for study. Most methodological standards could only be evaluated in 29 studies. DATA ABSTRACTION: Two investigators independently evaluated the quality of each report using a standard data sheet. Disagreements were resolved by consensus. DATA SYNTHESIS: The mathematical technique was used to develop the rule, and the results of the rule were described in 100% (29/29) of the reports. All the rules but 1 (97% [28/29]) were felt to be clinically sensible. The outcomes and predictive variables were clearly defined in 83% (24/29) and 59% (17/29) of the reports, respectively. Blind assessment of outcomes and predictive variables occurred in 41% (12/29) and 79% (23/29) of the reports, respectively, and the rules were prospectively validated in 79% (11/14). Reproducibility of predictive variables was assessed in only 3% (1/29) of the reports, and the effect of the rule on clinical use was prospectively measured in only 3% (1/30). Forty-one percent (12/29) of the rules were felt to be easy to use. CONCLUSIONS: Although clinical prediction rules comply with some methodological criteria, for other criteria, better compliance is needed.

Decision Support Techniques↗
PubMed1997

Variation in ED use of computed tomography for patients with minor head injury.

STUDY OBJECTIVE: To determine the frequency of utilization, yield for brain injury, incidence of missed injury, and variation in the use of computed tomography (CT) for ED patients with minor head injury. METHODS: This retrospective health records survey was conducted over a 12-month period in the EDs at seven Canadian teaching institutions. Included in this review were adult patients who sustained acute minor head injury, defined as witnessed loss of consciousness or amnesia and a Glasgow Coma Scale score of 13 or greater. Data were collected by research assistants who were trained to select cases and abstract data in a standardized fashion according to a resource manual. Subsequently, patient eligibility was reviewed by the study coordinator and principal investigator. RESULTS: Of the 1,699 patients seen, 521 (30.7%) were referred for CT, and 418 (79.8%) of these scans were negative for any type of brain injury. Overall, 105 (6.2%) of these patients sustained acute brain injury, including 9 (.5%) with an epidural hematoma Cochran's Q test for homogeneity demonstrated significant variation between the seven centers for rate of ordering CT (P < .0001), from a low of 15.9% to a high of 70.4%. All five cases of "missed" hematoma occurred at the institutions with the highest and third highest rates of CT use. After controlling for possible differences in case severity and patient characteristics at each hospital, logistic regression analysis revealed that five of seven hospitals were significantly associated with the use of CT (respected odds ratios [OR], .4, .5, .5, 3.2, and 4.7). Three of the centers (two with the highest ordering rates) showed significant heterogeneity in the ordering of CT among their attending staff physicians, from a low of 6.5% to a high of 80.0%. CONCLUSION: There was considerable variation among institutions and individual physicians in the ordering of CT for patients with minor head injury. Although emergency physicians were selective when ordering CT, the yield of radiography was very low at all hospitals. None of the cases of "missed" intracranial hematoma came from the lowest ordering institutions, indicating that patients may be managed safely with a selective approach to CT use. These findings suggest great potential for more standardized and efficient use of CT of the head, possibly through the use of a clinical decision rule.

Adolescent↗
PubMed1997

Ankle radiograph utilization after learning a decision rule: a 12-month follow-up.

OBJECTIVE: To test whether the reduction in ankle radiograph ordering was sustained during a 12-month period after a formal trial to introduce the Ottawa ankle rules. METHODS: A before-after clinical trial of ankle radiograph ordering practice was performed in a university-based ED. All 1,884 (947 "during intervention," 937 "postintervention") adults seen with acute ankle injuries during 2 12-month trial periods were evaluated. The behavioral intervention was the teaching of the Ottawa ankle rules and feedback of compliance with the rules during the intervention period. No further education about the ankle rules or feedback regarding compliance occurred during the postintervention year. Physicians were unaware of any postintervention surveillance. The primary outcome was the proportion of eligible patients referred for an ankle radiograph during the intervention and postintervention periods. RESULTS: During the intervention period (January 1-December 31, 1993), the proportion of patients who received an ankle radiograph [609 x-rayed of 947 patients seen (64.3%; 95% CI 61.2-67.4%)] did not differ from the proportion who received an x-ray in the postintervention period (January 1-December 31, 1994) [583 x-rayed of 937 patients seen (62.2%; 95% CI 59.1-65.3%), p = 0.65, power > 0.80 to detect a 10% increase in the radiograph ordering rate]. There was also no difference in the radiograph ordering rate in the first 3 months of the postintervention period compared with the last 3 months of the postintervention period (68.8% vs 64.7%, respectively, p > 0.30). CONCLUSIONS: Compliance with the Ottawa ankle rules was sustained during a 12-month postintervention surveillance period when physicians did not know they were being observed. Physicians will continue to use a simple clinical guideline once it has been learned.

Adolescent↗
PubMed1996

The Ontario trial of active compression-decompression cardiopulmonary resuscitation for in-hospital and prehospital cardiac arrest.

OBJECTIVE: To compare the impact of active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) and standard CPR on the outcomes of in-hospital and prehospital victims of cardiac arrest. DESIGN: Randomized controlled trial with blinding of allocation using a sealed container. SETTINGS: (1) Emergency departments, wards, and intensive care units of 5 university hospitals and (2) all locations outside hospitals in 2 midsized cities. PATIENTS: A total of 1784 adults who had cardiac arrest. INTERVENTION: Patients received either standard or ACD CPR throughout resuscitation. MAIN OUTCOME MEASURES: Survival for 1 hour and to hospital discharge and the modified Mini-Mental State Examination (MMSE). RESULTS: All characteristics were similar in the standard and ACD CPR groups for the 773 in-hospital patients and the 1011 prehospital patients. For in-hospital patients, there were no significant differences between the standard (n = 368) and ACD (n = 405) CPR groups in survival for 1 hour (35.1% vs 34.6%; P = .89), in survival until hospital discharge (11.4% vs 10.4%; P = .64), or in the median MMSE score of survivors (37 in both groups). For patients who collapsed outside the hospital, there were also no significant differences between the standard (n = 510) and ACD (n = 501) CPR groups in survival for 1 hour (16.5% vs 18.2%; P = .48), in survival to hospital discharge (3.7% vs 4.6%; P = .49), or in the median MMSE score of survivors (35 in both groups). Exploration of clinically important subgroups failed to identify any patients who appeared to benefit from ACD CPR. CONCLUSIONS: ACD CPR did not improve survival or neurologic outcomes in any group of patients with cardiac arrest.

Adolescent↗
PubMed1996

Prospective validation of a decision rule for the use of radiography in acute knee injuries.

OBJECTIVE: To validate a previously derived decision rule for the use of radiography in patients with acute knee injury. DESIGN: Prospectively administered survey. SETTING: Emergency departments of two university hospitals serving adults. PATIENTS: Convenience sample of 1096 of 1251 eligible adults with acute knee injuries; 124 patients were examined by two physicians. MAIN OUTCOME MEASURES: Attending emergency physicians assessed each patient for standardized clinical variables and determined the need for radiography according to the decision rule. Patients who did not have radiography underwent a structured telephone interview at day 14 to determine the possibility of a fracture. The rule was assessed for ability to correctly identify the criterion standard, fracture of the knee. An attempt was made to refine the rule by means of univariate and recursive partitioning analyses. RESULTS: The decision rule had a sensitivity of 1.0 (95% confidence interval [CI], 0.94 to 1.0) for identifying 63 clinically important fractures. Physicians correctly interpreted the rule in 96% of cases, and the k value for interpretation was 0.77 (95% CI, 0.65 to 0.89). The potential relative reduction in use of radiography was estimated to be 28%. The probability of fracture, if the decision rule were "negative," is estimated to be 0% (95% CI, 0% to 0.4%). Attempts to refine the rule led to a model with improved specificity but with an unacceptable loss of sensitivity. CONCLUSION: Prospective validation has shown this decision rule to be 100% sensitive for identifying fractures of the knee, to be reliable and acceptable, and to have the potential to allow physicians to reduce the use of radiography in patients with acute knee injury.

Adult↗
PubMed1996

Effectiveness of emergency medical services for victims of out-of-hospital cardiac arrest: a metaanalysis.

STUDY OBJECTIVE: To determine the relative effectiveness of differences in response time interval, proportion of bystander CPR, and type and tier of emergency medical services (EMS) system on survival after out of hospital cardiac arrest. METHODS: We performed a comprehensive literature search, excluding EMS systems other than those of interest (systems of interest were those comprising one tier with providers of basic life support [BLS] or advanced life support [ALS] and those comprising two tiers with providers of BLS or BLS-defibrillation followed by ALS), patient population of fewer than 100 cardiac arrests, studies in which we could not determine the total number of arrests of presumed cardiac origin, and studies lacking data on survival to hospital discharge. Metaanalysis using generalized linear model with dispersion estimation for random effects was then performed. RESULTS: Increased survival to hospital discharge was significantly associated with tier (P < .01), response time interval (P < .01), and bystander CPR (P = .04). A significant interaction was detected between response time interval and bystander CPR (P = .02). For the studies analyzed, survival was 5.2% in a one-tier EMS system or 10.5% in a two-tier EMS system. A 1-minute decrease in mean response time interval was associated with absolute increases in survival rates of .4% and .7% in a one-tier and two-tier EMS systems, respectively. CONCLUSION: Increased survival to hospital discharge may be associated with decreased response time interval and with the use of a two-tier EMS system as opposed to a one-tier system. The data available for this analysis were suboptimal. Policymakers need more methodologically rigorous research to have more reliable and valid estimates of the effectiveness of different EMS systems.

Cardiopulmonary Resuscitation↗
PubMed1996

Cost-effectiveness analysis of potential improvements to emergency medical services for victims of out-of-hospital cardiac arrest.

STUDY OBJECTIVE: To measure the incremental cost-effectiveness of various improvements to emergency medical services (EMS) systems aimed at increasing survival after out-of-hospital cardiac arrest. METHODS: We performed cost-effectiveness analysis based on (1) metaanalysis of effectiveness of the various EMS systems, (2) costing of each component of EMS systems, (3) modeling of the relationship between the proportion of cardiac arrest victims who receive CPR and the proportion of individuals trained, (4) modeling of the relationship between response time interval and the characteristics of the EMS system, (5) measurement of quality of life, and (6) decision analysis to combine the results of the first five components. RESULTS: The incremental cost-effectiveness ratio for a 48-second improvement in mean response time in a one-tier EMS system yielded by the addition of more EMS providers was $368,000 per quality-adjusted life year (QALY). For improved response time in a two-tier EMS system by the addition of more basic life support (BLS)/BLS-defibrillator (BLS-D) providers to the first tier, the ratio was $53,000 per QALY with pump vehicles or $159,000 per QALY with ambulances. Change from a one-tier EMS to a two-tier EMS system by the addition of initial BLS/BLS-D providers in pump vehicles as the first tier was associated with a cost per QALY of $40,000. Change from one-tier EMS to two-tier EMS by the addition of initial BLS/BLS-D providers in ambulances as the first tier was associated with a cost per QALY of $94,000. CONCLUSION: The most attractive options in terms of incremental cost-effectiveness were improved response time in a two-tier EMS system or change from a one-tier to a two-tier EMS system. Future research should be directed toward identification of the costs of instituting the first tier of a two-tier EMS system and identification of cost-effective methods of improving response time.

Cardiopulmonary Resuscitation↗
PubMed1995

Appearance scales to measure cosmetic outcomes of healed lacerations.

To develop an appearance scale that will allow the objective and scientific comparison of the cosmetic results of healed lacerations, 33 photographs of healed lacerations and incisions with variable cosmetic results were shown to four plastic surgeons. These plastic surgeons were asked to independently rate the photographs on two separate occasions using two scales, a Visual Analogue Scale and a Categorical Scale. Interobserver and intraobserver agreement were determined for each scale. Comparison of the scales with each other was done to assess consistency. The Visual Analogue Scale showed good interobserver agreement with an Intraclass Correlation Coefficient of 0.75. Intraobserver agreement was also high across the four observers with Pearson correlation coefficients ranging from 0.73 to 0.87. The agreement of the categorical scale was also good with a kappa coefficient for interobserver agreement of 0.53. The kappa coefficient for intraobserver agreement ranged from 0.48 to 0.72. Because the visual analogue scale and categorical scale showed good interobserver and intraobserver agreement, both may be considered good measurement tools in the comparison of alternate methods of laceration care.

Adult↗
PubMed1995

Randomized double-blind controlled trial comparing room-temperature and heated lidocaine for digital nerve block.

STUDY OBJECTIVE: To determine whether warming of lidocaine decreases the pain of its injection during digital nerve block. DESIGN: Prospective, randomized, double-blind, controlled trial. INTERVENTIONS: Twenty healthy volunteers received bilateral digital nerve blocks of their middle finger. They were first randomly assigned to receive either room-temperature (21 degrees C) or heated (42 degrees C) 2% lidocaine in their first block. They were then randomly assigned to receive the first block in either the right or left hand. The blocks were performed in a standardized fashion by a single physician, who was blinded to which solution was being used. The volunteers rated the pain of each digital block on a 100-mm visual analog scale (VAS). Efficacy of each digital block was tested at 5 minutes. RESULTS: Heating of the lidocaine was associated with a significantly lower median VAS pain score (31.5 versus 25.0; P < .05). There was no difference in pain score between the two solutions in relation to which hand was used (P = .29) or whether the injection was the first or the second (P = .37). When all factors (temperature, order, and hand) were considered in the ANOVA with respect to VAS pain score, the only significant relation found was that between the temperature of the solution and the VAS pain score (P = .028). CONCLUSION: Heating of lidocaine decreases the pain of injection during digital nerve block.

Adult↗
PubMed1995

Derivation of a decision rule for the use of radiography in acute knee injuries.

STUDY OBJECTIVE: To derive a highly sensitive decision rule for the selective use of radiography in acute knee injuries. DESIGN: Prospectively administered survey. SETTING: Emergency departments of two university hospitals. PARTICIPANTS: Convenience sample of 1,047 adults with acute knee injuries. RESULTS: Attending emergency physicians assessed each patient for 23 standardized clinical findings, which were recorded on data collection forms. A total of 127 patients was examined independently by two physicians to determine interobserver agreement. The outcome measure was fracture of the knee. Any patients who did not have ED radiography underwent a structured telephone interview to determine the possibility of a missed fracture. Those variables found to be both reliable (highest kappa values) and strongly associated with a fracture (highest chi 2 values) were further analyzed by a recursive-partitioning multivariate technique. The derived decision rule included the following variables: (1) age 55 years or older, (2) tenderness at the head of the fibula, (3) isolated tenderness of the patella, (4) inability to flex to 90 degrees, and (5) inability to bear weight both immediately and in the ED (four steps). The presence of one or more of these findings would have identified the 68 fractures in the study population with a sensitivity of 1.0 (95% confidence interval [Cl], .95 to 1.0) and a specificity of .54 (95% Cl, .51 to .57). Application of the rule would have led to a 28.0% relative reduction in the use of radiography from 68.6% to 49.4% in the study population. CONCLUSION: A practical, highly sensitive, and reliable decision rule for the use of radiography in acute knee injuries has been derived. Clinical application should await prospective validation of the rule.

Adult↗
PubMed1995

Cost-effectiveness analysis of the Ottawa Ankle Rules.

STUDY OBJECTIVE: To conduct an incremental cost-effectiveness analysis of implementation of the Ottawa Ankle Rules in emergency departments in the United States and Canada. DESIGN: A decision analytic approach to technology assessment. Clinical decision rules that allow physicians to be more selective in their use of radiography were compared with current practice in a decision analytic model. SETTING: A university hospital adult ED. PARTICIPANTS: ED physicians instructed in the use of the Ottawa Ankle Rules for adult patients with ankle injury. RESULTS: Radiography, waiting time, lost productivity, and medicolegal costs were calculated. In the United States, the savings varied between US$614,226 and US$3,145,910 per 100,000 patients, depending on the charge rate for radiography. In Ontario, Canada, the total savings were CAN$730,145 per 100,000 patients. One- and two-way sensitivity analyses that varied the rate of missed fractures, cost of radiography, probability of lawsuits, and cost of lawsuits did not change the results substantially. CONCLUSION: Implementation of the Ottawa Ankle Rules would result in significant savings of health care dollars despite the cost of missed fractures including litigation costs.

Adult↗