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Treatment benefit and the risk of suicidality in multicenter, randomized, controlled trials of sertraline in children and adolescents.

OBJECTIVE: The aim of this study was to examine the balance between the benefits of treatment and the risk of suicidality in children and adolescents in multicenter, randomized, controlled trials of sertraline versus placebo. METHOD: The published literature was searched for multicenter, randomized, placebo-controlled trials of sertraline for pediatric mental disorders. Four trials were identified: Two (pooled) in pediatric major depressive disorder (MDD; Wagner 2003) and two in obsessive-compulsive disorder (OCD; March et al. 1998; POTS Team 2004). Using intent-to-treat (ITT) analysis populations, the authors calculated the number needed to treat (NNT) for response and remission and the number needed to harm (NNH) for suicidality, and their ratio, for each clinical trial. RESULTS: NNTs ranged from 2 to 10, indicating clinically meaningful benefits. Benefit was greater for OCD than for MDD, and for adolescents as compared with children in MDD. No age effect was apparent for OCD. Suicidality was reported in 8 patients (5 assigned to sertraline and 3 assigned to placebo). All but 1 (a placebo-treated patient in the Pfizer OCD trial) were enrolled in the sertraline MDD trial. The NNH for suicidality in MDD was 64. Treatment emergent suicidality was more common in children (NNH 28.7) than in adolescents (NNH 706.3). Because no patient developed suicidality in sertraline-treated OCD patients, the NNH for sertraline in OCD approaches infinity. CONCLUSIONS: With the stipulation that doctor and patient preferences necessarily play a critical role in the choice of treatment, NNT to NNH ratios indicate a positive benefit-to-risk ratio for sertraline in adolescents with MDD and in patients of all ages with OCD.

Adolescent↗

Results of a prospective multicenter trial evaluating the ePTFE peritoneal onlay laparoscopic inguinal hernioplasty.

A 2.8-year prospective multicenter trial was conducted to evaluate the ePTFE peritoneal onlay laparoscopic inguinal hernioplasty. A total of 441 inguinal hernias were repaired in 351 patients (326 male; 25 female). Two hundred twenty-six of the hernias were direct, 185 indirect, 4 femoral, 26 pantaloon, 90 bilateral, and 92 recurrent. Standardized data collection forms were used and submitted for centralized data analysis. For the hernioplasty, Cooper's ligament was exposed and an 8 cm x 12 cm x 1 mm GORE-TEX Soft Tissue Patch was stapled circumferentially to Cooper's ligament and the endoabdominal fascia. Patients were followed at 1 week, 6 months, 1 year, and then annually. Three-month intervals were used as needed. There was a mean follow-up of 447 days, with 21% of the total repairs followed for more than 2 years and 56% for more than a year. The overall follow-up rate was 95.5%. The operative and postoperative complication rates were 0.45% and 8%, respectively. There were 17 recurrent hernias (3.8%). The range of experience among the investigators was 13 to 168 hernioplasties. With the completion of 25 cases per investigator, the recurrence rate fell to 0.39%. Postoperative analgesia averaged a 24-hr supply of medication; 12.2% of patients required no analgesia. Convalescence averaged 5.4 days, and return to work averaged 7.7 days. This multicenter trial demonstrates that the ePTFE laparoscopic peritoneal onlay inguinal hernioplasty is a safe and dependable repair, especially after the initial learning curve is surmounted.

Adolescent↗

Adjustment for bias due to errors in exposure assessments in multicenter cohort studies on diet and cancer: a calibration approach.

An advantage of multicenter cohort studies on diet and cancer is that these may include populations over a wide range of dietary exposure. With some simplifying assumptions, the information from such multicenter studies may be divided into 1) estimated relationships within each of the separate cohorts, between individual-level measurements of dietary exposure and disease outcome, and 2) an estimated between-cohort relationship, between the mean intake measurements and mean incidence rates. Errors in the dietary exposure measurements may lead to different amounts of bias in each of these estimated relationships, in particular when dietary questionnaire methods cannot easily be standardized. A calibration approach can be used to adjust for such differences in bias. This will improve the relative weighting of within- and between-cohort components of evidence for a diet-disease association.

Cohort Studies↗

Multicenter study evaluating a dual policy of postorchiectomy surveillance and selective adjuvant single-agent carboplatin for patients with clinical stage I seminoma.

BACKGROUND: After decades of irradiation as standard therapy for clinical stage I testicular seminoma, alternative treatment approaches have emerged including postorchiectomy surveillance and adjuvant chemotherapy. This study was performed to assess a dual policy of surveillance and selective single-agent carboplatin (for high-risk cases) in a multicenter setting. PATIENTS AND METHODS: From 1994 to 1999, 203 patients with stage I seminoma were included. Sixty (29.6%) were considered poor-risk cases (i.e. with vascular invasion and/or pathological tumor stage pT2 or greater) and received two courses of adjuvant carboplatin, whereas 143 (70.4%) without risk criteria underwent close surveillance. RESULTS: Median follow-up was 52 months (range 14-92). Relapses were observed in two (3.3%) patients treated with carboplatin and in 23 patients (16.1%) on surveillance, with a median time to recurrence of 11 months (range 3.9-39.6). All relapsing patients were rendered disease-free, mainly with cisplatin-based chemotherapy. Four patients died from tumor-unrelated causes. Actuarial 5-year overall survival was 96.7% and cause-specific survival was 100%. Five-year disease-free survival was 83.5% for patients on surveillance, and 96.6% for those receiving carboplatin. CONCLUSIONS: This dual treatment policy is feasible in a multicenter setting and preserves 70% of patients from adjuvant chemotherapy. Single-agent carboplatin is effective in reducing the relapse rate in patients with high-risk stage I seminoma. A better definition of local risk features would probably improve patient selection, thus minimizing the incidence of recurrences on surveillance.

Adolescent↗

A multicenter study of 4-chloro-m-cresol for diagnosing malignant hyperthermia susceptibility.

UNLABELLED: Standardization of the in vitro contracture test (IVCT) for malignant hyperthermia (MH) susceptibility has resulted in very rare false negative tests. However, false positive results stigmatizing the patient seem to be more frequent than false negative results and make supplementary tests desirable. This multicenter approach studied the usefulness of an IVCT with 4-chloro-m-cresol (4-CmC), a ryanodine receptor-specific agonist for a better definition of MH susceptibility. Diagnosis made by the standard IVCT was compared with the results of this 4-CmC test on muscle specimens of 202 individuals from 6 European MH centers. In the 4-CmC test, the results of the MH susceptible group differed significantly from both the MH normal and the MH equivocal group. 4-CmC revealed a qualitatively dose response-curve similar to caffeine. A correlation index of r = 0.79 for the concentration thresholds underlined the strong concordance of the caffeine and the 4-CmC effects. The optimal threshold concentration was determined to be 75 microM in the pooled data of all centers and is much lower than that of caffeine (2 mM), suggesting a more than 25-fold higher affinity of 4-CmC. The predictive value of 4-CmC is as high as that of caffeine and consequently higher than that of halothane. 4-CmC seems to be a suitable drug to refine diagnosis of MH susceptibility and could be used as an additional test substance. IMPLICATIONS: Although in vitro contracture testing for malignant hyperthermia diagnosis is well standardized, with a relatively high sensitivity and specificity, false test results cannot be excluded and may be associated with serious disabilities for the concerned individuals. In this multicenter study, 4-chloro-m-cresol was evaluated as a new test substance for the in vitro contracture testing. Its use improves the accuracy of in vitro diagnosis of malignant hyperthermia susceptibility.

Caffeine↗

Multicenter randomized comparison of the efficacy and safety of xenon and isoflurane in patients undergoing elective surgery.

BACKGROUND: All general anesthetics used are known to have a negative inotropic side effect. Since xenon does not have a negative inotropic effect, it could be an interesting future general anesthetic. The aim of this clinical multicenter trial was to test the hypothesis of whether recovery after xenon anesthesia is faster compared with an accepted, standardized anesthetic regimen and that it is as effective and safe. METHOD: A total of 224 patients in six centers were included in the protocol. They were randomly assigned to receive either xenon (60 +/- 5%) in oxygen or isoflurane (end-tidal concentration, 0.5%) combined with nitrous oxide (60 +/- 5%). Sufentanil (10 mcirog) was intravenously injected if indicated by defined criteria. Hemodynamic, respiratory, and recovery parameters, the amount of sufentanil, and side effects were assessed. RESULTS: The recovery parameters demonstrated a statistically significant faster recovery from xenon anesthesia when compared with isoflurane-nitrous oxide. The additional amount of sufentanil did not differ between both anesthesia regimens. Hemodynamics and respiratory parameters remained stable throughout administration of both anesthesia regimens, with advantages for the xenon group. Side effects occurred to the same extent with xenon in oxygen and isoflurane-nitrous oxide. CONCLUSION: This first randomized controlled multicenter trial on the use of xenon as an inhalational anesthetic confirms, in a large group of patients, that xenon in oxygen provides effective and safe anesthesia, with the advantage of a more rapid recovery when compared with anesthesia using isoflurane-nitrous oxide.

Adjuvants, Anesthesia↗

The prevention of anastomotic leakage after total gastrectomy with local decontamination. A prospective, randomized, double-blind, placebo-controlled multicenter trial.

OBJECTIVE: A prospective, randomized, double-blind, placebo controlled multicenter trial was undertaken in 205 patients treated with total gastrectomy for gastric malignancies to evaluate whether local antimicrobial measures reduce the incidence of esophagojejunal anastomotic leakage. SUMMARY BACKGROUND DATA: Anastomotic leakage of the esophagojejunostomy is always a septic complication of total gastrectomy for gastric malignancies, but it never has been attempted to prevent this complication with the administration of topical antimicrobial agents during the critical phase of anastomotic wound healing. METHODS: To evaluate the efficacy and safety of topical decontamination, the study was carried out as a prospective, randomized, double-blind and placebo-controlled clinical multicenter trial in patients with total gastrectomy for gastric cancer. Patients received either placebo or decontamination with polymyxin B (100 mg), tobramycin (80 mg), vancomycin (125 mg), and amphotericin B (500 mg) four times per day orally from the day before the operation until the seventh postoperative day. All patients received a perioperative intravenous prophylaxis with cefotaxime 2 x 2 g. Other interventions including the administration of antibiotics and fluids, were not affected by the study protocol. RESULTS: Of 260 patients who were randomized, total gastrectomy was not carried out in 55 patients. They dropped out of the study. Patients receiving an esophagojejunostomy were observed until day 42, when they were discharged from the clinic or died. An intention-to-treat analysis of the data was carried out. Among the 103 recipients of placebo, there were 11 (10.6%) with an anastomotic leakage of the esophagojejunostomy, and among the 102 recipients of decontamination, there were 3 (2.9%) with an anastomotic leakage of the esophagojejunostomy (p = 0.0492). Pulmonary infections were observed in 23 patients (22.3%) receiving placebo and in 9 patients (8.8%) who were decontaminated (p = 0.02). There were 11 deaths (10.6%) among the recipients of placebo and 5 deaths (4.9%) among the recipients of decontamination (p = 0.1). CONCLUSIONS: Decontamination with polymyxin, tobramycin, vancomycin, and amphotericin B during anastomotic wound healing is safe and effective in the prevention of esophagojejunal anastomotic leakage after total gastrectomy.

Aged↗

Accurate placement of central venous catheters: a prospective, randomized, multicenter trial.

OBJECTIVES: a) To define the frequency of dangerous (intracardiac) central venous catheter placement in a multicenter study of large community hospital intensive care units (ICUs) and to evaluate physician responses to this finding. b) To validate right atrial electrocardiography as a technique to assure adherence with recent Food and Drug Administration (FDA) guidelines regarding the location of central venous catheter tips. c) To conduct a literature review of vascular cannulation and its associated potentially lethal complications. DESIGN: Prospective, randomized, blinded, multicenter study. SETTING: Multidisciplinary ICUs in five large community teaching hospitals. PATIENTS: Consecutive patients (n = 112) who required a central venous catheter by either internal jugular vein or subclavian vein at four separate hospitals were assessed using 30-cm catheters. Consecutive patients (n = 50) in a fifth hospital who subsequently required a central venous catheter via the internal jugular vein or subclavian vein route were prospectively randomized to receive a 20-cm central venous catheter with either conventional surface-landmark guidance, or with the right atrial electrocardiography-guided technique. MAIN OUTCOME MEASURES: a) Occurrence rate of malpositioned central venous catheters. b) Ability of right atrial electrocardiography to aid in the accurate placement of central venous catheters. RESULTS: a) Using conventional placement techniques with a 30-cm catheter, 53 (47%) of 112 initial central venous catheter placements resulted in location of the catheter tip within the heart. Catheter tips were not repositioned to locations outside the right atrium after this finding was identified on initial post-procedure films. b) Using the right atrial electrocardiography technique to place 20-cm central venous catheters resulted in no catheter tip locations within the heart (0/25) vs. 14 (56%) of 25 (p < .0001) intracardiac placements using conventional techniques. c) The literature suggests that serious mechanical complications of central venous catheterization, although uncommon, are associated with a high mortality rate. Deaths are associated with intracardiac placement. CONCLUSIONS: a) The FDA guidelines regarding catheter tip location (catheter tip should not be in the right atrium) have not been widely publicized. b) The average safe insertion depth for a central venous catheter from the left or right internal jugular vein or subclavian vein is 16.5 cm for the majority of adult patients; a central venous catheter should not be routinely inserted to a depth of > 20 cm. Catheters longer than this size are rarely needed, and potentially dangerous. Catheter tip location is important to document following central venous catheter insertion. Thirty-centimeter central venous catheters should not be used when accessing the central circulation via internal jugular or subclavian veins. c) Right atrial electrocardiography is a technique that assures initial tip position outside the heart in accordance with FDA guidelines. This technique would virtually eliminate the major risk of death (i.e., cardiac perforation) associated with this procedure. d) Recently available, 15- and 16-cm central venous catheters have significant potential to minimize intracardiac placement of central venous catheters by either the internal jugular or subclavian vein route and may become the standard of care.

Catheterization, Central Venous↗

Multicenter, double-blind study of intravenous milrinone for patients with acute heart failure in Japan. Japan Intravenous Milrinone Investigators.

OBJECTIVES: Milrinone is a phosphodiesterase F-III inhibitor with positive inotropic and vasodilating activities. We investigated the hemodynamic response and pharmacokinetics of intravenous milrinone in patients with acute heart failure. DESIGN: Double-blind studies: a prospective, multicenter, double-blind, dose-finding study and a placebo-controlled, double-blind, comparative study. SETTING: Patients with acute heart failure (pulmonary artery occlusion pressure of > or = 18 mm Hg), who were hospitalized in the cardiac care units of 33 institutes in Japan, were entered into the study. PATIENTS: Fifty-four patients with acute or decompensated heart failure in the dose-finding study and 52 patients in the placebo-controlled, double-blind, comparative study. INTERVENTIONS: The present multicenter study consisted of a double-blind, dose-finding study (50-micrograms/kg intravenous loading dose, followed by 0.25, 0.5, or 0.75 microgram/kg/min of a continuous infusion of milrinone for 6 hrs, n = 54), and a placebo-controlled, double-blind, comparative study (50-micrograms/kg loading dose, followed by 0.5 microgram/kg/min of a continuous infusion of milrinone vs. placebo treatment, n = 52). We investigated the effects on cardiovascular hemodynamics, subjective symptoms, physical findings, and the pharmacokinetics of intravenous milrinone in a total of 106 patients with acute heart failure. MEASUREMENTS AND MAIN RESULTS: In the double-blind, dose-finding study, dose-dependent inotropic/vasodilating hemodynamic effects were documented for percent changes in cardiac index (+21.2%, +25.8%, and +30.9%, respectively) and pulmonary artery occlusion pressure (-12.8%, -17.0%, -41.3%, respectively) vs. plasma drug concentration at the equilibrium state (6 hrs after starting continuous infusion; 97 +/- 13, 197 +/- 22, and 284 +/- 28 ng/mL, respectively). Throughout the 6-hr infusion period, subjective symptoms were improved in 40%, 46.2%, and 70% of patients, respectively, for the three continuous infusion rates (0.25, 0.5, and 0.75 microgram/kg/min). In the placebo-controlled, double-blind, comparative study, the milrinone group exhibited marked improvement in cardiovascular hemodynamics (pulmonary artery occlusion pressure: from 26 +/- 6 to 15 +/- 3 mm Hg; cardiac index: from 2.6 +/- 0.9 to 3.3 +/- 1.1 L/min/m2) within 15 mins after starting drug administration. However, the placebo group showed no significant hemodynamic changes. Subjective symptoms and physical findings of acute heart failure improved in 47.6% and 40%, respectively, of patients within 60 mins after starting milrinone. The placebo group, however, showed no improvement providing inotropic/vasodilating (both 0%). CONCLUSION: Continuous infusion of milrinone (0.25 to 0.75 microgram/kg/min) after a 50-micrograms/kg loading dose is effective for inotropic/vasodilating hemodynamic support in patients with acute or decompensated heart failure.

Acute Disease↗

Confirmatory interleukin-1 receptor antagonist trial in severe sepsis: a phase III, randomized, double-blind, placebo-controlled, multicenter trial. The Interleukin-1 Receptor Antagonist Sepsis Investigator Group.

OBJECTIVE: To determine the therapeutic efficacy and safety of recombinant human interleukin-1 receptor antagonist (rhIL-1ra) in the treatment of patients with severe sepsis. DESIGN: Prospective, randomized, double-blind, placebo-controlled, multicenter trial with a planned, midstudy, interim analysis. SETTING: Ninety-one academic medical center intensive care units in North America and Europe. PATIENTS: Patients with severe sepsis or septic shock (n = 696) received standard supportive care and antimicrobial therapy for sepsis, in addition to rhIL-1ra or placebo. INTERVENTIONS: Patients were randomized to receive either rhIL-1ra (100 mg) or placebo (vehicle) by intravenous bolus, followed by a 72-hr continuous intravenous infusion of either rhIL-1ra (2.0 mg/kg/hr) or placebo. MEASUREMENTS AND MAIN RESULTS: The study was terminated after an interim analysis found that it was unlikely that the primary efficacy end points would be met. The 28-day, all-cause mortality rate was 33.1% (116/350) in the rhIL-1ra treatment group, while the mortality rate in the placebo group was 36.4% (126/346), yielding a 9% reduction in mortality rate (p = .36). The patients were well matched at the time of study entry; 52.9% of placebo-treated patients were in shock while 50.9% of rhIL-1ra-treated patients were in shock at the time of study entry (p = .30). The mortality rate did not significantly differ between treatment groups when analyzed on the basis of site of infection, infecting microorganism, presence of bacteremia, shock, organ dysfunction, or predicted risk of mortality at the time of study entry. No excess number of adverse reactions or microbial superinfections were attributable to rhIL-1ra treatment in this study. CONCLUSIONS: A 72-hr, continuous intravenous infusion of rhIL-1ra failed to demonstrate a statistically significant reduction in mortality when compared with standard therapy in this multicenter clinical trial. If rhIL-1ra treatment has any therapeutic activity in severe sepsis, the incremental benefits are small and will be difficult to demonstrate in a patient population as defined by this clinical trial.

Adult↗

Multicenter study of oxygen-insensitive handheld glucose point-of-care testing in critical care/hospital/ambulatory patients in the United States and Canada.

OBJECTIVES: Existing handheld glucose meters are glucose oxidase (GO)-based. Oxygen side reactions can introduce oxygen dependency, increase potential error, and limit clinical use. Our primary objectives were to: a) introduce a new glucose dehydrogenase (GD)-based electrochemical biosensor for point-of-care testing; b) determine the oxygen-sensitivity of GO- and GD-based electrochemical biosensor test strips; and c) evaluate the clinical performance of the new GD-based glucose meter system in critical care/hospital/ambulatory patients. DESIGN: Multicenter study sites compared glucose levels determined with GD-based biosensors to glucose levels determined in whole blood with a perchloric acid deproteinization hexokinase reference method. One site also studied GO-based biosensors and venous plasma glucose measured with a chemistry analyzer. Biosensor test strips were used with a handheld glucose monitoring system. Bench and clinical oxygen sensitivity, hematocrit effect, and precision were evaluated. SETTING: The study was performed at eight U.S. medical centers and one Canadian medical center. PATIENTS: There were 1,248 patients. RESULTS: The GO-based biosensor was oxygen-sensitive. The new GD-based biosensor was oxygen-insensitive. GD-based biosensor performance was acceptable: 2,104 (96.1%) of 2,189 glucose meter measurements were within +/-15 mg/dL (+/-0.83 mmol/L) for glucose levels of < or = 100 mg/dL (< or = 5.55 mmol/L) or within +/-15% for glucose levels of > 100 mg/dL, compared with the whole-blood reference method results. With the GD-based biosensor, the percentages of glucose measurements that were not within the error tolerance were comparable for different specimen types and clinical groups. Bracket predictive values were acceptable for glucose levels used in therapeutic management. CONCLUSIONS: The performance of GD-based, oxygen-insensitive, handheld glucose testing was technically suitable for arterial specimens in critical care patients, cord blood and heelstick specimens in neonates, and capillary and venous specimens in other patients. Multicenter findings benchmark the performance of bedside glucose testing devices. With the new +/-15 mg/dL --> 100 mg/dL --> +/-15% accuracy criterion, point-of-care systems for handheld glucose testing should score 95% (or better), as compared with the recommended reference method. Physiologic changes, preanalytical factors, confounding variables, and treatment goals must be taken into consideration when interpreting glucose results, especially in critically ill patients, for whom arterial blood glucose measurements will reflect systemic glucose levels.

Adult↗

Multicenter study of whole-blood creatinine, total carbon dioxide content, and chemistry profiling for laboratory and point-of-care testing in critical care in the United States.

OBJECTIVES: To introduce a creatinine biosensor and a total carbon dioxide content (TCO2) method for whole-blood measurements, to evaluate the clinical performance of a new transportable analyzer that simultaneously performs these two and six other tests (Na+, K+, Cl-, glucose, urea nitrogen, and hematocrit), and to assess the potential of the new analyzer for point-of-care testing in critical care by comparing results obtained by nonlaboratory personnel and by medical technologists. DESIGN: Multicenter sites compared whole-blood measurements with the transportable analyzer to plasma measurements from the same specimens with local reference instruments. One site compared whole-blood results produced by nonlaboratory personnel vs. medical technologists and evaluated day-to-day and within-day precision at the point of care. SETTINGS AND PATIENTS: Four medical centers in the United States. Venous and arterial specimens from 710 critically ill patients with a variety of diagnoses. Point-of-care testing in the emergency room and operating room. RESULTS: The linear regression analyses at the four medical centers showed the following: creatinine (a) slope, 0.91 to 1.22, (b) y intercept, -0.07 to 0.15 mg/dL, and (c) r2, 0.77 to 1.00; and TCO2: (a) slope, 0.64 to 1.00, (b) y intercept, 1.36 to 9.6 mmol/L, and (c) r2, 0.52 to 0.72 (yi, whole-blood analyses; xi, plasma reference measurements). Bland-Altman plots also were used to assess multicenter creatinine and TCO2 results. Of the other analytes, K+, glucose, and urea nitrogen had the highest r2-values. For the eight chemistry profile tests performed at the point of care (yi, nonlaboratory personnel results; xi, medical technologist results), the average value of r2 was 0.96 (SD 0.08) in the operating room and 0.96 (SD 0.06) in the emergency room, and mean paired differences (yi - xi) were not statistically or clinically significant. Precision was acceptable. CONCLUSIONS: The performance of the creatinine biosensor and the TCO2 method was acceptable for whole-blood samples. Comparisons of whole-blood results from the transportable analyzer and plasma results from the local reference instruments revealed analyte biases that may be attributed to differences between direct whole-blood analyses and indirect-diluted plasma measurements and other factors. Performance of nonlaboratory personnel and medical technologists was equivalent for point-of-care testing in critical care settings. The whole-blood analyzer should be useful when patient care demands immediate results.

Biosensing Techniques↗

Prediction of outcome in intensive care unit trauma patients: a multicenter study of Acute Physiology and Chronic Health Evaluation (APACHE), Trauma and Injury Severity Score (TRISS), and a 24-hour intensive care unit (ICU) point system.

OBJECTIVE: To conduct a multicenter study to validate the accuracy of the Acute Physiology and Chronic Health Evaluation (APACHE) II system, APACHE III system, Trauma and Injury Severity Score (TRISS) methodology, and a 24-hour intensive care unit (ICU) point system for prediction of mortality in ICU trauma patient admissions. METHODS: The study population consisted of retrospectively identified, consecutive ICU trauma admissions (n = 2,414) from six Level I trauma centers. Probabilities of death were calculated by using logistic regression analysis. The predictive power of each system was evaluated by using decision matrix analysis to compare observed and predicted outcomes with a decision criterion of 0.50 for risk of hospital death. The Youden Index (YI) was used to compare the proportion of patients correctly classified by each system. Measures of model calibration were based on goodness-of-fit testing (Hosmer-Lemeshow statistic less than 15.5) and model discrimination were based on the area under the receiver operating characteristic curve (AUC). RESULTS: Overall, APACHE II (sensitivity, 38%; specificity, 99%; YI, 37%; H-L statistic, 92.6; AUC, 0.87) and TRISS (sensitivity, 52%; specificity, 94%; YI, 46%; H-L statistic, 228.1; AUC, 0.82) were poor predictors of aggregate mortality, because they did not meet the acceptable thresholds for both model calibration and discrimination. APACHE III (sensitivity, 60%; specificity, 98%; YI, 58%; H-L statistic, 7.0; AUC, 0.89) was comparable to the 24-hour ICU point system (sensitivity, 51%; specificity, 98%; YI, 50%; H-L statistic, 14.7; AUC, 0.89) with both systems showing strong agreement between the observed and predicted outcomes based on acceptable thresholds for both model calibration and discrimination. The APACHE III system significantly improved upon APACHE II for estimating risk of death in ICU trauma patients (p < 0.001). Compared with the overall performance, for the subset of patients with nonoperative head trauma, the percentage correctly classified was decreased to 46% for APACHE II; increased to 71% for APACHE III (p < 0.001 vs. APACHE II); increased to 59% for TRISS; and increased to 62% for 24-hour ICU points. For operative head trauma, the percentage correctly classified was increased to 60% for APACHE II; increased to 61% for APACHE III; decreased to 43% for TRISS (p < 0.004 vs. APACHE III); and increased to 54% for 24-hour ICU points. For patients without head injuries, all of the systems were unreliable and considerably underestimated the risk of death. The percentage of nonoperative and operative patients without head trauma who were correctly classified was decreased, respectively, to 26% and 30% for APACHE II; 33% and 29% for APACHE III; 33% and 19% for TRISS; 20% and 23% for 24-hour ICU points. CONCLUSION: For the overall estimation of aggregate ICU mortality, the APACHE III system was the most reliable; however, performance was most accurate for subsets of patients with head trauma. The 24-hour ICU point system also demonstrated acceptable overall performance with improved performance for patients with head trauma. Overall, APACHE II and TRISS did not meet acceptable thresholds of performance. When estimating ICU mortality for subsets of patients without head trauma, none of these systems had an acceptable level of performance. Further multicenter studies aimed at developing better outcome prediction models for patients without head injuries are warranted, which would allow trauma care providers to set uniform standards for judging institutional performance.

APACHE↗

Complications of epilepsy surgery after 654 procedures in Sweden, September 1990-1995: a multicenter study based on the Swedish National Epilepsy Surgery Register.

OBJECTIVE: To present the first national multicenter study on complications after epilepsy surgery procedures to include all epilepsy surgery centers in Sweden: Göteborg, Linköping, Lund, Stockholm, Umeå, and Uppsala. METHODS: Every epilepsy surgery procedure in Sweden is reported to the Swedish National Epilepsy Surgery Register. The report includes relevant social and medical items and complications. A complication is defined as minor if it resolves within 3 months and major if it affects activities of daily living and lasts longer than 3 months. Follow-up data are recorded for 2 years after the operation. Intrinsic checkpoints and external revision validate the register data. RESULTS: During the inclusion period (September 1990-December 1995), 654 surgical procedures were performed (age range, 6 mo-67 yr). Of these, 205 were invasive electrode procedures (182 first investigations and 23 reinvestigations), and 449 were therapeutic procedures (375 first operations and 74 reoperations). After invasive electrode procedures, only minor complications were reported (6.3%). For all 449 therapeutic procedures (including reoperations), minor complications were reported in 8.9% and major complications in 3.1 %. Only one major complication was reported in a patient under the age of 35 years. CONCLUSION: This is the first national multicenter study on complications after epilepsy surgery. It demonstrates that these procedures as performed at six different centers in Sweden are safe, but also that risk is related to age. In patients younger than age 35 years, the risk for a major complication after invasive subdural strip electrode investigation and epilepsy surgery is low.

Adolescent↗

Verteporfin therapy in age-related macular degeneration (VAM): an open-label multicenter photodynamic therapy study of 4,435 patients.

PURPOSE: To provide broad clinical experience and to gather safety data on photodynamic therapy with verteporfin (Visudyne, Novartis AG, Basel, Switzerland), also termed verteporfin therapy, in patients with predominantly classic subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). The Verteporfin in Age-related Macular Degeneration (VAM) Study was designed to provide expanded access to verteporfin therapy after beneficial results for these cases were reported but before regulatory approval in North America. METHODS: This open-label multicenter study from September 1999 through June 2000 enrolled among 222 centers patients 50 years or older in the United States, or 40 years or older in Canada, with age-related macular degeneration and subfoveal CNV with a lesion composition that was predominantly classic CNV on fluorescein angiography. Corrected visual acuity with habitual eyewear in the office setting was 20/40 to 20/200, inclusive. All patients received verteporfin therapy and returned for follow-up every 3 months. At those follow-up examinations, additional courses of treatment were recommended if any fluorescein leakage from CNV was identified. Safety information was collected from patient self-reporting, questioning (in person and by telephone), and physician evaluation. Safety was assessed by evaluating the effect of treatment on corrected distance visual acuity and by evaluating adverse events. RESULTS: A total of 4,435 patients were enrolled of whom 4,051 (91%) completed the study after receiving 6,701 treatments. Most patients received only one treatment in VAM before regulatory approval of verteporfin in the United States and Canada. Three hundred patients (6.8%) experienced an adverse event considered by the treating ophthalmologist to be associated with treatment, including 115 (2.6%) with abnormal or decreased vision, of whom 25 (0.6%) experienced acute severe visual acuity decrease, and 14 (0.3%) with transient infusion-related back pain. Patients were advised to avoid exposure to direct sunlight for 24 hours; however, after verteporfin administration only 2 (0.05%) reported a photosensitivity reaction. An additional course of verteporfin therapy was administered to 1,739 of 2,314 patients (75.2%) who had a month 3 examination that was not their close-out visit and 177 of 266 (66.5%) who had a month 6 examination that was not their close-out visit. CONCLUSIONS: Verteporfin therapy exhibited no additional or new safety concerns. The therapy associated with a low incidence of adverse events when expanded access was provided in a large, open-label, multicenter study, including a low incidence (0.05%) of reported photosensitivity reactions despite a short photosensitivity protection period (24 hours) following verteporfin administration.

Adult↗

A multicenter retrospective study of the clinical results of the LINK SB Charité intervertebral prosthesis. The initial European experience.

OBJECTIVE: This study is a multicenter, retrospective review of the initial clinical results of an artificial disc replacement, the LINK SB Charité intervertebral prosthesis. METHODS: Independent analysis by chart review included patient demographics, surgical data, and a comparison of presurgical to follow-up data. Data were analyzed from 93 patients (average age = 43.0 +/- 7.3) in whom a total of 139 Model III prostheses (Waldemar Link GmbH & Co, Hamburg, Germany) were implanted. RESULTS: The predominant diagnostic indication for the disc was degenerative disc disease (52.4%). The L4-L5 and L5-S1 levels comprised 87.1% of all levels implanted. The average follow-up was 11.5 +/- 8.4 months. After disc implantation, a significant proportion of the patient sample experienced pain relief (P < 0.05). Improvements were also noted in pain intensity, walking distance, lumbar mobility, and the percentage of patients showing a positive SLR or neurological weakness. No difference in work status after disc implantation could be detected. Device failure, migration, or dislocation occurred in 6 of 93 (6.5%) patients. CONCLUSIONS: This study represents the largest multicenter case series of any functional artificial disc implantation. Carefully controlled, prospective studies that compare disc implantation and fusion are warranted.

Adult↗

The incidence of complications in endoscopic anterior thoracolumbar spinal reconstructive surgery. A prospective multicenter study comprising the first 100 consecutive cases.

STUDY DESIGN: A prospective multicenter study on 100 consecutive surgical procedures. OBJECTIVES: A prospective multicenter study was performed to evaluate the early perioperative complications in 100 endoscopic spinal procedures--78 video-assisted thoracic surgical procedures and 22 laparoscopic lumbar instrumentation and fusion procedures. SUMMARY OF BACKGROUND DATA: Endoscopic procedures have been widely applied in general surgery for appendectomy, cholecystectomy, liver resection, Nissen fundoplication, colon resection, and hernia repairs. Video-assisted thoracic surgery is widely used for pleural biopsy, lung resection, and sympathectomy. This is the first large series to date investigating the safety and potential complications using endoscopic surgery for anterior decompression or fusion of the thoracolumbar spine. METHODS: Video-assisted thoracic surgical procedures included multilevel anterior thoracic releases for deformity, 27 patients; anterior thoracic discectomies with spinal canal decompression, 41 patients; pyogenic vertebral osteomyelitis decompression, 2 patients; and vertebral corpectomy for neurologic decompression, 8 patients. Mean operative time was 2 hours, 34 minutes (range, 45 minutes to 6 hours), and mean length of stay was 4.97 days (range, 2-21 days). Anterior laparoscopic interbody stabilization and fusion at L4-5 or L5-S1 was performed in 22 patients. The mean operative time was 4 hours, 17 minutes (range, 2 hours, 40 minutes to 9 hours), and the mean length of stay was 5.6 days (range, 1-23 days). RESULTS: The most common video-assisted thoracic surgical complications were transient intercostal neuralgia (six patients) and atelectasis (five patients). The most common laparoscopic complication was bone graft donor site infection (two patients). There were two endoscopic cases that were converted to open procedures, one for extensive pleural adhesions and one for a common iliac vein laceration. CONCLUSIONS: The endoscopic spinal approaches proved to be safe operative procedures in 100 consecutive cases. There were no permanent iatrogenic neurologic injuries and no deep spinal infections.

Blood Loss, Surgical↗

Prospective, multicenter study of spinal cord stimulation for relief of chronic back and extremity pain.

STUDY DESIGN: This prospective, multicenter study was designed to investigate the efficacy and outcome of spinal cord stimulation using a variety of clinical and psychosocial outcome measures. Data were collected before implantation and at regular intervals after implantation. This report focuses on 70 patients who had undergone 1 year of follow-up treatment at the time of data analysis. OBJECTIVES: To provide a more generalizable assessment of long-term spinal cord stimulation outcome by comparing a variety of pain and functional/quality-of-life measures before and after management. This report details results after 1 year of stimulation. SUMMARY OF BACKGROUND DATA: The historically diverse methods, patient selection criteria, and outcome measures reported in the spinal cord stimulation literature have made interpretation and comparison of results difficult. Although short-term outcomes are generally consistent, long-term outcomes of spinal cord stimulation, as determined by prospective studies that assess multidimensional aspects of the pain complaint among a relatively homogeneous population, are not well established. METHODS: Two hundred nineteen patients were entered at six centers throughout the United States. All patients underwent a trial of stimulation before implant of the permanent system. Most were psychologically screened. One hundred eighty-two patients were implanted with a permanent stimulating system. At the time of this report, complete 1-year follow-up data were available on 70 patients, 88% of whom reported pain in the back or lower extremities. Patient evaluation of pain and functional levels was completed before implantation and 3, 6, 12, and 24 months after implantation. Complications, medication usage, and work status also were monitored. RESULTS: All pain and quality-of-life measures showed statistically significant improvement during the treatment year. These included the average pain visual analogue scale, the McGill Pain Questionnaire, the Oswestry Disability Questionnaire, the Sickness Impact Profile, and the Back Depression Inventory. Overall success of the therapy was defined as at least 50% pain relief and patient assessment of the procedure as fully or partially beneficial and worthwhile. Using this definition, spinal cord stimulation successfully managed pain in 55% of patients on whom 1-year follow-up is available. Complications requiring surgical intervention were reported by 17% (12 of 70) of patients. Medication usage and work status were not changed significantly. CONCLUSIONS: This prospective, multicenter study confirms that spinal cord stimulation can be an effective therapy for management of chronic low back and extremity pain. Significant improvements in many aspects of the pain condition were measured, and complications were minimal.

Adult↗