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At least 253 records · Page 14Linked to original sources
PubMed2002

Transjugular intrahepatic portosystemic shunt in the treatment of portal hypertension using memotherm stents: a prospective multicenter study.

PURPOSE: In a prospective multicenter study, efficacy and safety of transjugular intrahepatic portosystemic shunts (TIPS) were evaluated in the treatment of the complications of portal hypertension using a new self-expanding mesh-wire stent (Memotherm). METHODS: One hundred and eighty-one patients suffering from variceal bleeding (either acute or recurrent) or refractory ascites were enrolled. Postinterventional follow-up lasted for 8.4 months on average. Differences were analyzed by the log-rank test (chi-square) or Wilcoxon test. RESULTS: Shunt insertion was completed successfully in all patients (n = 181 patients, 100%). During follow-up, shunt occlusion was evident in 23 patients, and shunt stenosis was found in 33 patients (12.7% and 18.2%, respectively). Variceal rebleeding occurred in 20 of 139 patients (14.4%), with at least one episode of bleeding before TIPS treatment. The overall mortality rate of the patients treated by TIPS was 39.8%. In 51.4% of these cases (37 of 72 patients), however, the patients died within 30 days after TIPS placement. Analysis of subgroups showed that patients who underwent emergency TIPS for acute variceal bleeding had a significantly higher early mortality compared with other patient groups (p = 0.0014). CONCLUSION: In the present prospective multicenter study, we were able to show that insertion of Memotherm stents is an effective tool for TIPS. The occlusion rates seem to be comparable to those reported for the Palmaz stent. It could be shown that in particular, those patients who were treated for acute bleeding were at high risk of early mortality. Consequently, in such a critical condition, the indication for TIPS has to be set carefully.

Adult↗
PubMed2000

[Concept for nationwide cooperation in planning and implementing multicenter studies].

In Germany, good clinical multicenter studies that are not supported by pharmaceutical companies are rarely performed. Good supranational industry-sponsored studies are usually aimed at the registration of new (expensive) drugs. The preconditions for co-operation in conducting industry-independent studies which are of interest for the scientific community have been improved substantially in Germany by instituting the working group of co-operating arthritis centers, the so-called core documentation where 32,000 patients with rheumatic conditions were documented in 1997 and the institution of a sophisticated information system ("RheumaNet"). The executive board of the German Rheumatology Association has set up an "ad hoc commission" that agreed to institute a "Committee for the Coordination of Clinical Studies in Rheumatic Diseases". In this committee rheumatologists subspecialized from medicine, orthopedic, pediatrics working in universities, hospitals and private practice as well as specialists in statistics and epidemiology shall be represented. In principle this committee is independent of the co-operating arthritis centers and the RheumaNet. All members of the German Rheumatology Association are invited to cooperate with this committee by contributing to the clinically important questions and participating in clinical studies. The committee has to define key questions in rheumatology and shall plan and organize multicenter studies to answer these questions. In addition, study protocols of pharmaceutical companies may be examined as to their importance, quality, and feasibility.

Antirheumatic Agents↗
PubMed2000

Acute appendicitis in late adulthood: incidence, presentation, and outcome. Results of a prospective multicenter acute abdominal pain study and a review of the literature.

BACKGROUND: Acute appendicitis is the second most common cause of surgical abdominal disease in late adulthood. It is a serious condition: major errors in management are made frequently and the condition is associated with significant morbidity and mortality. Data collected within a multicenter prospective trial and a literature review were used to analyze diagnostic and therapeutic difficulties in detail. METHODS: In a multicenter intervention study (MEDWIS A 70) data from 2,280 patients with acute abdominal pain were collected prospectively. Patients with histologically proven acute appendicitis, aged 50 years and older (n=102), were compared with younger patients (n=417) to determine differences in presentation, clinical course, and outcome. The basis for the literature review was a Medline search for appendicitis in late adulthood and in the elderly, covering the years 1980-1998. In addition, studies on clinical presentation of acute appendicitis in all age groups were also reviewed and appropriate data were extracted. RESULTS: Patients aged 50 years and older with acute abdominal pain had a significantly higher incidence of surgery. Fourteen percent had acute appendicitis (27% in younger patients), with an increased complication rate (20% vs. 8%) and mortality (3% vs. 0.2%). Significantly more signs and symptoms suggestive of acute abdominal disease and peritonitis were recorded among older patients, reflecting the higher perforation rate (35% vs. 13%). Clinical presentation of appendicitis in younger patients was far more ambiguous. There were no significant differences in outcome between older and younger patients as regards perforations. Perforations are directly associated with treatment delay. Overall delay is a result of late presentation of older patients to hospital and postadmission delay. CONCLUSIONS: Appendicitis in late adulthood is characterized by a delay in treatment, high perforation rates, and unfavorable outcome parameters, all mutually correlating. Older patients with acute abdominal pain are high-risk patients, unlike their younger counterparts. They have to be clinically evaluated by experienced surgeons within a narrow time margin. The problem of late presentation and/or referral should be addressed, perhaps by education of primary care physicians and the public.

Abdomen, Acute↗
PubMed2005

European multicenter survey on the laparoscopic treatment of gastroesophageal reflux in patients aged less than 12 months with supraesophageal symptoms.

BACKGROUND: This multicenter survey includes neonates and infants who underwent surgery for primary gastroesophageal reflux (GER) who presented with supraesophageal symptoms of unknown origin with a minimum of 12 months postoperative follow-up. METHODS: A total of 726 patients underwent GER surgery in 10 European Centers in the period 1998-2002. Respiratory symptoms were present in 204 patients (28%); 135 patients (17%) had surgery under 1 year of age, and 46 of them (6.3%) because of respiratory symptoms. Surgery was performed without any previous medical treatment in 10 cases (21%). The type of procedure included 37 complete 360 degrees wraps (80%) (Nissen, 12, and Rossetti, 25) and nine partial wraps (20%) (Thal five, Lortat Jacob one, Toupet one, others two). Gastrostomy was associated in 17 cases (37%) (6 PEG and 11 modified Stamm). No gastric emptying procedures were recorded. RESULTS: No major intraoperative complications were reported. Six patients developed complications (13%) and a redo operation was performed in three (6.5%). Respiratory outcome after antireflux surgery was good in 35 patients (76%) and fair with significantly improved respiratory symptoms in 11 (24%). CONCLUSIONS: This multicenter survey underlines that GER has to be suspected and aggressively treated in infants with difficult-to-treat supraesophageal symptoms, and also in high-risk cases, in order to prevent major complications.

Europe↗
PubMed1998

Early results of a prospective multicenter study on 500 consecutive cases of laparoscopic colorectal surgery. Laparoscopic Colorectal Surgery Study Group (LCSSG).

BACKGROUND: Prospective randomized multicenter studies comparing laparoscopic with open colorectal surgery are not yet available. Reliable data from prospective multicenter studies involving consecutive patients are also lacking. On the basis of the personal caseloads of specialized surgeons or of retrospective analyses, it is difficult to judge the true effectiveness of this new technique. This study aims to investigate the results of laparoscopic colorectal surgery in consecutive patients operated on by unselected surgeons. METHODS: This observational study was begun August 1, 1995, in the German-speaking part of Europe (Germany and Austria) and 43 centers initially agreed to participate. All consecutive cases were documented. All data were rendered anonymous. Analysis was performed on an intention-to-treat basis. The study committee was blinded to the participating center. RESULTS: By the end of the 1st year, 500 patients (M:F ratio 0.83, mean age 62.9 years) had been treated by 18 centers; 269 operations were performed for benign indications and 231 for cancer (palliative and curative). Most operations were done on the distal colon or rectum. An anastomosis was performed in 84%, with an overall leakage rate of 5.3% (colon 3.6% and rectum 11.8%), which required surgical reintervention in 1.7%. The mean operating time was 176 min and showed a decreasing tendency over the period under study. The conversion rate was 7.0% and the overall complication rate 21.4%. The reoperation rate was 6.6%; the most common cause was bleeding. There was one ureteral lesion (0.2%), but urinary tract infections were fairly common (4.8%). A postoperative pneumonia was diagnosed in 1.6% of the cases. No thromboembolic complications were reported. The 30-day mortality rate was 1.4% and overall hospital mortality 1.8%. CONCLUSIONS: Laparoscopic colorectal operations are still rare (about 1% of all colorectal operations in Germany). Laparoscopic procedures are more common on the left colon and rectum than on the right colon. The surgical complication rate is acceptable, comparable with rates reported by others for open surgery. Cardiopulmonary and thromboembolic complications were rarely seen. Mortality and surgical morbidity rates do not differ significantly among participating centers. A learning curve, reflected by a shortening of the operating time and a somewhat lower conversion rate, was observed over the observation period.

Aged↗
PubMed1999

Laparoscopic colorectal anastomosis: risk of postoperative leakage. Results of a multicenter study. Laparoscopic Colorectal Surgery Study Group (LCSSG).

BACKGROUND: We report on a prospective observational multicenter study of more than 1,000 consecutive patients undergoing laparoscopic colorectal procedures. The aim of the current study was to investigate the safety of laparoscopic colorectal surgery as reflected by the anastomotic insufficiency rates in the various sections of the bowel, and to compare these rates with those of open colorectal surgery. METHODS: The study was begun on August 1, 1995. Twenty-four centers in Germany, Austria, and Switzerland participated in this prospective multicenter study. All patients undergoing laparoscopic colorectal surgery were included in the study. No selection criteria were applied, which means that every operation begun as a laparoscopic procedure was included. Data on patient demographics, surgical indications, surgical course, and patient outcome were recorded prospectively in a computer database. All data were rendered anonymous. RESULTS: Between August 1995 and February 1998, the 24 participating centers treated 1,143 patients (male/female ratio, 1:1.36; mean age, 60.7 years). In all, 626 operations were performed for benign indications and 517 for cancer. Most procedures involved the sigmoid colon and rectum (80.9%). An anastomosis was performed in 83% of the operations. Most of the anastomoses were laparoscopically assisted using the stapling technique. We observed an overall leakage rate of 4.25% (colon 2.9%; rectum 12.7%), and surgical reintervention was required in 1% of the cases. The rate of conversion to open surgery was 5.6%. Intraoperative complications occurred in 5.9%, and reoperation was necessary in 4.1% of the cases. The overall morbidity rate was 22.3%, and the 30-day mortality rate was 1.57%. CONCLUSIONS: The feasibility and safety of the laparoscopic colorectal approach is demonstrated clearly. The current study shows that the laparoscopic or laparoscopically assisted approach to colorectal surgery is not associated with a higher risk of anastomotic leaks. Morbidity and mortality rates with this method approximate those seen with conventional colorectal surgery.

Adult↗
PubMed2003

Technical success from endovascular aneurysm repair in the post-marketing era: a multicenter prospective trial.

Evaluation of post-marketing success with the Ancure Endovascular Graft (AEG) was accomplished by review of a multicenter, prospective trial involving 46 centers and 163 patients. A second cohort of patients (n = 350) treated with the AEG under a controlled-use interval prior to the prospective trial was simultaneously evaluated. Technical success in both groups of patients (96.9% and 97.4%, respectively) was similar to what was reported in pre-market clinical trials. Operative implantation complications unique to the AEG included graft limb stenosis/occlusion in 35.6 and 31.4%, contralateral pull wire being caught on hooks in 33.7 and 28%, failure to seal (type I endoleak) in 17.2 and 18.3%, jacket guard being stuck in 12.9 and 11%, contralateral wire being stuck in 6.8 and 7.1%, high jacket retraction force in 16 and 8.5%, and inability to retract jacket in 1.8 and 0.5% of patients involved in the multicenter trial and controlled-use interval, respectively. One of four patients undergoing conversion in the prospective trial had graft misdeployment as a mode of failure. Three were converted for access failure. The 30-day mortality rate in the prospective trial was 3.7%. Interventions to resolve implantation-related events included stenting, guide catheter manipulations, wire exchanges, and delivery catheter disassembly. These interventions were successful in virtually every case. Open surgical procedures were not needed to correct these operative problems. Results from this study demonstrate excellent technical success with the AEG in the post-market era. Interventions to resolve implantation complications, when utilized, are highly successful in facilitating AEG implantation and providing technical success.

Aortic Aneurysm↗
PubMed2004

Infragenicular polytetrafluoroethylene bypass with tapered versus straight vascular grafts: results from a prospective multicenter cohort study.

Both straight and tapered arterial grafts are commonly used for infragenicular bypass surgery. Opinions vary considerably regarding the use of each type of graft and depend on individual experience, as no trial yet has assessed clinical outcomes comparing both groups. We conducted a prospective, multicenter, cohort study to analyze results for each graft type. From a total of 81 patients, 50 underwent infragenicular bypass surgery with straight PTFE prostheses and 31 with tapered prostheses in a prospective, multicenter trial. Six different centers for vascular surgery took part in the trial. In clinical follow-up at discharge as well as 3, 6, 12, 18, 24, and 36 months after revascularization, various parameters were evaluated comparing patency rates, limb salvage, and major amputation rates. Significant differences were found in limb salvage rates between the two groups. Patients receiving a straight graft fared better in this regard. Further data suggest that short-term primary patency is also improved in straight prostheses. Sixty-four percent of these remained patent after 1 year, while only 50% of tapered prostheses were still patent. No differences between the groups were found for secondary patency. The advantages of straight prostheses seem to be reduction of thrombus formation and intimal hyperplasia. Furthermore, it appears that the surgeons participating in this study prefer the use of straight prostheses. Even though the group of patients that received tapered grafts had slightly more unfavorable preoperative conditions, the data still support the superiority of straight vascular grafts. However, prospective randomized trials are necessary to evaluate the benefit of different bypass designs definitively.

Aged↗
PubMed2004

Intraperitoneal treatment of incisional and umbilical hernias using an innovative composite mesh: four-year results of a prospective multicenter clinical trial.

Intraperitoneal positioning of conventional parietal mesh provides efficient reconstruction but causes visceral adhesion formation in 80-100% of the cases. The purpose of this clinical trial was to assess the performance and tolerance of a new generation of polyester mesh protected by a hydrophilic resorbable film. Eighty patients were included in a prospective multicenter clinical trial. Patients were treated for ventral hernia via an open approach (64%) or laparoscopically (36%). All meshes were implanted in a midline intraperitoneal location. The main objective was to evaluate the anti-adhesive capability of the mesh in relation to the viscera. In order to assess the absence of visceral adhesion objectively, an ultrasound (US) specific examination was initially validated (pre-operative prediction vs. per-operative findings) and then used during the follow-up. The usual clinical parameters were also collected to follow the patients on a period up to 4 years. Pre-operative US prediction vs. per-operative macroscopic findings: sensitivity 79%, overall accuracy 76%, negative predictive value 85%. After 12 months, 86% of the patients were ultrasonically adhesion free. Early post-operative complications were: seroma/hematoma (16%), subcutaneous infection (4%), cutaneous necrosis (1%) and occlusions (outside the mesh) (2.5%). No mortality was reported. Clinically, after 12-month follow-up, no complication related to post-operative adhesions to the mesh was noted: (occlusion 0%, fistula 0%). Late complications were: mesh sepsis (1%), new defects (4%) and recurrence (2.5%). Finally, 56 patients (75.7%) were clinically evaluated with a mean follow-up of 48+/-6 months. One direct recurrence was noted while six patients experienced new defect outside the mesh. No long-term severe complication such as occlusion or enterocutaneous fistula was observed. Based on a mean clinical follow-up of 4 years, the results of this prospective multicenter clinical trial demonstrate the safety and the efficiency of this composite mesh in the intraperitoneal treatment of incisional and umbilical hernia. In particular there was no early or long-term main complication due to the intraperitoneal location of the mesh.

Cicatrix↗
PubMed2002

A pragmatic discussion on establishing a multicenter digital imaging network.

Multicenter clinical trials for therapy evaluation of rare diseases are necessary. A digital imaging network improves the ability to share information between collaborating institutions for adrenoleukodystrophy. The DICOM 3.0 standard is used to move images over the Internet from contributing sites to the central clinical database and on to the reviewing physicians' workstations. Patient confidentiality and data integrity are ensured during transmission using virtual private network technology. Fifteen sites are participating in the network. Of these sites, 6 use the proposed protocol. The other 9 sites have either security policy issues or technical considerations that dictate alternative protocols. Network infrastructure, Internet access, image management practices, and security policies vary significantly between sites. Successful implementation of a multicenter digital imaging network requires flexibility in the implementation of network connectivity. Flexibility increases participation as well as complexity of the network.

Adrenoleukodystrophy↗
PubMed2003

A prospective, randomized, multicenter, controlled study of the safety of Seprafilm adhesion barrier in abdominopelvic surgery of the intestine.

INTRODUCTION: Seprafilm adhesion barrier (Seprafilm) has been proven to prevent adhesion formation after abdominal and pelvic surgery. This article reports safety results, including the postoperative incidence of abdominal and pelvic abscess and pulmonary embolism, from a large, multicenter trial designed to evaluate the safety and effectiveness of Seprafilm for reduction of adhesion-related postoperative bowel obstruction after abdominopelvic surgery. METHODS: A total of 1791 patients participated in this prospective, randomized, multicenter, multinational, single-blind, controlled study in patients undergoing abdominopelvic surgery, the majority of whom had inflammatory bowel disease. Just before closure of the abdomen, patients were randomized to a Seprafilm or no-treatment control group. Patients received an average of 4.4 and as many as 10 Seprafilm adhesion barriers applied to organs and tissue surfaces that sustained direct surgical trauma and to suspected adhesiogenic surfaces. Complications that occurred within the first month after surgery were evaluated. RESULTS: During the safety evaluation period, the difference between the Seprafilm and control groups for the incidence of abscess (4 vs. 3 percent, respectively) or pulmonary embolism (<1 percent in both groups) was not statistically significant (P > 0.05). Foreign body reaction was not reported in either group. Fistula (2 vs. <1 percent) and peritonitis (2 vs. <1 percent) occurred more frequently (P <or= 0.05) in the Seprafilm group. In a subpopulation of patients in whom Seprafilm was wrapped around a fresh bowel anastomosis, leak-related events, which included anastomotic leak, fistula, peritonitis, abscess, and sepsis, occurred more frequently (P <or= 0.05). There were no other differences in the incidence, severity, or causative relationship of complications between study groups. CONCLUSIONS: This study confirmed the safety of Seprafilm adhesion barrier with respect to abdominal abscess, pelvic abscess, and pulmonary embolism when administered to patients undergoing abdominopelvic surgery. Foreign body reaction was not reported for any patient. However, wrapping the suture or staple line of a fresh bowel anastomosis with Seprafilm should be avoided, because the data suggest that this practice may increase the risk of sequelae associated with anastomotic leak.

Abdomen↗
PubMed1993

Directional coronary atherectomy of saphenous vein graft narrowings: multicenter investigational experience.

Directional coronary atherectomy (DCA) of saphenous vein graft lesions was performed at 21 centers between June 1988 and September 1990, which represents the multicenter investigational experience. A total of 318 procedures were performed and 363 vein graft lesions were treated. Angiographic success with DCA was achieved in 86% of lesions and clinical success was achieved in 85% (269 of 318) of patients. Major complications occurred in 2.5% of patients, with Q wave myocardial infarction (MI) in 1.3%, death in 0.9%, and urgent bypass surgery in 0.9%. Other complications included non-Q wave MI in 4.4%, distal embolization in 7.2%, coronary occlusion in 1.9%, and vessel perforation in 0.6%. Although there was a trend toward lower success rates with ostial vein graft lesions (82% vs 88% for other graft sites) and with diffuse (length > 20 mm) graft lesions (75% vs 87% for shorter lesions), the differences were not significant. Baseline clinical and angiographic factors did not identify predictors of lower success or more frequent complications in the study group. Overall restenosis rate in the 149 patients with angiographic restudy was 57%. The restenosis rate was significantly lower with primary vein graft lesions (38%) compared with a 75% restenosis rate for grafts with prior restenosis, p < 0.001. This initial multicenter investigational experience indicates that directional coronary atherectomy is a safe and effective therapy for selected saphenous vein graft disease. Although the overall restenosis rate is relatively high, the restenosis rate following DCA of primary vein graft lesions is significantly lower than for vein grafts having had prior intervention.(ABSTRACT TRUNCATED AT 250 WORDS)

Atherectomy, Coronary↗
PubMed1992

Adverse reactions of low osmolality contrast media during cardiac angiography: a prospective randomized multicenter study.

A multicenter study was performed to determine the incidence of adverse reactions to two contrast media with similar low osmolality during cardiac angiography. The study was of a randomized double-blind design comparing ioxaglate (an ionic dimer) and iopamidol (a nonionic compound) and included 500 patients; 250 patients received ioxaglate and 250 iopamidol. There were 58 adverse reactions attributed to the contrast media in the ioxaglate group and 29 in the iopamidol group (p less than 0.001). Chest pain occurred in 11 patients in the ioxaglate group compared with 5 in the iopamidol group (p = 0.123). Nausea or vomiting was present in 20 and 2 patients, respectively (p less than 0.0003). Allergic adverse reactions, such as bronchospasm, urticaria and itching, occurred in 15 of the ioxaglate group and only 1 of the patients receiving iopamidol (p less than 0.0007). Fifty-two patients in the ioxaglate group had a known allergic history (not to contrast medium) or asthma, whereas 77 receiving iopamidol had a similar history. Seven of the 52 ioxaglate-treated patients developed an allergic adverse reaction compared with none of the 77 in the iopamidol group (p = 0.001). Of 41 patients receiving ioxaglate who were premedicated with diphenhydramine, 4 had an allergic adverse event. In the iopamidol group 45 patients received similar premedication and none had an allergic adverse reaction (p less than 0.03). Thus, this multicenter study shows that adverse reactions occur more often with ioxaglate than with iopamidol and that patients with an allergic history have a greater risk with ioxaglate therapy compared with iopamidol.

Adult↗
PubMed1996

Effectiveness and safety of diltiazem or lisinopril in treatment of hypertension after heart transplantation. Results of a prospective, randomized multicenter trail.

OBJECTIVES: The purpose of this study was to determine the effectiveness and safety of diltiazem or lisinopril for treatment of hypertension after heart transplantation. BACKGROUND: Systemic hypertension is common after heart transplantation, and to date there are no randomized, prospective multicenter treatment trials. METHODS: Members of the Cardiac Transplant Research Database Group developed and implemented a prospective, randomized multicenter trial of the effectiveness and safety of diltiazem or lisinopril in the treatment of hypertension in cyclosporine-treated patients after heart transplantation. RESULTS: One hundred sixteen patients with hypertension (blood pressure > or = 140/90 mm Hg) after heart transplantation were randomized for > or = 3 months of treatment. Of 55 diltiazem-treated patients, 21 (38%) were responders (diastolic blood pressure < 90 mm Hg), 23 (42%) were nonresponders (diastolic blood pressure > or = 90 mm Hg), and 11 (20%) were withdrawn from the study. Of 61 lisinopril-treated patients, 28 (46%) were responders, 22 (36%) were nonresponders, and 11 (18%) were withdrawn. There was no difference in baseline characteristics or percent responders between the two groups. Systolic pressure decreased from 157 +/- 2.3 to 130 +/- 2.0 mm Hg (mean +/- 1 SEM) in the diltiazem-treated responders and from 153 +/- 2.1 to 127 +/- 2.7 mm Hg in the lisinopril-treated responders (p < 0.0001). Diastolic pressure decreased from 100 +/- 0.9 to 85 +/- 1.6 mm Hg in the diltiazem-treated responders and from 100 +/- 1.0 to 84 +/- 2.0 mm Hg in the lisinopril-treated responders (p < 0.0001). There were a total of 35 reported adverse events, 22 of which led to withdrawal of the patient from the study. All drug-related side effects were considered minor and resolved with discontinuation of the drug. CONCLUSIONS: These results indicate that both diltiazem and lisinopril are safe for treatment of hypertension after heart transplantation, although titrated monotherapy with either drug controlled the condition in < 50% of patients.

Aged↗
PubMed1995

Rationale and design of the Dietary Approaches to Stop Hypertension trial (DASH). A multicenter controlled-feeding study of dietary patterns to lower blood pressure.

Epidemiologic studies have found that dietary patterns characterized by high intakes of certain minerals and fiber are associated with low blood pressure. Dietary Approaches to Stop Hypertension (DASH) is a multicenter, randomized, controlled-feeding trial designed to test the effects on blood pressure of two such dietary patterns consumed for 8 weeks. The two experimental diets will be compared with each other and with a control dietary pattern that is relatively low in potassium, magnesium, calcium, and fiber, and has a fat and protein profile mirroring current consumption. The first experimental diet, arguably termed "ideal," is high in fruits, vegetables, whole cereal products, low-fat dairy products, fish, chicken, and lean meats designed to be low in saturated fat and cholesterol; moderately high in protein; and high in minerals and fiber. The second experimental diet tests the effect of fruits and vegetables alone. Its potassium, magnesium, and dietary fiber content will be at the same high levels as the ideal dietary pattern, while its fat, protein, and calcium content will resemble that of the control dietary pattern. The study population will consist of 456 healthy men and women, aged 22 years or older, with systolic blood pressure less than 160 mm Hg and diastolic blood pressure 80 to 95 mm Hg. African-American and other minority groups will comprise 67% of the population. Participants will eat one of the three dietary patterns. The DASH trial has unique features. First, dietary patterns rather than single nutrients are being tested. Second, all food for the experimental diets is provided to the participants using a standardized multicenter protocol. Because the dietary patterns are constructed with commonly consumed food items, the results, if positive, may be conveniently implemented in dietary recommendations to the general public.

Adult↗
PubMed1994

Risk factors for the development of placebo adverse reactions in a multicenter clinical trial.

In this report, we examine the potential risk factors for both the incidence and the number of placebo adverse reactions among patients who were enrolled in the placebo control group in a multicenter clinical trial (n = 491). Of the nine baseline covariates analyzed, only clinical center was significantly related to both the presence and the number of adverse reactions. Placebo group patients at clinical centers 5 and 7 were more than twice as likely to experience an adverse reaction than were patients at clinical center 1. This finding, in light of the intensive effort we made to standardize the methods for adverse reaction detection and management, points out the difficulty in controlling for the inherent differences in the characteristics of the patient populations and clinic personnel at the clinical centers in a multicenter trial, and reinforces the need to stratify by clinical center prior to randomization.

Adult↗
PubMed2006

A cooperative network of trained sites for the conduct of a complex clinical trial: a new concept in multicenter clinical research.

BACKGROUND: The purpose of this report is to present a model of physicians in full-time clinical practice participating as investigators in multicenter clinical trials, sponsored by a pharmaceutical or medical device company. METHODS: This gas-exchange substudy was conducted as a pilot study to establish the feasibility of the 10-member EXERcise testing group of the Duke University Cooperative Cardiovascular Society (EXERDUCCS) consortium to perform a complex multicenter trial using cardiopulmonary exercise testing. An active interchange of information was established involving the principal investigator for the substudy, a dedicated full-time project coordinator, a medical director of the overall EXERDUCCS network site, the project coordinator for the sponsor, and all the participating EXERDUCCS investigators and coordinators. RESULTS: The sponsor set as a goal of enrollment of 6 subjects per site, and 8 of the 10 sites met this goal. As a result of the successful enrollment and completion of the study and substudy by the EXERDUCCS sites, the sponsor subsequently increased the payment stipends to the sites to compensate for the extra work and expense incurred. CONCLUSIONS: This cooperative experience accomplished several goals: (1) it allowed a complex clinical trial to be successfully completed in a time frame which would not have been possible using only single unconnected sites; (2) it educated the physician-investigators (and their personnel) in exercise cardiopulmonary; and (3) it prepared the sites for future clinical trials involving this methodology.

Angiotensin Receptor Antagonists↗
PubMed2004

A prospective multicenter clinical trial to evaluate the safety and effectiveness of the implantable miniature telescope.

PURPOSE: To evaluate the safety and preliminary efficacy of a novel visual prosthetic device, the Implantable Miniature Telescope, IMT (by Dr Isaac Lipshitz) (IMT), in a phase I trial in patients with significant bilateral central vision impairment from late-stage age-related macular degeneration (AMD). The IMT is designed to reduce the relative size of the scotoma by rendering enlarged (threefold) central visual field images over the central and peripheral retina. DESIGN: Prospective, multicenter, open-label clinical trial. METHODS: In this prospective, multicenter phase I trial, 14 patients aged 60 or older with bilateral geographic atrophy or disciform scar AMD, cataract, and best-corrected visual acuity (BCVA) between 20/80 and 20/400 had an IMT implanted in one eye. Distance and near BCVA, endothelial cell density, and quality of life, measured as activities of daily life (ADL), were evaluated preoperatively and postoperatively. RESULTS: At 12 months, 10 (77%) of 13 patients gained 2 more lines of either distance or near BCVA, and eight (62%) of 13 patients gained 3 or more lines in either distance or near BCVA. Mean endothelial cell density decreased by 13%. All adverse events resolved without sequelae. ADL scores improved in the majority of patients. CONCLUSION: The results of this phase I trial support further evaluation of the IMT in a larger study population with late-stage AMD. A phase II/III trial is in progress.

Activities of Daily Living↗