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PubMed2003

A prospective randomized multicenter study to evaluate the best day for embryo transfer: does the outcome justify prolonged embryo culture?

PURPOSE: This study aimed to evaluate the best day for embryo transfer in a prospective unrestricted randomized multicenter trial. METHODS: Data were collected on a preformed Excel-sheet which contained random numbers from 1 to 5 for each subsequent patient as a preprogrammed day for embryo transfer. Information was requested on patient's age, indication for sterility treatment, stimulation protocol used, numbers of oocytes retrieved, fertilized oocytes, cryopreserved embryos, and cell stage of embryos transferred. RESULTS: A total of 329 embryo transfers were performed, resulting in 106 clinical pregnancies (32.2%). Pregnancy rates achieved were 20.0% on day 1, 30.4% on days 2 and 3, and 50.0% on days 4 and 5 (p = 0.03). CONCLUSIONS: Within the scope of the present randomized multicenter trial, embryo transfers performed on days 4 and 5 enhanced the pregnancy rate significantly, compared to those of days 1, 2, and 3.

Adult↗
PubMed2004

Factors influencing medication adherence beliefs and self-efficacy in persons naive to antiretroviral therapy: a multicenter, cross-sectional study.

It is widely recognized that adherence to antiretroviral therapy is critical to long-term treatment success, yet rates of adherence to antiretroviral medications are frequently subtherapeutic. Beliefs about antiretroviral therapy and psychosocial characteristics of HIV-positive persons naive to therapy may influence early experience with antiretroviral medication adherence and therefore could be important when designing programs to improve adherence to antiretroviral therapy. As part of a multicenter AIDS Clinical Trial Group (ACTG 384) study, 980 antiretroviral-naive subjects (82% male, 47% White, median age 36 years, and median CD4 cell count 278 cells/mm3) completed a self-administered questionnaire prior to random treatment assignment of initial antiretroviral medications. Measures of symptom distress, general health and well-being, and personal and situational factors including demographic characteristics, social support, self-efficacy, depression, stress, and current adherence to (nonantiretroviral) medications were recorded. Associations among variables were explored using correlation and regression analyses. Beliefs about the importance of antiretroviral adherence and ability to take antiretroviral medications as directed (adherence self-efficacy) were generally positive. Fifty-six percent of the participants were "extremely sure" of their ability to take all medications as directed and 48% were "extremely sure" that antiretroviral nonadherence would cause resistance, but only 37% were as sure that antiretroviral therapy would benefit their health. Less-positive beliefs about antiretroviral therapy adherence were associated with greater stress, depression, and symptom distress. More-positive beliefs about antiretroviral therapy adherence were associated with better scores on health perception, functional health, social-emotional-cognitive function, social support, role function, younger age, and higher education (r values = 0.09-0.24, all p < .001). Among the subset of 325 participants reporting current use of medications (nonantiretrovirals) during the prior month, depression was the strongest correlate of nonadherence ( r = 0.33, p < .001). The most common reasons for nonadherence to the medications were "simply forgot" (33%), "away from home" (27%), and "busy" (26%). In conclusion, in a large, multicenter survey, personal and situational factors, such as depression, stress, and lower education, were associated with less certainty about the potential for antiretroviral therapy effectiveness and one's perceived ability to adhere to therapy. Findings from these analyses suggest a role for baseline screening for adherence predictors and focused interventions to address modifiable factors placing persons at high risk for poor adherence prior to antiretroviral treatment initiation.

Acquired Immunodeficiency Syndrome↗
PubMed2002

A multicenter, open-label, comparative trial of two daclizumab dosing strategies vs. no antibody induction in combination with tacrolimus, mycophenolate mofetil, and steroids for the prevention of acute rejection in simultaneous kidney-pancreas transplant recipients: interim analysis.

INTRODUCTION: The safety and efficacy of daclizumab (1 mg/kg/dose every 14 d for five doses) has been established in kidney and heart transplant recipients. Alternative dosing regimens based on pharmacokinetic simulation and limited clinical trials are being investigated. The purpose of this ongoing multicenter study is to determine the safety and efficacy of two dosing regimens of daclizumab as an adjunctive immunosuppressive agent compared with no antibody induction in simultaneous kidney-pancreas transplant (SKPT) recipients receiving tacrolimus (TAC), mycophenolate mofetil (MMF) and steroids as primary immunosuppression. METHODS: This is an interim report of a multicenter, prospective, open-label, randomized study with a target enrolment of 290 patients. Eligible SKPT patients were randomized to one of three groups: daclizumab 1 mg/kg/dose every 14 d for five doses (Group I), daclizumab 2 mg/kg/dose every 14 d for two doses (Group II), and no antibody induction (Group III). The primary endpoint of the study is a composite of the incidence of presumed or biopsy-proven kidney or pancreas rejection, graft loss, or death within the first 6 months post-transplantation. RESULTS: A total of 166 patients were randomized into the three groups [Group I (n = 70), Group II (n = 74), Group III (n = 22)]. Demographic and transplant characteristics were similar among the groups. At a minimum follow-up of 3 months, patient, kidney and pancreas graft survival rates were similar among the three groups. However, the rates of acute renal allograft rejection were 18% (Group I), 8% (Group II), and 36% (Group III), p < 0.05. The probabilities of either kidney or pancreas allograft rejection were 22% (Group I), 8% (Group II), and 38% (Group III). At 3 months, the actuarial event-free survival (no acute rejection, allograft loss, or death) rates were 67, 81 and 50% in Groups I, II, and III, respectively. There were no differences in the incidence of infectious complications among the groups and no serious adverse events associated with daclizumab were observed. CONCLUSIONS: The two-dose regimen (Group II) appears to be as effective as the five-dose regimen (Group I) in preventing acute rejection after SKPT and is associated with the lowest acute rejection rates and the highest rate of event-free survival (no rejection or graft loss). However, the benefits of daclizumab compared with no antibody induction await larger sample size accrual.

Adult↗
PubMed2000

Blinded, multicenter quality control study for the quantification of human immunodeficiency virus type 1 RNA in plasma by the Belgian AIDS reference laboratories.

OBJECTIVE: In order to evaluate the interlaboratory variation of HIV-1 RNA measurements in plasma, the Belgian AIDS reference laboratories organized a blinded multicenter quality control study. METHODS: Atest panel of coded spiked HIV-1 plasma samples reflecting the dynamic range of the assay was composed and distributed. The HIV-1 RNA concentration of these samples was determined by the eight Belgian AIDS reference laboratories by means of the Amplicor HIV-1 Monitor version 1.5 assay. RESULTS: Analysis of the results demonstrated that there was little interlaboratory variation for the high concentration range (4.0-5.7 log10 copies/mL), never exceeding 0.2 log10 copies/mL. However the standard deviation for the low concentration range (2.6-3.9 log10 copies/mL) reached up to 0.22 log10 copies/mL. CONCLUSIONS: Since interlaboratory variability never reached 0.5 log10 copies/mL and each of the laboratories was able to detect four-fold differences in plasma HIV-1 RNA levels, the Amplicor assay can be used in multicenter studies without a centralized analysis of samples. Furthermore, this well-characterized proficiency panel of spiked plasma samples could be used as a standard in the study of interassay comparisons.

Belgium↗
PubMed2001

The association of aneuploidy and mild fetal pyelectasis in an unselected population: the results of a multicenter study.

INTRODUCTION: Mild pyelectasis is a common finding and there is some debate as to its association with aneuploidy. The results of a large, prospective, multicenter study of mild pyelectasis designed to determine the incidence and association with aneuploidy in an unselected population are reported. METHODS: A large multicenter, prospective observational study of unselected fetuses with mild pyelectasis identified between 16 and 26 weeks' gestation in routine ultrasound departments. RESULTS: There were 737 fetuses with mild pyelectasis of which 12 had an abnormal karyotype. Pyelectasis was isolated in three fetuses with Down syndrome, but in one the mother was older (36 years). CONCLUSION: These data confirm the fact that the presence of mild fetal pyelectasis increases the risk for aneuploidy, in particular trisomy 21. However, other risk factors should be considered before embarking on fetal karyotyping, as for most pregnancies complicated by isolated mild pyelectasis, risks of aneuploidy will remain small.

Adult↗
PubMed1999

Correlation of histology to clinical rejection reversal: a thymoglobulin multicenter trial report.

UNLABELLED: Correlation of histology to rejection reversal: A Thymoglobulin Multicenter Trial report BACKGROUND: Histology may provide a link between clinical response to antirejection therapy and graft function. In a subset of centers, renal biopsy was a secondary end point for the Thymoglobulin Multicenter Trial. METHODS: Thirty-eight patients had a protocol biopsy one to two weeks following the end of therapy. Inclusion and post-treatment biopsies were graded and scored according to Banff criteria by a central pathologist who was blinded to the type and outcome of therapy and the timing of the biopsy. RESULTS: The majority of patients (31 of 38) had moderate rejection on their inclusion biopsy. An improvement of at least one Banff grade occurred in 58% of the patients. The treatment was clinically successful in 33 patients, but two thirds of the patients (25 out of 38) demonstrated residual inflammation in the graft. The degree of improvement of inflammation was proportionate to rejection severity (P = 0.006). Banff scoring indicated that residual inflammation was less in Thymoglobulin-treated patients than in those receiving Atgam (P < 0.05) and correlated with the incidence of recurrent rejection (P = 0.015). CONCLUSIONS: These data demonstrate a discrepancy between clinical and histological resolution of acute renal allograft rejection. Residual infiltrates in the graft following rejection therapy are common and, despite clinical improvement, may indicate an increased risk for recurrent rejection.

Acute Disease↗
PubMed2001

Comorbidity assessment using the Index of Coexistent Diseases in a multicenter clinical trial.

BACKGROUND: The Hemodialysis (HEMO) Study is a multicenter trial designed to determine whether hemodialysis dose and membrane flux affect survival. Comorbid conditions are also important determinants of survival, and thus, an accurate and reliable method to assess comorbidity was required. Comorbidity was being assessed at baseline and annually in the HEMO Study using the Index of Coexistent Disease (ICED). We describe the instrument, its implementation in the HEMO Study, and the results of comorbidity assessment in the first 1000 randomized patients in the trial. METHODS: The ICED aggregated the presence and severity of 19 medical conditions and 11 physical impairments within two scales: the Index of Disease Severity (IDS) and the Index of Physical Impairment (IPI). The final ICED score was determined by an algorithm combining the peak scores for the IDS and IPI. The range of the ICED was from 0 to 3, reflecting increasing severity. RESULTS: Study personnel at 15 clinical centers were trained to update and abstract data from the dialysis medical records. Availability of data, measures of construct validity, and measures of reliability were adequate; 99.8% and 60.6% of patients had comorbid conditions in at least one IDS or IPI category, respectively. The distribution of patients by ICED level was 0 (0.2%), 1 (34.9%), 2 (31.2%), and 3 (33.7%). In multivariable analysis, the following factors were significantly associated with more severe comorbidity: older age, diabetes and other causes of renal disease, a lower level of education, employment status (unemployed and retired), longer duration of dialysis, and lower serum creatinine. There was a significant variation in the severity of comorbidity among clinical centers after adjustment for other factors. The R2 of the model was 25.3%, indicating that a substantial proportion of the variation in the ICED was not explained by these factors. CONCLUSIONS: We conclude that comorbidity assessment using the ICED is feasible in multicenter clinical trials of dialysis patients. There is a large burden of comorbidity in dialysis patients, which is not well explained by the cause of renal disease, demographic, and socioeconomic factors and common clinical and laboratory measurements. These variables should not be considered substitutes for comorbid conditions in case-mix adjustment. Comorbidity assessment is useful to describe the sample population, to improve the precision of the treatment effect, and to use possibly as an outcome measurement.

Comorbidity↗
PubMedDate not supplied

Efficacy and safety of rizatriptan versus standard care during long-term treatment for migraine. Rizatriptan Multicenter Study Groups.

Rizatriptan is a novel, selective 5-HT1B/1D receptor agonist with a rapid onset of action after oral dosing for the acute treatment of migraine. We conducted a long-term (up to 1 year), multicenter, randomized study in 1831 patients treating more than 46,000 attacks to compare the efficacy and tolerability of rizatriptan 5 mg and 10 mg to standard care medications routinely used for the acute treatment of migraine attacks. Both doses of rizatriptan were highly effective, without evidence of tachyphylaxis. Rizatriptan 10 mg was consistently superior (P < 0.05), both to the 5-mg dose and to standard care, in providing relief in 90% of attacks, with 50% pain-free by 2 hours after dosing. The most common dose-related adverse events were nausea, somnolence, and asthenia/fatigue. Based on this large, multicenter, long-term trial, rizatriptan is an important new oral agent for the acute treatment of migraine.

Administration, Oral↗
PubMed2002

Interrater reliability among epilepsy centers: multicenter study of epilepsy surgery.

PURPOSE: To measure the interrater reliability of presurgical testing and surgical decisions among epilepsy centers. METHODS: Seven centers participating in an ongoing, prospective multicenter study of resective epilepsy surgery agreed to conform to a detailed protocol regarding presurgical evaluation and surgery. To assess quality assurance, each center independently reviewed 21 randomly selected surgical cases for preoperative study lateralization and localization, and surgical decisions. Interrater reliability was assessed by using intraclass correlation coefficients (ICCs), validated for use with multiple raters, and calculated in a two-way random model based on absolute agreement. RESULTS: Agreement for ICC values: > or = 0.75, excellent; 0.60-0.74, good; 0.40-0.59, fair; < or = 0.39, poor. One center was excluded for missing data. Agreement was excellent for extracranial EEG lateralization (0.8039), magnetic resonance imaging (MRI) lateralization (0.9521) and localization (0.9130), Wada lateralization (0.9453), and intracranial EEG localization (0.7905). Agreement was good for extracranial EEG localization (0.7384) and neuropsychological testing lateralization (0.7178) and localization (0.6891). Consensus about the decision to perform intracranial monitoring was fair (0.5397), in part reflecting one center's tendency toward intracranial monitoring. Overall agreements on whether to perform surgery (0.8311) and specific surgery recommended (0.8164) were excellent. CONCLUSIONS: High interrater reliability among six epilepsy centers was present for interpretation of most components of presurgical testing. Although consensus for the decision to perform intracranial monitoring was only fair, agreements for the ultimate decision about resective surgery and specific choice of resection were excellent. We believe that this study demonstrates the feasibility of implementing multicenter protocols for neurologic management, especially those involving localization, as well as protocols combining study results with clinical decision making.

Electroencephalography↗
PubMed2001

Prospective RBC phenotype matching in a stroke-prevention trial in sickle cell anemia: a multicenter transfusion trial.

BACKGROUND: Most sickle cell anemia patients undergo transfusion therapy to prevent complications. The Stroke Prevention Trial in Sickle Cell Anemia showed that transfusion therapy is effective in the primary prevention of stroke. Despite its efficacy, transfusion therapy is limited by alloimmunization. The purpose of this study was to determine if a multicenter trial could implement a transfusion program utilizing phenotypically matched blood to reduce alloimmunization. STUDY DESIGN AND METHODS: One hundred thirty children underwent RBC phenotyping and antibody screening with review of blood bank records. The protocol required use of WBC-reduced RBCs, which were matched for E, C, and Kell. Monthly alloantibody testing and review of transfusion forms were performed to determine compliance and the occurrence of any adverse events. RESULTS: Patient RBCs expressed a low frequency of Kell (2%), E (20%), and C (25%) antigens. Sixty-one patients received 1830 units. Ninety-seven percent of all units were WBC reduced. Only 29 units were inadvertently not matched for E, C, and Kell. Five patients (8%) developed a clinically significant alloantibody. Four developed a single antibody to E or Kell. Three patients (5%) developed a warm autoantibody. There were 11 transfusion reactions and 8 transfusion-associated events. Transfusion reactions included 6 febrile reactions (0.33%/unit), 3 allergic (0.16%/unit), and 2 hemolytic (0.11%/unit). Associated events included 4 episodes of hypertension (0.22%/unit), 3 crises (0.16%/unit), and 1 transient ischemic attack (0.05%/unit). CONCLUSION: This is the first multicenter study to show that extended RBC phenotyping can be implemented nationwide. Compared to studies, the alloimmunization rate dropped from 3 percent to 0.5 percent per unit, and hemolytic transfusion reactions dropped by 90 percent. It is recommended that all transfused sickle cell anemia patients be antigen matched for E, C, and Kell. Patients should be closely monitored during transfusions to avoid preventable risks.

Adolescent↗
PubMed1998

Role of renal allograft biopsy in multicenter clinical trials in transplantation.

There is current agreement that in the design of prospective clinical trials, patients should be assigned to various treatment groups based on histological diagnosis of acute renal allograft rejection. The Banff schema is satisfactory in reporting and grading histology for patient entry into clinical trials, particularly in multicenter studies because it standardizes the entry and randomization criteria and maintains reproducibility of the histological Interpretation between the different centers. It should be emphasized that for biopsy specimens to be effective tools for either clinical practice or clinical trials, they need to be obtained before therapeutic intervention and handled by experienced histopathology laboratory technicians. Adequate tissue sampling is necessary for diagnosis and for proper grading of rejection. It is recommended that a minimum of two cores of renal tissue are needed to avoid underestimation of rejection grade. Banff classification considers a biopsy specimen to be adequate if it contains seven or more glomeruli and at least a single artery. Examination of serial step sections through the tissue samples is crucial to identify focal lesions of toxicity and to properly score intimal arteritis and tubulitis. In addition, fast interpretation of the biopsy by an experienced nephropathologist or a transplant pathologist within 24 hours optimizes the utilization of the biopsy-acquired information. At the present time, it is premature to decide on the role of graft histology as an endpoint in clinical trials, but posttreatment biopsies should be encouraged in large, multicenter, prospective trials because they may be our only tools to study postrejection changes. Semiquantitative biopsy reporting systems should be routinely included in clinical databases to allow for the prospective examination of structure-function relationships and long-term outcomes following acute rejection.

Biopsy, Needle↗
PubMed1998

Prognosis of patients with acute renal failure requiring dialysis: results of a multicenter study.

Despite several decades of clinical experience, the mortality rate for patients with acute renal failure (ARF) requiring dialysis remains high, and the evaluation of the patients prognosis has been difficult. To date, the Acute Physiology and Chronic Health Evaluation II (APACHE II) scoring system has been used more frequently for prediction in studies of ARF than any other scoring system, but has not been prospectively validated in controlled multicenter studies of this entity. In a multicenter, prospective, controlled trial evaluating the use of biocompatible hemodialysis membranes (BCMs) in patients with ARF, we evaluated the extent to which the APACHE II scoring system, based on the physiological variables in the 24 hours before the onset of dialysis and the presence or absence of oliguria, is predictive of outcome. Analysis of survival and recovery of renal function for the 153 patients treated in this study show that APACHE II scores are predictive both of survival and recovery of renal function, whether analyzed separately by type of dialysis membrane used (BCM or bioincompatible [BICM]) or for both groups combined (all P < 0.01). There was no evidence of a significant center effect or interaction of APACHE II score with dialysis membrane in our study. After adjusting for the APACHE II score, there was a positive effect of the BCM on both probability of survival (P < 0.05) and recovery of renal function (P < 0.01). In patients dialyzed with BCMs, oliguria at onset of dialysis had an adverse effect on both survival and recovery of renal function (both P < 0.01). Receiver operator curves (ROCs) using APACHE II score and the use of BCMs in nonoliguric patients yielded a statistically significant improvement versus the use of APACHE II score alone in the area under the curve (AUC) for survival (0.747 to 0.801; P < 0.05) and recovery of renal function (0.712 to 0.775; P < 0.05). We conclude that the use of the APACHE II score determined at the time of initiation of dialysis for patients with ARF is a statistically significant predictor of patient survival and recovery of renal function. The use of the APACHE II score measured at the time of dialysis initiation, especially when modified by the presence or absence of oliguria, should help in predicting outcome when evaluating interventions for patients with ARF.

APACHE↗
PubMed2002

Quadruple hamstring anterior cruciate ligament reconstruction: a multicenter study.

PURPOSE: The use of blunt-threaded titanium interference screws for arthroscopic-assisted fixation of a quadruple-strand hamstring anterior cruciate ligament (ACL) reconstruction has recently been reported. However, the pitfalls of the low medial portal technique, rehabilitation protocol, and long-term results have not. The purpose of this multicenter study was to prospectively evaluate this technique's application to ACL instability in symptomatic patients as well as to develop a standardized rehabilitation protocol. TYPE OF STUDY: Observation cohort study. METHODS: One hundred-twenty patients had quadruple hamstring ACL reconstructions, followed the study protocol, and were seen at 2 years follow-up. They were evaluated using Lysholm score, Lachman test, anterior drawer test, pivot-shift test, KT-1000, effusion assessment, and the Tegner Sports Activity Scale. RESULTS: The average Lysholm score improved 42 points; Lachman test, effusion assessment, anterior drawer test, KT-1000, and Tegner Sports Activity Scale scores all improved. Of 120 ACL reconstructions, 5 failed. Of these, 3 failed from new late injury, 1 from technical error, and 1 from patient nonadherence to rehabilitation protocol. Some anterior knee pain was present in 30% of patients, and 22% had at some time experienced hamstring pain that did not interfere with athletic activity. CONCLUSIONS: This multicenter study reports success with quadruple hamstring ACL reconstruction using the low medial portal technique. Specific pitfalls and a rehabilitation protocol are also discussed. Low medial portal position is critical in successful surgery. Variations in screw size to accommodate the variation in graft construct size are also recommended.

Adolescent↗
PubMed2006

[Do the effects of inpatient vocational therapy and ergotherapy approaches differ in schizophrenic patients? Results of a controlled multicenter study of the german research network on schizophrenia].

For some decades, vocational therapy approaches have been an integral part of inpatient psychiatric treatment of patients with schizophrenia. Like most sociotherapeutic measures, they are largely hypothesis-based. So far, their effectiveness has been subjected to very little scientific scrutiny. The results of a multicenter study in which five vocational therapy models were compared with creativity-oriented ergotherapy in a prospective, randomized control group design are presented. Target criteria were job-relevant skills, psychopathology, general level of functioning, quality of life, self-efficacy, and speed of cognitive performance. 227 patients were enrolled in the study, which was carried out within the framework of the German Research Network on Schizophrenia funded by the German Federal Ministry for Education and Research (BMBF). Multicenter analyses in a pre-post comparison revealed only minimum differences between the experimental and the control group over a four-week intervention period. Job-oriented approaches cannot currently be assumed to be superior to creativity-oriented ergotherapy.

Adult↗
PubMed2006

Non-biopsy detection of intestinal metaplasia and dysplasia in Barrett's esophagus: a prospective multicenter study.

BACKGROUND AND STUDY AIMS: There have been no multicenter studies investigating the use of magnification chromoendoscopy (MCE) for the detection of intestinal metaplasia and dysplasia/cancer in Barrett's esophagus. Our aims were to assess the ability of MCE to predict the histological diagnosis (non-biopsy detection), to compare the yield of MCE-targeted versus random biopsies for dysplasia, and to compare procedure times. PATIENTS AND METHODS: In this prospective multicenter study, patients with known or suspected Barrett's esophagus underwent MCE with indigo carmine dye staining. Three mucosal patterns (ridge/villous, circular, and irregular/distorted) were standardized, based on past experience. Mucosal patterns were noted and target biopsies were obtained only if irregular/distorted patterns were identified. Otherwise, random four-quadrant biopsies were obtained. RESULTS: A total of 56 patients (mean age 64 years, mean length of Barrett's esophagus 2.7cm) were prospectively evaluated: 38 patients (67.8 %) had ridge/villous patterns, four patients (7.1 %) had circular patterns, four patients (7.1 %) had irregular/distorted patterns, and ten patients (17.8 %) had a combination of patterns. Histologically, intestinal metaplasia was not shown in eight patients (14.2 %), nondysplastic Barrett's esophagus was diagnosed in 30 patients (53.5 %), low-grade dysplasia was detected in 12 patients (21.4 %), and high-grade dysplasia was detected in six patients (10.7 %). An irregular/distorted pattern either throughout the entire segment of Barrett's esophagus or in combination with a ridge/villous or circular pattern had a sensitivity or 83 %, a specificity of 88 %, a positive predictive value of 45 %, and a negative predictive value of 98 % for high-grade dysplasia. The yield of high-grade dysplasia was similar for the two techniques but the time taken to perform MCE was less than the time taken to perform random biopsies. CONCLUSION: An irregular/distorted pattern is specific for high-grade dysplasia and so it may not be necessary to perform biopsies in patients with ridge/villous or circular mucosal patterns.

Adult↗
PubMed2002

High-resolution chromoendoscopy for classifying colonic polyps: a multicenter study.

BACKGROUND: Chromoendoscopy may reliably separate adenomatous from nonadenomatous polyps. The aim of this multicenter trial was to determine the accuracy of high-resolution chromoendoscopy for the determination of colonic polyp histology. METHODS: This multicenter trial included 4 academic centers and a primary care practice. In 299 patients referred for routine colonoscopy or sigmoidoscopy, 520 polyps 10 mm in size were sprayed with indigo carmine dye. Using a high-resolution endoscope, the endoscopist predicted the histology of each polyp based on its surface characteristics. Hyperplastic polyps had a "pitted" surface pattern of orderly arranged "dots" that resembled surrounding normal mucosa. Adenomatous polyps had at least one surface "groove" or "sulcus." Each polyp was subsequently resected for histopathologic evaluation. RESULTS: The resected polyps were comprised by 193 adenomas (37%), 225 hyperplastic polyps (43%), and 102 "other" types (20%). Forty polyps (7.7%) could not be classified by high resolution chromoendoscopy with indigo carmine dye. For the remaining polyps, the sensitivity, specificity, and negative predictive value of indigo carmine dye staining for adenomatous polyps were, respectively, 82%, 82%, and 88%. The results were consistent among the academic centers and the primary care practice. CONCLUSIONS: High-resolution chromoendoscopy with indigo carmine dye demonstrates morphologic detail of diminutive colorectal polyps that can reliably be used to separate adenomatous from nonadenomatous polyps.

Adenoma↗
PubMed2003

Comparison of analytic approaches for the economic evaluation of new technologies alongside multicenter clinical trials.

BACKGROUND: In reporting economic evaluations of clinical trials, results are often stated without a description of the methodology used to derive the cost estimates. We compared methods for measuring costs from multicenter clinical trials to determine the extent to which the methodology affects results. METHODS: Patient-level data (n = 1849) from 3 multicenter clinical trials of percutaneous coronary revascularization were used to compare 4 methods of estimating costs: 1) hospital charges; 2) hospital charges converted to costs by use of hospital-level cost-to-charge ratios; 3) hospital charges converted to costs by use of department-level cost-to-charge ratios; 4) itemized catheterization laboratory costs with nonprocedural hospital costs generated from department-level cost-to-charge ratios. RESULTS: The method used to approximate costs did not affect the main results of the economic comparisons for any of the trials. The magnitude of the cost estimates and the cost differences between treatment groups varied considerably by method, however. Charges were approximately twice as high as hospital cost estimates. At the patient level, costs generated by use of method 1 were within 10% of those generated by use of method 4 for only 5% of patients, compared with 34% and 22% of patients with methods 2 and 3, respectively. Only method 3 produced estimates of between-group cost differences that were consistently within $500 of the reference standard. CONCLUSION: Cost estimates derived from clinical trials in the cardiovascular arena vary substantially according to accounting methodology. Thus, in reporting the results of economic analyses, a detailed description of cost derivation is necessary, particularly when the absolute magnitude of the cost estimates is important to clinical decision-making or policy-level recommendations. For the purposes of group-level comparisons, conversion of hospital charges to costs on the basis of department-level cost-to-charge ratios appears to represent a reasonable compromise between accuracy and ease of implementation.

Angioplasty, Balloon, Coronary↗
PubMed2003

Measurement and analysis of visual acuity in multicenter randomized clinical trials in the United States: findings from a survey.

PURPOSE: To describe visual acuity (VA) testing and scoring methods used in multicenter randomized clinical trials in ophthalmology in the United States (USA) sponsored by the National Eye Institute (NEI). METHODS: A survey was conducted among multicenter studies in the US that included one or more randomized clinical trials and were sponsored by the NEI, National Institutes of Health. To be included in the survey, a study had to have VA reported in one or more publications or patient eligibility based on VA, a majority of study subjects 13 years of age or older, and a patient population primarily or exclusively from the US. A standard survey form was completed for each study based on information presented in the study manual of procedures and publications. Findings were summarized and displayed with frequency distributions. RESULTS: The survey included 24 studies, each with enrollment initiated in the period 1972 to 1999. VA was one of the study eligibility criteria for 19 (79%) studies, and VA or change in VA was the primary outcome in 12 (50%) studies. ETDRS charts have been employed in 16 of 19 studies initiated after the charts were published in 1982. All studies but one specified in the documents reviewed that VA testing was performed at multiple VA test distances. For studies that used ETDRS charts, methods of converting VA scores obtained at different test distances to a common scale fell into two categories: 11 studies used a method similar in nature to that first reported in the Macular Photocoagulation Study, and 7 studies used a method similar in nature to that first reported in the Krypton-Argon Regression of Neovascularization Study. conclusion The development of the ETDRS charts and a custom light box has led to more uniformity in VA test charts and chart illumination. However, details of VA measurement protocols vary widely from study to study. To assure comparable data across studies and ocular conditions, it would be useful to have a standard VA testing and scoring protocol with provisions for testing different levels of visual acuity that recommends a single method for converting scores from different test distances to a common scale and standard conversion of "off the chart" VA levels for calculation of means and changes in VA.

Data Collection↗