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PubMed2006

Dose-response in radiotherapy for localized prostate cancer: results of the Dutch multicenter randomized phase III trial comparing 68 Gy of radiotherapy with 78 Gy.

PURPOSE: To determine whether a dose of 78 Gy improves outcome compared with a conventional dose of 68 Gy for prostate cancer patients treated with three-dimensional conformal radiotherapy. PATIENTS AND METHODS: Between June 1997 and February 2003, stage T1b-4 prostate cancer patients were enrolled onto a multicenter randomized trial comparing 68 Gy with 78 Gy. Patients were stratified by institution, age, (neo)adjuvant hormonal therapy (HT), and treatment group. Four treatment groups (with specific radiation volumes) were defined based on the probability of seminal vesicle involvement. The primary end point was freedom from failure (FFF). Failure was defined as clinical failure or biochemical failure, according to the American Society of Therapeutic Radiation Oncology definition. Other end points were freedom from clinical failure (FFCF), overall survival (OS), and toxicity. RESULTS: Median follow-up time was 51 months. Of the 669 enrolled patients, 664 were included in the analysis. HT was prescribed for 143 patients. FFF was significantly better in the 78-Gy arm compared with the 68-Gy arm (5-year FFF rate, 64% v 54%, respectively), with an adjusted hazard ratio of 0.74 (P = .02). No significant differences in FFCF or OS were seen between the treatment arms. There was no difference in late genitourinary toxicity of Radiation Therapy Oncology Group and European Organisation for Research and Treatment of Cancer grade 2 or more and a slightly higher nonsignificant incidence of late gastrointestinal toxicity of grade 2 or more. CONCLUSION: This multicenter randomized trial shows a significantly improved FFF in prostate cancer patients treated with a higher dose of radiotherapy.

Aged↗
PubMed1994

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD). Part VI. Family history assessment: a multicenter study of first-degree relatives of Alzheimer's disease probands and nondemented spouse controls.

Although familial factors in Alzheimer's disease (AD) are well established, uniform family-history assessment in genetic and epidemiologic studies of AD is needed to reconcile the divergent estimates of the cumulative risk of this illness among relatives of AD probands. To answer the need, the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) has developed a standardized Family History Assessment of AD to identify the presence of AD, Parkinson's disease (PD), and Down's syndrome (DS) in family members. This paper describes the use of this new assessment instrument in 118 patients with AD (estimated mean age at onset [+/- SD] = 64.5 +/- 7.7 years) and their nondemented spouses who were enrolled in 11 different CERAD sites in the U.S. The first-degree relatives of the probands with AD had a significantly greater cumulative risk (p < 0.005) of AD or primary progressive dementia (24.8%) than did the relatives of spouse controls (15.2%). Furthermore, the cumulative risk for this disorder among female relatives of probands was significantly greater than that among male relatives. There were no differences between the families of probands and controls for the numbers of affected first-degree relatives with PD or DS. This is the first reported multicenter family-history study of AD, and it supports earlier reports of familial factors in AD and indicates a higher risk to female relatives of AD probands. The CERAD Family History Assessment instrument may be useful for further multicenter and epidemiologic studies designed to delineate familial factors associated with AD.

Age of Onset↗
PubMed1998

Incidence of myasthenia gravis in the Emilia-Romagna region: a prospective multicenter study. Emilia-Romagna Study Group on Clinical and Epidemiological Problems in Neurology.

A prospective multicenter study on the incidence of myasthenia gravis (MG) based on 2,924,710 people was performed from 1993 to 1994. The crude annual incidence rate of new diagnoses was 14.7:1,000,000. This study emphasizes the importance of a prospective multicenter approach in evaluating the true frequency of the disease.

Adolescent↗
PubMed2000

A multicenter assessment of dopamine transporter imaging with DOPASCAN/SPECT in parkinsonism. Parkinson Study Group.

BACKGROUND: In vivo imaging of the dopamine transporter (DAT) with SPECT is a quantitative biomarker for PD onset and severity. OBJECTIVE: To use a multicenter study to evaluate the diagnostic accuracy of DOPASCAN and SPECT in patients with PD, progressive supranuclear palsy (PSP), and essential tremor (ET), and in healthy controls (HC). METHODS: Ninety-six individuals with known clinical diagnosis were imaged with DOPASCAN at five sites with different multidetector SPECT systems. Both masked visual interpretation and region of interest (ROI) analysis were performed at each site and at a core analysis center. RESULTS: Visual interpretation of the images by an expert panel demonstrated a sensitivity of 0.98 and specificity of 0.83 comparing parkinsonian (PD + PSP) versus nonparkinsonian (ET + HC) controls. Quantitative analysis of putamen and caudate DOPASCAN uptake for each region in the PD or PSP groups was significantly reduced compared to the ET or HC groups. Comparison of parkinsonian (PD + PSP) versus nonparkinsonian (ET + HC) individuals demonstrated a reduction of 76% in mean putamen and 48% in mean caudate DOPASCAN uptake. CONCLUSIONS: DOPASCAN and SPECT imaging reliably and effectively distinguish between subjects with Parkinson's syndrome (PD + PSP) and without Parkinson's syndrome (HC + ET). This is the first multicenter assessment of dopamine transporter imaging demonstrating that this tool may be used widely to assess dopaminergic degeneration in patients with parkinsonism.

Aged↗
PubMed2005

An internet web site as a data collection platform for multicenter research.

The Internet can be an effective alternative for data collection for multicenter studies. It has major advantages over the "classical" method of using paper and traditional ("snail") mail. We developed an Internet site and implemented collection of data for a multicenter study of ethical decision-making. The Web site was built with Microsoft FrontPage as the authoring tool. Database management was performed with Microsoft Access. Security issues were the major concerns for the web design. Thirty-seven European centers enrolled 4248 patients during 1.5 yr using the Internet site. The use of this Internet site for data acquisition was highly effective, and the investigators were able to use the system without training. Overall satisfaction of the investigators was high. After security issues, interactivity and user-friendly design are the main cornerstones for the success of such a system.

Computer Security↗
PubMed2004

Performance evaluation of automated assays for beta-CrossLaps, N-MID-Osteocalcin and intact parathyroid hormone (BIOROSE Multicenter Study).

INTRODUCTION: Biochemical markers of bone metabolism have been mainly determined manually until now and the precision and accuracy of these methods have not always been satisfactory. This has been shown in several external quality assessment schemes (EQAS). OBJECTIVE AND STUDY DESIGN: A study named BIOROSE was undertaken to evaluate new automated assays for serum markers of bone metabolism. The main focus was to evaluate the assay performance in a multicenter setting with 20 laboratories participating in Germany. The evaluation consists of a familiarization phase to determine precision and accuracy and an EQAS to evaluate the comparability between laboratories. MATERIALS: The parameters beta-CrossLaps (CTX), N-MID-Osteocalcin (OC) and intact parathyroid hormone (PTH) were measured with reagents including calibrators and control sera obtained from Roche Diagnostics, Mannheim, Germany, with electrochemiluminescence immunoassays (ECLIA) on the automated analyzer Elecsys 2010. RESULTS: We calculated for the control samples, PCB 1-3, the mean and median values from the measured values of all participating laboratories and used these as target values. From these target values, a recovery range for the participating laboratories was calculated for beta-CrossLaps, OC and intact PTH of better than 80-126% for PCB 2 and PCB 3, and for PCB 1 (low concentration range) for beta-CrossLaps 79-129%, OC 90-120% and intact PTH 78-126%. The between-day imprecision was 2.4-7.2% for beta-CrossLaps, 1.1-5.9% for OC and 1.7-5.5% for intact PTH in the elevated range (sample PCB 2). In the EQAS, the inter-laboratory imprecision for beta-CrossLaps in the sample with a value of 0.8 ng/ml (above the upper limit of normal, which is 0.6 ng/ml) was 9.8% on day 1 and 9.7% on day 2. CONCLUSION: The performance evaluation of automated assays for beta-CrossLaps, N-MID-Osteocalcin and intact parathyroid hormone in the BIOROSE multicenter study showed that the participating laboratories had no problems in setting up these methods and they yielded results for precision and accuracy that are superior to results achieved in external quality assessment schemes for manually performed methods. In addition, at the clinically important decision level of the upper limit of the normal range, all three tested analytes gave precise results that improved medical decisions.

Automation↗
PubMedDate not supplied

Diagnosis and management of juvenile hyperthyroidism in Germany: a retrospective multicenter study.

This retrospective multicenter study was designed to survey the management of childhood and adolescent hyperthyroidism in six pediatric endocrinological units in Germany. Fifty-six patients aged between 1.1 and 17.0 yr (median 10.5 yr) were enrolled. Data were collected retrospectively from the patients' records by a trained pediatric endocrinologist using standardized questionnaires. After the diagnosis of hyperthyroidism was established on the basis of clinical and biological findings, treatment with antithyroid drugs (carbimazole, methimazole, thiamazole, propylthiouracil) was started in all patients. In 55/56 of the patients treated with antithyroid drugs, euthyroidism was achieved (98%). However, 26 patients (47%) were still hyperthyroid after discontinuation of the medication. Eight children with continued hyperthyroidism ultimately underwent subtotal thyroidectomy 13-136 (median 28) months after the initial diagnosis. Management principles of the participating centers were heterogeneous. As a consequence, prospective multicenter studies are urgently needed to establish clear standards for the diagnosis and therapy of childhood hyperthyroidism.

Adolescent↗
PubMed2006

Variation in standards of research compensation and child assent practices: a comparison of 69 institutional review board-approved informed permission and assent forms for 3 multicenter pediatric clinical trials.

OBJECTIVE: To systematically compare standards for compensation and child participant assent in informed permission, assent, and consent forms (IP-A-CFs) approved by 55 local institutional review boards (IRBs) reviewing 3 standardized multicenter research protocols. METHOD: Sixty-nine principal investigators participating in any of 3 national, multicenter clinical trials submitted standardized research protocols for their trials to their local IRBs for approval. Copies of the subsequently IRB-approved IP-A-CFs were then forwarded to an academic clinical research organization. This collection of IRB-approved forms allowed for a quasiexperimental retrospective evaluation of the variation in informed permission, assent, and consent standards operationalized by the local IRBs. RESULTS: Standards for compensation and child participant assent varied substantially across 69 IRB-approved IP-A-CFs. Among the 48 IP-A-CFs offering compensation, monetary compensation was offered by 33 as reimbursement for travel, parking, or food expenses, whereas monetary or material compensation was offered by 22 for subject inconvenience and by 13 for subject time. Compensation ranged widely within and across studies (study 1, $180-1425; study 2, $0-500; and study 3, $0-100). Regarding child participant assent, among the 57 IP-A-CFs that included a form of assent documentation, 33 included a line for assent on the informed permission or consent form, whereas 35 included a separate form written in simplified language. Of the IP-A-CFs that stipulated the documentation of assent, 31 specified > or =1 age ranges for obtaining assent. Informed permission or consent forms were addressed either to parents or child participants. CONCLUSION: In response to identical clinical trial protocols, local IRBs generate IP-A-CFs that vary considerably regarding compensation and child participant assent.

Adolescent↗
PubMed1997

Multicenter evaluation of the Micral-Test II test strip, an immunologic rapid test for the detection of microalbuminuria.

OBJECTIVE: To assess the performance of the Micral-Test II immunologic test strip for the detection of microalbuminuria, a multicenter evaluation in eight European study sites was performed. RESEARCH DESIGN AND METHODS: Using both the Micral-Test II test strip and the routine method for the determination of albumin concentration, we investigated 2,228 urine samples from diabetic patients. Additionally, interperson variability, color stability, and possible interfering factors (temperature, pH, leucocyturia, erythrocyturia, and drugs) were tested. RESULTS: For a cutoff concentration of 20 mg/l with respect to the routine methods, a sensitivity of 96.7% and a specificity of 71% were calculated for the Micral-Test II test strip. The negative predictive value was 0.95, and the positive predictive value was 0.78, with a prevalence of positive samples (laboratory method) of 52%. The interperson variability of color interpretation showed 93% concordant readings. The interference study showed an influence of oxytetracycline, leading to higher readings. There was no interference from pH. A sample temperature of < 10 degrees C led to lower readings. In the case of samples with massive leucocyturia and erythrocyturia that may delete the chromatographic process, waiting an additional 1-2 min is needed before reading. CONCLUSIONS: The results of the multicenter evaluation show that the Micral-Test II test strip permits an immediate and reliable semiquantitative determination of low albumin concentrations in urine samples with an almost user-independent color interpretation.

Albuminuria↗
PubMed2003

Traumatic subarachnoid hemorrhage on the computerized tomography scan obtained at admission: a multicenter assessment of the accuracy of diagnosis and the potential impact on patient outcome.

OBJECT: The goal of this study was fourfold: 1) to determine the incidence of traumatic subarachnoid hemorrhage (tSAH) in patients with traumatic brain injury (TBI); 2) to verify agreement in the diagnosis of tSAH in a multicenter study; 3) to assess the incidence of tSAH on the outcome of the patient; and 4) to establish whether tSAH itself leads to an unfavorable outcome or whether it is a sign of major brain trauma associated with severe posttraumatic lesions. METHODS: Computerized tomography (CT) scans obtained in 169 head-injured patients on admission to 12 Italian intensive care units during a 3-month period were examined. The scans were collected for neuroradiological review and were used for the analysis together with data from a multicenter database (Neurolink). A review committee found a high incidence of tSAH (61%) in patients with TBI and a moderate agreement among centers (K = 0.57). Significant associations were observed between the presence and grading of tSAH and patient outcomes, and between the presence of tSAH and the severity of the CT findings. Logistic regression analysis showed that the presence of tSAH and its grading alone do not assume statistical significance in the prediction of unfavorable outcome. CONCLUSIONS: Traumatic SAH frequently occurs in patients with TBI, but it is difficult to detect and grade. Traumatic SAH is associated with more severe CT findings and a worse patient outcome.

Adolescent↗
PubMed2003

Occipitocervical reconstruction with the Ohio Medical Instruments Loop: results of a multicenter evaluation in 30 cases.

OBJECT: Stabilization of the craniocervical junction (CCJ) remains a significant challenge. In this multicenter study, the authors present the results of an evaluation of a precontoured titanium implant, the Ohio Medical Instruments (OMI) Loop, for craniocervical fixation. METHODS: In this multicenter retrospective study the authors evaluated 30 patients (16 female, 14 male; mean age 53.8 years) with rheumatoid arthritis (15 cases), traumatic occipitoatlantoaxial instability (six cases), congenital vertebral anomalies (two cases), instability due to basilar invagination in the setting of Chiari malformation (two cases), or Down syndrome (one case), tumor (one case), os odontoideum (two cases), and pseudarthrosis/other (one case), who underwent OMI Loop-assisted occipitocervical reconstruction. The mean follow-up period was 25.4 months (range 6-60 months). A solid reconstruction was achieved in 29 of 30 cases; there was only one case of hardware failure requiring reoperation. Noncritical hardware failure occurred in two patients in whom partial occipital screw backout occurred but did not necessitate reoperation. There were no perioperative neurological complications. One patient (3.3%) experienced a delayed postoperative worsening of myelopathy at 1 year that resolved with further surgery. Postoperatively, in 66.6% of patients the degree of myelopathy remained stable (as measured by American Spinal Injury Association [ASIA] scores), whereas 30% improved by one or more ASIA grade. The rate of osseous fusion was 96.6% at a mean follow-up period of 25.4 months. CONCLUSIONS: The authors found that the OMI Loop is a versatile precontoured occipitocervical fixation device that can be applied to a wide range of CCJ lesions. It provides excellent immediate rigid fixation of the CCJ, a high rate of osseous fusion, and a low rate of hardware failure.

Adolescent↗
PubMed2005

Multicenter study investigating the postoperative progression of ossification of the posterior longitudinal ligament in the cervical spine: a new computer-assisted measurement.

OBJECT: Ossification of the posterior longitudinal ligament (OPLL) often progresses after surgery, and this may cause late-onset neurological deterioration. There have been few studies, however, to clarify any correlation between progression and clinical outcome, partly because of the lack of studies involving reliable and reproducible methods by which detection of progression is made possible. The authors conducted a multicenter study to investigate the occurrence of postoperative progression and to elucidate the possible risk factors in a large-scale patient population, and a novel computer-assisted measurement method was used to provide the basis for future clinical studies. METHODS: The authors analyzed lateral plain radiographs obtained immediately and at 1 and 2 years after surgery in 131 patients who underwent posterior decompression at 13 institutions. The x-ray films were transformed via scanner into digital images; the length and thickness of ossifications were measured using a new computer-assisted measurement system, and the incidence of progression was determined. Odds ratios for progression according to age group and types of OPLL were determined and compared to elucidate significant risk factors of progression. CONCLUSIONS: This is the first multicenter study to investigate the incidence of OPLL progression after posterior decompression by using a standardized measurement method. The rate of postoperative progression at 2 years was 56.5%, which was comparable with results reported in other studies. Progression occurred more frequently in younger-age rather than in older-age patient populations at both 1 and 2 years postoperatively. Mixed-type and continuous-type OPLL progressed more frequently than the segmental-type lesion at 2 years. The results of the present study could serve as basis for future studies to assess the efficacy of drug therapy to prevent OPLL progression.

Adult↗
PubMed2001

Epidemiologic and clinical survey of Behcet's disease in Korea: the first multicenter study.

The prevalence of Behcet's disease is the highest in the East Asian and the Mediterranean countries. Behcet's disease is also distributed in the Asian countries, but the nationwide survey has not been performed in Korea yet. The Korean Study Group for Behcet's Disease, founded in 1999, conducted a multicenter, retrospective survey on epidemiologic and clinical features of the patients with Behcet's disease from 20 hospitals around the nation from 1997 to 1999. Of 3,497 patients, 1,527 were classified into complete or incomplete type of Behcet's disease according to the revised Shimizu's classification. The sex ratio was 1:1.75 with the female predominance. Geographical distribution showed the highest frequency in Seoul (38.5%). Clinically, 98.8% had oral ulcers, 83.2% had genital ulcers, 84.3% had skin lesions and 50.9% had ocular lesions. As for the minor clinical manifestations, articular symptoms were the most frequent. The pathergy test showed positive in 15.4% of patients and revealed a higher positive rate in males (20.2%) than in females (12.7%). In conclusion, we performed the first multicenter study on Behcet's disease in Korea and revealed the female predominance, higher frequency of ocular lesions, and lower positivity of pathergy test in the patients.

Adolescent↗
PubMedDate not supplied

The design of the multicenter study of light reduction in retinopathy of prematurity (LIGHT-ROP).

BACKGROUND: The LIGHT-ROP Study was a multicenter, prospective, randomized, controlled, clinical trial designed to determine if a reduction in ambient light exposure to premature infants' eyes would reduce the incidence of retinopathy of prematurity (ROP). Previous clinical reports were contradictory and had one or more methodological flaws. METHODS: The LIGHT-ROP trial was designed in rigorous fashion to include randomization to treatment or control groups, masking of examiners, an adequate sample size of high-risk infants, a universal ROP classification system, a reliable and reproducible ophthalmologic examination protocol, a controlled method of light reduction, and monitoring of light levels in the nursery. The multicenter trial was conducted at three centers in Buffalo, Dallas, and San Antonio, with a separate coordinating center in Houston. The trial also utilized a separate data and safety monitoring committee. CONCLUSION: The design of the LIGHT-ROP study represents the most rigorous and largest clinical trial to date. It has demonstrated that light reduction does not reduce the incidence of confirmed ROP in high risk infants.

Humans↗
PubMed1994

DUEs for the '90s: multicentered, outcome-oriented.

The likely development of healthcare alliances and affiliations will create a logical role for multicentered DUEs that study treatment regimens or indications in a healthcare system made up of several institutions. Such a study is under way in New Jersey, involving 15 hospitals. The DUE is evaluating usage patterns of ticarcillin/clavulanate and two other broad-spectrum antibiotics. A multicenter DUE presents challenges, such as the need for additional resources and for consensus among disparate elements; but this methodology also opens up expanded roles for pharmacists, including participation in quality assurance activities.

Anti-Bacterial Agents↗
PubMed1989

A multicenter model for examining in vitro susceptibilities of bacteria to antibiotics.

In vitro bacterial susceptibility data are often considered in both hospital formulary and antibiotic prescribing decisions. In this multicenter study, susceptibility data from 105 United States hospitals resulted in a database containing 211,142 isolates for 31 different bacteria and 38 antibiotics. To identify susceptibility patterns of bacteria to antibiotic alternatives, this computerized database was subjected to confidence interval analysis, while controlling for potential sources of random error. This paper describes the multicenter study design and provides several examples of the type of information the analysis can provide to P & Committee members and to practitioners who ultimately must make decisions regarding antibiotic use, sometimes without the benefit of complete hospital-specific historical antibiogram data. Limitations on the interpretation of aggregate in vitro susceptibility data gained from multiple institutions are also discussed.

Anti-Bacterial Agents↗
PubMed1999

[Experience with combined interferon alpha-2b and ribavirin in the therapy of chronic hepatitis C. Experience with one-year therapy of 100 patients. Multicenter study].

It has been established that the long term interferon therapy in patients with chronic hepatitis C is able to produce sustained remission only in about 20 per cent of the cases. According to the newest data the combined interferon and ribavirin therapy significantly increases the remission of patients in naive, non-responder or relapsed cases. Clinical remission was confirmed by enzyme activity of alaninamino transferase (ALT) and HCV-RNA-PCR tests. In order to get exact data of the remission rate and the symptom free period, a prospective multicenter study has been introduced in Hungary. Ten leading hepatologic units have been involved into the trial. Till now the combined therapy with interferon-alfa-2b (3 MU, three times a week) and ribavirin--(1000-1200 mg daily) for one year has been finished in 100 cases with chronic hepatitis C. The mean value of ALT activity decreased near to the normal level, in 58 patients it was in the normal range. Side effects with mild or moderate grades have been found in 31 cases. The interim report of this multicenter study confirm the efficacy of this combined therapy in chronic hepatitis C.

Adolescent↗
PubMedDate not supplied

[The EMECAM project: the Spanish Multicenter Study on the Relationship between Air Pollution and Mortality. The background, participants, objectives and methodology].

In recent years, a growing number of studies suggests that increases in air pollution levels may have short-term impact on human health, even at pollution levels similar to or lower than those which have been considered to be safe to date. The different methodological approaches and the varying analysis techniques employed have made it difficult to make a direct comparison among all of the findings, preventing any clear conclusions from being drawn. This has led to multicenter projects such as the APHEA (Short-Term Impact of Air Pollution on Health. A European Approach) within a European Scope. The EMECAM Project falls within the context of the aforesaid multicenter studies and has a wide-ranging projection nationwide within Spain. Fourteen (14) cities throughout Spain were included in this Project (Barcelona, Metropolitan Area of Bilbao, Cartagena, Castellón, Gijón, Huelva, Madrid, Pamplona, Seville, Oviedo, Valencia, Vigo, Vitoria and Saragossa) representing different sociodemographic, climate and environmental situations, adding up to a total of nearly nine million inhabitants. The objective of the EMECAM project is that to asses the short-term impact of air pollution throughout all of the participating cities on the mortality for all causes, on the population and on individuals over age 70, for respiratory and cardiovascular design causes. For this purpose, with an ecological, the time series data analyzed taking the daily deaths, pollutants, temperature data and other factors taken from records kept by public institutions. The period of time throughout which this study was conducted, although not exactly the same for all of the cities involved, runs in all cases from 1990 to 1996. The degree of relationship measured by means of an autoregressive Poisson regression. In the future, the results of each city will be combined by means of a meta-analysis.

Air Pollutants↗