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Bruno Giraudeau

Publications and source records attributed to Bruno Giraudeau.

At least 19 recordsLinked to original sources
PubMed2006

Reporting of radiographic methods in randomised controlled trials assessing structural outcomes in rheumatoid arthritis.

BACKGROUND: Because an increasing number of clinical trials evaluating disease-modifying antirheumatic drugs in rheumatoid arthritis (RA) emphasise radiographic outcomes as a primary outcome, using a reproducible radiographic measure should be placed at a premium. AIM: To evaluate the reporting of radiographic methods in randomised trials assessing radiographic outcomes in RA. METHODS: Medline was searched for randomised controlled trials assessing radiographic outcomes published between January 1994 and December 2005 in general medical and specialty journals with a high impact factor. One reader extracted data (radiographic acquisition, assessment and reproducibility) using a standardised form. RESULTS: A total of 46 reports were included in the analysis. The mean (SD) methodological quality scores on the Jadad scale (range 0-5) and the Delphi list (0-9) were 2.9 (1.2) and 6.4 (1.3), respectively. Use of a standardised procedure for the acquisition of the radiographs was reported in 2 (4.3%) articles. 2 (4.3%) reports indicated that the quality of the radiographs was evaluated. In 65.2% of the reports, > or = 2 radiographic scores were used. Reporting of radiographic assessment was well detailed for number of readers (91.3%), information on readers (71.7%), blinding (91.4%) and how films were viewed (74.0%). The reproducibility of the reading was reported in 39.1% of the articles. CONCLUSION: The reporting of results of randomised controlled trials of radiographic outcomes in RA shows great variability in radiographic scores used. Reporting of radiographic methods could be improved upon, especially the acquisition procedure and the reproducibility of the reading.

Arthritis, Rheumatoid↗
PubMed2006

Sample size calculation for multicenter randomized trial: taking the center effect into account.

In multicenter trials, data from the same center are more similar than those from different centers. These similarities induce a correlation between data, known as the center effect, which is assessed by the intraclass correlation coefficient (ICC). Here, we derive a sample size formula for continuous data that takes into account this center effect. Our analytical developments lead to an elementary formula different from the classical one by a (1-rho) factor, where rho is the ICC. This work allows for adjusting and reducing the sample size according to the magnitude of the center effect and leads to a better consistency in the conduct of multicenter randomized trials.

Humans↗
PubMed2006

Planning a cluster randomized trial with unequal cluster sizes: practical issues involving continuous outcomes.

BACKGROUND: Cluster randomization design is increasingly used for the evaluation of health-care, screening or educational interventions. At the planning stage, sample size calculations usually consider an average cluster size without taking into account any potential imbalance in cluster size. However, there may exist high discrepancies in cluster sizes. METHODS: We performed simulations to study the impact of an imbalance in cluster size on power. We determined by simulations to which extent four methods proposed to adapt the sample size calculations to a pre-specified imbalance in cluster size could lead to adequately powered trials. RESULTS: We showed that an imbalance in cluster size can be of high influence on the power in the case of severe imbalance, particularly if the number of clusters is low and/or the intraclass correlation coefficient is high. In the case of a severe imbalance, our simulations confirmed that the minimum variance weights correction of the variation inflaction factor (VIF) used in the sample size calculations has the best properties. CONCLUSION: Publication of cluster sizes is important to assess the real power of the trial which was conducted and to help designing future trials. We derived an adaptation of the VIF from the minimum variance weights correction to be used in case the imbalance can be a priori formulated such as "a proportion (gamma) of clusters actually recruit a proportion (tau) of subjects to be included (gamma < or = tau)".

Analysis of Variance↗
PubMed2006

Quality of reporting of noninferiority and equivalence randomized trials.

CONTEXT: Noninferiority and equivalence trials aim to show that the experimental treatment is not clinically worse than (noninferior) or clinically similar to (equivalent) a control active treatment. These study objectives imply particular planning and analysis. OBJECTIVE: To assess the methodologic quality of reports of randomized controlled trials of noninferiority and equivalence. DESIGN: We searched MEDLINE and the Cochrane Central Register of Controlled Trials for reports of randomized controlled trials of noninferiority and equivalence hypotheses published between January 1, 2003, and December 31, 2004. MAIN OUTCOME MEASURES: Data extracted by use of a standardized form involved assessment of choice of noninferiority or equivalence margins, sample size calculation, sets of patients analyzed, method of statistical testing and reporting results, and conclusions. RESULTS: A total of 162 reports were included in the analysis (116 reports of noninferiority and 46 of equivalence). The margin defining noninferiority or equivalence was described in most reports (156 [96.3%]), with justification of the margin in only 33 (20.4%). Almost one quarter of the reports (35 [21.6%]) did not describe a sample size calculation, and an additional 11 (6.8%) did not take into account a prespecified noninferiority or equivalence margin. Less than half of the reports (69 [42.6%]) described both an intent-to-treat (ITT; all randomized patients are included in the analysis) or modified ITT (patients who never received treatment are excluded) and per-protocol (patients who did not complete the treatment are excluded) analysis, and only about half of those (39 [56.5%]) described both types of results. Results were displayed with confidence intervals in 136 reports (84.0%). Only 33 articles (20.3%) fulfilled reporting requirements specific to noninferiority and equivalence trials, 4 of them (12.1%) with misleading conclusions. CONCLUSIONS: Reporting of noninferiority and equivalence trials has important deficiencies: absence of noninferiority or equivalence margin, only an ITT (or a per-protocol) analysis performed, and results not adequately reported. Moreover, even for articles fulfilling these requirements, conclusions are sometimes misleading.

Bias↗
PubMed2006

Nasal carriage of methicillin-resistant staphylococcus aureus in vascular surgery.

The purpose of this study was to determine the prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) and to define risk factors allowing identification of high-risk patients for MRSA nasal carriage at admission to the vascular surgery unit. From March 23, 2004 to July 13, 2004, screening for nasal carriage of MRSA was conducted at admission to the vascular surgery unit and 1 week thereafter. To analyze risk factors for MRSA nasal carriage at admission to the vascular surgery unit, a case-control study was carried out in patients presenting colonization at the time of admission. A total of 308 patients underwent nasal screening for MRSA. Thirteen were colonized with MRSA (nine at admission and four acquired), i.e., 4.2% of patients. Methicillin-susceptible Staphylococcus aureus (MSSA) was found in 11.4% of patients who underwent screening. Six patients with MRSA infection were identified during the study period. The two patients who acquired infection were colonized at the time of admission. Arrival from another health-care facility and from another department was a significant risk factor for carriage of MRSA. The prevalence of nasal carriage in vascular surgery was 4.2%. Nasal screening is highly cost-effective since 60% of MRSA carriers were undetected using diagnostic specimens alone. French recommendations issued for cardiac and orthopedic surgery by the consensus conference on preoperative management of infectious risk on March 5, 2004, should be extended to vascular surgery.

Adult↗
PubMed2006

Assessment of cyclic changes of microvessels in ovine ovaries using Sonovue contrast-enhanced ultrasound.

Our objective was to detect variations of ovarian vascularization that occur in the estrus cycle of the ewe using an IV contrast agent. Five ewes were investigated using contrast-enhanced power Doppler after Sonovue injection at day 0, 3, 5, 10 and 13 of the cycle in two successive estrus cycles. Transvaginal ultrasound monitoring of each ewe was performed after a dose of Sonovue. Parameters derived from the time-intensity curves were compared. Quantification of the enhancement and wash-in period parameters changed significantly between ovaries and between the follicular and luteal periods of the cycle. Uptake time, wash-out time, total time of enhancement and area under the curve were the parameters with the smallest variation between ovaries. Wash-out time and area under the curve are two contrast parameters that did not change with cyclic changes. Thus, using these parameters in premenopausal women will allow more accurate detection of vascular modifications that may be associated with ovarian cancer.

Animals↗
PubMed2006

Diet, cancer, and the lipidome.

The potential for dietary fat to interfere with the development of breast cancer by delaying its occurrence makes the identification of defined molecules a mandatory step in cancer prevention. In order to circumvent the limitations and/or bias of dietary exposure assessment tools, biomarkers of past lipid intake such as the fatty acid composition of white adipose tissue have been used. When considered separately, candidate fatty acids identified as favorable on the basis of their association with breast cancer risk have usually led to inconsistent results in animal intervention studies. This inconsistency indicates that any approach based on a single fatty acid should be abandoned for an integrated view over the complex lipid interactions which finally determines the lipidome, the lipid profile that is found in individuals. This article presents a reappraisal of the role of the lipid profile through a comprehensive reanalysis of adipose tissue fatty acid composition obtained in patients with benign or malignant breast tumors as well as in experimental animals during dietary interventions. Rather than a single fatty acid, a composite indicator combining elevated monounsaturates and low omega6/omega3 fatty acid ratio was associated with breast cancer protection. This lipidome may become the template for identifying breast cancer risk related to diet, and for designing proper dietary modifications to delay the occurrence of breast cancer, although the universality of the findings cannot be assessed from a single study.

Adipose Tissue↗
PubMed2005

A checklist to evaluate a report of a nonpharmacological trial (CLEAR NPT) was developed using consensus.

BACKGROUND AND OBJECTIVE: To develop a checklist of items measuring the quality of reports of randomized clinical trials (RCTs) assessing nonpharmacological treatments (NPTs). STUDY DESIGN AND SETTING: The Delphi consensus method was used to select and reduce the number of items in the checklist. A total of 154 individuals were invited to participate: epidemiologists and statisticians involved in the field of methodology of RCTs (n = 55), members of the Cochrane Collaboration (n = 41), and clinicians involved in planning NPT clinical trials (n = 58). Participants ranked on a 10-point Likert scale whether an item should be included in the checklist. RESULTS: Fifty-five experts (36%) participated in the survey. They were experienced in systematic reviews (68% were involved in the Cochrane Collaboration) and in planning RCTs (76%). Three rounds of the Delphi method were conducted to achieve consensus. The final checklist contains 10 items and 5 subitems, with items related to the standardization of the intervention, care provider influence, and additional measures to minimize the potential bias from lack of blinding of participants, care providers, and outcome assessors. CONCLUSIONS: This tool can be used to critically appraise the medical literature, design NPT studies, and assess the quality of trial reports included in systematic reviews.

Consensus↗
PubMed2005

ERCC1 codon 118 polymorphism is a predictive factor for the tumor response to oxaliplatin/5-fluorouracil combination chemotherapy in patients with advanced colorectal cancer.

PURPOSE: The aim of our study was to assess whether the polymorphism of the nucleotide excision repair enzyme, excision repair cross-complementing rodent repair deficiency, complementation group 1 (ERCC1), had an effect on the tumor response in patients treated with standard chemotherapy regimens for a metastatic colorectal cancer. We have studied the synonymous polymorphism that causes a single nucleotide change C to T at codon 118 converting a codon of common usage (AAC) to a less used codon (AAT), both coding asparagine. This change results in a decreased ERCC1 gene expression, which impairs repair activity. EXPERIMENTAL DESIGN: Ninety-one patients with a median age of 55.1 years treated for a metastatic colorectal cancer were included in our retrospective study. The ERCC1 polymorphism was analyzed in the normal tissue of all patients. RESULTS: Twenty (22%) were homozygous for AAC codon (C/C genotype), 30 were (33%) homozygous for AAT codon (T/T genotype), and 41 (45%) were heterozygous (C/T genotype). The objective response rate to oxaliplatin in combination with 5-fluorouracil (5-FU) was significantly higher in the T/T genotype group compared with the C/T and the C/C genotype groups (61.9%, 42.3%, and 21.4%, respectively; P = 0.018). By contrast, no significant difference was observed when patients were treated with either 5-FU alone (45%, 29.2%, and 33.3%, respectively; P = 0.407) or in combination with irinotecan (46.1%, 25.0%, and 27.3%, respectively; P = 0.305). CONCLUSIONS: Our observations allowed us to define the first useful predictive criterion for oxaliplatin/5-FU response in patients with metastatic colorectal cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

A priori postulated and real power in cluster randomized trials: mind the gap.

BACKGROUND: Cluster randomization design is increasingly used for the evaluation of health-care, screening or educational interventions. The intraclass correlation coefficient (ICC) defines the clustering effect and be specified during planning. The aim of this work is to study the influence of the ICC on power in cluster randomized trials. METHODS: Power contour graphs were drawn to illustrate the loss in power induced by an underestimation of the ICC when planning trials. We also derived the maximum achievable power given a specified ICC. RESULTS: The magnitude of the ICC can have a major impact on power, and with low numbers of clusters, 80% power may not be achievable. CONCLUSION: Underestimating the ICC during planning cluster randomized trials can lead to a seriously underpowered trial. Publication of a priori postulated and a posteriori estimated ICCs is necessary for a more objective reading: negative trial results may be the consequence of a loss of power due to a mis-specification of the ICC.

Cluster Analysis↗
PubMed2005

Reporting of harm in randomized, controlled trials of nonpharmacologic treatment for rheumatic disease.

BACKGROUND: Reports of clinical trials usually emphasize benefits and give less attention to harms. PURPOSE: To compare the reporting of harm in trials of pharmacologic and nonpharmacologic treatment. DATA SOURCES: MEDLINE and the Cochrane Central Register of Controlled Trials. STUDY SELECTION: Reports of randomized, controlled trials assessing treatment of rheumatic disease that were published between January 1999 and January 2005. DATA EXTRACTION: A standardized abstraction form was used to extract data. DATA SYNTHESIS: 193 articles were analyzed. After adjustment for medical area, sample size, funding source, and multicenter trials, data on harm were more often described in pharmacologic treatment reports than in nonpharmacologic treatment reports in reporting adverse events (odds ratio, 5.2 [95% CI, 2.1 to 12.9]), reporting withdrawals due to adverse events (odds ratio, 4.6 [CI, 2.0 to 10.9]), reporting severity (odds ratio, 3.7 [CI, 1.5 to 9.1]), and allocating space for describing harm (odds ratio, 1.6 [CI, 1.2 to 2.3]). LIMITATIONS: Extrapolating results to trials in areas other than rheumatic disease is questionable. CONCLUSIONS: The lack of reporting harm in trials assessing nonpharmacologic treatment in rheumatic disease is an important barrier to evaluating the benefit-harm balance of nonpharmacologic treatments.

Antirheumatic Agents↗
PubMed2005

Anisotropy changes in post-menopausal osteoporosis: characterization by a new index applied to trabecular bone radiographic images.

Bone intrinsic strength is conditioned by several factors, including material property and trabecular micro-architecture. Bone mineral density (BMD) is a good surrogate for material property. Architectural anisotropy is of special interest in mechanics-architecture relations and characterizes the degree of directional organization of a material. We have developed anisotropy indices from the Fast Fourier Transform (FFT) on bone radiographs. We have validated these indices in a cross-sectional uni-center case-control study including 39 postmenopausal women with vertebral fracture and 70 age-matched control cases. BMD was measured at the lumbar spine and femoral neck. A fractal analysis of texture was performed on calcaneus radiographs at three regions of interest (ROIs), and the result was expressed as the H parameter (fractal dimension =H-2). The anisotropy evaluation was based on the FFT spectrum of these three ROIs extracted on calcaneus radiographs. On the FFT spectrum, we have measured the spreading angle of the longitudinal trabeculae called the dispersion longitudinal index (DLI) and the spreading angle of the transversal trabeculae called the dispersion transversal index (DTI). From the measured parameters, an anisotropy index was derived, and the degree of anisotropy (DA) calculated with DLI and DTI. We have compared the results from the vertebral fracture cases and control cases. The best distinction was obtained for the largest ROI located in the great tuberosity of the calcaneus for all parameters ( P <10(-4)).( )The DA parameter showed a higher value in vertebral fracture cases (1.746+/-0.169) than in control cases (1.548+/-0.136); P <10(-4), and the difference persisted after removal of the subjects with hormonal replacement therapy. The analysis of the receiver operating characteristics (ROC) has shown the best results with DA and Hmean: areas under curves (AUCs) respectively of 0.765 and 0.683, while AUCs associated to LS-BMD and FN-BMD were 0.614 and 0.591 lower, respectively. We determined the odds ratios (OR) by uni- and multivariate analysis. Crude ORs were respectively 3.91 (95% CI: 2.22-6.87) and 3.08 (95% CI: 1.72-5.52) for DA and Hmean. Crude ORs were respectively 1.71 (95% CI: 1.15-2.56) and 1.56 (95% CI: 1.05-2.31) for LS-BMD and FN-BMD. All ORs were statistically significant, and those associated to Hmean and anisotropy indices were higher than those of BMD measurements. From a multivariate analysis including anisotropy indices, Hmean, age and FN-BMD, the remaining significant ORs were respectively 6.33 (95% CI: 2.80-14.30) and 3.08 (95% CI: 1.48-6.37) for DA and Hmean. These data have shown that anisotropy indices on calcaneus radiographs can distinguish vertebral fracture cases from control cases. This analysis provides complementary information concerning the BMD and fractal parameter. These data suggest that we can improve the fracture risk evaluation by adding information related to the directional organization of trabecular bone derived from the FFT spectrum on conventional radiographic images.

Aged↗
PubMed2005

Violation of the intent-to-treat principle and rate of missing data in superiority trials assessing structural outcomes in rheumatic diseases.

OBJECTIVE: To evaluate the methodologic quality of and identify methodologic issues in superiority trials assessing structural outcomes in rheumatic diseases. METHODS: We searched Medline and the Cochrane Central Register of Controlled Trials for reports of randomized controlled trials assessing structural outcomes in osteoarthritis (OA), rheumatoid arthritis (RA), and osteoporosis (OP) published between January 1994 and December 2003 in high-impact factor general medical and specialty journals. One reader extracted data (quality assessment, intent-to-treat analysis [ITT analysis], rate of missing data, and methods of handling missing data), using a standardized form. RESULTS: A total of 81 reports were included in the analysis (37 on OP, 34 on RA, and 10 on OA). The mean +/- SD methodologic quality scores on the Jadad scale (possible range 0-5) and the Delphi list (possible range 0-9) were 2.9 +/- 1.2 and 6.4 +/- 1.3, respectively. Although it was reported in 54 articles (66.7%) that the analysis was done on an ITT basis, full ITT analysis was performed in only 6 of the studies (7.4%), modified ITT analysis in 11 (13.6%), and case-complete analysis in 48 (59.3%); the analysis was unclear in 16 articles (19.8%). The rate of missing data on structural outcomes could be determined in only 63 articles (77.8%) and was >20% in approximately one-third of these reports. Methods for handling missing data on structural outcomes were described in 19 articles (23.5%) and were, in general, inappropriate. CONCLUSION: Lack of ITT analysis and a high rate of missing data in superiority trials assessing structural outcomes may bias results from such trials. Our recommendations for improving these shortcomings may help researchers plan, analyze, and report the results of such trials.

Arthritis, Rheumatoid↗
PubMed2005

Treatment of chronic hepatitis C in patients unresponsive to interferon. Interest of re-treatment combining interferon induction therapy and ribavirin (a multicenter pilot study).

AIM: About 45% of patients with chronic hepatitis C are unresponsive to the present reference treatment combining pegelated interferon plus ribavirin; before pegylated interferon was available the non-response rate was around 60%. This open multicenter pilot study, initiated before pegylated interferon became available, was designed to evaluate, in patients unresponsive to interferon monotherapy, the rate of biological and virological response and side-effects of the ribivirin-alpha 2b interferon combination. METHODS: The combination protocol was ribavirin (1 to 1.2 g/d) plus alpha 2b interferon at induction doses (9 MU/d the first week; 4.5 MU/d the eleven following weeks; 3 MU/2 days the 36 following weeks). RESULTS: Among the 27 included patients, 17 (63%) were viremia-negative (PCR) after 12 weeks of treatment, 9 (33%) were complete responders (undetectable viremia and normal transaminases) at the end of treatment (48 weeks) and of follow-up (72 weeks). Patients with non-1, non-4 genotypes who derived full benefit from this therapeutic strategy (6/7 (86%) were complete responders: 4/5 with genotype 3 and 2/2 with genotype 5). Quality-of-life was impaired during treatment, especially during the first 12 weeks of high-dose interferon therapy. CONCLUSION: While waiting for new therapeutic possibilities, these good results suggest interferon induction at the beginning of treatment remains a valid option.

Adult↗