Showing papers on "Subgroup analysis published in 2010"

Systematic review and meta-analysis of the efficacy of appropriate empiric antibiotic therapy for sepsis

Abstract: Quantifying the benefit of early antibiotic treatment is crucial for decision making and can be assessed only in observational studies. We performed a systematic review of prospective studies reporting the effect of appropriate empirical antibiotic treatment on all-cause mortality among adult inpatients with sepsis. Two reviewers independently extracted data. Risk of bias was assessed using the Newcastle-Ottawa score. We calculated unadjusted odds ratios (ORs) with 95% confidence intervals for each study and extracted adjusted ORs, with variance, methods, and covariates being used for adjustment. ORs were pooled using random-effects meta-analysis. We examined the effects of methodological and clinical confounders on results through subgroup analysis or mixed-effect meta-regression. Seventy studies were included, of which 48 provided an adjusted OR for inappropriate empirical antibiotic treatment. Inappropriate empirical antibiotic treatment was associated with significantly higher mortality in the unadjusted and adjusted comparisons, with considerable heterogeneity occurring in both analyses (I2 > 70%). Study design, time of mortality assessment, the reporting methods of the multivariable models, and the covariates used for adjustment were significantly associated with effect size. Septic shock was the only clinical variable significantly affecting results (it was associated with higher ORs). Studies adjusting for background conditions and sepsis severity reported a pooled adjusted OR of 1.60 (95% confidence interval = 1.37 to 1.86; 26 studies; number needed to treat to prevent one fatal outcome, 10 patients [95% confidence interval = 8 to 15]; I2 = 46.3%) given 34% mortality with inappropriate empirical treatment. Appropriate empirical antibiotic treatment is associated with a significant reduction in all-cause mortality. However, the methods used in the observational studies significantly affect the effect size reported. Methods of observational studies assessing the effects of antibiotic treatment should be improved and standardized.

Interferon Alpha Adjuvant Therapy in Patients With High-Risk Melanoma: A Systematic Review and Meta-analysis

Abstract: BACKGROUND Based on previous meta-analyses of randomized controlled trials (RCTs), the use of interferon alpha (IFN-alpha) in the adjuvant setting improves disease-free survival (DFS) in patients with high-risk cutaneous melanoma. However, RCTs have yielded conflicting data on the effect of IFN-alpha on overall survival (OS). METHODS We conducted a systematic review and meta-analysis to examine the effect of IFN-alpha on DFS and OS in patients with high-risk cutaneous melanoma. The systematic review was performed by searching MEDLINE, EMBASE, Cancerlit, Cochrane, ISI Web of Science, and ASCO databases. The meta-analysis was performed using time-to-event data from which hazard ratios (HRs) and 95% confidence intervals (CIs) of DFS and OS were estimated. Subgroup and meta-regression analyses to investigate the effect of dose and treatment duration were also performed. Statistical tests were two-sided. RESULTS The meta-analysis included 14 RCTs, published between 1990 and 2008, and involved 8122 patients, of which 4362 patients were allocated to the IFN-alpha arm. IFN-alpha alone was compared with observation in 12 of the 14 trials, and 17 comparisons (IFN-alpha vs comparator) were generated in total. IFN-alpha treatment was associated with a statistically significant improvement in DFS in 10 of the 17 comparisons (HR for disease recurrence = 0.82, 95% CI = 0.77 to 0.87; P < .001) and improved OS in four of the 14 comparisons (HR for death = 0.89, 95% CI = 0.83 to 0.96; P = .002). No between-study heterogeneity in either DFS or OS was observed. No optimal IFN-alpha dose and/or treatment duration or a subset of patients more responsive to adjuvant therapy was identified using subgroup analysis and meta-regression. CONCLUSION In patients with high-risk cutaneous melanoma, IFN-alpha adjuvant treatment showed statistically significant improvement in both DFS and OS.

interferon Alpha Adjuvant t herapy in Patients With High-r isk Melanoma: A Systematic r eview and Meta-analysis

Abstract: Background Based on previous meta-analyses of randomized controlled trials (RCTs), the use of interferon alpha (IFN-a) in the adjuvant setting improves disease-free survival (DFS) in patients with high-risk cutaneous melanoma. However, RCTs have yielded conflicting data on the effect of IFN-a on overall survival (OS). Methods We conducted a systematic review and meta-analysis to examine the effect of IFN-a on DFS and OS in patients with high-risk cutaneous melanoma. The systematic review was performed by searching MEDLINE, EMBASE, Cancerlit, Cochrane, ISI Web of Science, and ASCO databases. The meta-analysis was performed using time-toevent data from which hazard ratios (HRs) and 95% confidence intervals (CIs) of DFS and OS were estimated. Subgroup and meta-regression analyses to investigate the effect of dose and treatment duration were also performed. Statistical tests were two-sided. Results The meta-analysis included 14 RCTs, published between 1990 and 2008, and involved 8122 patients, of which 4362 patients were allocated to the IFN-a arm. IFN-a alone was compared with observation in 12 of the 14 trials, and 17 comparisons (IFN-a vs comparator) were generated in total. IFN-a treatment was associated with a statistically significant improvement in DFS in 10 of the 17 comparisons (HR for disease recurrence = 0.82, 95% CI = 0.77 to 0.87; P < .001) and improved OS in four of the 14 comparisons (HR for death = 0.89, 95% CI = 0.83 to 0.96; P = .002). No between-study heterogeneity in either DFS or OS was observed. No optimal IFN-a dose and/or treatment duration or a subset of patients more responsive to adjuvant therapy was identified using subgroup analysis and meta-regression. Conclusion In patients with high-risk cutaneous melanoma, IFN-a adjuvant treatment showed statistically significant im

A meta-analysis of the effect of neuromuscular training on the prevention of the anterior cruciate ligament injury in female athletes.

Abstract: Female athletes are more prone to anterior cruciate ligament (ACL) injury than their male counterparts, presumably because of anatomical, hormonal, and neuromuscular differences. Of these three, only the neuromuscular component can be modified by preventive exercise. We aimed to evaluate the effect of a neuromuscular protocol on the prevention of ACL injury by performing meta-analysis, and to identify essential factors by subgroup analysis. An extensive literature review was conducted to identify relevant studies, and eventually, only seven randomized controlled trials or prospective cohort studies were included in the analysis. The odds ratios (OR) and the confidence interval (CI) for the overall effects of training and of potentially contributory factors were estimated. The OR and the 95% CI for the overall effect of the preventive training were 0.40 and [0.27, 0.60], respectively. Subgroup analysis revealed that an age under 18, soccer rather than handball, pre- and in-season training rather than either pre- or in-season training, and the plyometrics and strengthening components rather than balancing were significant. Meta-analysis showed that pre- and in-season neuromuscular training with an emphasis on plyometrics and strengthening exercises was effective at preventing ACL injury in female athletes, especially in those under 18 years of age. Further study is required to develop a relevant training program protocol of appropriate intensity.

Comparison of two red-cell transfusion strategies after pediatric cardiac surgery: a subgroup analysis.

Abstract: Objective: To determine the impact of a restrictive vs. a liberal transfusion strategy on new or progressive multiple organ dysfunction syndrome in children post cardiac surgery. The optimal transfusion threshold after cardiac surgery in children is unknown. Design: Randomized, controlled trial. Setting: Tertiary pediatric intensive care units. Patients: Participants are a subgroup of pediatric patients post cardiac surgery from the TRIPICU (Transfusion Requirements in Pediatric Intensive Care Units) study. Exclusion criteria specific to the cardiac surgery subgroup included: age

The effect of intravenous opioid patient-controlled analgesia with and without background infusion on respiratory depression: A meta-analysis

Abstract: Background: Although the addition of a background infusion for intravenous patient-controlled analgesia (IV-PCA) has been identified as a risk factor for the development of respiratory depression, this has not clearly been examined in a systematic fashion. The authors undertook a systematic review and meta-analysis of available randomized controlled trials (RCTs) to examine whether the addition of a background or continuous infusion to an IV-PCA regimen would be associated with an increased risk of respiratory depression. Methods: Studies were identified by searching the National Library of Medicine’s PubMed database (1966 to November 30, 2008). Inclusion criteria were a clearly defined analgesic technique of demand-only IV-PCA versus IV-PCA utilizing both a demand dose and background infusion, opioid medication used, and randomized trials. Data were abstracted and analyzed with the RevMan 4.2.7 (The Cochrane Collaboration, 2004). Results: The search yielded 687 abstracts from which the original articles were obtained and data abstracted with a total of 14 articles analyzed. There were 402 subjects in the continuous IV-PCA with demand group versus the 394 subjects in the demand-only IV-PCA group. Addition of a background infusion to the demand dose for IV-PCA with opioids was associated with a significant increased risk for respiratory depression (odds ratio [OR] = 4.68, 95% confidence interval [CI]: 1.20-18.21). Subgroup analysis revealed that this increased risk was seen in adult but not in pediatric patients. Conclusions: Our meta-analysis indicates that the addition of a continuous or background infusion to the demand dose for IV-PCA is associated with a higher incidence of respiratory events than demand IV-PCA alone in adult but not in pediatric patients; however, our overall results should be interpreted with caution due to the relatively small sample size and the wide range of definitions for respiratory depression in studies examined.

Follow-up disparities after trauma: a real problem for outcomes research

Abstract: Introduction The objectives of this study were to (1) determine risk factors associated with failure to follow-up (FTF) after traumatic injury and (2) in those patients who do follow up, to determine if information within the electronic medical record (EMR) is an adequate data-collection tool for outcomes research. Methods A 6-year retrospective analysis was conducted on all admitted trauma patients using data from the trauma registry, National Death Index, 2000 Census Data, and the EMR. Bivariate and logistic regression analyses identified risk factors for FTF. A subgroup analysis evaluated the utility of using the EMR to determine basic functional outcomes (Glasgow outcome scale, diet, ambulation, and employment status). Results A total of 14,784 patients were discharged, and 61% had follow-up appointments. Lower income, higher poverty rates, and lower education were significantly (P < .05) associated with FTF. Logistic regression analysis (excluding census data) identified that older age, lower Injury Severity Score, less severe head injury, nonwhite race, blunt injury, death after discharge, zip code within 25 miles, and patients discharged to home independently predicted FTF after traumatic injury. A subgroup analysis of the EMR showed the inability to reliably determine functional outcomes. Conclusions There are several disparities related to follow-up after trauma. Furthermore, charting deficiencies, even with an EMR, highlight the weaknesses of data available for trauma outcomes research. Trauma process improvement programs could target patients at risk for not following up and use a structured electronic outpatient note.

Long-term antibiotics for the prevention of recurrent urinary tract infection in children: a systematic review and meta-analysis

Abstract: Objective To evaluate the effectiveness and safety of long-term prophylactic antibiotics for recurrent urinary tract infection (UTI) in children through meta-analysis of randomised controlled trials. Methods Electronic databases and reference lists of review articles were searched for relevant trials. Outcome measures were recurrence of symptomatic UTI, repeat positive urine culture, new or deteriorated renal scarring and adverse events during and after treatment. Results Eleven trials with 2046 patients were identified. Analysis suggested rates of recurrent symptomatic UTI were not significantly different between antibiotic (12.4%) and control groups (15.5%) (RR 0.83, 95% CI 0.66 to 1.05). Subsequent sensitivity and subgroup analyses according to patient vesicoureteric reflux (VUR) status, patient characteristics, history of UTI, site of UTI and duration of treatment also produced no significant effect. However, when trials were divided by study quality, only in trials with adequate allocation concealment was recurrent symptomatic UTI reduced by antibiotic prophylaxis. Prophylactic antibiotics reduced the risk of repeat positive urine culture (RR 0.50, 95% CI 0.34 to 0.74). A subgroup analysis limited to patients without VUR showed similar results (0.52, 0.33 to 0.83), whereas patients with VUR showed a non-significant decrease (0.82, 0.61 to 1.09) in risk of repeat positive urine culture. Seven studies reported the rate of new or deteriorated renal scars and showed no significant difference (0.95, 0.51 to 1.78). Conclusions Evidence is lacking that prophylactic antibiotics reduce the incidence of recurrent childhood UTI. Since the reviewed studies had limitations in methodological design, large scale, high quality, placebo-controlled, double-blind trials are required.

Outcome Evaluation of the Veterans Affairs Salt Lake City Integrative Health Clinic for Chronic Pain and Stress-Related Depression, Anxiety, and Post-Traumatic Stress Disorder

Abstract: Objectives: The purpose of this longitudinal outcome research study was to determine the effectiveness of the Integrative Health Clinic and Program (IHCP) and to perform a subgroup analysis investigating patient benefit. The IHCP is an innovative clinical service within the Veterans Affairs Health Care System designed for nonpharmacologic biopsychosocial management of chronic nonmalignant pain and stress-related depression, anxiety, and symptoms of post-traumatic stress disorder (PTSD) utilizing complementary and alternative medicine and mind–body skills. Methods: A post-hoc quasi-experimental design was used and combined with subgroup analysis to determine who benefited the most from the program. Data were collected at intake and up to four follow-up visits over a 2-year time period. Hierarchical linear modeling was used for the statistical analysis. The outcome measures included: Health-Related Quality of Life (SF-36), the Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI). Subgr...

Chest compressions before defibrillation for out-of-hospital cardiac arrest: A meta-analysis of randomized controlled clinical trials

Abstract: Current 2005 guidelines for advanced cardiac life support strongly recommend immediate defibrillation for out-of-hospital cardiac arrest. However, findings from experimental and clinical studies have indicated a potential advantage of pretreatment with chest compression-only cardiopulmonary resuscitation (CPR) prior to defibrillation in improving outcomes. The aim of this meta-analysis is to evaluate the beneficial effect of chest compression-first versus defibrillation-first on survival in patients with out-of-hospital cardiac arrest. Main outcome measures were survival to hospital discharge (primary endpoint), return of spontaneous circulation (ROSC), neurologic outcome and long-term survival. Randomized, controlled clinical trials that were published between January 1, 1950, and June 19, 2010, were identified by a computerized search using SCOPUS, MEDLINE, BIOS, EMBASE, the Cochrane Central Register of Controlled Trials, International Pharmaceutical Abstracts database, and Web of Science and supplemented by conference proceedings. Random effects models were used to calculate pooled odds ratios (ORs). A subgroup analysis was conducted to explore the effects of response interval greater than 5 min on outcomes. A total of four trials enrolling 1503 subjects were integrated into this analysis. No difference was found between chest compression-first versus defibrillation-first in the rate of return of spontaneous circulation (OR 1.01 [0.82-1.26]; P = 0.979), survival to hospital discharge (OR 1.10 [0.70-1.70]; P = 0.686) or favorable neurologic outcomes (OR 1.02 [0.31-3.38]; P = 0.979). For 1-year survival, however, the OR point estimates favored chest compression first (OR 1.38 [0.95-2.02]; P = 0.092) but the 95% CI crossed 1.0, suggesting insufficient estimate precision. Similarly, for cases with prolonged response times (> 5 min) point estimates pointed toward superiority of chest compression first (OR 1.45 [0.66-3.20]; P = 0.353), but the 95% CI again crossed 1.0. Current evidence does not support the notion that chest compression first prior to defibrillation improves the outcome of patients in out-of-hospital cardiac arrest. It appears that both treatments are equivalent. However, subgroup analyses indicate that chest compression first may be beneficial for cardiac arrests with a prolonged response time.

Effect of Combined Aspirin and Extended-Release Dipyridamole Versus Clopidogrel on Functional Outcome and Recurrence in Acute, Mild Ischemic Stroke PRoFESS Subgroup Analysis

Abstract: Background and Purpose— Long-term antiplatelet therapy is effective at reducing recurrence after ischemic stroke. However, the relative safety and efficacy of combined aspirin-dipyridamole or clopidogrel are not known in patients with acute ischemic stroke. Methods— The factorial PRoFESS secondary prevention trial assessed antiplatelet and blood pressure–lowering strategies in 20 332 patients, 1360 of whom were randomized within 72 hours of ischemic stroke to combined aspirin (Asp; 25 mg BID) and extended-release dipyridamole (ER-DP; 200 mg BID, n=672) or clopidogrel (75 mg/d, n=688). The primary outcome for this post hoc subgroup analysis was functional outcome at 30 days; secondary outcomes included recurrence and death by 90 days. Analyses were adjusted for baseline prognostic variables and blood pressure treatment assignment. Results— Patients were representative of the whole trial (age 67 years, National Institutes of Health Stroke Scale score 3, small-artery occlusion 59%), and baseline variables we...

Evidence-based urology in practice: when to believe a subgroup analysis?

Abstract: Shian-Shiang Wang* † , Yen-Chuan Ou*, Chen-Li Cheng* and Philipp Dahm ‡ for the Evidence Based Urology Working Group *Division of Urology, Department of Surgery, Taichung Veterans General Hospital, † Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan, and ‡ Department of Urology, University of Florida, College of Medicine, Gainesville, FL, USA Accepted for publication 28 July 2009

Atorvastatin in stroke: a review of SPARCL and subgroup analysis.

Abstract: Statin therapy in patients with cardiovascular disease is associated with reduced incidence of stroke. The Stroke Prevention by Aggressive Reduction of Cholesterol Levels (SPARCL) trial showed daily treatment with 80 mg of atorvastatin in patients with a recent stroke or transient ischemic attack (TIA) reduced the incidence of fatal or nonfatal stroke by 16%. Several post hoc analyses of different subgroups followed the SPARCL study. They have not revealed any significant differences when patients were sorted by age, sex, presence of carotid disease or type of stroke, with the exception of intracranial hemorrhage as the entry event. Lower low-density lipoprotein cholesterol levels in addition to possible neuroprotective mechanisms due to atorvastatin treatment correlate with improved risk reduction. Although not predefined subgroups and subject to an insufficient power, these post hoc studies have generated new clinical questions. However, clinicians should avoid denying therapy based on such subgroup analysis. At this point, the best evidence powerfully demonstrates stroke and TIA patients should be prescribed high dose statin therapy for secondary stroke prevention.

Glutathione S-transferase M1 polymorphism and breast cancer susceptibility: a meta-analysis involving 46,281 subjects.

Abstract: Published data on the association between present/null polymorphism of glutathione S-transferase M1 (GSTM1) and breast cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Medline, PubMed, Embase, and Web of Science were searched. Crude ORs with 95% CIs were used to assess the strength of association between the GSTM1 present/null polymorphism and breast cancer risk. The pooled ORs were performed for null versus present genotype. A total of 59 studies including 20,993 cases and 25,288 controls were involved in this meta-analysis. Overall, significantly elevated breast cancer risk was associated with null genotype when all studies were pooled into the meta-analysis (OR = 1.10, 95% CI = 1.04-1.16). In the subgroup analysis by ethnicity, significantly increased risks were found for Caucasians (OR = 1.05, 95% CI = 1.00-1.10) and Asians (OR = 1.21, 95% CI = 1.08-1.35). When stratified by population-based studies or hospital-based studies, statistically significantly elevated risks were found among population-based studies (OR = 1.11, 95% CI = 1.03-1.20). In the subgroup analysis by menopausal status, statistically significantly increased risks were found among postmenopausal women (OR = 1.15, 95% CI = 1.04-1.28). In conclusion, this meta-analysis suggests that the GSTM1 null genotype is a low-penetrant risk factor for developing breast cancer.

Gemcitabine-based cytotoxic doublets chemotherapy for advanced pancreatic cancer: updated subgroup meta-analyses of overall survival

Abstract: Objective: Previous meta-analyses showed a survival advantage with gemcitabine (GEM)-based combinations over GEM in advanced pancreatic cancer. Therefore, it would be valuable to explore the specific active regimens based on a subgroup meta-analysis. Methods: Updated data by comprehensive search of the literature from databases and conference proceedings. Subgroup meta-analysis compared GEM with GEM-based doublets chemotherapy in terms of 6-month overall survival (OS) and 1-year OS. Results: Eighteen randomized controlled trials with 4237 patients were included, which were divided into five subgroups: GEM/capecitabine, GEM/cisplatin, GEM/5-fluorouracil, GEM/irinotecan and GEM/oxaliplatin. In each subgroup, risk ratios (RRs) for 6-month OS were 0.85 (P = 0.04), 0.99 (P= 0.88), 0.95 (P= 0.46), 1.03 (P = 0.77) and 0.80 (P = 0.001), respectively, and RRs for 1-year OS were 0.94 (P= 0 . 14), 0.99 (P = 0.75), 0.96 (P= 0.19), 1.00 (P= 0.97) and 0.93 (P = 0.05), respectively. A meta-analysis of the trials with adequate information on performance status (PS) was performed in four trials with 1325 patients. Patients with a good PS did not show a survival benefit when receiving combination chemotherapy. RRs for 6-month and 1-year OS were 0.82 (P= 0.18) and 0.93 (P= 0.08). In contrast, application of combination chemotherapy to patients with a poor PS appeared to be harmful. RRs were 1.17 (P = 0.04) for 6-month OS and 1.09 (P = 0.04) for 1-year OS. Conclusions: The meta-analysis indicated a significant survival benefit when GEM was either combined with capcitabine or oxaliplatin. On the basis of a preliminary subgroup analysis, pancreatic cancer patients with a poor PS appeared to have a worse survival benefit from GEM-based cytotoxic doublets.

Strengthening Unmarried Parents' Relationships: The Early Impacts of Building Strong Families, Technical Supplement

Abstract: This technical supplement provides additional detail about research design, analytic methods, variable construction used for the 15-month analysis, and discussion of subgroup analysis. It also includes additional impact results not presented in the main report.

Factors associated with nonresponse to a computer-tailored asthma management program for urban adolescents with asthma.

Abstract: Background. The ability to identify potentially resistant participants early in the course of an intervention could inform development of strategies for behavior change and improve program effectiveness. Objective. The objective of this analysis was to identify factors related to nonresponse (i.e., lack of behavior change) to an asthma management intervention for urban teenagers. The intervention targeted several behaviors, including medication adherence, having a rescue inhaler nearby, and smoking. Methods. A discriminate analysis was conducted using data from a randomized trial of the intervention. Included in this analysis are participants who reported a physician diagnosis of asthma, completed a baseline questionnaire, were randomized to the treatment group, completed ≥2 of 4 educational sessions, and completed ≥2 of 3 follow-up questionnaires. Ninety students met criteria for inclusion in this subgroup analysis. Results. In logistic regression models for medication adherence, nonresponse was related ...

Discrepancy of the Effects of Zinc Supplementation on the Prevention of Radiotherapy-Induced Mucositis Between Patients With Nasopharyngeal Carcinoma and Those With Oral Cancers: Subgroup Analysis of a Double-Blind, Randomized Study

Abstract: The purpose of this study was to determine the effect of zinc supplementation on radiation-induced mucositis in patients with nasopharyngeal carcinoma (NPC) and those with oral cancers (OC). A total of 100 patients with head and neck cancers engaged in a randomized double blind study. All participants were placed into two randomized groups (experimental and control). The experimental group received a standard dose of zinc supplements, and the control group was given a placebo. Subgroup analyses were performed between 40 NPC and 43 OC patients. It was found that patients with OC in the control group developed Grade 2 and Grade 3 mucositis sooner than those in the experimental group. However, the benefits were not found to extend to patients with NPC. The results indicated that zinc supplementation prescribed in conjunction with radiotherapy postponed the development of severe mucositis solely for patients with OC. The pretreatment oral mucosa condition and areca chewing habit might account for such discrepancy.

No Higher Risk of CRPS After External Fixation of Distal Radial Fractures - Subgroup Analysis Under Randomised Vitamin C Prophylaxis § ~!2009-11-13~!2010-01-01~!2010-02-17~!

Abstract: Operative and conservative treatment of wrist fractures might lead to complex regional pain syndrome (CRPS) type I. In our multicenter dose response study in which patients with distal radial fractures were randomly allocated to placebo or vitamin C in a daily dose of 200mg, 500mg or 1500mg during 50 days, an operated subgroup was analyzed. 48 (of 427) fractures) were operated (11.2%). Twenty-nine patients (60%) were treated with external fixation, 14 patients (29%) with K-wiring according to Kapandji and five patients (10%) with internal plate fixation. The 379 remaining patients were treated with a plaster. In the operated group of patients who received vitamin C no CRPS (0/37) was seen in comparison with one case of CRPS (Kapandji technique) in the operated group who received placebo (1/11 = 9%, p=.23). There was no CRPS after external fixation. In the conservatively treated group 17 cases of CRPS (17/379 = 4.5%) occurred in comparison with one in case of CRPS in the operated group (1/48 = 2.1%, p=.71). External fixation doesn’t necessarily lead to a higher incidence of CRPS in distal radial fractures. Vitamin C may also play a role in this. This subgroup analysis in operated distal radial fractures showed no CRPS occurrence with vitamin C prophylaxis.

Factors influencing the association between CYP17 T34C polymorphism and the risk of breast cancer: meta-regression and subgroup analysis.

Abstract: A number of studies have been investigated the association between CYP17 T34C polymorphism and the risk of breast cancer; the results of these studies are inconsistent, however. This fact implies that the effect of CYP17 T34C polymorphism on susceptibility to breast cancer may be modified by other risk factors. In order to provide a more definitive conclusion, a full meta-analysis combining and summarizing 24 studies was first performed. Both traditional method and Bayesian approach were applied. Odds ratio was estimated using a dominant mode of inheritance after a biological justification for the choice of genetic model. The results of homogeneity analysis (H = 1.16, I 2 = 25.4%, and P = 0.127) suggested the presence of heterogeneity across the studies. Thus, random effects models simulated by the DerSimonian–Laird method were employed. The capability of a Bayesian approach was highlighted in the estimation of a pooled odds ratio and 95% confidence interval. The results of meta-analysis (OR = 1.001, CI = 0.832–1.208) suggest no significant association in the combined populations. Furthermore, Bayesian meta-regression and subgroup analysis were conducted to investigate the sources of heterogeneity. The risk factors evaluated in the study were menopausal status, ethnicity, age at menarche, age at first birth, parity, use of oral contraceptives, body mass index (BMI), and use of hormone repair therapy (HRT). After these population stratifications, there was evidence indicating that a possible impact of menopausal status, age at menarche, and BMI on the association between CYP17 T34C polymorphism and the risk of breast cancer.