Medical Research Journals

Anita P. Courcoulas M.D., M.P.H., F.A.C.S Professor of Surgery Director, Minimally Invasive Bariatric & General Surgery University of Pittsburgh Medical Center MedicalResearch.com Interview with:  Anita P. Courcoulas M.D., M.P.H., F.A.C.S Professor of Surgery Director, Minimally Invasive Bariatric & General Surgery University of Pittsburgh Medical Center Medical Research: What are the main findings of the study? Dr. Courcoulas: This paper was not a study but a summary of findings from a multidisciplinary workshop (and not a consensus panel) convened in May 2013 by the National Institute of Diabetes and Digestive and Kidney Diseases and the National Heart, Lung, and Blood Institute. The goal of the workshop was to summarize the current state of knowledge of bariatric surgery, review research findings on the long-term outcomes of bariatric surgery, and establish priorities for future research.

Dr. Jeff Peipert MD, PhD Institute for Public Health Robert J. Terry Professor, Department of Obstetrics & Gynecology, School of Medicine Washington University in St. LouisMedicalResearch.com Interview with: Dr. Jeff Peipert MD, PhD Institute for Public Health Robert J. Terry Professor, Department of Obstetrics & Gynecology, School of Medicine Washington University in St. Louis Medical Research: What are the main findings of this study? Dr. Peipert: In the Contraceptive CHOICE Project, over 70% of teenage girls and women who were provided no-cost contraception and were educated about the effectiveness and benefits of long-acting reversible contraceptive (LARC) methods selected the intrauterine device (IUD) or contraceptive implant.  This group of over 1400 young women aged 15-19 years had rates of pregnancy, birth, and abortion that were far below national rates for sexually experienced teens.

Matthew B. Schabath, Ph.D Assistant Member, Department of Cancer Epidemiology  Moffitt Cancer Center Tampa, Florida MedicalResearch.com: Interview with: Matthew B. Schabath, Ph.D Assistant Member, Department of Cancer Epidemiology Moffitt Cancer Center Tampa, Florida   Medical Research: What are the main findings of the study? Dr. Schabath: Overall, the results from these analyses demonstrated that men who consumed the highest amounts of alcohol were associated with an increased risk for genital human papillomavirus (HPV) infections.

Dr Nita Forouhi Lead Scientist and Programme Leader MRC Epidemiology Unit University of Cambridge School of Clinical MedicineMedicalResearch.com Interview with: Dr Nita Forouhi, MRCP, PhD, FFPHM Lead Scientist and Programme Leader MRC Programme Leader and Consultant Public Health Physician MRC Epidemiology Unit University of Cambridge School of Clinical Medicine Cambridge Biomedical Campus Cambridge, UK Medical Research: What are the main findings of the study? Dr. Forouhi: This large study found that low blood concentrations of 25-hydroxyvitamin D [25(OH)D], a clinical indicator of vitamin D status, were associated with an increased risk of type 2 diabetes, but this did not appear to be a cause-effect relationship. To investigate these associations, we did two things. We first did a systematic review and meta-analysis across 22 published studies and confirmed that there was a strong inverse relation between vitamin D levels and the risk of future new-onset type 2 diabetes among people who did not initially have diabetes. We then used a genetic approach, called Mendelian randomisation, which allows us to test a cause-effect relationship, and found that genetically lower vitamin D levels were not related to risk of type 2 diabetes. This means that we were able to distinguish between association and causation, and concluded that the vitamin D levels did not have a causal link with type 2 diabetes.

MedicalResearch.com Interview with: Dr. Anil Nigam MD MSc FRCPC Director, Research Program in Preventive Cardiology at ÉPIC Centre Montreal Heart Institute Associate Professor, Department of Medicine at Université de MontréalMedicalResearch.com Interview with: Dr. Anil Nigam MD MSc FRCPC Director, Research Program in Preventive Cardiology at ÉPIC Centre Montreal Heart Institute Associate Professor, Department of Medicine at Université de Montréal Medical Research: What are the main findings of the study? Dr. Nigam: The main finding is that high-dose fish oil rich in marine omega-3 fatty acids did not reduce recurrence of atrial fibrillation in individuals with paroxysmal or persistent atrial fibrillation not receiving conventional anti-arrhythmic therapy.

MedicalResearch.com Interview with: Dr. Raul Santos Unidade Clínica de Lipides InCor-HCFMUSP Sao Paulo, Brazil. Medical Research: What are the main findings of the study? Dr. Santos: Evolocumab 420 mg injected subcutaneously every 4 weeks reduced LDL-C by 31% on average, in relation to placebo, in Homozygous familial hypercholesterolemia patients that were using maximally tolerated lipid lowering therapy but not on lipid apheresis regimen. Patients were separated according to the type of LDL receptor mutation, those with at least one allele codifyng a defective mutation on the LDL receptor (residual receptor activity 2-25%) had on average a 41% reduction on LDL-cholesterol. The 2 patients  homozygotes with alleles that codify a null mutation )receptor activity < 2%), did not respond to treatment. This was expected since PCSK9 inhibitors need a functional LDL receptor do work. Basically they increase the expression of the receptor that facilitates the clearance from plasma of circulating LDL particles. In those patients with defective LDL receptor  mutations there was 24% reduction of lipoprotein(a) concentrations, an extra risk factor for cardiovascular disease in familial hypercholesterolemia patients.

Professor F. J. Raal FRCP, FRCPC, FCP(SA), Cert Endo, MMED, PhD Director, Carbohydrate & Lipid Metabolism Research Unit Professor & Head, Division of Endocrinology & Metabolism Faculty of Health Sciences, University of the Witwatersrand Johannesburg Hospital Johannesburg South AfricaMedicalResearch.com Interview with: Professor F. J. Raal FRCP, FRCPC, FCP(SA), Cert Endo, MMED, PhD Director, Carbohydrate & Lipid Metabolism Research Unit Professor & Head, Division of Endocrinology & Metabolism Faculty of Health Sciences, University of the Witwatersrand Johannesburg Hospital Johannesburg South Africa Medical Research: What are the main findings of the study? Dr. Raal: Heterozygous familial hypercholesterolaemia (HeFH)  is one of the most common inherited disorder in man affects between 1:250 to 1:300 persons worldwide. Thus, there are likely more than 3 million patients with heterozygous familial hypercholesterolaemia in the United States and Europe alone. The RUTHERFORD-2 study was a large world-wide multinational study  of the use of the PCSK9-inhibitor, evolocumab, in over 300 patients with heterozygous familial hypercholesterolaemia (HeFH). Evolocumab administered either 140 mg biweekly or 420 mg monthly as a subcutaneous injection, much like an insulin injection, was well tolerated with minimal side effects,  and markedly reduced levels of LDL cholesterol or “bad cholesterol”  by over 60% compared to placebo.

Dr. David Gerber MD Associate Professor of Internal Medicine Division of Hematology and Oncology Harold C. Simmons Cancer Center at UT Southwestern Medical CenterMedicalResearch.com Interview with: Dr. David Gerber MD Associate Professor of Internal Medicine Division of Hematology and Oncology Harold C. Simmons Cancer Center at UT Southwestern Medical Center Medical Research: What are the main findings of the study? Dr. Gerber: Fewer than 3% of adult cancer patients in the United States are enrolled in clinical trials.  Increasingly numerous and stringent eligibility criteria are a major factor limiting participation in clinical trials.  We examined the longstanding and widespread practice of excluding patients with prior cancer from oncology clinical trials.  This policy presumably reflects concerns that a prior cancer would interfere with the conduct, outcomes, or interpretation of a clinical trial, although there is no clear evidence supporting that assumption. We examined more than 50 National Cancer Institute (NCI)-sponsored lung cancer clinical trials.  We found that 80% excluded patients with prior cancers.  This exclusion criterion was applied broadly, including to more than two-thirds of trials with non-survival endpoints.  We then examined national Surveillance Epidemiology and End Results (SEER)-Medicare linked data to estimate the proportion of patients who would be excluded from these trials due to prior cancer.  We found that up to 18% of potential patients are excluded for this reason alone.  In large phase 3 clinical trials, that corresponds to more than 200 patients.

MedicalResearch.com Interview with: Joanna Chikwe MD Associate Professor Department of Cardiovascular Surgery Mount Sinai Medical Center and Natalia N. Egorova, PhD Department of Health Evidence and Policy, Icahn School of Medicine at Mount Sinai New York, New York Medical Research: What are the main findings of the study? Answer: This is one of the largest studies to date on the long-term outcomes of patients after aortic valve replacement. We found that bioprosthetic valves are as safe as mechanical valves in younger patients (age 50-69) - specifically, long-term death rates and stroke risk were very similar in patients who had either valve type. The main differences lay in the risk of other long-term complications: patients who had bioprosthetic valves were more likely to need repeat surgery in the long-term, whereas patients who had mechanical valves were more likely to experience a major bleeding event.

Dr. Yann C Klimentidis, PhD Assistant professor of Epidemiology and Biostatistics Mel and Enid Zuckerman College of Public Health University of Arizona Medical CenterMedicalResearch.com Interview Invitation with: Dr. Yann C Klimentidis, PhD Assistant professor of Epidemiology and Biostatistics Mel and Enid Zuckerman College of Public Health University of Arizona Medical Center   Medical Research: What are the main findings of the study? Dr. Klimentidis: The main finding is that the association of physical activity with type-2 diabetes risk is weakest among those who are at high genetic risk for type-2 diabetes. Furthermore, we find that this trend is stronger among women as compared to men, and that it appears to be driven mainly by genetic risk to insulin resistance, as opposed to genetic risk for reduced beta-cell function.

Karin Amrein, MD, MSc Assistant Professor Department of Internal Medicine Division of Endocrinology and Metabolism Medical University of Graz 8036 Graz, AustriaMedicalResearch.com Interview with: Karin Amrein, MD, MSc Assistant Professor Department of Internal Medicine Division of Endocrinology and Metabolism Medical University of Graz 8036 Graz, Austria Medical Research: What are the main findings of the study? Dr. Amrein: This is the first large clinical trial on vitamin D in critical care. In a double-blind, randomized, placebo-controlled clinical trial, a population of mixed adult ICU patients with vitamin D deficiency (defined as 25-hydroxyvitamin D [25(OH)D] level ≤ 20ng/ml) was assigned to receive either vitamin D3 or placebo. We used a high loading dose of vitamin D3 followed by monthly maintenance doses of 90,000 IU for a total of 5 months. Because of a substantially increased risk for skeletal complications below 12ng/ml of 25-hydroxyvitamin D, we used this threshold for a predefined subgroup analysis. Overall, high-dose vitamin D3 compared with placebo did not reduce hospital length of stay (primary endpoint), intensive care unit (ICU) length of stay, hospital mortality, or 6 month-mortality

MedicalResearch.com Interview with: Ben Metcalf BsC (co-author) on behalf or A/Prof Rana Hinman PhD Centre for Health, Exercise and Sports Medicine, Department of Physiotherapy, School of Health Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Australia Medical Research: What are the main findings of the study? Dr. Metcalf: This study investigated whether acupuncture is an effective treatment for people aged more than 50 years with chronic knee pain. Participants in our study were randomly assigned to one of four groups; needle acupuncture, laser acupuncture, sham laser acupuncture or no treatment. The people in the treatment groups received acupuncture treatment from a family physician for 12 weeks. Participants were assessed after treatment and again after one year. There were no significant differences in knee pain or physical function between active and sham laser acupuncture at 12 weeks or at one year. Both needle and laser acupuncture resulted in modest improvements in pain compared with no treatment at 12 weeks that were not maintained at one year. Needle acupuncture improved physical function at 12 weeks compared with no treatment but was not different from sham acupuncture and was not maintained at one year.

Megan A. Adams, MD Gastroenterology Fellow University of MichiganMedicalResearch.com Interview with Megan A. Adams, MD Gastroenterology Fellow University of Michigan   Medical Research: What are the main findings of the study? Dr. Adams: Surveys of doctors indicate that their fear of a malpractice lawsuit for missing a diagnosis of esophageal cancer might drive the overuse of tests called upper endoscopies in patients who are at low risk for the cancer. To examine whether this perception of medical liability risk accurately reflects the real likelihood of a malpractice claim, we looked at a national database of malpractice claims, and compared the rate of claims for delay in diagnosis of esophageal cancer in patients without alarm symptoms (weight loss, dysphagia, iron deficiency anemia), with the rate of claims alleging performance of an upper endoscopy without a good reason for performing the procedure. The database contained 278,220 claims filed against physicians in 1985-2012. The incidence of reported medical liability claims for failure to screen for esophageal cancer in patients without alarm features was quite low (19 claims in 11 years, 4 paid). In contrast, there were 17 claims in 28 years for complications of upper endoscopies with questionable indication (8 paid).

MedicalResearch.com Interview with: Marwan Badri MBChB, MRCP Cardiovascular disease fellow Lankenau Medical Center Wynnewood Pa Medical Research : What is the background for this study? Dr. Badri: Recent years witnessed increased emphasis of the role of clinical guidelines in cardiovascular care. Physicians are encouraged to practice within the framework of major society guidelines to deliver better, more cost-effective patient care. It is therefore vital that the recommendations in these guidelines are applicable to most of the patient population. Since some clinical trials have been shown in the past to unfavorably exclude women, racial minorities and elderly patients, we conducted this study to see if the clinical trials used to form the American College of Cardiology/American Heart Association adequately represent these patient groups.

Georgina Long BSc PhD MBBS FRACP Associate Professor of Melanoma Biology and Translational Research Melanoma Institute Australia and the University of Sydney MedicalResearch.com Interview with: Georgina Long BSc PhD MBBS FRACP Associate Professor of Melanoma Biology and Translational Research Melanoma Institute Australia and the University of Sydney Medical Research: Could you provide some background on this project? Why did you decide to do this research project? What prior work led up to this latest paper? Dr. Long: Pre-clinically, we had data that showed that the combination of BRAF inhibitor + MEK inhibitor
  • Decreased skin proliferative toxicity seen with BRAF inhibitors alone (seen as hyperproliferative lesions in rats)
  • and delayed the emergence of resistance I.e. The tumours in the mice reduced in size more, and stayed reduced for longer.We then confirmed this concept in a randomised phase 2 study, although it was not powered for a definitive progression free survival (PFS_ difference like a phase 3 trial is, we saw a strong difference in response rate and in PFS, yet there were only 54 patients per arm.

dr_iffat_rahmanMedicalResearch.com Interview Invitation with: Dr. Iffat Rahman Ph.D. Unit of Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Box 210, 17177 Stockholm, Sweden Medical Research: What are the main findings of the study? Dr. Rahman: Our study suggests that moderate to high level of physical activity could protect against heart failure in women.

MedicalResearch.com Interview with: Professor Usha Menon,  Evangelia-Ourania Fourkala PhD and Matthew Burrell PhD Gynaecological Cancer Research Centre, Women's Cancer, UCL EGA Institute for Women's Health, University College London, UK Medical Research: What are the main findings of the study? Response: Our study has shown that skirt size is a good proxy for central obesity. Each unit increase in UK skirt size every ten years between the age of 20 and 60 was associated with a 33% increase in postmenopausal breast cancer in our cohort.

MedicalResearch.com Interview with: Prof. Dr. med. Alain Nordmann Innere Medizin FMH Basel, Switzerland Medical Research: What are the main findings of the study? Dr. Nordmann: Based on available randomised controlled trials, garlic preparations seem to lower blood pressure in individuals with hypertension in the short term. However, the quality of the studies and the lack of long-term data preclude the routine use of garlic preparations to lower blood pressure in individuals qualifying for antihypertensive drug therapy.

MedicalResearch.com Interview with: Katharina Mayer MD Deutsches Herzzentrum München, Technische Universität München, Munich, Germany Medical Research: What are the main findings of the study? Dr. Mayer: Patients whose platelets do not respond well to aspirin carry a higher risk of death or stent thrombosis. Platelet response to aspirin is an independent predictor of ischemic events in patients undergoing percutaneous coronary interventions (PCI).

Stewart Agras, M.D. Professor of Psychiatry Emeritus Stanford University School of MedicineMedicalResearch.com Interview with: Stewart Agras, M.D. Professor of Psychiatry Emeritus Stanford University School of Medicine MedicalResearch: What was the study about? Dr. Agras: Family-based treatment (FBT) has been shown to be more effective than individual psychotherapy for the treatment of adolescent anorexia nervosa. This treatment focuses on helping the family to re-feed their child. The question posed in this study was whether Family-based treatment would have any advantages over Systemic family therapy (SyFT) focusing on family interactions that may affect the maintenance of the disorder. The participants were 164 adolescents with anorexia nervosa and their families – one of the largest studies of its type.

Dr. Song Hee Hong PhD Associate Professor, Health Outcomes and Policy Research Dept. Clinical Pharmacy University of Tennessee Health Science Center Memphis, TN 38163MedicalResearch.com Interview with: Dr. Song Hee Hong PhD Associate Professor, Health Outcomes and Policy Research Dept. Clinical Pharmacy University of Tennessee Health Science Center Memphis, TN 38163 Medical Research: What are the main findings of the study? Dr. Hong: Use of GDDP (generic drug discount programs) increased to 23.1% in 2010 from 3.6% of patients receiving any prescription drugs in 2007. Generic drug discount programs were more valued among the elderly, sicker and uninsured populations. The lower use of Generic drug discount programs among racial/ethnic minorities observed when the program was deployed no longer existed when the program matured.

MedicalResearch.com Interview with: Dr. MichaelD. Keall PhD Otago University, Wellington, New Zealand Medical Research: What are the main findings of the study? Dr. Keall: We found that home injuries from falls could be reduced by 26% by making some simple modifications to people’s homes, consisting of handrails for steps and stairs, grab rails for bathrooms, outside lighting, edging for outside steps and slip-resistant surfacing for outside surfaces such as decks and porches.

Prof Mika Kivimäki PhD Department of Epidemiology and Public Health, University College London, London, UK Hjelt Institute, Medical Faculty, University of Helsinki, Helsinki, FinlandMedicalResearch.com Interview with: Prof Mika Kivimäki PhD Department of Epidemiology and Public Health, University College London, London, UK Hjelt Institute, Medical Faculty, University of Helsinki, Helsinki, Finland Medical Research: What are the main findings of the study? Prof. Kivimäki: In our study, we pooled published and unpublished data from 222 120 men and women from the USA, Europe, Japan, and Australia. Of them, 4963 individuals developed type 2 diabetes during the mean follow-up of 7.6 years. This is the largest study to date on this topic. In an analysis stratified by socioeconomic status, the association between long working hours and diabetes was evident in the low socioeconomic status group, but was null in the high socioeconomic status group. The association in the low socioeconomic status group did not change after taking into account age, sex, obesity, physical activity, and shift working. So, the association was very robust. In brief, the main finding of our meta-analysis is that the link between longer working hours and type 2 diabetes was apparent only in individuals in the low socioeconomic status groups.

Jerry D. Estep, M.D., FACC Assistant Professor of Medicine, Weill Cornell Medical College Medical Director, Heart Transplant & LVAD Program Methodist DeBakey Heart & Vascular Center Houston Methodist HospitalMedicalResearch.com Interview with: Jerry D. Estep, M.D., FACC Assistant Professor of Medicine, Weill Cornell Medical College Medical Director, Heart Transplant & LVAD Program Methodist DeBakey Heart & Vascular Center Houston Methodist Hospital Medical Research: What are the main findings of the study? Dr. Estep: There were two major findings: 1-Non-invasive Doppler echocardiographic and invasive measures of mean right atrial pressure (RAP) (r = 0.863; p < 0.0001), systolic pulmonary artery pressure (sPAP) (r=0.880; p<0.0001), right ventricular outflow tract stroke volume (r=0.660; p < 0.0001), and pulmonary vascular resistance (r = 0.643; p= 0.001) correlated significantly. 2-An algorithm integrating mitral inflow velocities, RAP, sPAP, and left atrial volume index was 90% accurate in distinguishing normal from elevated left ventricular filling pressures.

Agneta Åkesson Associate professor, senior lecturer  Photo by Anna Persson                                                                   Nutritional Epidemiology IMM Institute of Environmental Medicine Karolinska Institutet Stockholm, SwedMedicalResearch.com Interview with Agneta Åkesson Associate professor, senior lecturer                                                  Nutritional Epidemiology IMM Institute of Environmental Medicine Karolinska Institutet Stockholm, Sweden Medical Research: What are the main findings of the study? Dr. Åkesson: Our study indicates that a healthy diet together with low-risk lifestyle practices such as being physically active, not smoking and having a moderate alcohol consumption, and with the absence of abdominal adiposity may prevent the vast majority of myocardial infarctions in men.

A001_C001_03160QMedicalResearch.com Interview with: Dr. Philippe Courtet MD PhD Centre Hospitalier Régional Universitaire de Montpellier, Institut National de la Santé et de la Récherche Médicale , Université Montpellier, Montpellier, France Fondation Fondamental, Créteil, France Medical Research: What are the main findings of the study? Dr. Courtet: Depressed outpatients who are beginning the treatment with a SSRI at higher dose than recommended present an increased risk (x2) of worsening of suicidal ideation during the first 6 weeks of treatment. This is consistent with the study by Miller et al published in the same journal few weeks ago, reporting a double risk of suicide attempt in young subjects (<24 yrs) who are begun an SSRI at higher dose than recommended. Our results showed that the increased suicide risk with the high dose of SSRI is not restricted to youngsters and is independent of the severity of the depression.

MedicalResearch.com Interview with: Todd C. Lee, MD, MPH Division of General Internal Medicine and Infectious Diseases Department of Medicine, McGill University Health Centre McGill Centre for Quality Improvement, Montreal, Quebec, Canada Medical Research: What are the main findings of the study? Dr. Lee: We found that in our cross-sectional study of six inpatient units in five hospitals that, in general, only 11% of patients were wearing lower body garments despite the fact that probably 55% of them could have been doing so.  The remainder were wearing open backed gowns.  When specifically asked, the majority of these patients would like to have been afforded the opportunity to wear more dignified attire and the patients were surprised that they were allowed to do so.

Dr. Csaba P. Kovesdy, MD Professor of Medicine University of Tennessee Health Science Center Chief of Nephrology Memphis Veterans Affairs Medical CentMedicalResearch.com: Interview Invitation Dr. Csaba P. Kovesdy, MD Professor of Medicine University of Tennessee Health Science Center Chief of Nephrology Memphis Veterans Affairs Medical Center Medical Research: What are the main findings of the study? Dr. Kovesdy: We applied the structure of a clinical trial of hypertension management to our cohort of >600,000 patients with prevalent Chronic Kidney Disease (CKD). We first identified patients with baseline uncontrolled hypertension (using the definition applied by the SPRINT trial), then isolated the ones who had a decline in their baseline systolic blood pressure to two different levels (<120 and 120-139 mmHg) in response to a concomitant increase in prescribed antihypertensives, similar to what would happen in a trial examining two different systolic blood pressure targets. We then matched patients in the two groups to end up with identical baseline characteristics, similar to a randomized trial. When we examined the all-cause mortality of these two groups, we found that the group with follow-up systolic blood pressure of <120 had a 70% higher mortality.

Andrea Gershon MD, MSc, FRCP(C) Scientist, Institute for Clinical Evaluative Sciences Respirologist, Division of Respirology, Sunnybrook Health Sciences Centre Assistant Professor of Medicine, University of Toronto ICES Central Bayview Avenue, Toronto, OntarioMedicalResearch.com Interview with: Andrea Gershon MD, MSc, FRCP(C) Scientist, Institute for Clinical Evaluative Sciences Respirologist, Division of Respirology, Sunnybrook Health Sciences Centre Assistant Professor of Medicine, University of Toronto ICES Central Bayview Avenue, Toronto, Ontario Medical Research: What are the main findings of the study? Dr. Gershon: Within a large real world population of people with COPD, those who initiated combination long-acting beta-agonists (LABA) and inhaled corticosteroids (ICS) were less likely to die or be hospitalized for COPD than those who initiated LABA alone. Further those who initiated LABA/ICS combination therapy did not appear to have more pneumonia or osteoporotic fractures – side effects that have been associated with ICS use—than those initiating LABA alone. A second interesting finding was that people with a co-diagnosis of asthma experienced a greater incremental benefit of LABA/ICS over LABA than people without a co-diagnosis of asthma. Finally, we found that people who were not also taking an inhaled long-acting anticholinergic medication experienced a greater incremental benefit of LABA/ICS over LABA than people who were.

MedicalResearch.com Interview  Dongyi (Tony) Du, MD, PhD Division of Epidemiology FDA/CDRH/OSB Medical Research: What are the main findings of the study? Dr. Du: The risk for death on the date of surgery was 60% higher for recipients of mechanical aortic valves than recipients of bioprosthetic aortic valves (OR, 1.61 [95%CI, 1.27-2.04; P < .001]; risk ratio [RR], 1.60). The risk difference decreased to 16% during the 30 days after the date of surgery (OR, 1.18 [95%CI, 1.09-1.28; P < .001]; RR, 1.16). The risk for operative mortality was 19% higher for recipients of mechanical compared with bioprosthetic valves (OR, 1.21 [95%CI, 1.13-1.30; P < .001]; RR, 1.19). The number needed to treat with mechanical valves to observe 1 additional death on the surgery date was 290; to observe 1 additional death within 30 days of surgery, 121.