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Victor M Montori

Publications and source records attributed to Victor M Montori.

At least 19 recordsLinked to original sources
PubMed2006

Association of bodyweight with total mortality and with cardiovascular events in coronary artery disease: a systematic review of cohort studies.

BACKGROUND: Studies of the association between obesity, and total mortality and cardiovascular events in patients with coronary artery disease (CAD) have shown contradictory results. We undertook a systematic review to determine the extent and nature of this association. METHODS: We selected cohort studies that provided risk estimates for total mortality, with or without cardiovascular events, on the basis of bodyweight or obesity measures in patients with CAD, and with at least 6 months' follow-up. CAD was defined as history of percutaneous coronary intervention, coronary artery bypass graft, or myocardial infarction. We obtained risk estimates for five predetermined bodyweight groups: low, normal weight (reference), overweight, obese, and severely obese. FINDINGS: We found 40 studies with 250,152 patients that had a mean follow-up of 3.8 years. Patients with a low body-mass index (BMI) (ie, <20) had an increased relative risk (RR) for total mortality (RR=1.37 [95% CI 1.32-1.43), and cardiovascular mortality (1.45 [1.16-1.81]), overweight (BMI 25-29.9) had the lowest risk for total mortality (0.87 [0.81-0.94]) and cardiovascular mortality (0.88 [0.75-1.02]) compared with those for people with a normal BMI. Obese patients (BMI 30-35) had no increased risk for total mortality (0.93 [0.85-1.03]) or cardiovascular mortality (0.97 [0.82-1.15]). Patients with severe obesity (> or =35) did not have increased total mortality (1.10 [0.87-1.41]) but they had the highest risk for cardiovascular mortality (1.88 [1.05-3.34]). INTERPRETATION: The better outcomes for cardiovascular and total mortality seen in the overweight and mildly obese groups could not be explained by adjustment for confounding factors. These findings could be explained by the lack of discriminatory power of BMI to differentiate between body fat and lean mass.

Angioplasty, Balloon, Coronary↗
PubMed2006

Testosterone therapy in adult men with androgen deficiency syndromes: an endocrine society clinical practice guideline.

OBJECTIVE: The objective was to provide guidelines for the evaluation and treatment of androgen deficiency syndromes in adult men. PARTICIPANTS: The Task Force was composed of a chair, selected by the Clinical Guidelines Subcommittee of The Endocrine Society, five additional experts, a methodologist, and a professional writer. The Task Force received no corporate funding or remuneration. EVIDENCE: The Task Force used systematic reviews of available evidence to inform its key recommendations. The Task Force used consistent language and graphical descriptions of both the strength of recommendation and the quality of evidence, using the recommendations of the Grading of Recommendations, Assessment, Development, and Evaluation group. CONSENSUS PROCESS: Consensus was guided by systematic reviews of evidence and discussions during three group meetings, several conference calls, and e-mail communications. The drafts prepared by the panelists with the help of a professional writer were reviewed successively by The Endocrine Society's Clinical Guidelines Subcommittee, Clinical Affairs Committee, and Council. The version approved by the Council was placed on The Endocrine Society's web site for comments by members. At each stage of review, the Task Force received written comments and incorporated needed changes. CONCLUSIONS: We recommend making a diagnosis of androgen deficiency only in men with consistent symptoms and signs and unequivocally low serum testosterone levels. We suggest the measurement of morning total testosterone level by a reliable assay as the initial diagnostic test. We recommend confirmation of the diagnosis by repeating the measurement of morning total testosterone and in some patients by measurement of free or bioavailable testosterone level, using accurate assays. We recommend testosterone therapy for symptomatic men with androgen deficiency, who have low testosterone levels, to induce and maintain secondary sex characteristics and to improve their sexual function, sense of well-being, muscle mass and strength, and bone mineral density. We recommend against starting testosterone therapy in patients with breast or prostate cancer, a palpable prostate nodule or induration or prostate-specific antigen greater than 3 ng/ml without further urological evaluation, erythrocytosis (hematocrit > 50%), hyperviscosity, untreated obstructive sleep apnea, severe lower urinary tract symptoms with International Prostate Symptom Score (IPSS) greater than 19, or class III or IV heart failure. When testosterone therapy is instituted, we suggest aiming at achieving testosterone levels during treatment in the mid-normal range with any of the approved formulations, chosen on the basis of the patient's preference, consideration of pharmacokinetics, treatment burden, and cost. Men receiving testosterone therapy should be monitored using a standardized plan.

Evidence-Based Medicine↗
PubMed2006

Testosterone use in men and its effects on bone health. A systematic review and meta-analysis of randomized placebo-controlled trials.

CONTEXT: Androgen-deficient men are at increased risk of osteoporosis. The extent to which testosterone can prevent and treat osteoporosis in men remains unclear. OBJECTIVE AND DESIGN: We performed a systematic review and meta-analysis of randomized placebo-controlled trials in men to estimate the effect of testosterone use on bone health outcomes. DATA SOURCES: The review encompassed librarian-designed search strategies using MEDLINE (1966 to March 2005), EMBASE (1988 to March 2005), and Cochrane CENTRAL (inception to March 2005); a review of reference lists from included studies; and content expert files. DATA COLLECTION: Independently and in duplicate, we assessed the methodological quality of the eligible trials and collected data on bone mineral density and bone fractures at the longest point of complete follow-up. DATA SYNTHESIS: We included eight trials enrolling 365 patients. Two trials followed patients for more than 1 yr. Meta-analysis of these trials showed that, compared with placebo, im testosterone was associated with an 8% (95% confidence interval, 4%, 13%) gain in lumbar bone mineral density and transdermal testosterone had no significant impact. Testosterone use was associated with a nonsignificant 4% (95% confidence interval, -2%, 9%) gain in femoral neck bone mineral density with unexplained differences in results across trials (26% of these differences were not explained by chance alone). No trials measured or reported the effect of testosterone on fractures. CONCLUSIONS: Intramuscular testosterone moderately increased lumbar bone density in men; the results on femoral neck bone density are inconclusive. Without bone fracture data, the available trials offer weak and indirect inferences about the clinical efficacy of testosterone on osteoporosis prevention and treatment in men.

Bone Density↗
PubMed2006

A new preference-based analysis for randomized trials can estimate treatment acceptability and effect in compliant patients.

BACKGROUND AND OBJECTIVES: Development of a new method of analysis to evaluate the acceptability of (or preferences for) the treatments in a randomized trial, and the benefit of treatment among compliers. MATERIALS AND METHODS: We characterize trial participants through the groups who would: accept either treatment if offered (compliers); refuse one treatment but accept the other if it is offered to them (two groups of preferers); or prefer one treatment and insist on it if it is not offered to them initially (two groups of insisters). RESULTS: We show that in our framework, one can always estimate the proportions of patients in these five preference groups. However, constraints are required to estimate the corresponding outcome rates, and thus estimate the treatment effect in the compliers. We propose two possible sets of constraints and illustrate them by numerical examples. CONCLUSIONS: The traditional intention-to-treat analysis avoids biases associated with the alternative per-protocol or as-treated approaches, but it provides imperfect information about the expected treatment effect among patients who are committed to taking the treatment. Many physicians and patients want to know the expected benefit if they adhere to the therapy. Our preference-based analysis provides an estimate of treatment benefit among such patients.

Carotid Stenosis↗
PubMed2006

The impact of penicillin resistance on short-term mortality in hospitalized adults with pneumococcal pneumonia: a systematic review and meta-analysis.

BACKGROUND: The clinical impact of penicillin resistance on the outcome of pneumococcal pneumonia has remained controversial. We performed a meta-analysis of prospective cohort studies to examine the association between penicillin resistance and short-term all-cause mortality for pneumococcal pneumonia. METHODS: We retrieved studies published in any language by a comprehensive search of the Medline, Current Contents, and Embase databases for all appropriate articles published up to January 2005. We also manually reviewed bibliographies of retrieved articles, recent national treatment guidelines, and review articles. We included prospective cohort studies that involved adult subjects, and we examined the association between penicillin resistance and short-term mortality for pneumococcal pneumonia. Two reviewers independently extracted data on crude and adjusted risk estimates of all-cause mortality for pneumococcal infections with different levels of penicillin resistance and assessed the methodological quality of selected studies. We also contacted authors to obtain additional information. We performed meta-analyses using a random-effect model. RESULTS: Of 1152 articles identified in the search, 10 studies that involved 3430 patients (most of whom were hospitalized) were included. The mortality rate was 19.4% in the penicillin-nonsusceptible Streptococcus pneumoniae group and 15.7% in the penicillin-susceptible S. pneumoniae group. The combined relative risks of all-cause mortality for the penicillin-nonsusceptible, -intermediate, and -resistant S. pneumoniae groups, compared with the penicillin-susceptible S. pneumoniae group, were 1.31 (95% confidence interval [CI], 1.08-1.59), 1.34 (95% CI, 1.13-1.60), and 1.29 (95% CI, 1.01-1.66), respectively. The combined adjusted relative risks of mortality for penicillin-nonsusceptible versus penicillin-susceptible S. pneumoniae group was 1.29 (95% CI, 1.04-1.59) for the 6 studies that adjusted for age, comorbidities, and severity of illness. There was minimal between-study heterogeneity in these analyses. CONCLUSION: Penicillin resistance is associated with a higher mortality rate than is penicillin susceptibility in hospitalized patients with pneumococcal pneumonia. Additional efforts are needed to understand the mechanisms of this association.

Aged↗
PubMed2006

Can contraindications compromise evidence-based, patient-centered clinical practice?

BACKGROUND: Despite their often weak evidence base, contraindications convey the unequivocally adverse risk-benefit profile of an intervention in a specific clinical context. However, some patients in that context may nonetheless prefer the contraindicated intervention (with its potential benefits and risks) to the available alternatives. The impact of contraindications on treatment decisions remains unexplored. OBJECTIVE: To provide an estimate of the impact of the "contraindication" label on treatment decisions. METHODS: We conducted an international 6-wave email/internet and fax survey of practicing clinicians who were members of the American Diabetes Association or the College of Physicians and Surgeons of Ontario and had available email addresses and fax numbers. Each participant considered one of two patient scenarios. In each scenario, the patient expressed a strong preference for use of a medication that carried a "contraindication" label despite weak evidence of harm. We designed these scenarios so that respondents who placed greater weight on patient preferences and research evidence than on the label "contraindication" would be ready to prescribe the contraindicated medication. We determined the frequency with which the label "contraindication" dominated participants' treatment decisions despite patient preferences and weak evidence of harm. RESULTS: 466 participants responded (22% response rate). Depending on the group and scenario, contraindications dominated the decisions of 47% to 89% of surveyed clinicians, superseding patient preferences and research evidence. CONCLUSIONS: The label "contraindication" may often dominate clinicians' decisions about treatment and may compromise evidence-based, patient-centered clinical practice. Further research should elucidate the process that leads to the formulation of contraindications and its impact on treatment decision-making.

Attitude of Health Personnel↗
PubMed2006

Drug insight: Testosterone and selective androgen receptor modulators as anabolic therapies for chronic illness and aging.

Several regulatory concerns have hindered development of androgens as anabolic therapies, despite unequivocal evidence that testosterone supplementation increases muscle mass and strength in men; it induces hypertrophy of type I and II muscle fibers, and increases myonuclear and satellite cell number. Androgens promote differentiation of mesenchymal multipotent cells into the myogenic lineage and inhibit their adipogenic differentiation, by facilitating association of androgen receptors with beta-catenin and activating T-cell factor 4. Meta-analyses indicate that testosterone supplementation increases fat-free mass and muscle strength in HIV-positive men with weight loss, glucocorticoid-treated men, and older men with low or low-normal testosterone levels. The effects of testosterone on physical function and outcomes important to patients have not, however, been studied. In older men, increased hematocrit and increased risk of prostate biopsy and detection of prostate events are the most frequent, testosterone-related adverse events. Concerns about long-term risks have restrained enthusiasm for testosterone use as anabolic therapy. Selective androgen-receptor modulators that are preferentially anabolic and that spare the prostate hold promise as anabolic therapies. We need more studies to determine whether testosterone or selective androgen-receptor modulators can induce meaningful improvements in physical function and patient-important outcomes in patients with physical dysfunction associated with chronic illness or aging.

Aging↗
PubMed2006

A shared treatment decision-making approach between patients with chronic conditions and their clinicians: the case of diabetes.

In this paper, we discuss the Charles et al. approach to shared treatment decision-making (STDM) as applied to patients with chronic conditions and their clinicians. We perceive differences between the type of treatment decisions (e.g. end-of-life care, surgical treatment of cancer) that generated existing approaches of shared decision-making for acute care conditions (including the Charles et al. model) and the treatment decisions that patients with chronic conditions need to make and revisit on an ongoing basis. For instance, treatment decisions in the chronic care setting are more likely to require a more active patient role in carrying out the decision and to offer a longer window of opportunity to make decisions and to revisit and reverse them without important loss than acute care decisions. The latter may require minimal patient participation to realize, are often urgent, and may be irreversible. Given these differences, we explore the applicability of the Charles et al. model of STDM in the chronic care context, especially chronic care that relies heavily on patient self-management (e.g. diabetes). To apply the Charles et al. model in this clinical context, we suggest the need to emphasize the patient-clinician relationship as one of partners in making difficult treatment choices and to add a new component to the shared decision-making approach: the need for an ongoing partnership between the clinical team (not just the clinician) and the patient. In the last section of the paper, we explore potential healthcare system barriers to STDM in chronic care delivery. Throughout the discussion we identify areas for further research.

Aged↗
PubMed2006

Systematic evaluation of the quality of randomized controlled trials in diabetes.

OBJECTIVE: We sought to systematically ascertain the quality of randomized controlled trials (RCTs) in diabetes. RESEARCH DESIGN AND METHODS: We identified the 10 most recently published trials as of 31 October 2003 in each of six general medical, five diabetes, and five metabolism and nutrition journals and further enriched our sample with 10 additional RCTs from each of five journals that published the most eligible RCTs in a year. We explored the association between trial characteristics and reporting quality using univariate analyses and a preplanned multivariate regression model. RESULTS: After excluding redundant reports of included trials and one trial that measured outcomes on the health system and not on patients, we included 199 RCTs: 119 assessed physiological and other laboratory outcomes, 42 assessed patient-important outcomes (e.g., morbidity and mortality, quality of life), and 38 assessed surrogate outcomes (e.g., disease progression or regression, HbA(1c), cholesterol). Fifty-three percent were of low methodological quality, as were one-third (36-40%) of trials reporting patient-important or surrogate outcomes and two-thirds (64%) of laboratory investigations. Independent predictors of low quality were nonprofit funding source (odds ratio 3.1 [95% CI 1.5-6.2]), measure of physiological and laboratory outcomes (2.3 [1.2-4.4]), and cross-over design (2.3 [1.1-4.8]), all characteristics of laboratory clinical investigations. CONCLUSIONS: There is ample room for improving the quality of diabetes trials. To enhance the practice of evidence-based diabetes care, trialists need to pay closer attention to the rigorous implementation and reporting of important methodological safeguards against bias in randomized trials.

Diabetes Mellitus↗
PubMed2006

A pen-and-paper coronary risk estimator for office use with patients with type 2 diabetes.

OBJECTIVE: To develop a pen-and-paper coronary heart disease (CHD) 10-year risk estimator for patients with type 2 diabetes based on the United Kingdom Prospective Diabetes Study (UKPDS) risk equation (based on 4000 patients with diabetes but only available electronically). PATIENTS AND METHODS: We used data collected from adults with type 2 diabetes from 6 primary care practices that participated in a randomized trial in Rochester, Minn; patients were enrolled in the study from July 2001 to December 2003, with follow-up through June 2004. We used multivariable linear regression of the CHD risk estimate to formulate prediction equations to estimate average (<15%), elevated, or high (>30%) 10-year CHD risk according to sex, age, diabetes duration, smoking, hemoglobin A1c level, systolic blood pressure, ratio of total cholesterol to high-density lipoprotein cholesterol, and microalbuminuria categories. We selected cut points for the predicted score, seeking to (1) maximize the number of patients with total agreement between our estimator and the UKPDS risk equation, (2) avoid any patient's risk being either overestimated or underestimated by 2 risk categories, and (3) overestimate rather than underestimate coronary risk. RESULTS: A total of 535 patients with type 2 diabetes participated in this study, 400 in the generation cohort and 135 in the validation cohort. Of the 400 patients in the generation cohort, our estimator had an 82% total agreement with the UKPDS calculation, 11% overestimated risk, and 7% underestimated UKPDS coronary risk (weighted kappa=0.77). Results were similar in the 135 patients in the validation cohort (kappa=0.79) and in an independent validation cohort of 52 patients attending a referral diabetes clinic (kappa=0.68). CONCLUSION: The pen-and-paper estimator facilitates the point-of-care estimation of coronary risk in situations in which use of a desktop or handheld version of the electronic UKPDS risk engine is not practical or feasible. In our experience, estimation of risk using this tool, when done with patients, can further patients' insight into their risk of coronary events, often leading to enlightened discussions about modification of Individual risk factors.

Aged↗
PubMed2005

Randomized trials stopped early for benefit: a systematic review.

CONTEXT: Randomized clinical trials (RCTs) that stop earlier than planned because of apparent benefit often receive great attention and affect clinical practice. Their prevalence, the magnitude and plausibility of their treatment effects, and the extent to which they report information about how investigators decided to stop early are, however, unknown. OBJECTIVE: To evaluate the epidemiology and reporting quality of RCTs involving interventions stopped early for benefit. DATA SOURCES: Systematic review up to November 2004 of MEDLINE, EMBASE, Current Contents, and full-text journal content databases to identify RCTs stopped early for benefit. STUDY SELECTION: Randomized clinical trials of any intervention reported as having stopped early because of results favoring the intervention. There were no exclusion criteria. DATA EXTRACTION: Twelve reviewers working independently and in duplicate abstracted data on content area and type of intervention tested, reporting of funding, type of end point driving study termination, treatment effect, length of follow-up, estimated sample size and total sample studied, role of a data and safety monitoring board in stopping the study, number of interim analyses planned and conducted, and existence and type of monitoring methods, statistical boundaries, and adjustment procedures for interim analyses and early stopping. DATA SYNTHESIS: Of 143 RCTs stopped early for benefit, the majority (92) were published in 5 high-impact medical journals. Typically, these were industry-funded drug trials in cardiology, cancer, and human immunodeficiency virus/AIDS. The proportion of all RCTs published in high-impact journals that were stopped early for benefit increased from 0.5% in 1990-1994 to 1.2% in 2000-2004 (P<.001 for trend). On average, RCTs recruited 63% (SD, 25%) of the planned sample and stopped after a median of 13 (interquartile range [IQR], 3-25) months of follow-up, 1 interim analysis, and when a median of 66 (IQR, 23-195) patients had experienced the end point driving study termination (event). The median risk ratio among truncated RCTs was 0.53 (IQR, 0.28-0.66). One hundred thirty-five (94%) of the 143 RCTs did not report at least 1 of the following: the planned sample size (n = 28), the interim analysis after which the trial was stopped (n = 45), whether a stopping rule informed the decision (n = 48), or an adjusted analysis accounting for interim monitoring and truncation (n = 129). Trials with fewer events yielded greater treatment effects (odds ratio, 28; 95% confidence interval, 11-73). CONCLUSIONS: RCTs stopped early for benefit are becoming more common, often fail to adequately report relevant information about the decision to stop early, and show implausibly large treatment effects, particularly when the number of events is small. These findings suggest clinicians should view the results of such trials with skepticism.

Clinical Trials Data Monitoring Committees↗
PubMed2005

How strong is the evidence for the use of perioperative beta blockers in non-cardiac surgery? Systematic review and meta-analysis of randomised controlled trials.

OBJECTIVE: To determine the effect of perioperative beta blocker treatment in patients having non-cardiac surgery. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Seven search strategies, including searching two bibliographic databases and hand searching seven medical journals. STUDY SELECTION AND OUTCOMES: We included randomised controlled trials that evaluated beta blocker treatment in patients having non-cardiac surgery. Perioperative outcomes within 30 days of surgery included total mortality, cardiovascular mortality, non-fatal myocardial infarction, non-fatal cardiac arrest, non-fatal stroke, congestive heart failure, hypotension needing treatment, bradycardia needing treatment, and bronchospasm. RESULTS: Twenty two trials that randomised a total of 2437 patients met the eligibility criteria. Perioperative beta blockers did not show any statistically significant beneficial effects on any of the individual outcomes and the only nominally statistically significant beneficial relative risk was 0.44 (95% confidence interval 0.20 to 0.97, 99% confidence interval 0.16 to 1.24) for the composite outcome of cardiovascular mortality, non-fatal myocardial infarction, and non-fatal cardiac arrest. Methods adapted from formal interim monitoring boundaries applied to cumulative meta-analysis showed that the evidence failed, by a considerable degree, to meet standards for forgoing additional studies. The individual safety outcomes in patients treated with perioperative beta blockers showed a relative risk for bradycardia needing treatment of 2.27 (95% CI 1.53 to 3.36, 99% CI 1.36 to 3.80) and a nominally statistically significant relative risk for hypotension needing treatment of 1.27 (95% CI 1.04 to 1.56, 99% CI 0.97 to 1.66). CONCLUSION: The evidence that perioperative beta blockers reduce major cardiovascular events is encouraging but too unreliable to allow definitive conclusions to be drawn.

Adrenergic beta-Antagonists↗
PubMed2005

Milk thistle and indinavir: a randomized controlled pharmacokinetics study and meta-analysis.

OBJECTIVES: To determine whether ingestion of milk thistle affects the pharmacokinetics of indinavir. METHODS: We conducted a three-period, randomized controlled trial with 16 healthy participants. We randomized participants to milk thistle or control. All participants received initial dosing of indinavir, and baseline indinavir levels were obtained (AUC(0-8)) (phase I). The active group were then given 450 mg milk-thistle extract capsules to be taken t.i.d. from day 2 to day 30. The control group received no plant extract. On day 29 and day 30, indinavir dosing and sampling was repeated in both groups as before (phase II). After a wash-out period of 7 days, indinavir dosing and sampling were repeated as before (phase III). RESULTS: All participants completed the trial, but two were excluded from analysis due to protocol violation. There were no significant between-group differences. Active group mean AUC(0-8) indinavir decreased by 4.4% (90% CI, -27.5% to -26%, P=0.78) from phase I to phase II in the active group, and by 17.3% (90% CI, -37.3% to +9%, P=0.25) in phase III. Control group mean AUC(0-8) decreased by 21.5% (90% CI, -43% to +8%, P=0.2) from phase I to phase II and by 38.5% (90% CI, -55.3% to -15.3%, P=0.01) of baseline at phase III. To place our findings in context, milk thistle-indinavir trials were identified through systematic searches of the literature. A meta-analysis of three milk thistle-indinavir trials revealed a non-significant pooled mean difference of 1% in AUC(0-8) (95% CI, -53% to 55%, P=0.97). CONCLUSIONS: Indinavir levels were not reduced significantly in the presence of milk thistle.

Adult↗