Showing papers on "Confidence interval published in 2015"
TL;DR: MINOCA should be considered as a working diagnosis with multiple potential causes that require evaluation so that directed therapies may improve its guarded prognosis.
Abstract: Background—Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a puzzling clinical entity with no previous evaluation of the literature. This systematic review aims to (1) quantify the prevalence, risk factors, and 12-month prognosis in patients with MINOCA, and (2) evaluate potential pathophysiological mechanisms underlying this disorder. Methods and Results—Quantitative assessment of 28 publications using a meta-analytic approach evaluated the prevalence, clinical features, and prognosis of MINOCA. The prevalence of MINOCA was 6% [95% confidence interval, 5%–7%] with a median patient age of 55 years (95% confidence interval, 51–59 years) and 40% women. However, in comparison with those with myocardial infarction associated with obstructive coronary artery disease, the patients with MINOCA were more likely to be younger and female but less likely to have hyperlipidemia, although other cardiovascular risk factors were similar. All-cause mortality at 12 months was lower in MINOCA (4.7%;...
622 citations
TL;DR: In this article, the authors proposed a confidence interval that does not require equal variances or equal covariances and demonstrated that the proposed method performed better than alternative methods, and also presented some sample size formulas that approximate the sample size requirements for desired power or desired confidence interval precision.
Abstract: Summary
Cronbach's alpha is one of the most widely used measures of reliability in the social and organizational sciences. Current practice is to report the sample value of Cronbach's alpha reliability, but a confidence interval for the population reliability value also should be reported. The traditional confidence interval for the population value of Cronbach's alpha makes an unnecessarily restrictive assumption that the multiple measurements have equal variances and equal covariances. We propose a confidence interval that does not require equal variances or equal covariances. The results of a simulation study demonstrated that the proposed method performed better than alternative methods. We also present some sample size formulas that approximate the sample size requirements for desired power or desired confidence interval precision. R functions are provided that can be used to implement the proposed confidence interval and sample size methods. Copyright © 2014 John Wiley & Sons, Ltd.
578 citations
TL;DR: Evidence of constituent-associated health effects, long-term effects and morbidity in China is still inadequate and combined estimates of the health effects of exposure to particulate matter from quantitative reviews could provide vital information for epidemiology-based health impact assessments.
543 citations
TL;DR: A meta-analysis of twin and adoption studies of AUD found evidence for modest shared environmental effects suggesting that environmental factors also contribute to the familial aggregation of AUDs.
Abstract: Background. To clarify the role of genetic and environmental risk factors in alcohol use disorders (AUDs), we performed a meta-analysis of twin and adoption studies and explored the impact of sex, assessment method (interview v. hospital/population records), and study design (twin v. adoption study) on heritability estimates. Method. The literature was searched for all unique twin and adoption studies of AUD and identified 12 twin and five adoption studies. The data were then reconstructed and analyzed using ordinal data full information maximum likelihood in the OpenMx program. Heterogeneity was tested with likelihood ratio tests by equating the parameters across studies. Results. There was no evidence for heterogeneity by study design, sex or assessment method. The best-fit estimate of the heritability of AUD was 0.49 [95% confidence interval (CI) 0.43–0.53], and the proportion of shared environmental variance was 0.10 (95% CI 0.03–0.16). Estimates of unique environmental proportions of variance differed significantly across studies. Conclusions. AUD is approximately 50% heritable. The multiple genetically informative studies of this syndrome have produced consistent results that support the validity of this heritability estimate, especially given the different potential methodological weaknesses of twin and adoption designs, and of assessments of AUD based on personal interviews v. official records. We also found evidence for modest shared environmental effects suggesting that environmental factors also contribute to the familial aggregation of AUDs.
474 citations
TL;DR: This study was aimed at systematically reviewing evidence of the association between breastfeeding and performance in intelligence tests and found no evidence of a negative association.
Abstract: Aim: This study was aimed at systematically reviewing evidence of the association between breastfeeding and performance in intelligence tests. Methods: Two independent searches were carried out using Medline LILACS SCIELO and Web of Science. Studies restricted to infants and those where estimates were not adjusted for stimulation or interaction at home were excluded. Fixed- and random-effects models were used to pool the effect estimates and a random-effects regression was used to assess potential sources of heterogeneity. Results: We included 17 studies with 18 estimates of the relationship between breastfeeding and performance in intelligence tests. In a random-effects model breastfed subjects achieved a higher IQ [mean difference: 3.44 points (95% confidence interval: 2.30; 4.58)]. We found no evidence of publication bias. Studies that controlled for maternal IQ showed a smaller benefit from breastfeeding [mean difference 2.62 points (95% confidence interval: 1.25; 3.98)]. In the meta-regression none of the study characteristics explained the heterogeneity among the studies. Conclusion: Breastfeeding is related to improved performance in intelligence tests. A positive effect of breastfeeding on cognition was also observed in a randomised trial. This suggests that the association is causal. ©2015 The Authors. Open Access.
456 citations
TL;DR: In this paper, a systematic review and meta-analysis was conducted to assess the recent burden of hypertension in Sub-Saharan Africa, based on studies published between 2000 and 2013. But only 7% of individuals with hypertension were receiving treatment across the studies, and only 6% of those with hypertension had controlled blood pressure.
Abstract: The burden of hypertension in Sub-Saharan Africa has been increasing over the past few decades. However, a large proportion of the population with hypertension remains undiagnosed, untreated, or inadequately treated, contributing to the rising burden of cardiovascular disease in the region. We conducted a systematic review and meta-analysis to assess the recent burden of hypertension in Sub-Saharan Africa, based on studies published between 2000 and 2013. We pooled data from 33 surveys involving over 110 414 participants of mean age 40 years. Hypertension prevalence varied widely across the studies (range 15%-70%), partly because of differences in participant mean ages (31-76 years). The predicted prevalence of hypertension at mean participant ages of 30, 40, 50, and 60 years were 16%, 26%, 35%, and 44%, respectively, with a pooled prevalence of 30% (95% confidence interval, 27%-34%). Of those with hypertension, only between 7% and 56% (pooled prevalence: 27%; 95% confidence interval, 23%-31%) were aware of their hypertensive status before the surveys. Overall, 18% (95% confidence interval, 14%-22%) of individuals with hypertension were receiving treatment across the studies, and only 7% (95% confidence interval, 5%-8%) had controlled blood pressure. This review found a high prevalence of hypertension, as well as low percentage of hypertension awareness, treatment, and control in Sub-Saharan Africa, highlighting the need for implementation of timely and appropriate strategies for diagnosis, control, and prevention.
398 citations
St Thomas' Hospital1, University Hospital of North Norway2, UCL Institute of Child Health3, Erasmus University Rotterdam4, Aristotle University of Thessaloniki5, French Institute of Health and Medical Research6, Institut national de la recherche agronomique7, Oslo University Hospital8, Queen's University Belfast9, University of Cambridge10, University of Bordeaux11, University of London12, Technische Universität München13, UCL Institute of Ophthalmology14, King's College London15
TL;DR: Myopia is becoming more common in Europe; although education levels have increased and are associated with myopia, higher education seems to be an additive rather than explanatory factor.
342 citations
TL;DR: Primary and secondary prevention randomised clinical trials on antioxidant supplements versus placebo or no intervention found no significant difference in the estimated intervention effect in the primary prevention and the secondary prevention trials, and meta-regression analysis found the risk of bias and type of antioxidant supplement were the only significant predictors of intertrial heterogeneity.
Abstract: BACKGROUND: Our previous systematic review has demonstrated that antioxidant supplements may increase mortality. We have now updated this review.OBJECTIVES: To assess the beneficial and harmful effects of antioxidant supplements for prevention of mortality in adults.METHODS:Search methods: We searched The Cochrane Library, Medline, Embase, Lilacs, the Science Citation Index Expanded, and Conference Proceedings Citation Index-Science to February 2011. We scanned bibliographies of relevant publications and asked pharmaceutical companies for additional trials. Selection criteria:We included all primary and secondary prevention randomized clinical trials on antioxidant supplements (beta-carotene, vitamin A, vitamin C, vitamin E, and selenium) versus placebo or no intervention. Data collection and analysis: Three authors extracted data. Random-effects and fixed-effect model meta-analyses were conducted. Risk of bias was considered in order to minimize the risk of systematic errors. Trial sequential analyses were conducted to minimize the risk of random errors. Random effects model meta-regression analyses were performed to assess sources of intertrial heterogeneity.MAIN RESULTS: Seventy-eight randomized trials with 296,707 participants were included. Fifty-six trials including 244,056 participants had low risk of bias. Twenty-six trials included 215,900 healthy participants. Fifty-two trials included 80,807 participants with various diseases in a stable phase. The mean age was 63 years (range 18 to 103 years). The mean proportion of women was 46%. Of the 78 trials, 46 used the parallel-group design, 30 the factorial design, and 2 the cross-over design. All antioxidants were administered orally, either alone or in combination with vitamins, minerals, or other interventions. The duration of supplementation varied from 28 days to 12 years (mean duration 3 years; median duration 2 years). Overall, the antioxidant supplements had no significant effect on mortality in a random-effects model meta-analysis (21,484 dead/183,749 (11.7%) versus 11,479 dead/112,958 (10.2%); 78 trials, relative risk (RR) 1.02, 95% confidence interval (CI) 0.98 to 1.05) but significantly increased mortality in a fixed-effect model (RR 1.03, 95% CI 1.01 to 1.05). Heterogeneity was low with an I2- of 12%. In meta-regression analysis, the risk of bias and type of antioxidant supplement were the only significant predictors of intertribal heterogeneity. Meta-regression analysis did not find a significant difference in the estimated intervention effect in the primary prevention and the secondary prevention trials. In the 56 trials with a low risk of bias, the antioxidant supplements significantly increased mortality (18,833 dead/146,320 (12.9%) versus 10,320 dead/97,736 (10.6%); RR 1.04, 95% CI 1.01 to 1.07). This effect was confirmed by trial sequential analysis. Excluding factorial trials with potential confounding showed that 38 trials with low risk of bias demonstrated a significant increase in mortality (2822 dead/26,903 (10.5%) versus 2473 dead/26,052 (9.5%); RR 1.10, 95% CI 1.05 to 1.15). In trials with low risk of bias, beta-carotene (13,202 dead/96,003 (13.8%) versus 8556 dead/ 77,003 (11.1%); 26 trials, RR 1.05, 95% CI 1.01 to 1.09) and vitamin E (11,689 dead/97,523 (12.0%) versus 7561 dead/73,721 (10.3%); 46 trials, RR 1.03, 95% CI 1.00 to 1.05) significantly increased mortality, whereas vitamin A (3444 dead/24,596 (14.0%) versus 2249 dead/16,548 (13.6%); 12 trials, RR 1.07, 95% CI 0.97 to 1.18), vitamin C (3637 dead/36,659 (9.9%) versus 2717 dead/ 29,283 (9.3%); 29 trials, RR 1.02, 95% CI 0.98 to 1.07), and selenium (2670 dead/39,779 (6.7%) versus 1468 dead/22,961 (6.4%); 17 trials, RR 0.97, 95% CI 0.91 to 1.03) did not significantly affect mortality. In univariate meta-regression analysis, the dose of vitamin A was significantly associated with increased mortality (RR 1.0006, 95% CI 1.0002 to 1.001, P = 0.002).AUTHORS' CONCLUSIONS: We found no evidence to support antioxidant supplements for primary or secondary prevention. Beta-carotene and vitamin E seem to increase mortality, and so may higher doses of vitamin A. Antioxidant supplements need to be considered as medicinal products and should undergo sufficient evaluation before marketing.
339 citations
TL;DR: Mycoplasma genitalium infection was significantly associated with increased risk of cervicitis, pelvic inflammatory disease, and infertility, and in subanalyses accounting for coinfections, all associations were stronger and statistically significant.
Abstract: To determine the association between Mycoplasma genitalium infection and female reproductive tract syndromes through meta-analysis, English-language, peer-reviewed studies were identified via PubMed, Embase, Biosis, Cochrane Library, and reference review. Two reviewers independently extracted data. Random-effects models were employed to calculate summary estimates, between-study heterogeneity was evaluated using I(2) statistics, publication bias was assessed via funnel plots and the Begg and Egger tests, and methodologic quality was rated. Mycoplasma genitalium infection was significantly associated with increased risk of cervicitis (pooled odds ratio [OR], 1.66 [95% confidence interval {CI}, 1.35-2.04]), pelvic inflammatory disease (pooled OR, 2.14 [95% CI, 1.31-3.49]), preterm birth (pooled OR, 1.89 [95% CI, 1.25-2.85]), and spontaneous abortion (pooled OR, 1.82 [95% CI, 1.10-3.03]). Risk of infertility was similarly elevated (pooled OR, 2.43 [95% CI, .93-6.34]). In subanalyses accounting for coinfections, all associations were stronger and statistically significant. Testing of high-risk symptomatic women for M. genitalium may be warranted.
336 citations
TL;DR: Frailty is demonstrated to be a significant predictor of future falls among community-dwelling older people despite various criteria used to define frailty.
298 citations
TL;DR: A simple formula is presented to calculate the sample size needed to be able to identify, with a chosen level of confidence, problems that may arise with a given probability.
TL;DR: The probability of attaining normal weight or maintaining weight loss is low and obesity treatment frameworks grounded in community-based weight management programs may be ineffective.
Abstract: Objectives: Obesity is an increasing clinical and public health concern. This study aimed to answer the question: ‘What is the probability of an obese person attaining normal body weight?’
Methods: A sample of men and women aged 20 years and over was drawn from the Clinical Practice Research Datalink (CPRD). Participants who received bariatric surgery were excluded. The probability of attaining either normal weight, or 5% reduction in body weight, were estimated.
Findings: Data were analysed for 278,982 participants including 76,704 obese men and 99,791 obese women. During a maximum of 9 years’ follow-up, 1,283 men and 2,245 women attained normal body weight. In simple obesity (BMI 30•0-34•9 Kg/m2), the annual probability of attaining normal weight was 1 in 210 for men and 1 in 124 for women, increasing to 1 in 1,290 for men and 1 in 677 for women with morbid obesity (BMI 40•0-44•9 Kg/m2). The annual probability of achieving a 5% weight reduction was 1 in 8 for men, and 1 in 7 for women with morbid obesity. Among participants who lost 5% body weight, 52•7% (95% confidence interval 52•4 to 53•0%) showed weight regain at two years and 78•0% (77•7 to 78•3%) at five years.
Conclusions: The low probability of attaining normal weight, or maintaining weight loss, raises questions concerning whether current obesity treatment frameworks, grounded in community-based weight management programmes, may be expected to achieve public health impact.
TL;DR: Small samples (5–15 participants) that are common in pre-tests of questionaires may fail to uncover even common problems, and a default sample size of 30 participants is recommended.
Abstract: Purpose To provide guidance regarding the desirable size of pre-tests of psychometric questionnaires, when the purpose of the pre-test is to detect misunderstandings, ambiguities, or other difficulties participants may encounter with instrument items (called «problems»). Methods We computed (a) the power to detect a problem for various levels of prevalence and various sample sizes, (b) the required sample size to detect problems for various levels of prevalence, and (c) upper confidence limits for problem prevalence in situations where no problems were detected. Results As expected, power increased with problem prevalence and with sample size. If problem prevalence was 0.05, a sample of 10 participants had only a power of 40 % to detect the problem, and a sample of 20 achieved a power of 64 %. To achieve a power of 80 %, 32 participants were necessary if the prevalence of the problem was 0.05, 16 participants if prevalence was 0.10, and 8 if prevalence was 0.20. If no problems were observed in a given sample, the upper limit of a two-sided 90 % confidence interval reached 0.26 for a sample size of 10, 0.14 for a sample size of 20, and 0.10 for a sample of 30 participants. Conclusions Small samples (5‐15 participants) that are common in pre-tests of questionaires may fail to uncover even common problems. A default sample size of 30 participants is recommended.
TL;DR: In this article, a 1-SD decrease in leukocyte telomere length was significantly associated with stroke (odds ratio, 1.21; 95% confidence interval 1.06-1.37; I 2=61%), myocardial infarction (1.24, 95% probability 1.04 −1.47, I 2 =68%), and type 2 diabetes mellitus (1,10−1.72).
Abstract: Background— Telomeres are repetitive, gene-poor regions that cap the ends of DNA and help maintain chromosomal integrity. Their shortening is caused by inflammation and oxidative stress within the cellular environment and ultimately leads to cellular senescence. Shortened leukocyte telomere length is hypothesized to be a novel biomarker for age and age-related diseases, yet reports on its association with cardiometabolic outcomes in the literature are conflicting.
Methods and Results— MEDLINE (1966 to present) and EMBASE (1980 to present) were last searched on September 9, 2013. Reference lists of retrieved citations were hand searched for relevant studies. No restrictions were placed on sample size, language, or publication type or date. Fifteen cohort and 12 case–control studies reporting the association between leukocyte telomere length and stroke, myocardial infarction, and type 2 diabetes mellitus were independently selected for inclusion by 2 reviewers. Data extraction and risk of bias assessment were completed independently by 2 reviewers using predefined criteria. Studies were pooled using the generic inverse variance method and both fixed and random effects models. A 1-SD decrease in leukocyte telomere length was significantly associated with stroke (odds ratio, 1.21; 95% confidence interval, 1.06–1.37; I 2=61%), myocardial infarction (odds ratio, 1.24; 95% confidence interval, 1.04–1.47; I 2=68%), and type 2 diabetes mellitus (odds ratio, 1.37; 95% confidence interval, 1.10–1.72; I 2=91%). Stratification by measurement technique, study design, study size, and ethnicity explained heterogeneity in certain cardiometabolic outcomes.
Conclusions— Shortened leukocyte telomere length demonstrates a significant association with stroke, myocardial infarction, and type 2 diabetes mellitus. Larger, well-designed studies are needed to confirm these findings and explore sources of heterogeneity.
TL;DR: A three-level meta-analytic model is evaluated to account for dependent effect sizes, extending the simulation results of Van den Noortgate, López-López, Marín-Martínez, and Sánchez-Meca Behavior Research Methods by allowing for a variation in the number of effect sizes per study.
Abstract: In meta-analysis, dependent effect sizes are very common. An example is where in one or more studies the effect of an intervention is evaluated on multiple outcome variables for the same sample of participants. In this paper, we evaluate a three-level meta-analytic model to account for this kind of dependence, extending the simulation results of Van den Noortgate, Lopez-Lopez, Marin-Martinez, and Sanchez-Meca Behavior Research Methods, 45, 576-594 (2013) by allowing for a variation in the number of effect sizes per study, in the between-study variance, in the correlations between pairs of outcomes, and in the sample size of the studies. At the same time, we explore the performance of the approach if the outcomes used in a study can be regarded as a random sample from a population of outcomes. We conclude that although this approach is relatively simple and does not require prior estimates of the sampling covariances between effect sizes, it gives appropriate mean effect size estimates, standard error estimates, and confidence interval coverage proportions in a variety of realistic situations.
TL;DR: Study sample size, which is likely a proxy for case assessment method, and the use of DSM‐IV‐TR diagnostic criteria are the major sources of heterogeneity across studies, which refines the population prevalence estimate of TS in children to be 0.3% to 0.9%.
Abstract: The aim of this study was to refine the population prevalence estimate of Tourette Syndrome (TS) in children and to investigate potential sources of heterogeneity in previously published studies. A systematic review was conducted and all qualifying published studies of TS prevalence were examined. Extracted data were subjected to a random-effects meta-analysis weighted by sample size; meta-regressions were performed to examine covariates that have previously been proposed as potential sources of heterogeneity. Twenty-six articles met study inclusion criteria. Studies derived from clinically referred cases had prevalence estimates that were significantly lower than those derived from population-based samples (P = 0.004). Among the 21 population-based prevalence studies, the pooled TS population prevalence estimate was 0.52% (95% confidence interval CI: 0.32-0.85). In univariable meta-regression analysis, study sample size (P = 0.002) and study date (P = 0.03) were significant predictors of TS prevalence. In the final multivariable model including sample size, study date, age, and diagnostic criteria, only sample size (P < 0.001) and diagnostic criteria (omnibus P = 0.003; Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision [DSM-IV-TR]: P = 0.005) were independently associated with variation in TS population prevalence across studies. This study refines the population prevalence estimate of TS in children to be 0.3% to 0.9%. Study sample size, which is likely a proxy for case assessment method, and the use of DSM-IV-TR diagnostic criteria are the major sources of heterogeneity across studies. The true TS population prevalence rate is likely at the higher end of these estimates, given the methodological limitations of most studies. Further studies in large, well-characterized samples will be helpful to determine the burden of disease in the general population.
TL;DR: The association between mortality and weight discrimination was generally stronger than thatbetween mortality and other attributions for discrimination, and it is feared that weight discrimination may shorten life expectancy.
Abstract: Discrimination based on weight is a stressful social experience linked to declines in physical and mental health. We examined whether this harmful association extends to risk of mortality. Participants in the Health and Retirement Study (HRS; N = 13,692) and the Midlife in the United States Study (MIDUS; N = 5,079) reported on perceived discriminatory experiences and attributed those experiences to a number of personal characteristics, including weight. Weight discrimination was associated with an increase in mortality risk of nearly 60% in both HRS participants (hazard ratio = 1.57, 95% confidence interval = [1.34, 1.84]) and MIDUS participants (hazard ratio = 1.59, 95% confidence interval = [1.09, 2.31]). This increased risk was not accounted for by common physical and psychological risk factors. The association between mortality and weight discrimination was generally stronger than that between mortality and other attributions for discrimination. In addition to its association with poor health outcomes, weight discrimination may shorten life expectancy.
TL;DR: In this article, the authors identify different systolic blood pressure trajectories from childhood, their correlated risk factors, and early-midlife cardiovascular outcomes, and identify subgroups at risk of developing adult hypertension early in life.
Abstract: Previous studies examining blood pressure change over time have modeled an average population trajectory. Recent research among older adults suggests there may be subgroups with different blood pressure trajectories. Identifying subgroups at risk of developing adult hypertension early in life can inform effective risk reduction efforts. We sought to identify different systolic blood pressure trajectories from childhood, their correlated risk factors, and early-midlife cardiovascular outcomes. Blood pressure data at ages 7, 11, 18, 26, 32, and 38 years from a longitudinal, representative birth cohort study (n=975) were used to identify 4 distinct trajectory groups via group-based trajectory modeling: normal (21.8%), high-normal (43.3%), prehypertensive (31.6%), and hypertensive (4.2%). The categories refer to blood pressure beginning at the age of 7 years and most recently measured at the age of 38 years. Family history of high blood pressure (odds ratio [OR], 43.23; 95% confidence interval [CI], 5.27-354.65), male sex (OR, 109.48; 95% CI, 26.82-446.96), being first born (OR, 2.5; 95% CI, 1.00-8.69) and low birth weight (OR, 2.79; 95% CI, 2.49-3.09) were associated with hypertensive group membership (compared with the normal group). Higher body mass index and cigarette smoking resulted in increasing blood pressure across trajectories, particularly for the higher blood pressure groups. Prehypertensive and hypertensive trajectory groups had worse cardiovascular outcomes by early midlife. Harmful blood pressure trajectories are identifiable in childhood, associated with both antecedent and modifiable risk factors over time, and predict adult cardiovascular disease risk. Early detection and subsequent targeted prevention and intervention may reduce the lifecourse burden associated with higher blood pressure.
TL;DR: Computer navigation reduced the overall rate of revision and the rate revision for loosening/lysis following total knee arthroplasty in patients less than sixty-five years of age.
Abstract: Background: Computer navigation for total knee arthroplasty has improved alignment compared with that resulting from non-navigated total knee arthroplasty. This study analyzed data from the Australian Orthopaedic Association National Joint Replacement Registry to examine the effect of computer navigation on the rate of revision of primary total knee arthroplasty.
Methods: The cumulative percent revision following all non-navigated and navigated primary total knee arthroplasties performed in Australia from January 1, 2003, to December 31, 2012, was assessed. In addition, the type of and reason for revision as well as the effect of age, surgeon volume, and use of cement for the prosthesis were examined. Kaplan-Meier estimates of survivorship were used to describe the time to first revision. Hazard ratios (HRs) from Cox proportional hazards models, with adjustment for age and sex, were used to compare revision rates.
Results: Computer navigation was used in 44,573 (14.1% of all) primary total knee arthroplasties, and the rate of its use increased from 2.4% in 2003 to 22.8% in 2012. Overall, the cumulative percent revision following non-navigated total knee arthroplasty at nine years was 5.2% (95% confidence interval [CI] = 5.1 to 5.4) compared with 4.6% (95% CI = 4.2 to 5.1) for computer-navigated total knee arthroplasty (HR = 1.05 [95% CI = 0.98 to 1.12], p = 0.15). There was a significant difference in the rate of revision following non-navigated total knee arthroplasty compared with that following navigated total knee arthroplasty for younger patients (HR = 1.13 [95% CI = 1.03 to 1.25], p = 0.011). Patients less than sixty-five years of age who had undergone non-navigated total knee arthroplasty had a cumulative percent revision of 7.8% (95% CI = 7.5 to 8.2) at nine years compared with 6.3% (95% CI = 5.5 to 7.3) for those who had undergone navigated total knee arthroplasty. Computer navigation led to a significant reduction in the rate of revision due to loosening/lysis (HR = 1.38 [95% CI = 1.13 to 1.67], p = 0.001), which is the most common reason for revision of total knee arthroplasty.
Conclusions: Computer navigation reduced the overall rate of revision and the rate revision for loosening/lysis following total knee arthroplasty in patients less than sixty-five years of age.
Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
TL;DR: There is currently only limited evidence to suggest that stepped care should be the dominant model of treatment organization, and evidence on (cost-) effectiveness compared with high-intensity psychological therapy alone, as well as with matched care, is required.
Abstract: Background In stepped care models patients typically start with a low-intensity evidence-based treatment. Progress is monitored systematically and those patients who do not respond adequately step up to a subsequent treatment of higher intensity. Despite the fact that many guidelines have endorsed this stepped care principle it is not clear if stepped care really delivers similar or better patient outcomes against lower costs compared with other systems. We performed a systematic review and meta-analysis of all randomized trials on stepped care for depression. Method We carried out a comprehensive literature search. Selection of studies, evaluation of study quality and extraction of data were performed independently by two authors. Results A total of 14 studies were included and 10 were used in the meta-analyses (4580 patients). All studies used screening to identify possible patients and care as usual as a comparator. Study quality was relatively high. Stepped care had a moderate effect on depression (pooled 6-month between-group effect size Cohen's d was 0.34; 95% confidence interval 0.20–0.48). The stepped care interventions varied greatly in number and duration of treatment steps, treatments offered, professionals involved, and criteria to step up. Conclusions There is currently only limited evidence to suggest that stepped care should be the dominant model of treatment organization. Evidence on (cost-) effectiveness compared with high-intensity psychological therapy alone, as well as with matched care, is required.
TL;DR: In this paper, a systematic review and meta-analysis of prospective cohort studies to evaluate the relation of active smoking with risk of total mortality and cardiovascular events among diabetic patients was performed.
Abstract: Background—The prevalence of smoking in diabetic patients remains high, and reliable quantification of the excess mortality and morbidity risks associated with smoking is important for diabetes management. We performed a systematic review and meta-analysis of prospective cohort studies to evaluate the relation of active smoking with risk of total mortality and cardiovascular events among diabetic patients. Methods and Results—We searched Medline and Embase databases through May 2015, and multivariate-adjusted relative risks were pooled by using random-effects models. A total of 89 cohort studies were included. The pooled adjusted relative risk (95% confidence interval) associated with smoking was 1.55 (1.46–1.64) for total mortality (48 studies with 1 132 700 participants and 109 966 deaths), and 1.49 (1.29–1.71) for cardiovascular mortality (13 studies with 37 550 participants and 3163 deaths). The pooled relative risk (95% confidence interval) was 1.44 (1.34–1.54) for total cardiovascular disease (16 st...
TL;DR: A subjective five-category global assessment scale (GAS) was used as an external anchor to determine the minimum important change (MIC) in the 15D scores, which can be regarded as the generic MIC thresholds for improvement/deterioration.
Abstract: To facilitate the interpretation of empirical results produced by the 15D, a generic, preference-based instrument for measuring health-related quality of life (HRQoL), a subjective five-category global assessment scale (GAS) was used as an external anchor to determine the minimum important change (MIC) in the 15D scores. Altogether 4,903 hospital patients representing sixteen disease entities and having the 15D score at baseline repeated the HRQoL assessment at 6 months after treatment and answered the question: compared to the situation before treatment, my overall health status is now (1) much better, (2) slightly better, (3) much the same, (4) slightly worse, (5) much worse. Regression analysis was used to estimate the MIC for improvement/deterioration, defined as the lower/upper limit of 99.9 % confidence interval of the regression coefficient, standardized for baseline HRQoL, for categories (2) and (4), respectively, and confirmed by ROC curve analysis. The limits or intervals for classifying the changes of 15D scores into GAS categories were >.035 for (1), .015–.035 for (2),>−.015 and<.015 for (3), −.035–−.015 for (4) and <−.035 for (5). The lower/upper limits of ±.015 for categories (2) and (4) can be regarded as the generic MIC thresholds for improvement/deterioration, respectively. The generic MICs for the change of 15D scores are ±.015. Follow-up studies using the 15D should report the mean change in the 15D score, its statistical significance, relationship to the MIC, and the distribution of the changes of the 15D scores into the five categories.
TL;DR: An alternative to the bootstrap is demonstrated, a computationally efficient influence curve based approach to obtaining a variance estimate for cross-validated AUC.
Abstract: In binary classification problems, the area under the ROC curve (AUC) is commonly used to evaluate the performance of a prediction model. Often, it is combined with cross-validation in order to assess how the results will generalize to an independent data set. In order to evaluate the quality of an estimate for cross-validated AUC, we obtain an estimate of its variance. For massive data sets, the process of generating a single performance estimate can be computationally expensive. Additionally, when using a complex prediction method, the process of cross-validating a predictive model on even a relatively small data set can still require a large amount of computation time. Thus, in many practical settings, the bootstrap is a computationally intractable approach to variance estimation. As an alternative to the bootstrap, we demonstrate a computationally efficient influence curve based approach to obtaining a variance estimate for cross-validated AUC.
TL;DR: A fast analytic method that uses polygenic scores, based on the formula for the non-centrality parameter of the association test of the score, that provides nearly unbiased estimates and confidence intervals with good coverage, although estimation of the variance is less reliable when jointly estimated with the covariance.
Abstract: Several methods have been proposed to estimate the variance in disease liability explained by large sets of genetic markers. However, current methods do not scale up well to large sample sizes. Linear mixed models require solving high-dimensional matrix equations, and methods that use polygenic scores are very computationally intensive. Here we propose a fast analytic method that uses polygenic scores, based on the formula for the non-centrality parameter of the association test of the score. We estimate model parameters from the results of multiple polygenic score tests based on markers with p values in different intervals. We estimate parameters by maximum likelihood and use profile likelihood to compute confidence intervals. We compare various options for constructing polygenic scores, based on nested or disjoint intervals of p values, weighted or unweighted effect sizes, and different numbers of intervals, in estimating the variance explained by a set of markers, the proportion of markers with effects, and the genetic covariance between a pair of traits. Our method provides nearly unbiased estimates and confidence intervals with good coverage, although estimation of the variance is less reliable when jointly estimated with the covariance. We find that disjoint p value intervals perform better than nested intervals, but the weighting did not affect our results. A particular advantage of our method is that it can be applied to summary statistics from single markers, and so can be quickly applied to large consortium datasets. Our method, named AVENGEME (Additive Variance Explained and Number of Genetic Effects Method of Estimation), is implemented in R software.
TL;DR: Perturbation-based balance training appears to reduce fall risk among older adults and individuals with Parkinson disease and some appropriate studies were not included.
Abstract: Background Older adults and individuals with neurological conditions are at an increased risk for falls. Although physical exercise can prevent falls, certain types of exercise may be more effective. Perturbation-based balance training is a novel intervention involving repeated postural perturbations aiming to improve control of rapid balance reactions.
Purpose The purpose of this study was to estimate the effect of perturbation-based balance training on falls in daily life.
Data Sources MEDLINE (1946–July 2014), EMBASE (1974–July 2014), PEDro (all dates), CENTRAL (1991–July 2014), and Google Scholar (all dates) were the data sources used in this study.
Study Selection Randomized controlled trials written in English were included if they focused on perturbation-based balance training among older adults or individuals with neurological conditions and collected falls data posttraining.
Data Extraction Two investigators extracted data independently. Study authors were contacted to obtain missing information. A PEDro score was obtained for each study. Primary outcomes were proportion of participants who reported one or more falls (ie, number of “fallers”) and the total number of falls. The risk ratio (proportion of fallers) and rate ratio (number of falls) were entered into the analysis.
Data Synthesis Eight studies involving 404 participants were included. Participants who completed perturbation-based balance training were less likely to report a fall (overall risk ratio=0.71; 95% confidence interval=0.52, 0.96; P =.02) and reported fewer falls than those in the control groups (overall rate ratio=0.54; 95% confidence interval=0.34, 0.85; P =.007).
Limitations Study authors do not always identify that they have included perturbation training in their intervention; therefore, it is possible that some appropriate studies were not included. Study designs were heterogeneous, preventing subanalyses.
Conclusions Perturbation-based balance training appears to reduce fall risk among older adults and individuals with Parkinson disease.
TL;DR: Using a simple algorithm incorporating baseline hs-cTnI values and the absolute change within the first hour allows safe rule-out as well as accurate rule-in of acute myocardial infarction in 70% of patients presenting with suspected acute my Cardiac Infarction.
TL;DR: In previous studies, BC risk reduction after RRSO in BRCA1/2 mutation carriers may have been overestimated because of bias, and a design that maximally eliminated bias was found, there was no evidence for a protective effect.
Abstract: Background: Previous studies have reported a breast cancer (BC) risk reduction of approximately 50% after risk-reducing salpingo-oophorectomy (RRSO) in BRCA1/2 mutation carriers, but may have been subject to several types of bias. The purpose of this nationwide cohort study was to assess potential bias in the estimated BC risk reduction after RRSO. Methods: We selected BRCA1/2 mutation carriers from an ongoing nationwide cohort study on Hereditary Breast and Ovarian Cancer in the Netherlands (HEBON). First, we replicated the analytical methods as previously applied in four major studies on BC risk after RRSO. Cox proportional hazards models were used to calculate hazard ratios and conditional logistic regression to calculate odds ratios. Secondly, we analyzed the data in a revised design in order to further minimize bias using an extended Cox model with RRSO as a time-dependent variable to calculate the hazard ratio. The most important differences between our approach and those of previous studies were the requirement of no history of cancer at the date of DNA diagnosis and the inclusion of person-time preceding RRSO. Results: Applying the four previously described analytical methods and the data of 551 to 934 BRCA1/2 mutation carriers with a median follow-up of 2.7 to 4.6 years, the odds ratio was 0.61 (95% confidence interval [CI] = 0.35 to 1.08), and the hazard ratios were 0.36 (95% CI = 0.25 to 0.53), 0.62 (95% CI = 0.39 to 0.99), and 0.49 (95% CI = 0.33 to 0.71), being similar to earlier findings. For the revised analysis, we included 822 BRCA1/2 mutation carriers. After a median follow-up period of 3.2 years, we obtained a hazard ratio of 1.09 (95% CI = 0.67 to 1.77). Conclusion: In previous studies, BC risk reduction after RRSO in BRCA1/2 mutation carriers may have been overestimated because of bias. Using a design that maximally eliminated bias, we found no evidence for a protective effect.
TL;DR: Shorter mean annual withdrawal times during screening colonoscopies were independently associated with lower adenoma detection rates and increased risk of interval colorectal cancer.
TL;DR: Prophylactic systemic antifungal therapy reduces the incidence of invasive fungal infection in very preterm or very low birth weight infants and Meta-analysis does not demonstrate a statistically significant effect on mortality.
Abstract: Background Invasive fungal infection is an important cause of mortality and morbidity in very low birth weight infants. Early diagnosis is difficult, and treatment is often delayed. The available data are insufficient to conclude that topical/oral prophylaxis (usually nystatin and/or miconazole) prevents invasive fungal infection or mortality in very low birth weight infants. Systemic antifungal agents (usually azoles) are increasingly used as prophylaxis against invasive fungal infection. Objectives To assess the effect of prophylactic systemic antifungal therapy on mortality and morbidity in very low birth weight infants. Search strategy The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of the Cochrane Controlled Trials Register (The Cochrane Library, Issue 2, 2007), MEDLINE (1966 - May 2007), EMBASE (1980 - May 2007), conference proceedings, and previous reviews. Selection criteria Randomised controlled trials that compared the effect of prophylactic systemic antifungal therapy versus placebo, or no drug, or another antifungal agent or dose regimen, in very low birth weight infants. Data collection and analysis Data were extracted using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by each author, and synthesis of data using relative risk, risk difference, and weighted mean difference. The pre-specified outcomes were death prior to hospital discharge, long-term neurodevelopment, incidence of invasive fungal infection, emergence of antifungal resistance, and adverse drug reactions. Main results Seven eligible trials enrolling a total of 638 participating infants were identified. Meta-analysis of data from four trials that compared prophylactic fluconazole versus placebo revealed a statistically significant reduction in the risk of invasive fungal infection in the infants who received prophylaxis [typical relative risk: 0.23 (95% confidence interval 0.11, 0.46); typical risk difference: -0.11 (95% confidence interval -0.16, -0.06); number needed to treat: 9 (95% confidence interval 6, 17)]. There was no statistically significant difference in the risk of death prior to hospital discharge [typical relative risk: 0.61 (95% confidence interval 0.37, 1.03); typical risk difference: -0.05 (95% confidence interval -0.11, -0.00)]. Only one trial reported long term neurodevelopmental outcomes. There were no statistically significant differences in the incidence of developmental delay, or motor or sensory neurological impairment in children assessed at a median age of 16 months. One small trial that compared systemic versus oral/topical prophylaxis did not detect a statistically significant effect on invasive fungal infection or mortality. Two trials compared different dosing regimens of prophylactic intravenous fluconazole. These did not detect any significant differences in infection rates or mortality. Authors' conclusions Prophylactic systemic antifungal therapy reduces the incidence of invasive fungal infection in very low birth weight infants. This finding should be interpreted cautiously. The incidence of invasive fungal infection was very high in the control groups of some of the included trials. Furthermore, the trials may have been affected by ascertainment bias since use of prophylactic fluconazole may reduce the sensitivity of microbiological culture for detecting fungi in blood, urine, or cerebrospinal fluid. Meta-analysis does not demonstrate a statistically significant effect on overall mortality rates, but the 95% confidence interval around this estimate of effect is wide. There are currently only limited data on the long-term neurodevelopmental consequences for infants exposed to this intervention. In addition, there is a need for further data on the effect of the intervention on the emergence of organisms with antifungal resistance.
TL;DR: Based on meta-analysis, split-dose regimens increase the quality of colon cleansing and are preferred by patients compared with day-before preparations, and additional research is required to evaluate oral sulfate solution-based and PEG low-volume regimens further.