Evidence report/technology assessment最新文献

Objectives: To describe the overall prevalence of ARV resistance in the developing world, focusing on: (1) treatment naïve populations, (2) the resistance consequences of prevention of mother to child transmission (pMTCT) drug regimens, and (3) the relationship of medication adherence to resistance.

Data sources: We searched PubMed(R), EMBASE, the Cochrane Controlled Clinical Trials Register Database, and the Cochrane Database of Reviews of Effectiveness (DARE). Additional sources of evidence included the Stanford University HIV Drug Resistance Database; reports of WATCH: Worldwide Analysis of Resistance Transmission over Time of Chronically and Acute Infected HIV-1 infected persons; a recent unpublished pMTCT overview; and various conference proceedings. Studies that did not report original research, that reported data already reported in another article, and case studies of fewer than 20 individuals were excluded. Of 1,122 titles identified, 117 journal articles and presentations were included.

Review methods: We abstracted data on geographic region, number of participants, subject demographics, HIV viral clade, medications taken (if any), years of data collection, how people were selected for resistance testing, and how and when resistance was assessed. Because of study heterogeneity, pooling was not possible; thus, the data are summarized qualitatively. Differences by region, population group, and HIV viral clade are described.

Results: The patterns of ARV resistance among treatment naïve populations worldwide appear to reflect geographic trends in use of ARV medications. A worldwide surveillance program (WATCH) found the rate of resistance (to any drug) among treatment naïve individuals was 5.5 percent in Africa, 7.4 percent in East Asia, 5.7 percent in Southeast Asia, and 6.4 percent in Latin America, lower than in North America (11.4 percent) and Europe (10.6 percent). Resistance data on HIV clades other than A, B, C, and D were too scarce to permit reliable conclusions. We also identified very few studies designed to assess the effect of health services delivery factors or medication adherence on the development of resistance in patients in developing countries. Evidence provided by longitudinal analyses suggests that, among women taking intrapartum single dose nevirapine (SD-NVP) to prevent mother-to-child transmission of HIV, both the overall prevalence of NNRTI resistance as well as the frequency of mutant virus in the overall viral population decreases with time since SD-NVP prophylaxis was received.

Conclusions: In future resistance studies, rare HIV clades should be over-sampled in order to provide statistically meaningful data. Resistance surveillance programs should be maintained throughout the developing world, and data should be reported and analyzed in a consistent and timely manner. Where resources permit, studies of

Objectives: Systematic review of outcomes of three treatments for osteoarthritis (OA) of the knee: intra-articular viscosupplementation; oral glucosamine, chondroitin or the combination; and arthroscopic lavage or debridement.

Data sources: We abstracted data from: 42 randomized, controlled trials (RCTs) of viscosupplementation, all but one synthesized among six meta-analyses; 21 RCTs of glucosamine/chondroitin, 16 synthesized among 6 meta-analyses; and 23 articles on arthroscopy. The search included foreign-language studies and relevant conference proceedings.

Review methods: The review methods were defined prospectively in a written protocol. We sought systematic reviews, meta-analyses, and RCTs published in full or in abstract. Where randomized trials were few, we sought other study designs. We independently assessed the quality of all primary studies.

Results: Viscosupplementation trials generally report positive effects on pain and function scores compared to placebo, but the evidence on clinical benefit is uncertain, due to variable trial quality, potential publication bias, and unclear clinical significance of the changes reported. The Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT), a large (n=1,583), high-quality, National Institutes of Health-funded, multicenter RCT showed no significant difference compared to placebo. Glucosamine sulfate has been reported to be more effective than glucosamine hydrochloride, which was used in GAIT, but the evidence is not sufficient to draw conclusions. Clinical studies of glucosamine effect on glucose metabolism are short term, or if longer (e.g., 3 years), excluded patients with metabolic disorders. The best available evidence for arthroscopy, a single sham-controlled RCT (n=180), showed that arthroscopic lavage with or without debridement was equivalent to placebo. The main limitations of this trial are the use of a single surgeon and enrollment of patients at a single Veterans Affairs Medical Center. No studies reported separately on patients with secondary OA of the knee. The only comparative study was an underpowered, poor-quality trial comparing viscosupplementation to arthroscopy with debridement.

Conclusions: Osteoarthritis of the knee is a common condition. The three interventions reviewed in this report are widely used in the treatment of OA of the knee, yet the best available evidence does not clearly demonstrate clinical benefit. Uncertainty regarding clinical benefit can be resolved only by rigorous, multicenter RCTs. In addition, given the public health impact of OA of the knee, research on new approaches to prevention and treatment should be given high priority.

Objectives: To review and synthesize the literature in the following areas: the association of specific circulating 25(OH)D concentrations with bone health outcomes in children, women of reproductive age, postmenopausal women and elderly men; the effect of dietary intakes (foods fortified with vitamin D and/or vitamin D supplementation) and sun exposure on serum 25(OH)D; the effect of vitamin D on bone mineral density (BMD) and fracture or fall risk; and the identification of potential harms of vitamin D above current reference intakes.

Data sources: MEDLINE(R) (1966-June Week 3 2006); Embase (2002-2006 Week 25); CINAHL (1982-June Week 4, 2006); AMED (1985 to June 2006); Biological Abstracts (1990-February 2005); and the Cochrane Central Register of Controlled Trials (2nd Quarter 2006).

Review methods: Two independent reviewers completed a multi-level process of screening the literature to identify eligible studies (title and abstract, followed by full text review, and categorization of study design per key question). To minimize bias, study design was limited to randomized controlled trials (RCTs) wherever possible. Study criteria for question one were broadened to include observational studies due to a paucity of available RCTs, and question four was restricted to systematic reviews to limit scope. Data were abstracted in duplicate and study quality assessed. Differences in opinion were resolved through consensus or adjudication. If clinically relevant and statistically feasible, meta-analyses of RCTs on vitamin D supplementation and bone health outcomes were conducted, with exploration of heterogeneity. When meta-analysis was not feasible, a qualitative systematic review of eligible studies was conducted.

Results: 167 studies met our eligibility criteria (112 RCTs, 19 prospective cohorts, 30 case-controls and six before-after studies). The largest body of evidence on vitamin D status and bone health was in older adults with a lack of studies in premenopausal women and infants, children and adolescents. The quality of RCTs was highest in the vitamin D efficacy trials for prevention of falls and/or fractures in older adults. There was fair evidence of an association between low circulating 25(OH)D concentrations and established rickets. However, the specific 25(OH)D concentrations associated with rickets is uncertain, given the lack of studies in populations with dietary calcium intakes similar to North American diets and the different methods used to determine 25(OH)D concentrations. There was inconsistent evidence of an association of circulating 25(OH)D with bone mineral content in infants, and fair evidence that serum 25(OH)D is inversely associated with serum PTH. In adolescents, there was fair evidence for an association between 25(OH)D levels and changes in BMD. There were very few studies in pregnant and lactating women, and insufficient evidence for

Objectives: The RTI International-University of North Carolina at Chapel Hill Evidence-based Practice Center (RTI-UNC EPC) systematically updated evidence on the management of uterine fibroids, specifically incidence and prevalence of fibroids, treatment outcomes, comparisons of treatment, modifiers of outcomes, and costs.

Data sources: We searched MEDLINE(R), Cochrane Collaboration resources, and Embase.

Review methods: We included studies published in English from February 2000 through August 2006. We excluded studies with low sample size (based on study design, cases series < 100 and cohorts < 40) or lack of relevance to uterine fibroids. Of 107 included studies, 3 were good quality, 56 fair, and 48 poor.

Results: The cumulative incidence by age 50 is 70 percent to 80 percent; black women are more likely to get fibroids at younger ages. Appearance of new fibroids and growth of existing fibroids after treatment are poorly studied. Trials of preoperative medical management indicate that treatment reduces fibroid volume but do not provide sufficient evidence of improvement in important operative outcomes. When women are treated for reasons other than symptom relief, such as when pregnancy is desired, weak evidence supports treating submucous fibroids via hysteroscopy. No well-conducted trials in U.S. populations directly compared treatment options, including the option of expectant management, or followed women to determine whether the intervention met their treatment objectives. Common procedures such as hysterectomy and myomectomy, including choice among types of myomectomy, still cannot be meaningfully compared. Studies comparing uterine artery embolization (UAE) with other procedures reported procedure time and length of stay favoring UAE, but inconsistency of the direction of effect for complications and absence of key information on longer-term outcomes suggest that this evidence base is inadequate to comment on the relative risks and benefits of UAE versus hysterectomy or myomectomy. Costs of fibroid treatment, despite shorter average lengths of stay, are rising.

Conclusions: The dearth of high-quality evidence supporting the effectiveness of most interventions for uterine fibroids is remarkable, given how common this problem is. The current state of the literature does not permit definitive conclusions about benefit, harm, or relative costs to help guide women's choices. Significant research gaps include well-conducted trials in U.S. populations that directly compare interventions on short- and, especially, long-term outcomes, studies on therapeutics for medical management, and information on treatment decisions for women who desire a pregnancy.

Objectives: To review and synthesize the state of research on a variety of meditation practices, including: the specific meditation practices examined; the research designs employed and the conditions and outcomes examined; the efficacy and effectiveness of different meditation practices for the three most studied conditions; the role of effect modifiers on outcomes; and the effects of meditation on physiological and neuropsychological outcomes.

Data sources: Comprehensive searches were conducted in 17 electronic databases of medical and psychological literature up to September 2005. Other sources of potentially relevant studies included hand searches, reference tracking, contact with experts, and gray literature searches.

Review methods: A Delphi method was used to develop a set of parameters to describe meditation practices. Included studies were comparative, on any meditation practice, had more than 10 adult participants, provided quantitative data on health-related outcomes, and published in English. Two independent reviewers assessed study relevance, extracted the data and assessed the methodological quality of the studies.

Results: Five broad categories of meditation practices were identified (Mantra meditation, Mindfulness meditation, Yoga, Tai Chi, and Qi Gong). Characterization of the universal or supplemental components of meditation practices was precluded by the theoretical and terminological heterogeneity among practices. Evidence on the state of research in meditation practices was provided in 813 predominantly poor-quality studies. The three most studied conditions were hypertension, other cardiovascular diseases, and substance abuse. Sixty-five intervention studies examined the therapeutic effect of meditation practices for these conditions. Meta-analyses based on low-quality studies and small numbers of hypertensive participants showed that TM(R), Qi Gong and Zen Buddhist meditation significantly reduced blood pressure. Yoga helped reduce stress. Yoga was no better than Mindfulness-based Stress Reduction at reducing anxiety in patients with cardiovascular diseases. No results from substance abuse studies could be combined. The role of effect modifiers in meditation practices has been neglected in the scientific literature. The physiological and neuropsychological effects of meditation practices have been evaluated in 312 poor-quality studies. Meta-analyses of results from 55 studies indicated that some meditation practices produced significant changes in healthy participants.

Conclusions: Many uncertainties surround the practice of meditation. Scientific research on meditation practices does not appear to have a common theoretical perspective and is characterized by poor methodological quality. Firm conclusions on the effects of meditation practices in healthcare cannot be drawn based on the available evidence. Future r

Objectives: To determine the efficacy, effectiveness, and safety of cardiac resynchronization therapy (CRT) and/or implantable cardioverter defibrillators (ICD) in patients with left ventricular systolic dysfunction (LVSD).

Data sources: A systematic and comprehensive literature search was conducted to identify randomized controlled trials (RCTs) evaluating efficacy and observational studies evaluating effectiveness or safety of CRT and/or ICD in patients with LVSD.

Review methods: Study selection, quality assessment, and data extraction were completed by several investigators in duplicate and independently. Random-effects models were used for analyses.

Results: From 11,340 citations, we identified 14 RCTs (4,420 patients) for the CRT efficacy review, 106 studies (9,209 patients) for the CRT effectiveness review, 89 studies (9,677 patients) for the CRT safety review, 12 RCTs (8,516 patients) for the ICD efficacy review, 48 studies (15,097 patients) for the ICD effectiveness review, and 49 studies (12,592 patients) for the ICD safety review-all studies enrolled only patients with LVSD. An additional 12 studies (68,848 patients) were included for an analysis of peri-implant outcomes for all patients with ICD (i.e., not only LVSD patients). All patients in the CRT studies had LVSD (mean LVEF from 21 to 30 percent) and prolonged QRS duration (mean from 155 to 209 msec), and 91 percent had New York Heart Association (NYHA) class III or IV symptoms. In patients with LVSD and heart failure symptoms, CRT improved ejection fraction (weighted mean difference 3.0 percent [95% CI, 0.9 to 5.1]), quality of life (weighted mean reduction in Minnesota Living with Heart Failure Questionnaire 8.0 points [95% CI, 5.6 to 10.4 points]), and function (59 percent of CRT recipients vs. 37 percent of controls improved by at least one NYHA class in the RCTs and between 63 percent and 82 percent of CRT recipients improved by at least one NYHA class in observational studies). The proportion of patients hospitalized for HF was reduced by 37 percent (95% CI, 7 to 57 percent) and all-cause mortality was reduced by 22 percent (95% CI, 9 to 33 percent; NNT=29 over 6 months). Implant success rate was 93 percent, 0.3 percent of patients with LVSD died during implantation. Over a median 11-month followup, 6.6 percent of CRT devices exhibited lead problems and 5 percent malfunctioned. In patients with LVSD, ICD reduced all-cause mortality by 20 percent (95% CI, 10 to 29 percent; NNT=20 over 35 months). ICD implant success rate was 99 percent and peri-implant deaths occurred in 1.2 percent of LVSD patients and 1.3 percent of all implantees. The frequency of post-implantation complications in LVSD patients per 100 patient years included 1.4 (95% CI, 1.2 to 1.6) device malfunctions, 1.5 (95% CI, 1.3 to 1.8) lead problems, 0.6 (95% CI, 0.5 to 0.8) implant site infections, and 19.1 (95% CI, 16.5 to 2

Objectives: Hereditary Nonpolyposis Colorectal Cancer (HNPCC) has been defined clinically and genetically. The disorder has traditionally been recognized in kindreds with a clustering of related cancers in association with mutations in DNA mismatch repair genes. HNPCC is associated with a substantially increased risk for several forms of malignancy but particularly colorectal and endometrial cancer. There were three main objectives of this report: (1) to assess the sensitivity, specificity, and reliability of laboratory and genetic tests commonly used in evaluating patients for HNPCC (analytic validity); (2) to summarize the accuracy of commonly used clinical and laboratory characteristics for predicting the presence of HNPCC in patients with colorectal cancer (clinical validity) and use these estimates to describe the efficiency of various strategies for identifying patients with a mismatch repair mutation; (3) to describe the benefits and harms related to screening and testing patients with colorectal cancer and their family members for HNPCC.

Data sources: Published literature identified through an electronic search (through April 2006), review of relevant bibliographies, and suggestions from technical experts.

Review methods: We evaluated studies critically and summarized the data qualitatively or by meta-analysis when studies used similar methodology and endpoints. We used decision trees to describe the efficiency of various strategies for identifying patients with HNPCC from a hypothetical population of patients with colorectal cancer.

Results: We included a total of 104 studies of which 40 addressed issues related to clinical validity, 3 to analytic validity, and 61 to benefits and harms. We identified only three studies on analytic validity and thus there exists a major gap in the published literature with regard to the accuracy and reliability of specific tests used in the evaluation of HNPCC. Among unselected patients with colorectal cancer who fulfilled the Amsterdam I criteria, 44% (95% CI: 35, 52%) carried pathogenic mismatch repair mutations (mainly in the MLH1 and MSH2 genes). The proportion was somewhat higher (51% [95% CI: 35, 66%]) among studies that performed sequencing on all available samples. The prevalence of MMR mutation carriers may be higher when genetic testing includes evaluation for large genomic deletions/rearrangements and when testing is also performed on MSH6 and PMS2. Approximately 71% (95% CI 63, 78%) of colorectal cancers from patients who fulfilled the Amsterdam I criteria demonstrated microsatellite instability while 40% (95% CI: 28, 53%) demonstrated loss of protein expression by immunohistochemistry. Of nine clinical strategies considered for detecting the presence of mismatch repair mutations in patients with colorectal cancer, the combination of three clinical predictors (age less than 50 years old at diagnosis; or a

Objectives: We reviewed the evidence on the effects of breastfeeding on short- and long-term infant and maternal health outcomes in developed countries.

Data sources: We searched MEDLINE(R), CINAHL, and the Cochrane Library in November of 2005. Supplemental searches on selected outcomes were searched through May of 2006. We also identified additional studies in bibliographies of selected reviews and by suggestions from technical experts.

Review methods: We included systematic reviews/meta-analyses, randomized and non-randomized comparative trials, prospective cohort, and case-control studies on the effects of breastfeeding and relevant outcomes published in the English language. Included studies must have a comparative arm of formula feeding or different durations of breastfeeding. Only studies conducted in developed countries were included in the updates of previous systematic reviews. The studies were graded for methodological quality.

Results: We screened over 9,000 abstracts. Forty-three primary studies on infant health outcomes, 43 primary studies on maternal health outcomes, and 29 systematic reviews or meta-analyses that covered approximately 400 individual studies were included in this review. We found that a history of breastfeeding was associated with a reduction in the risk of acute otitis media, non-specific gastroenteritis, severe lower respiratory tract infections, atopic dermatitis, asthma (young children), obesity, type 1 and 2 diabetes, childhood leukemia, sudden infant death syndrome (SIDS), and necrotizing enterocolitis. There was no relationship between breastfeeding in term infants and cognitive performance. The relationship between breastfeeding and cardiovascular diseases was unclear. Similarly, it was also unclear concerning the relationship between breastfeeding and infant mortality in developed countries. For maternal outcomes, a history of lactation was associated with a reduced risk of type 2 diabetes, breast, and ovarian cancer. Early cessation of breastfeeding or not breastfeeding was associated with an increased risk of maternal postpartum depression. There was no relationship between a history of lactation and the risk of osteoporosis. The effect of breastfeeding in mothers on return-to-pre-pregnancy weight was negligible, and the effect of breastfeeding on postpartum weight loss was unclear.

Conclusions: A history of breastfeeding is associated with a reduced risk of many diseases in infants and mothers from developed countries. Because almost all the data in this review were gathered from observational studies, one should not infer causality based on these findings. Also, there is a wide range of quality of the body of evidence across different health outcomes. For future studies, clear subject selection criteria and definition of "exclusive breastfeeding," reliable collection of feeding data, controlli

Objectives: To assess how nurse to patient ratios and nurse work hours were associated with patient outcomes in acute care hospitals, factors that influence nurse staffing policies, and nurse staffing strategies that improved patient outcomes.

Data sources: MEDLINE (PubMed), CINAHL, Cochrane Databases, EBSCO research database, BioMed Central, Federal reports, National Database of Nursing Quality Indicators, National Center for Workforce Analysis, American Nurses Association, American Academy of Nurse Practitioners, and Digital Dissertations.

Review methods: In the absence of randomized controlled trials, observational studies were reviewed to examine the relationship between nurse staffing and outcomes. Meta-analysis tested the consistency of the association between nurse staffing and patient outcomes; classes of patient and hospital characteristics were analyzed separately.

Results: Higher registered nurse staffing was associated with less hospital-related mortality, failure to rescue, cardiac arrest, hospital acquired pneumonia, and other adverse events. The effect of increased registered nurse staffing on patients safety was strong and consistent in intensive care units and in surgical patients. Greater registered nurse hours spent on direct patient care were associated with decreased risk of hospital-related death and shorter lengths of stay. Limited evidence suggests that the higher proportion of registered nurses with BSN degrees was associated with lower mortality and failure to rescue. More overtime hours were associated with an increase in hospital related mortality, nosocomial infections, shock, and bloodstream infections. No studies directly examined the factors that influence nurse staffing policy. Few studies addressed the role of agency staff. No studies evaluated the role of internationally educated nurse staffing policies.

Conclusions: Increased nursing staffing in hospitals was associated with lower hospital-related mortality, failure to rescue, and other patient outcomes, but the association is not necessarily causal. The effect size varied with the nurse staffing measure, the reduction in relative risk was greater and more consistent across the studies, corresponding to an increased registered nurse to patient ratio but not hours and skill mix. Estimates of the size of the nursing effect must be tempered by provider characteristics including hospital commitment to high quality care not considered in most of the studies. Greater nurse staffing was associated with better outcomes in intensive care units and in surgical patients.

Objectives: To determine if testing for cytochrome P450 (CYP450) polymorphisms in adults entering selective serotonin reuptake inhibitor (SSRI) treatment for non-psychotic depression leads to improvement in outcomes, or if testing results are useful in medical, personal, or public health decisionmaking.

Data sources: We searched MEDLINE, the Cochrane Database of Abstracts of Reviews of Effects, PsychInfo, HealthSTAR, and CINAHL, and reviewed the reference lists of included articles and relevant review articles and meta-analyses for eligible studies. We also included documents from the U.S. Food and Drug Administration (FDA) that could be publicly accessed.

Review methods: We developed an analytic framework and identified key questions to guide the review process. Project-specific inclusion/exclusion criteria were also developed and were used by paired researchers independently to review both abstracts and full-text articles; both researchers were required to agree on inclusion status at the full-text stage. Abstractors evaluated each included article for factors affecting internal and external validity.

Results: A review of 1,200 abstracts led to the final inclusion of 37 articles. The evidence indicates the existence of tests with high sensitivity and specificity for detecting only a few of the more common known polymorphisms of 2D6, 2C19, 2C8, 2C9, and 1A1. There is mixed evidence regarding the association between CYP450 genotypes and SSRI metabolism, efficacy, and tolerability in the treatment of depression, mainly from a series of heterogeneous studies in small samples. There are no data regarding: (a) if testing for CYP450 polymorphisms in adults entering SSRI treatment for non-psychotic depression leads to improvement in outcomes versus not testing, or if testing results are useful in medical, personal, or public health decisionmaking; (b) if CYP450 testing influences depression management decisions by patients and providers in ways that could improve or worsen outcomes; or (c) if there are direct or indirect harms associated with testing for CYP450 polymorphisms or with subsequent management options.

Conclusions: There is a paucity of good-quality data addressing the questions of whether testing for CYP450 polymorphisms in adults entering SSRI treatment for non-psychotic depression leads to improvement in outcomes, or whether testing results are useful in medical, personal, or public health decisionmaking.