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Total Sample Size (total + sample_size)
Selected AbstractsAcupuncture for schizophrenia: a systematic review and meta-analysisINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 11 2009M. S. Lee Summary Background:, Acupuncture is one of the most popular types of complementary/alternative medicine. It is sometimes used as a treatment for schizophrenia. Aims:, The objective of this review is to assess systematically the clinical evidence for or against acupuncture as a treatment for schizophrenia. Methods:, We searched 20 databases from their inception to May 2009 without language restrictions. All randomised clinical trials (RCTs) of acupuncture, with or without electrical stimulation or moxibustion for patients with schizophrenia were considered for inclusion. Results:, Thirteen RCTs, all originating from China, met the inclusion criteria. One RCT reported significant effects of electroacupuncture (EA) plus drug therapy for improving auditory hallucunations and positive symptom compared with sham EA plus drug therapy. Four RCTs showed significant effects of acupuncture for response rate compared with antipsychotic drugs [n = 360, relative risk (RR): 1.18, 95% confidence interval (CI): 1.03,1.34, p = 0.01; heterogeneity: ,2 = 0.00, ,2 = 2.98, p = 0.39, I2 = 0%]. Seven RCTs showed significant effects of acupuncture plus antipsychotic drug therapy for response rate compared with antipsychotic drug therapy (n = 457, RR: 1.15, 95% CI: 1.04,1.28, p = 0.008, heterogeneity: ,2 = 0.00, ,2 = 6.56, p = 0.36, I2 = 9%). Two RCTs tested laser acupuncture against sham laser acupuncture. One RCT found beneficial effects of laser acupuncture on hallucination and the other RCT showed significant effects of laser acupuncture on response rate, Brief Psychiatric Rating Scale and clinical global index compared with sham laser. The methodological quality was generally poor and there was not a single high quality trial. Conclusion:, These results provide limited evidence for the effectiveness of acupuncture in treating the symptoms of schizophrenia. However, the total number of RCTs, the total sample size and the methodological quality were too low to draw firm conclusions. As all studies originated from China, international studies are needed to test whether there is any effect. [source] Analysis of factors that affect maternal behaviour and breeding success in great apes in captivityINTERNATIONAL ZOO YEARBOOK, Issue 1 2006M. T. ABELLO In this paper the relationship between maternal behaviour and breeding success (or failure) in great apes is described. Data were gathered from a questionnaire survey returned by 48 zoos and from available studbook data, giving a total sample size of 687 individuals [Gorillas Gorilla gorilla (n= 277), Bonobos Pan paniscus (n= 37), Chimpanzees Pan troglodytes (n= 216) and Orangutans Pongo pygmaeus (n= 157)] born between 1990 and 2000 at 86 institutions. The factors influencing maternal behaviour are discussed. Particular attention is paid to the importance of learning and experience for the development of good maternal skills. The rearing background and social-group circumstances of the breeding , were analysed, including her rearing situation (own mother, conspecific surrogate or hand-reared), opportunity (or not) to observe maternal behaviour in conspecifics during development and previous breeding experience. The effects of maternal training are also analysed. The results show that for a , great ape to demonstrate good maternal skills, the most effective experience is to have been reared by her own mother and to have observed maternal behaviour in a social group comprising mature individuals and infants. This gives ,, the opportunity to observe and learn how to care adequately for their own offspring. [source] REVIEW: Questionnaires in ecology: a review of past use and recommendations for best practiceJOURNAL OF APPLIED ECOLOGY, Issue 3 2005PIRAN C. L. WHITE Summary 1Questionnaires, or social surveys, are used increasingly as a means of collecting data in ecology. We present a critical review of their use and give recommendations for good practice. 2We searched for papers in which questionnaires were used in 57 ecological academic journals, published over the period 1991,2003 inclusive. This provided a total sample size of 168 questionnaires from 127 papers published in 22 academic journals. 3Most questionnaires were carried out in North America and western Europe, and addressed species-level issues, principally focusing on mammals. The majority were concerned with impacts of species and/or their conservation, and just under half with human,wildlife interactions. 4Postal survey was the method used most frequently to carry out the questionnaires, followed by in-person interviews. Some questionnaires were conducted by telephone, and none was web-based. 5Most questionnaires were concerned with obtaining factual information or perceptions of facts. Ground-truthing (independent verification of the facts) was carried out in less than 10% of questionnaires. 6The mean (± SE) sample size (number of respondents) per questionnaire was 1422 ± 261 and the average (± SE) response rate was 63 ± 3%. These figures varied widely depending on the methods used to conduct the questionnaire. 7The analysis of data was mostly descriptive. Simple univariate methods were the most frequently used statistical tools, and data from a third of questionnaires were not subjected to any analysis beyond simple descriptions of the results. 8Synthesis and applications. We provide recommendations for best practice in the future use of questionnaires in ecology, as follows: (i) the definition of the target population, any hypotheses to be tested and procedures for the selection of participants should be clearly documented; (ii) questionnaires should be piloted prior to their use; (iii) the sample size should be sufficient for the statistical analysis; (iv) the rationale for the choice of survey method should be clearly stated; (v) the number of non-respondents should be minimized; (vi) the question and answer format should be kept as simple as possible; (vii) the structure of the questionnaire and the data emerging from it should be unambiguously shown in any publication; (viii) bias arising from non-response should be quantified; (ix) the accuracy of data should be assessed by ground-truthing where relevant; (x) the analysis of potentially interrelated data should be done by means of modelling. Researchers should also consider whether alternative, interpretative methods, such as in-depth interviews or participatory approaches, may be more appropriate, for example where the focus is on elucidating motivations or perceptions rather than testing factual hypotheses. [source] Effectiveness of acupuncture for Parkinson's disease: A systematic reviewMOVEMENT DISORDERS, Issue 11 2008Myeong Soo Lee PhD Abstract The objective of this review is to assess the clinical evidence for or against acupuncture as a treatment for Parkinson's disease (PD). We searched the literature using 17 databases from their inception to September 2007 (searched again 3rd January 2008), without language restrictions. We included all randomized clinical trials (RCTs) regardless of their design. Methodological quality was assessed using the Jadad score. Eleven RCTs met all inclusion criteria. Three RCTs assessed the effectiveness of acupuncture on Unified Parkinson's Disease Rating Scale (UPDRS) compared with placebo acupuncture. A meta-analysis of these studies showed no significant effect (n = 96, WMD, 5.7; 95% CI ,2.8 to 14.2, P = 0.19, heterogeneity: tau2 = 0, ,2 = 0.97, P = 0.62, I2 = 0%). Another six RCTs compared acupuncture plus conventional drugs on improvement of symptoms of PD with drugs only. A meta-analysis of two of these studies suggested a positive effect of scalp acupuncture (n = 106, RR, 1.46, 95% CI = 1.15 to 1.87, P = 0.002; heterogeneity: tau2 = 0.00, ,2 = 1.14, P = 0.29, I2 = 12%). Two further RCTs tested acupuncture versus no treatment. The meta-analysis of these studies also suggested beneficial effects of acupuncture. The results of the latter two types of RCTs fail to adequately control for nonspecific effects. In conclusion, the evidence for the effectiveness of acupuncture for treating PD is not convincing. The number and quality of trials as well as their total sample size are too low to draw any firm conclusion. Further rigorous trials are warranted. © 2008 Movement Disorder Society [source] Optimal Robust Two-Stage Designs for Genome-Wide Association StudiesANNALS OF HUMAN GENETICS, Issue 6 2009Thuy Trang Nguyen Summary Optimal robust two-stage designs for genome-wide association studies are proposed using the maximum of the recessive, additive and dominant linear trend test statistics. These designs combine cost-saving two-stage genotyping with robustness against misspecification of the genetic model and are much more efficient than designs based on a single model specific test statistic in detecting multiple loci with different modes of inheritance. For given power of 90%, typical cost savings of 34% can be realised by increasing the total sample size by about 13% but genotyping only about half of the sample for the full marker set in the first stage and carrying forward about 0.06% of the markers to the second stage analysis. We also present robust two-stage designs providing optimal allocation of a limited budget for pre-existing samples. If a sample is available which would yield a power of 90% when fully genotyped, genotyping only half of the sample due to a limited budget will typically cause a loss of power of more than 55%. Using an optimal two-stage approach in the same sample under the same budget restrictions will limit the loss of power to less than 10%. In general, the optimal proportion of markers to be followed up in the second stage strongly depends on the cost ratio for chips and individual genotyping, while the design parameters of the optimal designs (total sample size, first stage proportion, first and second stage significance limit) do not much depend on the genetic model assumptions. [source] Optimal Two-Stage Design for Case-Control Association Analysis Incorporating Genotyping ErrorsANNALS OF HUMAN GENETICS, Issue 3 2008Y. Zuo Summary Two-stage design is a cost effective approach for identifying disease genes in genetic studies and it has received much attention recently. In general, there are two types of two-stage designs that differ on the methods and samples used to measure allele frequencies in the first stage: (1) Individual genotyping is used in the first stage; (2) DNA pooling is used in the first stage. In this paper, we focus on the latter. Zuo et al. (2006) investigated statistical power of such a design, among other things, but the cost of the study was not taken into account. The purpose of this paper is to study the optimal design under the given overall cost. We investigate how to allocate the resources to the two stages. Note that in addition to the measurement errors associated with DNA pooling, genotyping errors are also unavoidable with individual genotyping. Therefore, we discuss the optimal design combining genotyping errors associated with individual genotyping. The joint statistical distributions of test statistics in the first and second stages are derived. For a fixed cost, our results show that the optimal design requires no additional samples in the second stage but only that the samples in the first stage be re-used. When the second stage uses an entirely independent sample, however, the optimal design under a given cost depends on the population allele frequency and allele frequency difference between the case and control groups. For the current genotyping costs, we can roughly allocate 1/3 to 1/2 of the total sample size to the first stage for screening. [source] Adaptive patient enrichment designs in therapeutic trialsBIOMETRICAL JOURNAL, Issue 2 2009Sue-Jane Wang Abstract The utility of clinical trial designs with adaptive patient enrichment is investigated in an adequate and well-controlled trial setting. The overall treatment effect is the weighted average of the treatment effects in the mutually exclusive subsets of the originally intended entire study population. The adaptive enrichment approaches permit assessment of treatment effect that may be applicable to specific nested patient (sub)sets due to heterogeneous patient characteristics and/or differential response to treatment, e.g. a responsive patient subset versus a lack of beneficial patient subset, in all patient (sub)sets studied. The adaptive enrichment approaches considered include three adaptive design scenarios: (i) total sample size fixed and with futility stopping, (ii) sample size adaptation and futility stopping, and (iii) sample size adaptation without futility stopping. We show that regardless of whether the treatment effect eventually assessed is applicable to the originally studied patient population or only to the nested patient subsets; it is possible to devise an adaptive enrichment approach that statistically outperforms one-size-fits-all fixed design approach and the fixed design with a pre-specified multiple test procedure. We emphasize the need of additional studies to replicate the finding of a treatment effect in an enriched patient subset. The replication studies are likely to need fewer number of patients because of an identified treatment effect size that is larger than the diluted overall effect size. The adaptive designs, when applicable, are along the line of efficiency consideration in a drug development program. [source] | |||||||||||||