Sample Size

Results: Twenty five (58%) control patients died at home compared with 124 (67%) patients allocated to hospital at home. This difference was not significant; intention to treat analysis did not show that hospital at home increased the number of deathsat home. Seventy three patients ...

Post-tonsillectomy swallowing pain is a common and distressing side effect after tonsillectomy and thus of great clinical interest. Up until now, there is no randomized controlled patient- and observer-blinded study evaluating the efficacy of acupuncture against swallowing pain after tonsillectomy. We therefore compared the potency of specific verum acupuncture points related to a Chinese medical diagnosis in reducing postoperative swallowing pain with non-specific control points on the body as well as a non-acupuncture group who received standard medication only. The standardized pain therapy after tonsillectomy was orally administered nonsteroidal anti-inflammatory drugs (NSAID) (diclofenac 3 × 50 mg oral). The patients (n = 123) treated with NSAID were asked about their acute pain after taking a sip of water between the first and fifth postoperative day. Participants’ pain was assessed using visual analog (VAS) [zero (0) for no pain up to ten (10) for the acute reported outset pain] before and 20 min, 1, 2 and 3 h after acupuncture treatment or standard pain medication, respectively. The functional assessment of diagnosis and treatment point-combination occurred by means of the “Heidelberg Model” of Traditional Chinese Medicine (TCM). Verum acupuncture lead to a significant additional pain relief. In comparison to the acupuncture, they also reported an average of 3 h duration of adequate pain-relief past taking the NSAID. This trial strongly supports a specific acupuncture scheme for the treatment of postoperative swallowing pain after tonsillectomy. It may particularly serve as an alternative pain treatment in case of NSAID intolerances.

Aims/hypothesis There has been much focus on the potential role of mitochondria in the aetiology of type 2 diabetes and the metabolic syndrome, and many case–control mitochondrial association studies have been undertaken for these conditions. We tested for a potential association between common mitochondrial variants and a number of quantitative traits related to type 2 diabetes in a large sample of >2,000 healthy Australian adolescent twins and their siblings, many of whom were measured on more than one occasion. Methods To the best of our knowledge, this is the first mitochondrial association study of quantitative traits undertaken using family data. The maternal inheritance pattern of mitochondria means established association methodologies are unsuitable for analysis of mitochondrial data in families. We present a methodology, implemented in the freely available program Sib-Pair for performing such an analysis. Results Despite our study having the power to detect variants with modest effects on these phenotypes, only one significant association was found after correction for multiple testing in any of four age groups. This was for mt14365 with triacylglycerol levels (unadjusted p = 0.0006). This association was not replicated in other age groups. Conclusions/interpretation We find little evidence in our sample to suggest that common European mitochondrial variants contribute to variation in quantitative phenotypes related to diabetes. Only one variant showed a significant association in our sample, and this association will need to be replicated in a larger cohort. Such replication studies or future meta-analyses may reveal more subtle effects that could not be detected here because of limitations of sample size.

In this paper the authors show that the largest eigenvalue of the sample covariance matrix tends to a limit under certain conditions when both the number of variables and the sample size tend to infinity. The above result is proved under the mild restriction that the fourth moment of the elements of the sample sums of squares and cross products (SP) matrix exist.

The needle biopsy technique described by Bergström is the most commonly used technique to obtain samples to assess muscle metabolism. Sampling of muscle, particularly the vastus lateralis, has become an essential tool in biomedical and clinical research. Optimal sample size is critical for availability of tissue for processing. To evaluate the effectiveness of a novel technique to obtain adequate sample size using wall suction applied to needle muscle biopsy, we collected samples from subjects in on-going clinical studies for gene expression.Muscle biopsy samples of the vastus lateralis using 6 mm Bergström needles under local anesthesia were obtained from 55 subjects who had volunteered to participate in this research project. The vastus lateralis was biopsied according to the methods described by Bergström with a 6 mm biopsy needle. Wall suction was applied to the inner bore of the biopsy needle after the needle was inserted into the muscle.The mean sample of biopsy taken using the 6 mm was 233 mg (n = 55). The wall suction (200 mm Hg) applied to the needle pulled the surrounding tissue into the central bore of the needle. The quality of the samples was adequate for all biochemical assays. The biopsy technique did not result in any complications due to infection or bleeding.Using a novel technique of connecting a 6 mm Bergström biopsy needle to wall suction, we have obtained 200 to 300 mg muscle biopsy specimens uniformly, with ease, and minimal discomfort. An increase in sample size allows for a wider variety of biochemical and histopathological analysis.

Systematic methods for improving response rates in surveys has been an area of interest for researchers for some time following the articulation of the Total Design Method (Dillman 1978) which included applying aspects of social influence and social exchange theory to encourage responses. One part of the literature focused on the idea of offering a tangible but token incentive to respondents at the time of the request for data. Subsequent research and experience has shown that appropriate incentives do improve respondent cooperation in terms of obtaining better response rates (eg Singer and Wilmot 1997; Yammarino, Skinner and Childers 1991). The focus of most work has been on using monetary or token material incentives for surveys of individuals, so little is known about the problem of how to motivate businesses and the individuals in them to respond. The situation of National Statistical Organisations (NSOs) conducting surveys of businesses is also different to that of many other s...

A method was validated for the multi-residue analysis of 82 pesticides in grapes at ≤25 ng/g level. Berry samples (10 g) mixed with sodium sulphate (10 g) were extracted with ethyl acetate (10 mL); cleaned by dispersive solid phase extraction and the results were obtained by liquid chromatography–tandem mass spectrometry. Reduction in sample size and proportion of ethyl acetate for extraction did not affect accuracy or precision of analysis when compared to the reported methods and was also statistically similar to the QuEChERS technique. The method was rugged (HorRat < 0.5) with <20% measurement uncertainties. Limit of quantification was <10 ng/g with recoveries 70–120% for most pesticides. The method offers cheaper and safer alternative to typical multi-residue analysis methods for grape.

Design/methodology/approach – The paper used a mail-survey of companies listed in the Directory of the Federation of Malaysian Manufacturers (FMM), year 2003. The FMM Directory provides a database of over 2,000 manufacturing firms of various sizes producing a broad range of ...

In this paper, we consider constructing reliable confidence intervals for regression parameters using robust M-estimation allowing for the possibility of time series correlation among the errors. The change of variance function is used to approximate the theoretical coverage ...