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Baseline Measurements (baseline + measurement)
Selected AbstractsOn the Role of Baseline Measurements for Crossover Designs under the Self and Mixed Carryover Effects ModelBIOMETRICS, Issue 1 2010Yuanyuan Liang Summary It is well known that optimal designs are strongly model dependent. In this article, we apply the Lagrange multiplier approach to the optimal design problem, using a recently proposed model for carryover effects. Generally, crossover designs are not recommended when carryover effects are present and when the primary goal is to obtain an unbiased estimate of the treatment effect. In some cases, baseline measurements are believed to improve design efficiency. This article examines the impact of baselines on optimal designs using two different assumptions about carryover effects during baseline periods and employing a nontraditional crossover design model. As anticipated, baseline observations improve design efficiency considerably for two-period designs, which use the data in the first period only to obtain unbiased estimates of treatment effects, while the improvement is rather modest for three- or four-period designs. Further, we find little additional benefits for measuring baselines at each treatment period as compared to measuring baselines only in the first period. Although our study of baselines did not change the results on optimal designs that are reported in the literature, the problem of strong model dependency problem is generally recognized. The advantage of using multiperiod designs is rather evident, as we found that extending two-period designs to three- or four-period designs significantly reduced variability in estimating the direct treatment effect contrast. [source] Haemodynamic effects of ,75 mmHg negative pressure therapy in a porcine sternotomy wound modelINTERNATIONAL WOUND JOURNAL, Issue 1 2009Arash Mokhtari Abstract Previous research has shown ,125 mmHg to be the optimal negative pressure for creating an environment that promotes wound healing, and this has therefore been adopted as a standard pressure for patients with deep sternal wound infection. However, it has not yet been clearly shown that ,125 mmHg is the optimal pressure from a haemodynamic point of view. Furthermore, there have been reports of cardiac rupture during ,125 mmHg negative pressure therapy. We therefore studied the effects of a lower pressure: ,75 mmHg. Twelve pigs were used. After median sternotomy, sealed negative pressure therapy of ,75 mmHg was applied. Baseline measurements were made and continuous recording of the cardiac output, end-tidal CO2 production, mean arterial pressure, mean pulmonary pressure (pulmonary artery pressure), systemic vascular resistance, pulmonary vascular resistance, left atrial pressure and central venous pressure was started. Six pigs served as controls. No statistically significant difference was observed in any of the haemodynamic parameters studied, compared with the controls. The present study shows that, with a suitable foam application technique, ,75 mmHg can be applied without compromising the central haemodynamics. [source] Respiratory Changes in Vasovagal SyncopeJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2000ARVINDER S. KURBAAN M.D. Respiratory Changes in Vasovagal Syncope. introduction: Respiratory changes accompany the cardiovascular changes during head-up. tilt test-induced vasovagal syncope. Methods and Results: Using the 45-minute 60° head-up Westminster protocol, 29 patients were studied (mean age 53.9 ± 20.0 years; 19 females). Two groups resulted: tilt-induced vasovagal syncope positive and negative. The cardiorespiratory parameters blood pressure (BP), heart rate (HR), tidal volume, and minute volume were measured. Comparisons of the cardiorespiratory parameters were made within the positive group and negative group, and then between the two groups. There were 14 in the positive group and 15 in the negative group. Baseline measurements were normalized to 1.0. Comparing the late tilt periods between the positive and negative groups, there were differences in BP (P < 0.002), HR (P < 0.002), tidal volume (P < 0.05), and minute volume (P < 0.002). In the positive group comparing early with late intervals: BP l.11 ± 0.09 versus 0.49 ± 0.17, P < 0.0001; HR 1.18 ± 0.12 versus 0.85 ±0.35, P < 0.009; tidal volume 1.39 ± 0.34 versus 2.17 ± 1.00, P < 0.015; and minute volume 1.24 ± 0.26 versus 3.3 ± 2.03, P < 0.0025. There were no comparable cardiorespiratory changes in the negative group. Conclusion: There were significant differences in the respiratory and cardiovascular parameters measured between those who were positive and those who were negative for tilt-induced vasovagal syncope. Within the positive group, in addition to the falls in HR and BP, there were significant increases in minute volume and tidal volume during late tilt. This suggests that there may be a role for respiratory sensors in vasovagal syncope that may permit earlier and hence possibly more effective therapy for selected patients. [source] Longitudinal study of the Home Falls and Accidents Screening Tool in identifying older people at increased risk of fallsAUSTRALASIAN JOURNAL ON AGEING, Issue 2 2009Lynette Mackenzie Aim:, To evaluate the predictive validity and responsiveness of the Home Falls and Accidents Screening Tool (HOME FAST). Methods:, A prospective study of 727 community dwelling Veterans and war widows aged 70 years and over. The outcome was 6-month recall of any fall at 3-year follow-up. Baseline measurements were taken of common falls risk factors, and home hazards (using the HOME FAST). Changes in the prevalence of HOME FAST items were calculated and a logistic regression model was computed to determine predictors of falls at follow-up. Results:, Prevalence of 14 HOME FAST items was significantly reduced from baseline to follow-up (P , 0.05). Falls were significantly related to the baseline HOME FAST score (odds ratio (OR) 1.016, 95% confidence interval (CI) 1.004,1.098, P = 0.006), and a reduction in home hazards at follow-up (OR 0.984, 95% CI 0.973,0.996, P = 0.02). Conclusion:, The HOME FAST can predict falls in older people and is responsive to change. [source] Effects of a community intervention to reduce the serving of alcohol to intoxicated patronsADDICTION, Issue 6 2010Katariina Warpenius ABSTRACT Aims To assess the effects of an alcohol prevention programme to reduce the serving of alcoholic beverages to intoxicated clients on licensed premises. Research design A controlled pre- (2004) and post-intervention study (2006) design. Intervention A community-based programme combining law enforcement, responsible beverage service training, information campaigns and policy initiatives in one Finnish town (Jyväskylä). Participants and measurements A male actor pretended to be clearly under the influence of alcohol and tried to buy a pint of beer at licensed premises. For the baseline measurement, every bar and nightclub was visited in the intervention and the control areas (94 licensed premises in total). Post-intervention data were gathered with the same principles (100 licensed premises in total). A researcher observed every visit and documented the results. Results In the post-intervention study there was a statistically significant increase in refusals to serve denials alcohol to the actor in the intervention area (from 23% to 42% of the licensed premises) compared to refusals in the control area (from 36% to 27% of the licensed premises). Conclusion Previous research has documented that multi-component community-based interventions can have a significant impact on over-serving of alcohol when training and house policies are combined with effective law enforcement. The present findings also demonstrate that comprehensive Responsible Beverage Service (RBS) interventions applied at a local community level can be effective in decreasing service to intoxicated clients in a Nordic context. [source] Preventing heavy alcohol use in adolescents (PAS): cluster randomized trial of a parent and student intervention offered separately and simultaneouslyADDICTION, Issue 10 2009Ina M. Koning ABSTRACT Aims To evaluate the effectiveness of two preventive interventions to reduce heavy drinking in first- and second-year high school students. Design and setting Cluster randomized controlled trial using four conditions for comparing two active interventions with a control group from 152 classes of 19 high schools in the Netherlands. Participants A total of 3490 first-year high school students (mean 12.68 years, SD = 0.51) and their parents. Intervention conditions (i) Parent intervention (modelled on the Swedish Örebro Prevention Program) aimed at encouraging parental rule-setting concerning their children's alcohol consumption; (ii) student intervention consisting of four digital lessons based on the principles of the theory of planned behaviour and social cognitive theory; (iii) interventions 1 and 2 combined; and (iv) the regular curriculum as control condition. Main outcome measures Incidence of (heavy) weekly alcohol use and frequency of monthly drinking at 10 and 22 months after baseline measurement. Findings A total of 2937 students were eligible for analyses in this study. At first follow-up, only the combined student,parent intervention showed substantial and statistically significant effects on heavy weekly drinking, weekly drinking and frequency of drinking. At second follow-up these results were replicated, except for the effects of the combined intervention on heavy weekly drinking. These findings were consistent across intention-to-treat and completers-only analyses. Conclusions Results suggest that adolescents as well as their parents should be targeted in order to delay the onset of drinking, preferably prior to onset of weekly drinking. [source] Alcohol-specific rules, personality and adolescents' alcohol use: a longitudinal person,environment studyADDICTION, Issue 7 2007Haske Van Der Vorst ABSTRACT Aims To examine the bi-directional associations between providing alcohol-specific rules and adolescents' alcohol use. Further, to explore person,environment interactions, we tested whether Big Five personality traits moderate the assumed association between providing alcohol-specific rules and adolescents' alcohol use. Design Longitudinal data (three waves in 2 years) from 428 families, consisting of both parents and two adolescents (aged 13,16 years) were used for the analyses. Analyses were conducted on four samples: a group of older adolescents and a group of younger adolescents who already consumed alcohol, and a group of older and younger adolescents who were not drinking at baseline measurement. Findings In general, results of structural equation modelling showed that providing clear alcohol-specific rules lowers the likelihood of drinking initiation, regardless of the age of the youngsters. Once adolescents have established a drinking pattern, the impact of parental alcohol-specific rules declined or even disappeared. Finally, the Big Five personality traits did not moderate the association between providing alcohol-specific rules and adolescents' alcohol involvement. Conclusions In sum, in particular during the initiation phase of drinking, parents could prevent the drinking of their offspring, regardless of the age or personality of their youngsters, by providing clear alcohol-specific rules. [source] Sealing ability of occlusal resin composite restoration using four restorative proceduresEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 6 2008Danuchit Banomyong The purpose of this work was to investigate fluid flow after restoration using four restorative procedures. Micro-gap, internal dye leakage, and micropermeability of bonded interfaces were also investigated. Each tooth was mounted, connected to a fluid flow-measuring device, and an occlusal cavity was prepared. Fluid flow after cavity preparation was recorded as the baseline measurement, and the cavity was restored using one of four restorative procedures: bonding with total-etch (Single Bond 2) or self-etch (Clearfil SE Bond) adhesives without lining; or lining with resin-modified glass-ionomer cement (GIC) (Fuji Lining LC) or conventional GIC (Fuji IX) and then bonding with the total-etch adhesive. Fluid flow was recorded after restoration and at specific time-points up to 6 months thereafter and recorded as a percentage. Micro-gap formation was analyzed using resin replicas and scanning electron microscopy. Internal leakage of 2% methylene blue dye was observed under a light microscope. In micro-permeability testing, fluorescent-dye penetration was investigated using confocal laser microscopy. None of the restorative procedures provided a perfectly sealed restoration. Glass-ionomer lining did not reduce fluid flow after restoration, and micro-gaps were frequently detected. The self-etch adhesive failed to provide a better seal than the total-etch adhesive, and even initial gap formation was rarely observed for the former. Penetration of methylene blue and fluorescent dyes was detected in most restorations. [source] Assessment of the 10-Year Probability of Osteoporotic Hip Fracture Combining Clinical Risk Factors and Heel Bone Ultrasound: The EPISEM Prospective Cohort of 12,958 Elderly Women,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 7 2008Didier Hans Abstract This study aimed to develop a hip screening tool that combines relevant clinical risk factors (CRFs) and quantitative ultrasound (QUS) at the heel to determine the 10-yr probability of hip fractures in elderly women. The EPISEM database, comprised of ,13,000 women ,70 yr of age, was derived from two population-based white European cohorts in France and Switzerland. All women had baseline data on CRFs and a baseline measurement of the stiffness index (SI) derived from QUS at the heel. Women were followed prospectively to identify incident fractures. Multivariate analysis was performed to determine the CRFs that contributed significantly to hip fracture risk, and these were used to generate a CRF score. Gradients of risk (GR; RR/SD change) and areas under receiver operating characteristic curves (AUC) were calculated for the CRF score, SI, and a score combining both. The 10-yr probability of hip fracture was computed for the combined model. Three hundred seven hip fractures were observed over a mean follow-up of 3.2 yr. In addition to SI, significant CRFs for hip fracture were body mass index (BMI), history of fracture, an impaired chair test, history of a recent fall, current cigarette smoking, and diabetes mellitus. The average GR for hip fracture was 2.10 per SD with the combined SI + CRF score compared with a GR of 1.77 with SI alone and of 1.52 with the CRF score alone. Thus, the use of CRFs enhanced the predictive value of SI alone. For example, in a woman 80 yr of age, the presence of two to four CRFs increased the probability of hip fracture from 16.9% to 26.6% and from 52.6% to 70.5% for SI Z-scores of +2 and ,3, respectively. The combined use of CRFs and QUS SI is a promising tool to assess hip fracture probability in elderly women, especially when access to DXA is limited. [source] Significant improvement in sleep in people with intellectual disabilities living in residential settings by non-pharmaceutical interventionsJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 8 2009T. Hylkema Abstract Background Although about 15 to 50 percent of people with intellectual disabilities (ID) living in residential settings suffer from sleep problems, scant attention is paid to these problems. Most available studies focus on pharmaceutical solutions. In this study we focus on improving sleep in people with intellectual disabilities living in residential settings by non-pharmaceutical interventions. Method The design is a multiple case study using actigraphy. Following a baseline measurement of people with ID, we recommended an intervention such as bedtime scheduling. This was followed by an effect measurement. Results Sleep efficiency, sleep latency and rising latency improved significantly. The time spent in bed also decreased significantly and the hours of sleep while in bed increased significantly. Conclusion For people with ID, sleep can be improved by non-pharmaceutical interventions. A multidisciplinary approach is helpful in selecting an adequate intervention. [source] Current in vivo wear of metal-on-metal bearings assessed by exercise-related rise in plasma cobalt levelJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 11 2006Munir Khan Abstract Baseline metal ion levels are elevated in patients with metal-on-metal (MOM) hip arthroplasty. Interpretation of baseline levels is difficult as measurements are influenced by wear, corrosion, and metal ion release from stored metal in the body. Schmalzried et al. demonstrated that "wear is the function of use, not time." The specific research question we asked was: Does physiological exercise increase the wear of metal-on-metal articulation which can be measured from the plasma metal ion levels? Patients with three different well functioning MOM bearings [two types of resurfacing (BHR 46.8 mm and Cormet 48 mm) and Metasul 28 mm] were included. Blood samples were taken immediately before, immediately after, and 1 h after exercise to determine cobalt and chromium levels. A significant increase (p,<,0.005) in serum cobalt and chromium of 13% and 11%, respectively, was noticed after the exercise. Rise of cobalt levels in patients with a resurfacing MOM was 8.5 times (BHR group) or 6.5 times (Cormet group) larger than in those with a Metasul MOM (p,=,0.021 and p,=,0.047). Neither rise of metal levels nor baseline levels correlated with any other factor (p,>,0.27). Exercise-related elevations of plasma cobalt level provides information on current in vivo wear production that cannot be inferred from a baseline measurement of cobalt levels. Chromium levels cannot provide reliable information on the in vivo wear of the devices. Diameter was the important feature of the implant in determining exercise-related elevations of plasma cobalt level. Exercise-related elevations of plasma cobalt level is a potential in vivo tool to understand and improve the tribology of metal,metal bearings. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:2029,2035, 2006 [source] Expanding the Utility of the Biphasic Alcohol Effects Scale (BAES) and Initial Psychometric Support for the Brief-BAES (B-BAES)ALCOHOLISM, Issue 5 2009Sandra Y. Rueger Background:, The utility of one of the most widely used subjective alcohol assessment tools, the Biphasic Alcohol Effects Scale (BAES) has been somewhat limited based on lack of psychometric studies in large and diverse samples, a range of alcohol doses, the length of the measure, and the original instructional set which precluded baseline measurement and disclosed to subjects that they received alcohol. Methods:, The current study investigated the factor structure of the BAES with a modified instructional set at pre-drink baseline and after consumption of various doses of alcohol, in a sample of 190 men and women, heavy and light social drinkers. This study tested the psychometric properties of a brief version of the BAES (Brief-BAES or B-BAES). Results:, Results demonstrated robust support of the stimulant and sedative constructs across all conditions, and demonstrated strong psychometric support for the 6-item B-BAES. Discussion:, This is the first comprehensive study to expand the utility of the BAES by instructional set, baseline measurement, at various alcohol doses, and by drinking history and sex. In addition, the introduction of the B-BAES may further increase the utility of this scale, particularly in paradigms with repeated measurement or time constraints. [source] Monitoring for drug side-effects in inflammatory bowel diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2002R. N. Cunliffe The side-effects suitable for monitoring in patients with inflammatory bowel disease being treated with the four main groups of drugs (5-aminosalicylic acid preparations, azathioprine and 6-mercaptopurine, methotrexate, and corticosteroids) are reviewed. On the basis of the reported frequency, severity and timing of side-effects, a practical scheme of monitoring is recommended. This includes a baseline measurement of full blood count, creatinine and liver function tests in all patients. In the absence of worrying symptoms, we recommend the following: (i) no monitoring for sulfasalazine; (ii) for other 5-aminosalicylic acid preparations, the meas- urement of creatinine at 6 and 12 months and then annually; (iii) for azathioprine/6-mercaptopurine, thiopurine methyltransferase genotype/phenotype determination has no role in treatment monitoring, but a full blood count at 2 weeks, 1 month, 3 months and then every 3 months should be performed; (iv) for methotrexate, a full blood count and liver function tests should be performed every 3 months; (v) for steroids, dual energy X-ray absorptiometry bone scanning should be performed at the start of therapy, every year in which steroids are used if the T score is < 0, and every 3,5 years if the T score is > 0. [source] Evaluation of an AIF correction algorithm for dynamic susceptibility contrast-enhanced perfusion MRIMAGNETIC RESONANCE IN MEDICINE, Issue 1 2008Peter Brunecker Abstract For longitudinal studies in patients suffering from cerebrovascular diseases the poor reproducibility of perfusion measurements via dynamic susceptibility-weighted contrast-enhanced MRI (DSC-MRI) is a relevant concern. We evaluate a novel algorithm capable of overcoming limitations in DSC-MRI caused by partial volume and saturation issues in the arterial input function (AIF) by a blood flow stimulation-study. In 21 subjects, perfusion parameters before and after administration of blood flow stimulating L -arginine were calculated utilizing a block-circulant singular value decomposition (cSVD). A total of two different raters and three different rater conditions were employed to select AIFs: Besides 1) an AIF selection by an experienced rater, a beginner rater applied a steady state-oriented strategy, returning; 2) raw; and 3) corrected AIFs. Highly significant changes in regional cerebral blood flow (rCBF) by 9.0% (P < 0.01) could only be found when the AIF correction was performed. To further test for improved reproducibility, in a subgroup of seven subjects the baseline measurement was repeated 6 weeks after the first examination. In this group as well, using the correction algorithm decreased the SD of the difference between the two baseline measurements by 42%. Magn Reson Med 60:102,110, 2008. © 2008 Wiley-Liss, Inc. [source] Characterization of autonomic dysfunction in patients with irritable bowel syndrome using fingertip blood flowNEUROGASTROENTEROLOGY & MOTILITY, Issue 5 2008T. Tanaka Abstract, Fingertip blood flow (FTBF) as measured by laser Doppler flowmetry (LDF) measurement is considered an indicator of sympathetic nerve function. We evaluated autonomic function in patients with irritable bowel syndrome (IBS) by assessing FTBF with both LDF and continuous-wave (cw) Doppler sonography. Firstly, the two methods were compared in 40 healthy volunteers. Next, 59 patients with IBS as well as 118 healthy volunteer controls were studied. In the supine position, FTBF in the right index finger was measured with cw Doppler sonography, whereas FTBF in the left index finger was assessed with LDF. After baseline measurement for at least 5 min, the volunteers received sympathetic stimulation from cold stress applied without notification in the form of an icebag (0 °C) upon the left forearm for 1 min. The new cw Doppler sonography method can be used in place of the old LDF method for clinical purposes. FTBF velocity before stimulation (Vpre) was significantly lower in the IBS group than that in the healthy volunteers (P < 0.01). In addition, the time required for FTBF to return to Vpre after stimulation was significantly longer in the IBS group than that in the control group. (P = 0.02). Thus, measurement of FTBF with cw Doppler sonography can be useful in the assessment of sympathetic nerve function. The IBS patients showed an abnormal FTBF response suggesting the presence of excess sympathetic activity. [source] Impact of baseline ECG collection on the planning, analysis and interpretation of ,thorough' QT trialsPHARMACEUTICAL STATISTICS: THE JOURNAL OF APPLIED STATISTICS IN THE PHARMACEUTICAL INDUSTRY, Issue 2 2009Venkat Sethuraman Abstract The current guidelines, ICH E14, for the evaluation of non-antiarrhythmic compounds require a ,thorough' QT study (TQT) conducted during clinical development (ICH Guidance for Industry E14, 2005). Owing to the regulatory choice of margin (10,ms), the TQT studies must be conducted to rigorous standards to ensure that variability is minimized. Some of the key sources of variation can be controlled by use of randomization, crossover design, standardization of electrocardiogram (ECG) recording conditions and collection of replicate ECGs at each time point. However, one of the key factors in these studies is the baseline measurement, which if not controlled and consistent across studies could lead to significant misinterpretation. In this article, we examine three types of baseline methods widely used in the TQT studies to derive a change from baseline in QTc (time-matched, time-averaged and pre-dose-averaged baseline). We discuss the impact of the baseline values on the guidance-recommended ,largest time-matched' analyses. Using simulation we have shown the impact of these baseline approaches on the type I error and power for both crossover and parallel group designs. In this article, we show that the power of study decreases as the number of time points tested in TQT study increases. A time-matched baseline method is recommended by several authors (Drug Saf. 2005; 28(2):115,125, Health Canada guidance document: guide for the analysis and review of QT/QTc interval data, 2006) due to the existence of the circadian rhythm in QT. However, the impact of the time-matched baseline method on statistical inference and sample size should be considered carefully during the design of TQT study. The time-averaged baseline had the highest power in comparison with other baseline approaches. Copyright © 2008 John Wiley & Sons, Ltd. [source] Myocardial cell injury is common in children with septic shockACTA PAEDIATRICA, Issue 3 2009Rakesh Lodha Abstract Objective: To determine the prevalence of myocardial cell injury in children with septic shock by estimating the levels of biochemical markers of myocardial injury, troponin I (TnI) and creatine kinase MB (CK-MB). Patients: Children aged 3 months to 16 years were admitted to paediatric intensive care unit (PICU) with septic shock. Children with sepsis without shock and children with hypovolaemic shock were enrolled as controls. Measurements and Main Results: Serum TnI and CK-MB levels were measured at admission and serially at 24 h, 48 h and 96 h in children with septic shock, while baseline measurement of the same markers was taken from the controls. In total, 88% (15/18) of children with septic shock had elevated TnI levels compared with 25% (5/20) with sepsis and 6.7% (1/15) with hypovolaemic shock (p < 0.001). Serial TnI levels at admission, 24 h, 48 h and 96 h were higher in the nonsurvivors. There was a positive correlation between the baseline TnI levels and the predicted mortality using the paediatric index of mortality (PIM2) scores at admission (r = 0.51, p = 0.03). Conclusion: A majority of children with septic shock have evidence of myocardial cell injury. The estimation of serum TnI levels may help in better prognostication of children with septic shock. [source] The relationship between baseline value and its change: problems in categorization and the proposal of a new methodEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 4 2005Yu-Kang Tu Oral health researchers have shown great interest in the relationship between the initial status of diseases and subsequent changes following treatment. Two main approaches have been adopted to provide evidence of a positive association between baseline values and their changes following treatment. One approach is to use correlation or regression to test the relationship between baseline measurements and subsequent change (correlation/regression approach). The second approach is to categorize the lesions into subgroups, according to threshold values, and subsequently compare the treatment effects across the two (or more) subgroups (categorization approach). However, the correlation/regression approach suffers a methodological weakness known as mathematical coupling. Consequently, the statistical procedure of testing the null hypothesis becomes inappropriate. Categorization seems to avoid the problem of mathematical coupling, although it still suffers regression to the mean. We show, first, how the appropriate null hypothesis may be established to analyze the relationship between baseline values and change in the correlation approach and, second, we use computer simulations to investigate the impact of regression to the mean on the significance testing of the differences in the average treatment effects (or average baseline values) in the categorization approach. Data available from previous literature are reanalyzed by testing the appropriate null hypotheses and the results are compared to those from testing the usual (incorrect) null hypothesis. The results indicate that both the correlation and categorization approaches can give rise to misleading conclusions and that more appropriate methods, such as Oldham's method and our new approach of deriving the correct null hypothesis, should be adopted. [source] Sampling and analytical plus subsampling variance components for five soil indicators observed at regional scaleEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 5 2009B. G. Rawlins Summary When comparing soil baseline measurements with resampled values there are four main sources of error. These are: i) location (errors in relocating the sample site), ii) sampling errors (representing the site with a sample of material) iii) subsampling error (selecting material for analysis) and iv) analytical error (error in laboratory measurements). In general we cannot separate the subsampling and analytical sources of error (since we always analyse a different subsample of a specimen), so in this paper we combine these two sources into subsampling plus analytical error. More information is required on the relative magnitudes of location and sampling errors for the design of effective resampling strategies to monitor changes in soil indicators. Recently completed soil surveys of the UK with widely differing soils included a duplicate site and subsampling protocol to quantify ii), and the sum of iii) and iv) above. Sampling variances are estimated from measurements on duplicate samples , two samples collected on a support of side length 20 m separated by a short distance (21 m). Analytical and subsampling variances are estimated from analyses of two subsamples from each duplicate site. After accounting for variation caused by region, parent material class and land use, we undertook a nested analysis of data from 196 duplicate sites across three regions to estimate the relative magnitude of medium-scale (between sites), sampling and subsampling plus analytical variance components, for five topsoil indicators: total metal concentrations of copper (Cu), nickel (Ni) and zinc (Zn), soil pH and soil organic carbon (SOC) content. The variance components for each indicator diminish by about an order of magnitude from medium-scale, to sampling, to analytical plus subsampling. Each of the three fixed effects (parent material, land use and region) were statistically significant for each of the five indicators. The most effective way to minimise the overall uncertainty of our observations at sample sites is to reduce the sampling variance. [source] Blood pressure and vascular reactivity to endothelin-1, phenylephrine, serotonin, KCl and acetylcholine following chronic alcohol consumption in vitroFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 3 2001Tijen Utkan Ethanol has been reported to cause hypertension, the mechanism of which is unknown. Therefore, the effect of chronic ethanol consumption on vascular responsiveness and blood pressure was investigated. Systolic blood pressure was recorded weekly by tail-cuff method. Aortic rings from rats fed chow ad libitum or pair-fed liquid diets containing either ethanol (7.2% v/v) or isocaloric carbohydrate for 4 weeks were placed in organ chambers for isometric tension measurement. There was a mild but significant elevation of the systolic blood pressure in the alcohol-fed rats by week 1 compared to baseline measurements and this remained higher. No significant changes in reactivity of rat isolated aortas to phenylephrine, serotonin, endothelin-1 (ET-1) and KCl were seen in chronic ethanol consumption. In addition, the sensitivity (i.e. pD2) of alcohol-fed aortic rings to the vasoconstrictors was also unchanged compared to controls. Chronic ethanol consumption, however, increased relaxation to acetylcholine with increased pD2 values, but did not alter relaxation to sodium nitroprusside, a cyclic guanosine monophosphate (cGMP)-dependent direct smooth muscle dilator. The results indicate that chronic ethanol consumption significantly potentiates endothelium-dependent relaxations in aortic rings, probably through interference with the production and/or the release of nitric oxide (NO) or adaptive alterations in muscarinic receptors on the endothelial cells, and that increased vascular responsiveness to several vasoconstrictors is not a mechanism responsible for the blood pressure elevation in the chronic alcohol consumption in rats. [source] Case management educational intervention with public health nurses: cluster randomized controlled trialJOURNAL OF ADVANCED NURSING, Issue 10 2010Wen-I. liu w.-i., edwards h. & courtney m. (2010) Case management educational intervention with public health nurses: cluster randomized controlled trial. Journal of Advanced Nursing,66(10), 2234,2244. Abstract Aim., This paper is a report of a study conducted to determine the effectiveness of a community case management collaborative education intervention in terms of satisfaction, learning and performance among public health nurses. Background., Previous evaluation studies of case management continuing professional education often failed to demonstrate effectiveness across a range of outcomes and had methodological weaknesses such as small convenience samples and lack of control groups. Method., A cluster randomized controlled trial was conducted between September 2005 and February 2006. Ten health centre clusters (five control, five intervention) recruited 163 public health nurses in Taiwan to the trial. After pre-tests for baseline measurements, public health nurses in intervention centres received an educational intervention of four half-day workshops. Post-tests for both groups were conducted after the intervention. Two-way repeated measures analysis of variance was performed to evaluate the effect of the intervention on target outcomes. Results., A total of 161 participants completed the pre- and post-intervention measurements. This was almost a 99% response rate. Results revealed that 97% of those in the experimental group were satisfied with the programme. There were statistically significant differences between the two groups in knowledge (P = 0·001), confidence in case management skills (P = 0·001), preparedness for case manager role activities (P = 0·001), self-reported frequency in using skills (P = 0·001) and role activities (P = 0·004). Conclusion., Collaboration between academic and clinical nurses is an effective strategy to prepare nurses for rapidly changing roles. [source] Evaluation of a Prediction Model for Long-Term Fracture Risk,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2005L Joseph Melton III MD Abstract The NOF cost-effectiveness model, based on clinical risk factors and femoral neck aBMD, predicted overall fracture risk in a cohort of postmenopausal women followed for up to 22 years. Introduction: To assess the ability of a statistical model to predict long-term fracture risk for a population of postmenopausal women, we compared observed fractures to those predicted by the National Osteoporosis Foundation's (NOF) cost-effectiveness model. Materials and Methods: In this population-based study, 393 postmenopausal Rochester, MN, women had baseline measurements of femoral neck areal BMD (aBMD) and assessment of the clinical risk factors (personal fracture history, family history of osteoporotic fracture, low body weight, and smoking status) that were included in the NOF model. They were then followed prospectively for up to 22 years. Fractures were ascertained by periodic interview and review of community medical records. Standardized incidence ratios (SIRs) compared observed fractures to predicted numbers. Results: During 4782 person-years of follow-up, 212 women experienced 503 fractures, two-thirds of which were caused by moderate trauma. When undiagnosed (incidentally noted) vertebral and rib fractures were excluded, there was general concordance between observed and predicted fractures of the hip (SIR, 0.78; 95% CI, 0.56-1.01), distal forearm (SIR, 1.22; 95% CI, 0.86-1.68), spine (SIR, 0.76; 95% CI, 0.50-1.11), and all other sites combined (SIR, 1.18; 95% CI, 0.97-1.42). Fracture prediction by the NOF model was about as good after 10 years as it was earlier during follow-up. Conclusions: This study validates the ability of a statistical model based on femoral neck aBMD and common clinical risk factors to predict the actual occurrence of fractures in a cohort of postmenopausal white women. [source] Fracture Prediction From Bone Mineral Density in Japanese Men and Women,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2003Saeko Fujiwara Abstract In a cohort of 2356 Japanese elderly, after adjusting for age and prevalent vertebral fracture, baseline BMD predicted the risk of spine and hip fracture with similar RR to that obtained from previous reports in whites. The RR per SD decrease in BMD for fracture declined with age. Introduction: Low bone mineral density (BMD) is one of the most important predictors of a future fracture. However, we are not aware of any reports among Japanese in Japan. Materials and Methods: We examined the association of BMD with risk of fracture of the spine or hip among a cohort of 2356 men and women aged 47,95 years, who were followed up by biennial health examinations. Follow-up averaged 4 years after baseline measurements of BMD that were taken with the use of DXA. Vertebral fracture was assessed using semiquantitative methods, and the diagnosis of hip fracture was based on medical records. Poisson and Cox regression analysis were used. Results: The incidence was twice as high in women as in men, after adjusting for age. After adjusting for baseline BMD and prevalent vertebral fracture, however, the gender difference was no longer significant. Age, baseline BMD of spine and femoral neck, and prior vertebral fracture predicted vertebral fracture and hip fracture. Loss of absolute BMD of the femoral neck predicted spine fracture, after adjusting for baseline BMD; rates of change in percent BMD, weight, height, body mass index, and age at menopause did not. The predictive value of baseline BMD for vertebral fracture risk was similar in men and women. The relative risk (RR) for vertebral fracture and hip fracture per SD decrease in BMD declined with age, after adjustment for prevalent vertebral fractures. Conclusions: Baseline BMD, loss of femoral neck BMD, and prior vertebral fracture predict the risk of spine and hip fracture in Japanese with similar RR to that obtained from previous reports in whites. The RR per SD decrease in BMD for fracture declined with age, suggesting that factors other than BMD might play a greater role in the elderly. [source] Anti-gingivitis efficacy of a stabilized 0.454% stannous fluoride/sodium hexametaphosphate dentifriceJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2005A controlled 6-month clinical trial Abstract Objective: Stannous fluoride is a broad-spectrum anti-microbial agent that has been used in dentistry as a chemical adjunct to prevent dental caries and gingivitis. The objective of this study was to assess the anti-gingivitis efficacy of a stabilized 0.454% stannous fluoride/sodium hexametaphosphate dentifrice relative to a negative control. Methods: This was a randomized, 6-month, double-blind, parallel-group gingivitis study conducted according to the guidelines for evaluating chemotherapeutic products for the control of gingivitis outlined by the American Dental Association. A stabilized 0.454% stannous fluoride/sodium hexametaphosphate dentifrice was tested against a commercially available negative control dentifrice. Following baseline measurements, subjects received a dental prophylaxis. Subjects were then instructed to brush twice daily for 60 s using their assigned product. Oral soft-hard-tissue examinations and clinical examinations using the Modified Gingival Index, Gingival Bleeding Index, and the Turesky modification of the Quigley,Hein Plaque Index were performed at baseline, 3 and 6 months post-treatment. Results: A total of 143 subjects were enrolled and 130 of them completed the 6-month study. After 6 months of product usage, the experimental group had 21.7% less gingivitis (p<0.001), 57.1% less bleeding (p<0.001), and 6.9% less plaque (p=0.01) on average compared with the negative control group. No adverse oral soft-hard-tissue effects or extrinsic tooth staining was observed in the study. Conclusion: The results demonstrate that use of the stabilized 0.454% stannous fluoride/sodium hexametaphosphate dentifrice over a 6-month period provided statistically significant reductions in gingivitis, gingival bleeding, and plaque when compared with a negative control dentifrice. [source] Training physicians to increase patient trustJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 3 2000David H. Thom MD PhD Abstract Patient trust in the physician is an important aspect of the patient,physician relationship that has recently become a focus of interest, in part due to the rise of managed care in the US healthcare system. In a previous study, we identified physician behaviours reported by patients as important to establishing their trust in the physician. The current study attempted to modify these behaviours via a short training programme and thereby to increase patient trust and improve associated outcomes. After baseline measurements, 10 physicians were randomized to the intervention group and 10 remained as a control group. While intervention physicians showed a net improvement in 16 of 19 specific patient-reported behaviours when compared to control physicians, these differences were not statistically significant. There was also no significant difference in patient trust, patient satisfaction, continuity, self-reported adherence, number of referrals or number of diagnostic tests ordered. This short training course in a group of self-selected physicians was not a sufficiently strong intervention to achieve the desired effect. Suggestions are given for designing a stronger training intervention. [source] Efficacy of subgingivally applied minocycline in the treatment of chronic periodontitisJOURNAL OF PERIODONTAL RESEARCH, Issue 1 2005Hsein-Kun Lu Background:, The use of adjunctive minocycline with mechanical debridement in treating periodontitis has been widely studied using different methods. However, the results from these studies are equivocal. Objective:, The purpose of this study was to clarify the efficacy of the adjunctive use of subgingival minocycline application plus scaling/root planing as compared with the results of one episode of scaling/root planing in the treatment of chronic periodontitis. Methods:, Fifteen patients were enrolled in this split-mouth clinical trial. Probing depth, clinical attachment loss, gingival index, and bleeding on probing were evaluated at the baseline before scaling/root planing and 6, 10, 14, and 18 weeks later according to a single-blind protocol. The amount of interleukin-1, (interleukin-1, pg/site) at each lesion was also simultaneously measured in gingival crevicular fluid in a parallel comparison design. After full-mouth baseline measurements and scaling/root planing, 78 lesions with a residual mean probing depth of 5 mm at anterior teeth were selected and equally distributed in either right or left sites based on a split-mouth symmetrical design and randomly assigned to one of two treatment groups (with or without minocycline administration, n = 39 for each group). Results:, Probing depth significantly decreased from the baseline (week 0) to week 6 after scaling/root planing (p < 0.05) in both groups, but there was no statistically significant difference between the two groups (p > 0.05). However, at weeks 10, 14, and 18, the experimental group showed significantly greater improvement in pocket reduction than the control group (p < 0.05). Similarly, both groups also showed significant decreases in gingival index scores from weeks 0,6 (p < 0.05), but gingival index reductions at weeks 10, 14, and 18 were statistically significant in favor of the experimental group (p < 0.05). The experimental group had more attachment gain than the control group at weeks 14 and 18 (p < 0.05). Values of interleukin-1, (pg/site) at the experimental sites were significantly reduced at weeks 10, 14, and 18, as compared to values at control sites (p < 0.01). Finally, the incidence of bleeding on probing showed no differences between the two groups for any time interval (p > 0.05). Conclusions:, In this 18-week clinical trial, the results suggested that scaling/root planing with adjunctive subgingival administration of minocycline ointment has a significantly better and prolonged effect compared to scaling/root planing alone on the reduction of probing depth, clinical attachment loss, gingival index, and interleukin-1, content, but not on bleeding on probing. [source] Effects of 6 Months of Aging in Water on Hardness and Surface Roughness of Two Microhybrid Dental CompositesJOURNAL OF PROSTHODONTICS, Issue 4 2008Rafael Ratto De Moraes DDS Abstract Purpose: This study assessed the effect of 6 months of aging in water on surface roughness and surface/subsurface hardness of two microhybrid resin composites. Materials and Methods: Filtek Z250 and Charisma were tested. Cylindrical specimens were obtained and stored in distilled water for 24 hours or 6 months, at 37°C. For Knoop hardness evaluation, the specimens were transversely wet-flattened, and indentations were made on surface and subsurface layers. Data were submitted to three-way ANOVA and Tukey's test (,, 0.05). Surface roughness baseline measurements were made at 24 hours and repeated after 6 months of storage. Data were submitted to repeated measures ANOVA and Tukey's test (,, 0.05). Results: Surface hardness (KHN, kg/mm2) means (± standard deviation) ranged from 55 ± 1 to 49 ± 4 for Z250 and from 50 ± 2 to 41 ± 3 for Charisma, at 24 hours and 6 months, respectively. Subsurface means ranged from 58 ± 2 to 61 ± 3 for Z250 and from 50 ± 1 to 54 ± 2 for Charisma, at 24 hours and 6 months. For both composites, the aged specimens presented significantly softer surfaces (p < 0.01). For the subsurface hardness, alteration after storage was detected only for Charisma, which presented a significant rise in hardness (p < 0.01). Z250 presented significantly harder surface and subsurface layers in comparison with Charisma. Surface roughness (Ra, ,m) means ranged from 0.07 ± 0.00 to 0.07 ± 0.01 for Z250 and from 0.06 ± 0.01 to 0.07 ± 0.01 for Charisma, at 24 hours and 6 months, respectively. For both composites, no significant roughness alteration was detected during the study (p= 0.386). Conclusions: The 6-month period of storage in water presented a significant softening effect on the surfaces of the composites, although no significant deleterious alteration was detected for the subsurface hardness. In addition, the storage period had no significant effect on the surface roughness of the materials. [source] Influence of a high fibre diet on glycaemic control and quality of life in dogs with diabetes mellitusJOURNAL OF SMALL ANIMAL PRACTICE, Issue 2 2002P. A. GRAHAM A study was undertaken to evaluate a high fibre diet used in the management of 10 dogs with naturally occurring insulin-dependent diabetes mellitus. Following baseline measurements of health and glycaemic control, the dogs were fed a canned diet containing a blend of insoluble and soluble dietary fibres and were monitored during the ensuing four months. Switching to the high fibre diet was associated with significantly lower mean 24-hour and postprandial plasma glucose concentrations, which were maintained over the study period. The high fibre diet was also associated with significant reductions in plasma concentrations of fructosamine, glycated haemoglobin, free glycerol and cholesterol, and there were significant improvements in dog activity and demeanour. Bodyweight declined during the fourth month of feeding the diet, which is likely to have resulted from underfeeding relative to increased activity. The results indicate that a high fibre diet can significantly improve glycaemic control and quality of life in dogs with diabetes mellitus. [source] Response of fractional synthesis rate (FSR) of fibrinogen, concentration of D-dimer and fibrinolytic balance to physical activity-based intervention in obese childrenJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 8 2008P. BALAGOPAL Summary.,Background:,Physical activity-induced reduction in obesity-related hyperfibrinogenemia in children has been reported. The underlying mechanisms remain elusive. Further, the effect of such interventions on fibrinolysis in children is scarce. Objectives: To investigate in obese children, before and after a physical activity-based intervention: (i) the mechanistic role of fractional synthesis rate (FSR) of fibrinogen in the reduction of hyperfibrinogenemia; and (ii) the changes in fibrinolytic factors. Methods:,Subjects included 21 (age > 14 < 18 years; Tanner stage, IV,V) children (15 obese, BMI >95%tile for age and sex and six lean, BMI <85%tile). After baseline measurements of FSR of fibrinogen, and concentrations of fibrinogen, D-dimer, PAI-1 and t-PA in all children, studies were repeated after a 3-month randomized controlled physical activity-based lifestyle intervention in obese children only. Results:,FSR of fibrinogen was higher (P = 0.002) in the obese (vs. lean) group, which was reduced (P = 0.001) after intervention. This almost completely accounted for the reduction in obesity-related hyperfibrinogenemia. High levels of D-dimer decreased (P = 0.001) after intervention, whereas fibrinolysis was not enhanced. Conclusions:,The direct reduction in the FSR of fibrinogen and the remarkable correlation between the magnitudes of reduction in fibrinogen FSR and concentration signify a mechanistic role for FSR in the regulation of physical activity-induced reversal of hyperfibrinogenemia in obese children. The congruent reductions in the FSR of fibrinogen and the concentrations of fibrinogen and D-dimer in response to intervention despite depressed fibrinolysis suggest an overall improvement in the hypercoagulable state in obese children with physical activity-based lifestyle intervention. [source] A cluster randomized controlled trial to determine the efficacy of Trauma Risk Management (TRiM) in a military population,JOURNAL OF TRAUMATIC STRESS, Issue 4 2010Neil Greenberg Trauma Risk Management is a peer-support program that aims to promote help-seeking in the aftermath of traumatic events. Prior to its implementation, the British military conducted a randomized controlled trial of Trauma Risk Management against standard care in 12 warships; 6 were randomized to use Trauma Risk Management after collecting baseline measurements. Follow up after 12,18 months found no significant change in psychological health or stigma scores in either group; however, the studied vessels only encountered low numbers of critical incidents. Additionally, measurements of organizational functioning were modestly better in the Trauma Risk Management ships. The authors conclude that within organizations using Trauma Risk Management may be beneficial and may, in time, lead to a valuable cultural shift. [source] | ||||||||||||||||||||||||||||||||||