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Cohen's D (cohen + d)
Selected AbstractsDifferential age-related changes in motor unit properties between elbow flexors and extensorsACTA PHYSIOLOGICA, Issue 1 2010B. H. Dalton Abstract Aim:, Healthy adult ageing of the human neuromuscular system is comprised of changes that include atrophy, weakness and slowed movements with reduced spinal motor neurone output expressed by lower motor unit discharge rates (MUDRs). The latter observation has been obtained mostly from hand and lower limb muscles. The purpose was to determine the extent to which elbow flexor and extensor contractile properties, and MUDRs in six old (83 ± 4 years) and six young (24 ± 1 years) men were affected by age, and whether any adaptations were similar for both muscle groups. Methods:, Maximal isometric voluntary contraction (MVC), voluntary activation, twitch contractile properties, force,frequency relationship and MUDRs from sub-maximal to maximal intensities were assessed in the elbow flexors and extensors. Results:, Both flexor and extensor MVCs were significantly (P < 0.05) less (,42% and ,46% respectively) in the old than in the young. Contractile speeds and the force,frequency relationship did not show any age-related differences (P > 0.05). For the elbow flexors contraction duration was ,139 ms and for the extensors it was ,127 ms for both age groups (P > 0.05). The mean MUDRs from 25% MVC to maximum were lower (,10% to ,36%) in the old than in the young (P < 0.01). These age-related differences were larger for biceps (Cohen's d = 8.25) than triceps (Cohen's d = 4.79) brachii. Conclusion:, Thus, at least for proximal upper limb muscles, mean maximal MUDR reductions with healthy adult ageing are muscle specific and not strongly related to contractile speed. [source] Cognitive training in Alzheimer's disease: a meta-analysis of the literatureACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2006D. I. Sitzer Objective:, To systematically review the literature and summarize the effect of cognitive training (CT) for Alzheimer's disease (AD) patients on multiple functional domains. Method:, Effect sizes (Cohen's d) were calculated for 17 controlled studies identified through a comprehensive literature review. Results:, An overall effect size of 0.47 was observed for all CT strategies across all measured outcomes. Mean effect sizes were higher for restorative (0.54) than for compensatory (0.36) strategies. Domain-specific effect sizes ranged from 2.16 (verbal and visual learning) to ,0.38 (visuospatial functioning). Data are also presented on the relative impact of restorative and compensatory strategies for each domain of functioning. Conclusion:, CT evidenced promise in the treatment of AD, with primarily medium effect sizes for learning, memory, executive functioning, activities of daily living, general cognitive problems, depression, and self-rated general functioning. Restorative strategies demonstrated the greatest overall effect on functioning. Several limitations of the published literature are discussed. [source] Prospective outcome of early intervention for individuals at ultra-high-risk for psychosisEARLY INTERVENTION IN PSYCHIATRY, Issue 4 2008GeumSook Shim Abstract Aim: Based on previous reports of second-generation antipsychotic agents having a beneficial effect on prodromal symptoms, we investigated the effectiveness and tolerability of atypical antipsychotic therapies in individuals at high risk for developing psychosis. Methods: We examined prodromal symptoms and functioning in individuals at ultra-high-risk for psychosis using an uncontrolled prospective design with pre- and post-treatment measures. Results: Of the 27 subjects taking antipsychotics during the study period, 15 took part in at least one follow-up assessment. Overall Com prehensive Assessment of At-Risk Mental States scores significantly improved at the last evaluation point, with a medium-size effect of Cohen's d = 0.54 (95% confidence interval, ,0.02 to 1.08) (mean follow-up period = 8.8; SD = 8.3 months). Depression and anxiety symptoms were markedly reduced, and global and social functioning also significantly improved. Of the 27 subjects, two (7.4%) converted to psychosis and 16 (59.3%) experienced at least one treatment-emergent adverse event, but no subjects exhibited serious adverse events. Conclusions: The results of this study support treating high-risk individuals with antipsychotics to reduce prodromal symptoms with adequate safety. [source] Progressive stage transition does mean getting better: a further test of the Transtheoretical Model in recovery from alcohol problemsADDICTION, Issue 6 2009Nick Heather ABSTRACT Aims To test two central assumptions of the Transtheoretical Model (TTM) regarding recovery from alcohol problems: (i) individuals making a forward transition from pre-action to action stages will show greater drinking improvements than those remaining in pre-action stages; and (ii) individuals remaining in pre-action stages will not demonstrate improvements in drinking outcomes. Design and setting Large, multi-centre, randomized controlled trial of treatment for alcohol problems [United Kingdom Alcohol Treatment Trial (UKATT)]. Measurements Stage of change, drinks per drinking day and percentage days abstinent at baseline, 3- and 12-month follow-ups. Findings In support of TTM assumption 1, improvements in drinking outcomes were consistently greater among clients who showed a forward stage transition (Cohen's d = 0.68) than among those who did not (d = 0.10). Two tests of assumption 2 showed a significant improvement in drinking outcomes in non-transition groups, inconsistent with the TTM; one test showed a significant deterioration and the other showed equivalent drinking outcomes across time. An explanation is offered as to why, under the relevant assumption of the TTM, clients in non-transition groups showed small changes in drinking outcomes. Conclusions In contrast to a previous study by Callaghan and colleagues, our findings largely support the TTM account of recovery from alcohol problems in treatment. The discrepancy can be explained by the use in our study of a more reliable and valid method for assigning stage of change. [source] Results from two randomized clinical trials evaluating the impact of quarterly recovery management checkups with adult chronic substance usersADDICTION, Issue 6 2009Christy K Scott ABSTRACT Aims Post-discharge monitoring and early reintervention have become standard practice when managing numerous chronic conditions. These two experiments tested the effectiveness of recovery management checkup (RMC) protocols for adult chronic substance users. Intervention RMC included quarterly monitoring; motivational interviewing to provide personalized feedback and to resolve ambivalence about substance use; treatment linkage, engagement and retention protocols to increase the amount of treatment received. Participants and setting Recruited from sequential addiction treatment admissions, participants in the two experiments were, on average, 36 and 38 years of age, mainly female (59% versus 46%), African American (85% versus 80%) and met past-year criteria for dependence (87% versus 76%). Design Participants in both experiments were assigned randomly to the RMC or control condition and interviewed quarterly for 2 years. Measurement The Global Appraisal of Individual Needs (GAIN) was the main assessment instrument. Findings RMC participant outcomes were better than control participants in both experiments. Effect sizes were larger in the second experiment in terms of reducing days to readmission (Cohen's d = 0.41 versus d = 0.22), successive quarters in the community using substances (d = ,0.32 versus ,0.19), past-month symptoms of abuse/dependence (d = ,0.23 versus ,0.02) and increasing the days of abstinence over 2 years (d = +0.29 versus 0.04). Conclusion RMC, which provided ongoing monitoring and linkage, is feasible to conduct and is effective for adults with chronic substance dependence. [source] Effect of self-monitoring on binge eating: treatment response or ,binge drift'?EUROPEAN EATING DISORDERS REVIEW, Issue 1 2006Tom Hildebrandt Abstract The current study aimed to determine if subjective bulimic episodes (SBEs) and objective bulimic episodes (OBEs) have different reactive effects to self-monitoring. Fourteen women with bulimia nervosa (57%) or binge eating disorder (43%) were diagnosed using the Eating Disorder Examination (EDE; version 12.0). During the 7-days post-interview, participants filled out daily self-monitoring records indicating the food consumed and any episodes of loss of control over eating. These records were reviewed and coded for OBEs and SBEs using the EDE coding scheme. Paired samples t -tests indicated that participants' average number of daily OBEs significantly decreased from baseline to the period of self-monitoring (t,=,2.41, p,<,0.05, Cohen's d,=,0.90), whereas there was a significant increase from baseline to self-monitoring in their average number of SBEs (t,=,,2.41, p,<,0.05, Cohen's d,=,0.86). Of the 12 participants who showed a decrease in OBEs, 75% showed a concurrent increase in SBEs. The data suggest that the reactivity of OBEs to minimal or brief interventions may in part be due to binge drift, or the reduction of OBEs at the expense of increasing SBEs. Copyright © 2006 John Wiley & Sons, Ltd and Eating Disorders Association. [source] The construct validity of three entry level personality inventories used in the UK: cautionary findings from a multiple-inventory investigation,EUROPEAN JOURNAL OF PERSONALITY, Issue S1 2003Neil Anderson This paper reports psychometric analyses into the convergent and divergent validity of three popular entry-level measures of occupational personality in the UK and Continental Europe. A sample of 504 individuals completed all three measures: the British version of the Hogan Personality Inventory (HPI), the Occupational Personality Questionnaire (OPQ Version FS5.2), and the Business Personality Indicator (BPI). In addition, independent ratings of the conceptual loading of primary source scales onto the Five Factor Model (FFM) were obtained (n,=,66). Data were used in a three-stage analytical procedure directed at examining psychometric and construct validity. Results are reported for descriptive statistics (means, standard deviations, Cohen's d), internal consistency reliability (Cronbach's alphas), and exploratory factor analyses. Findings into the construct validity of first-order scales (i.e. primary source scales) and second-order scales (i.e. FFM loadings) are presented in detail, including multitrait,multimethod (MTMM) analyses of convergent and divergent validity. For some scales, the observed variability in our sample suggested significant range restriction/enhancement. It was found that scale reliabilities were generally lower than those typically reported by the test publishers, and that published factor structures for these measures could not be replicated by the authors for this sample of individuals. Further independent construct validity research into occupational personality inventories is encouraged based upon our proposed model of single-, dual-, and multiple-inventory construct validation studies. Practically, our findings suggest that when IWO psychologists or personnel professionals aim to select/screen job applicants for a particular personality trait those who are selected may vary depending on (i) which personality inventory is used, (ii) the actual variability in the applicant sample tested, and (iii) reliability of the scales under consideration. As such, this study sounds a note of caution. Future research is called for to replicate these findings. Copyright © 2003 John Wiley & Sons, Ltd. [source] The De-Escalating Aggressive Behaviour Scale: development and psychometric testingJOURNAL OF ADVANCED NURSING, Issue 9 2009Johannes Nau Abstract Title.,The De-Escalating Aggressive Behaviour Scale: development and psychometric testing. Aim., This paper is a report of a study to develop and test the psychometric properties of a scale measuring nursing students' performance in de-escalation of aggressive behaviour. Background., Successful training should lead not merely to more knowledge and amended attitudes but also to improved performance. However, the quality of de-escalation performance is difficult to assess. Method., Based on a qualitative investigation, seven topics pertaining to de-escalating behaviour were identified and the wording of items tested. The properties of the items and the scale were investigated quantitatively. A total of 1748 performance evaluations by students (rater group 1) from a skills laboratory were used to check distribution and conduct a factor analysis. Likewise, 456 completed evaluations by de-escalation experts (rater group 2) of videotaped performances at pre- and posttest were used to investigate internal consistency, interrater reliability, test,retest reliability, effect size and factor structure. Data were collected in 2007,2008 in German. Findings., Factor analysis showed a unidimensional 7-item scale with factor loadings ranging from 0·55 to 0·81 (rater group 1) and 0·48 to 0·88 (rater group 2). Cronbach's alphas of 0·87 and 0·88 indicated good internal consistency irrespective of rater group. A Pearson's r of 0·80 confirmed acceptable test,retest reliability, and interrater reliability Intraclass Correlation 3 ranging from 0·77 to 0·93 also showed acceptable results. The effect size r of 0·53 plus Cohen's d of 1·25 indicates the capacity of the scale to detect changes in performance. Conclusion., Further research is needed to test the English version of the scale and its validity. [source] A meta-analysis of the effects of internet- and computer-based cognitive-behavioral treatments for anxietyJOURNAL OF CLINICAL PSYCHOLOGY, Issue 1 2009Mark A. Reger Abstract Internet-and computer-based cognitive-behavioral treatments have been introduced as novel approaches to deliver standard, quality treatment that may reduce barriers to care. The purpose of this review is to quantitatively summarize the literature examining the treatment effects of Internet- or computer-based treatment (ICT) on anxiety. Nineteen randomized controlled ICT trials were identified and subjected to fixed and random effects meta-analytic techniques. Weighted mean effect sizes (Cohen's d) showed that ICT was superior to waitlist and placebo assignment across outcome measures (ds=.49,1.14). The effects of ICT also were equal to therapist-delivered treatment across anxiety disorders. However, conclusions were limited by small sample sizes, the rare use of placebo controls, and other methodological problems. In addition, the number of available studies limited the opportunity to conduct analyses by diagnostic group; there was preliminary support for the use of ICT for panic disorder and phobia. Large, well-designed, placebo-controlled trials are needed to confirm and extend the results of this meta-analysis. © 2008 Wiley Periodicals, Inc. J Clin Psychol 65: 1,21, 2009. [source] Y haplogroups and aggressive behavior in a Pakistani ethnic groupAGGRESSIVE BEHAVIOR, Issue 1 2009S. Shoaib Shah Abstract Studies show that personality dimensions such as aggression are influenced by genetic factors and that allelic variants located on the Y chromosome influence such behavior. We investigated polymorphisms on the male-specific region of the human Y chromosome in 156 unrelated males from the same ethnic background, who were administered the Punjabi translation of the Buss and Perry Aggression Questionnaire that measures four aspects that constitute aggressive behavior, i.e. physical aggression, verbal aggression, anger, and hostility. A value of .85 for Cronbach's coefficient , indicates considerable internal consistency and suggests that the psychometric properties of the aggression questionnaire can be adapted for the Pakistani population. A mean score±SD of 69.70±19.95 was obtained for the questionnaire. Each individual was genotyped following a phylogenetic hierarchical approach to define evolutionary Y haplogroups. Five Y haplogroups that are commonly found in Eurasia and Pakistan comprised 87% (n=136) of the population sample, with one haplogroup, R1a1, constituting 55% of the sampled population. A comparison of the total and four subscale mean scores across the five common Y haplogroups that were present at a frequency ,3% in this ethnic group revealed no overall significant differences. However, effect-size comparisons allowed us to detect an association of the haplogroups R2 (Cohen's d statistic=.448,.732) and R1a1 (d=.107,.448) with lower self-reported aggression mean scores in this population. Aggr. Behav. 35:68,74, 2009. © 2008 Wiley-Liss, Inc. [source] Long-term effects of a psycholinguistic treatment for dyslexiaJOURNAL OF RESEARCH IN READING, Issue 2 2003Jurgen Tijms Short and long-term effects of a treatment for dyslexia are evaluated. The treatment is based on psycholinguistic theory and assumes that dyslexia is due to poor lexico-phonological processing of words. The treatment is computer-based and focuses on learning to recognise and to make use of the phonological and morphological structure of Dutch words. The results of the treatment were clear improvements in reading words, reading text and spelling. Effect sizes of standardised treatment gains were large (Cohen's d>0.80 for all variables). Following the treatment, participants attained an average level of text-reading and spelling. The attained level of reading words and reading text was found to be stable over a four-year follow-up period. Spelling showed a slight decline one year after the treatment, but remained stable thereafter.1 [source] A randomized controlled trial of cognitive-behavior therapy for Cambodian refugees with treatment-resistant PTSD and panic attacks: A cross-over designJOURNAL OF TRAUMATIC STRESS, Issue 6 2005Devon E. Hinton We examined the therapeutic efficacy of a culturally adapted cognitive-behavior therapy for Cambodian refugees with treatment-resistant posttraumatic stress disorder (PTSD) and comordid panic attacks. We used a cross-over design, with 20 patients in the initial treatment (IT) condition and 20 in delayed treatment (DT). Repeated measures MANOVA, Group & times; Time ANOVAs, and planned contrasts indicated significantly greater improvement in the IT condition, with large effect sizes (Cohen's d) for all outcome measures: Anxiety Sensitivity Index (d = 3.78), Clinician-Administered PTSD Scale (d = 2.17), and Symptom Checklist 90-R subscales (d = 2.77). Likewise, the severity of (culturally related) neck-focused and orthostasis-cued panic attacks, including flashbacks associated with these subtypes, improved across treatment. [source] A controlled study of imagery rehearsal for chronic nightmares in sexual assault survivors with PTSD: A preliminary reportJOURNAL OF TRAUMATIC STRESS, Issue 4 2000Barry Krakow Imagery-rehearsal therapy for chronic nightmares was assessed in a randomized, controlled study of sexual assault survivors with posttraumatic stress disorder (PTSD). Nightmares, sleep quality, and PTSD were assessed at baseline for 169 women, who were randomized into two groups: treatment (n = 87) and wait-list control (n = 82). Treatment consisted of two 3-hr sessions and one 1-hr session conducted over 5 weeks. Of 169 participants, 91 women (Treatment, n = 43, Control, n = 48) completed a 3-month follow-up and 78 did not. At follow-up, nightmare frequency and PTSD severity decreased and sleep quality improved in the treatment group with small to minimal changes in the control group. Treatment effects were moderate to high (Cohen's d ranged from 0.57 to 1.26). Notwithstanding the large dropout rate, imagery-rehearsal therapy is an effective treatment for chronic nightmares in sexual assault survivors with PTSD and is associated with improvement in sleep quality and decreases in PTSD severity. [source] Research Review: The relationship between childhood violence exposure and juvenile antisocial behavior: a meta-analytic reviewTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 7 2009Helen W. Wilson Background:, The connection between childhood violence exposure and antisocial behavior in adolescence has received much attention and has important implications for understanding and preventing criminal behavior. However, there are a limited number of well-designed prospective studies that can suggest a causal relationship, and little is known about the magnitude of the relationship. Methods:, This meta-analysis provides a quantitative comparison of 18 studies (N = 18,245) assessing the relationship between childhood (before age 12) violence exposure and adolescent antisocial behavior. An overall effect size (Cohen's d) was calculated for each study, an average for the 18 studies, and averages for subsets of analyses within studies. Results:, Results indicated a small effect from prospective studies (d = .31) and a large effect from cross-sectional studies (d = .88). The effect for victimization (d = .61) was larger than for witnessing violence (d = .15). Conclusions:, Effect size varied across studies employing different methodologies, populations, and conceptualizations of violence exposure and antisocial behavior. These findings do not support a simple, direct link from early violence exposure to antisocial behavior but suggest that many factors influence this relationship. [source] Medication adherence skills training for middle-aged and elderly adults with bipolar disorder: development and pilot studyBIPOLAR DISORDERS, Issue 6 2007Colin A Depp Objectives:, To present the rationale, development, and pilot study of a medication adherence skills training (MAST-BD) intervention for older adults with bipolar disorder (BPD). We developed a 12-week manualized group intervention that combined educational, motivational, medication management skills and symptom management training adapted for older adults. Methods:, Among 21 older outpatients with BPD (mean age = 60 years; SD = 6), the feasibility and acceptability of MAST-BD were assessed in a quasi-experimental clinical trial. We also obtained preliminary effect sizes associated with pre,post change on measures of self-reported adherence to psychiatric medications, performance-based medication management ability, attitudes toward medication, depressive and manic symptoms, and health-related quality of life. Results:, At baseline, 55% of participants reported recent non-adherence to psychiatric medications and were, on average, suffering from moderately severe depressive symptoms and minimal symptoms of mania. A total of 76% of participants completed the intervention, and 86% of sessions were attended by completers. Participants reported high levels of satisfaction with the intervention and manual. Pre,post improvement by small to medium effect sizes (Cohen's d = 0.30,0.57) was seen in medication adherence, medication management ability, depressive symptoms, and selected indices of health-related quality of life. Conclusions:, Notwithstanding the limitations of this small preliminary study, the results are encouraging in that the MAST-BD intervention was feasible, acceptable to patients, and associated with improvement in key outcomes. Suggestions for further development of medication adherence interventions for this neglected group of patients are discussed. [source] Heart rate variability (HRV) in adolescent females with anxiety disorders and major depressive disorderACTA PAEDIATRICA, Issue 4 2010E Henje Blom Abstract Aim:, The aim of this study was to investigate heart rate variability (HRV) in a clinical sample of female adolescents with anxiety disorders (AD) and/or major depressive disorder (MDD) compared with healthy controls and to assess the effect of selective serotonin reuptake inhibitors (SSRI) on HRV. Methods:, Heart rate variability was measured in adolescent female psychiatric patients with AD and/or MDD (n = 69), mean age 16.8 years (range: 14.5,18.4), from 13 out-patient clinics and in healthy controls (n = 65), mean age 16.5 years (range: 15.9,17.7). HRV was registered in the sitting position during 4 min with no interventions. Results:, Logarithmically transformed high frequency HRV (HF), low frequency HRV (LF) and standard deviation of inter beat intervals (SDNN) were lower in the clinical sample compared with the controls (Cohen's d for HF = 0.57, LF = 0.55, SDNN = 0.60). This was not explained by body mass index, blood pressure or physical activity. Medication with SSRI explained 15.5% of the total variance of HF, 3.0% of LF and 6.5% of SDNN. Conclusions:, Adolescent female psychiatric patients with AD and/or MDD show reduced HRV compared with healthy controls. Medication with SSRI explained a part of this difference. [source] Parent-completed developmental screening in a Norwegian population sample: a comparison with US normative dataACTA PAEDIATRICA, Issue 11 2004H Janson Aim: To compare normative data of a Norwegian translation of the Ages and Stages Questionnaires with original US normative data. Methods: Norwegian-born mothers randomly selected from the population register completed Norwegian translations of the Ages and Stages Questionnaires, a series of 19 age-specific child development screening questionnaires each made up of 30 items in five domains: Communication, Gross Motor, Fine Motor, Problem Solving, and Personal-Social. Domain score group differences with original US normative data on 10 age-specific questionnaires (for ages 4, 8, 12, 16, 20, 24, 30, 36, 48, and 60 mo) were investigated. The Norwegian data consisted of 1341 children, varying between 82 and 176 per age interval. Results: On the whole, parents' reports of their children's development were very similar in the two data sets. Only five out of 50 mean comparisons revealed a mean difference either greater than a Cohen's d of 0.5 or greater than the smallest increment on a domain score. The variation in scores tended to be somewhat smaller in the Norwegian sample. Conclusion: It seems reasonable to expect that domain scores on the Ages and Stages Questionnaires may be interpreted in the same way in Norway and the United States, and these results may also generalize to other Western settings. These findings from a true random sample also increase the confidence in the original normative data. [source] The Dodo Bird Verdict Is Alive and Well,MostlyCLINICAL PSYCHOLOGY: SCIENCE AND PRACTICE, Issue 1 2002Lester Luborsky We examined 17 meta-analyses of comparisons of active treatments with each other, in contrast to the more usual comparisons of active treatments with controls. These meta-analyses yielded a mean uncorrected absolute effect size for Cohen's d of .20, which is small and non-significant (an equivalent Pearson's r would be. 10). The smallness of this effect size confirms Rosenzweig's supposition in 1936 about the likely results of such comparisons. In the present sample, when such differences were corrected for the therapeutic allegiance of the researchers involved in comparing the different psychotherapies, these differences tend to become even further reduced in size and significance, as shown previously by Luborsky, Diguer, Seligman, et al. (1999). [source] | |||||||||||||