			Home About us Contact

Random Assignment (random + assignment)

Distribution by Scientific Domains

Medical Sciences	60%
Business, Economics, Finance and Accounting	26%
4 Other Domains	14%

Selected Abstracts

Effect of isometric exercise and body scanning on cigarette cravings and withdrawal symptoms

ADDICTION, Issue 7 2009
Michael Ussher
ABSTRACT Aims To examine the acute effects of a guided relaxation routine (body scan) and isometric exercise on desire to smoke and tobacco withdrawal symptoms. Design Experimental comparison of three conditions. Participants Forty-eight individuals reporting smoking ,10 cigarettes daily. Intervention Random assignment to one of three interventions delivered via a 10-minute audio: isometric exercise (IE, n = 14), body scanning (BS, n = 18) or a reading about natural history (control group, n = 16). Interventions were delivered twice on the same day: in the laboratory, then in their ,normal' environment. Measurements Desire to smoke (primary outcome) and withdrawal symptoms were rated at pre-intervention and up to 30 minutes post-intervention. Findings Controlling for baseline scores, post-intervention desire to smoke and withdrawal symptoms were significantly lower for IE and BS groups, compared with the controls, in both environments. There were no significant differences for IE versus BS. For desire to smoke, controlling for baseline values, ratings in the laboratory were significantly lower for IE and BS versus the control up to 30 minutes post-intervention. In the normal environment, these ratings were significantly lower only up to 5 minutes post-intervention. Conclusions Brief IE and BS interventions are effective for reducing desire to smoke and withdrawal symptoms in temporarily abstaining smokers. These interventions were found to be more effective in the laboratory than in the smoker's normal environment, but this may be an artefact of there not being a sufficient ,wash-out' period between interventions. These techniques may be beneficial for managing desire to smoke and tobacco withdrawal. [source]

Comparative efficacy of rapid-release nicotine gum versus nicotine polacrilex gum in relieving smoking cue-provoked craving

ADDICTION, Issue 11 2005
Raymond Niaura
ABSTRACT Aims Most relapse episodes occur when smokers are confronted with craving provoked by situational cues. Current nicotine gum can help relieve cue-provoked cravings, but faster effects may result in more rapid relief. We tested a prototype formulation of a new rapid-release nicotine gum (RRNG) that provides more rapid release and absorption of nicotine, for its ability to provide faster and better craving relief compared to current nicotine polacrilex gum (NPG). Design Random assignment to RRNG or NPG, used during a smoking cue provocation procedure. Participants and setting A total of 319 smokers were exposed to a smoking cue in the laboratory by being asked to light but not smoke a cigarette of their preferred brand. Subjects then chewed a piece of 2 mg RRNG (n = 159) or 2 mg NPG (n = 160) according to randomized assignment. Measurements Craving assessments were completed at regular intervals before and after cue exposure (baseline, pre-cue, and 3, 6, 9, 12, 15, 18, 21, 25, 30 and 35 minutes after the cue). Findings Smokers chewing RRNG showed significantly lower craving than NPG subjects starting with the first assessment at 3 minutes (P < 0.025). Repeated-measures ANOVA revealed a significant treatment × time interaction (P < 0.05),craving scores dropped more rapidly in RRNG subjects compared to NPG subjects. Survival analyses also indicated superiority of RRNG in achieving more rapid self-reported meaningful relief (P < 0.05) and complete relief (P < 0.05) of craving. Conclusions Rapid-release nicotine gum reduced cue-provoked craving more rapidly compared to NPG, and thus merits further study in cessation efficacy trials. [source]

Growth Hormone Administration and Exercise Effects on Muscle Fiber Type and Diameter in Moderately Frail Older People

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 7 2001
James V. Hennessey MD
OBJECTIVE: Reduced muscle mass and strength are characteristic findings of growth hormone deficiency (GHD) and aging. We evaluated measures of muscle strength, muscle fiber type, and cross sectional area in response to treatment with recombinant human growth hormone (rhGH) with or without a structured resistance exercise program in frail older subjects. DESIGN: Placebo-controlled, randomized, double blind trial. SETTING: Outpatient clinical research center at an urban university-affiliated teaching hospital. PARTICIPANTS: Thirty-one consenting older subjects (mean age 71.3 ± 4.5 years) recruited as a subset of a larger project evaluating rhGH and exercise in older people, who underwent 62 quadricep-muscle biopsies. INTERVENTION: Random assignment to a 6-month course of one of four protocols: rhGH administered subcutaneously daily at bedtime, rhGH and a structured resistance exercise program, structured resistance exercise with placebo injections, or placebo injections only. MEASUREMENTS: Muscle biopsy specimens were obtained from the vastus lateralis muscle. Isokinetic dynamometry strength tests were used to monitor individual progress and to adjust the weights used in the exercise program. Serum insulin-like growth factor-I (IGF-I) was measured and body composition was measured using a Hologic QDR 1000W dual X-ray densitometer. RESULTS: The administration of rhGH resulted in significant increase in circulating IGF-I levels in the individuals receiving rhGH treatment. Muscle strength increased significantly in both the rhGH/exercise (+55.6%, P = .0004) as well as the exercise alone (+47.8%, P = .0005) groups. There was a significant increase in the proportion of type 2 fibers between baseline and six months in the combined rhGH treated subjects versus those not receiving rhGH (P = .027). CONCLUSIONS: Our results are encouraging in that they suggest an effect of growth hormone on a specific aging-correlated deficit. IGF-I was increased by administrating rhGH and muscle strength was increased by exercise. The administration of rhGH to frail older individuals in this study resulted in significant changes in the proportions of fiber types. Whether changes in fiber cross-sectional area or absolute number occur with long-term growth hormone administration requires further study. [source]

Amoxicillin plus metronidazole in the treatment of adult periodontitis patients

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 4 2001
A double-blind placebo-controlled study
Abstract Background, aims: The aim of this double-blind, parallel study was to evaluate the adjunctive effects of systemically administered amoxicillin and metronidazole in a group of adult periodontitis patients who also received supra- and subgingival debridement. Methods: 49 patients with a diagnosis of generalised severe periodontitis participated in the study. Random assignment resulted in 26 patients in the placebo (P) group with a mean age of 40 years and 23 patients in the test (T) group which had a mean age of 45 years. Clinical measurements and microbiological assessments were taken at baseline and 3 months after completion of initial periodontal therapy with additional placebo or antibiotic treatment. Patients received coded study medication of either 375 mg amoxicillin in combination with 250 mg metronidazole or identical placebo tablets, every 8 hours for the following 7 days. Results: At baseline, no statistically significant differences between groups were found for any of the clinical parameters. Except for the plaque, there was a significantly larger change in the bleeding, probing pocket depth (PPD) and clinical attachment level (CAL) in the T-group as compared to the P-group after therapy. The greatest reduction in PPD was found at sites with initial PPD of 7 mm, 2.5 mm in the P-group and 3.2 mm in the T-group. The improvement in CAL was most pronounced in the PPD category 7 mm and amounted to 1.5 mm and 2.0 mm in the P- and T-groups, respectively. No significant decrease was found in the number of patients positive for any of the test species in the P-group. The number of patients positive for Porphyromonas gingivalis, Bacteroides forsythus and Prevotella intermedia in the T-group showed a significant decrease. After therapy there was a significant difference between the P- and the T- group in the remaining number of patients positive for P. gingivalis, B. forsythus and Peptostreptococcus micros. 4 subgroups were created on the basis of the initial microbiological status for P. gingivalis positive (Pg-pos) and negative patients (Pg-neg) in the P- and the T-groups. The difference in reduction of PPD between Pg-pos and Pg-neg patients was particularly evident with respect to the changes in % of sites with a probing pocket depth 5 mm. This % decreased from 45% at baseline to 23% after treatment in the Pg-pos placebo subgroup and decreased from 46% to 11% in the Pg-pos test subgroup (p0.005). In contrast, the changes in the proportions of sites with a probing pocket depth 5 mm in the Pg-neg placebo and Pg-neg test subgroup were similar, from 43% at baseline to 18% after treatment versus 40% to 12%, respectively. Conclusions: This study has shown that systemic usage of metronidazole and amoxicillin, when used in conjunction with initial periodontal treatment in adult periodontitis patients, achieves significantly better clinical and microbiological results than initial periodontal treatment alone. Moreover, this research suggests that especially patients diagnosed with P. gingivalis benefit from antibiotic treatment. Zusammenfassung Zielsetzung: Das Ziel dieser placebokontrollierten Doppelblindstudie mit parallelen Gruppen war es, die zusätzlichen Effekte der systemischen Gabe von Amoxicillin und Metronidazol bei Patienten mit Erwachsenenparodontitis zu untersuchen, bei denen auch eine supra- und subgingivale Instrumentierung durchgeführt worden war. Material und Methoden: 49 Patienten mit einer generalisierten schweren Erwachsenenparodontitis nahmen an der Studie teil. Zufällige Zuweisung der Therapien führte zu 26 Patienten in der Placebo-Gruppe (P) mit einem mittleren Alter von 40 und 23 Patienten in der Test-Gruppe (T) mit einem mittleren Alter von 45 Jahren. Klinische Messungen und mikrobiologische Untersuchungen wurden zu Beginn der Therapie sowie 3 Monate nach parodontaler Initialbehandlung mit zusätzlicher Placebo- bzw. Antibiotikagabe durchgeführt. Nachdem alle Zähne mit pathologisch vertieften Taschen subgingival instrumentiert worden waren, erhielten die Patienten eine kodierte Studienmedikation, die entweder aus 375 mg Amoxicillin und 250 mg Metronidazol oder identisch aussehenden Placebotabletten bestand, die die Patienten für 7 Tage alle 8 Stunden einnehmen sollten. Ergebnisse: Zu Beginn der Studie bestand kein statistisch signifikanter Unterschied zwischen den Versuchsgruppen hinsichtlich klinischer Parameter. Nicht für den Plaque Index, aber für Sondierungsblutung, Sondierungstiefen (ST) und klinische Attachmentlevel (PAL) kam es in der T-Gruppe zu signifikant stärkeren Veränderungen im Vergleich zur P-Gruppe. Die stärkste ST-Reduktion bzw. die größten Attachmentgewinne wurden bei Stellen gefunden, die initial ST 7 mm aufgewiesen hatten: P-Gruppe: ST=2.5 mm, PAL=1.5 mm; T-Gruppe: ST=3.2 mm, PAL=2.0 mm. Für keines der untersuchten Parodontalpathogene wurde eine signifikante Reduktion in der P-Gruppe beobachtet, während sich in der T-Gruppe eine signifikante Reduktion für Porphyromonas gingivalis, Bacteroides forsythus und Prevotella intermedia ergab. Nach Therapie ergab sich ein statistisch signifikanter Unterschied zwischen T- und P-Gruppe hinsichtlich Persistenz von P. gingivalis, B. forsythus und Peptostreptococcus micros. Entsprechend dem initialen mikrobiologischen Status für P. gingivalis wurden 4 Untergruppen gebildet: P. gingivalis positive (Pg+) oder (Pg,) Patienten in der T-bzw. P-Gruppe. Der Unterschied zwischen Pg+ und Pg, Patienten war besonders groß hinsichtlich der Veränderung des %-Anteils der Stellen mit ST5 mm. Dieser verringerte sich in der Pg+ P-Untergruppe von 45% auf 23% und in der Pg+ T-Untergruppe von 46% auf 11% (p0.005). Im Unterschied dazu war die Reduktion des Anteils der ST 5 mm in der Pg, P- und T-Untergruppen gleich: P-Gruppe: 43% auf 18%; T-Gruppe von 40% auf 12%. Schlußfolgerungen: Die systemische Gabe von Amoxicillin und Metronidazol zusätzlich zu subgingivaler Instrumentierung bei Patienten mit Erwachsenenparodontitis führt zu signifikant günstigeren klinischen und mikrobiologischen Ergebnissen als die konventionelle Therapie allein. Insbesondere Patienten mit P. gingivalis scheinen von dieser unterstützenden antibiotischen Therapie zu profitieren. Résumé Le but de cette étude parallèle en double aveugle était d'évaluer les effets supplémentaires apportés par l'administration d'amoxicilline et de metronidazole dans un groupe de patients atteints de parodontite de l'adulte qui ont reçu également un débridement supra et sous gingival. 49 patients présentant un diagnostic de parodontite généralisée sévère participèrent à l'étude. La composition des groupes sélectionnés au hasard, était de 26 patients dans le groupe placebo (P) avec un âge moyen de 40 ans et 23 patients dans le groupe test (T) avec une moyenne d'âge de 45 ans. Des mesures cliniques et des prélèvements microbiologiques étaient réalisés initialement et 3 mois après la fin de la thérapeutique parodontale initiale complétée par un placebo ou un traitement antibiotique. Les patients recevaient des médicaments codés pour l'étude de 375 mg amoxicilline combiné avec 250 mg de metronidazol ou des comprimés placebo identiques, toutes les 8 heures pendant les 7 jours suivants. Initalement, aucune différence statistiquement significative entre les groupes n'était observée, pour aucun des paramètres cliniques. En dehors de la plaque, il y avait une modification plus élevée significative pour le saignement, la profondeur de poche au sondage (PPD) et le niveau clinique d'attache (CAL) dans le groupe T, par rapport au groupe P, après traitement. La plus grande réduction pour PPD était observée pour les sites ayant une profondeur de poche au sondage intiale>ou égale à 7 mm, 2.5 mm dans le groupe P et 3.2 mm dans le groupe T. L'amélioration du CAL était plus prononcée pour la catégorie >ou égale à 7 mm et allait jusqu'à 1.5 et 2.0 mm dans les groupes P et T, respectivement. Aucune diminution significative n'était trouvée pour le nombre de patients positifs pour n'importe quelle espèce test dans le groupe P. Le nomber de patients positifs pour Porphyromonas gingivalis, Bacteroides forsythus et Prevotella intermedia dans le groupe T présentait une diminution significative. Après thérapeutique, il y avait une différence significative entre les groupe P et T, en ce qui concerne le nombre de patients positifs pour P. gingivalis, B. forsythus et Peptostreptococcus micros. 4-sous groupes furent créés sur la base de l'état microbiologique pour les patients positifs àP. gingivalis (Pg-pos), et négatifs (Pg-neg), dans les groupes P et T. La différence de réduction de PPD entre les patients Pg-pos et Pg-neg était particulièrement évidente en ce qui concernait les changements en % de sites présentant une profondeur de poche au sondage >ou égale à 5 mm. Ce % diminuait de 45% initialement à 23% après traitement dans le sous-groupe Pg-pos placebo et de 46% à 11% dans le sous-groupe Pg-pos test (p<0.005). A l'inverse, les changements observés dans les proportions de sites avec une profondeur de poche au sondage >5 mm dans les sous-groupes Pg-neg placebo et Pg-neg test étaient similaires, de 43% initialement à 18% après traitement contre 40% à 12% respectivement. En conclusion, cette étude a montré que l'utilisation systèmique de metronidazole et d'amoxicilline, lorsqu'elle est utilisée en complément du traitement parodontal initial chez des patients atteints de parodontite de l'adulte, donne, de façon significative, de meilleurs résultats cliniques et microbiologiques qu'un traitement parodontal initial seul. De plus, cette recherche suggère que les patients porteurs du P. gingivalis bénéficient particulièrement d'un traitement antibiotique. [source]

A randomised controlled trial of moxibustion for breech presentation

BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 6 2005
Francesco Cardini
Objectives To evaluate the efficacy of moxibustion for the correction of fetal breech presentation in a non-Chinese population. Design Single-blind randomised controlled trial (RCT). Setting Six obstetric departments in Italy. Sample Healthy non-Chinese nulliparous pregnant women at 32,33 weeks + 3 days of gestational age with the fetus in breech presentation. Methods Random assignment to treatment or observation. Treatment consisted of moxibustion (stimulation with heat from a stick of Artemisia vulgaris) at the BL 67 acupuncture point (Zhiyin) for one or two weeks. Two weeks after recruitment, each participant was subjected to an ultrasonic examination of the fetal presentation. Main outcome measure Number of participants with cephalic presentation in the 35th week. Results The study was interrupted when 123 participants had been recruited (46% of the planned sample). Intermediate data monitoring revealed a high number of treatment interruptions. At this point no difference was found in cephalic presentation in the 35th week (treatment group: 22/65, 34%; control group: 21/58, 36%; RR 0.95; 99% CI 0.59,1.5). Conclusions The results underline the methodological problems evaluating of a traditional treatment transferred from a different cultural context. They do not support either the effectiveness or the ineffectiveness of moxibustion in correcting fetal breech presentation. [source]

Emollients in a propanol-based hand rub can significantly decrease irritant contact dermatitis

CONTACT DERMATITIS, Issue 6 2005
Günter Kampf
The objective of this study is to determine the effect of emollients in a propanol-based hand rub on skin dryness and erythema. In this prospective, randomized, controlled, double-blind trial, 35 subjects participated; of them approximately half were atopic (modified Erlanger atopy score ,8). 2 propanol-based formulations were tested in a repeated open application test, 1 contained a mixture of emollients (0.81%, w/w). 2 aliquots of 0.7 ml of each formulation were applied twice per day over 2 weeks to the cubital fossa of each subject after random assignment of the preparations. Treatment areas were assessed before each application and 3 days postfinal application by visual inspection for erythema and dryness according to a standard scale. The sum score over all assessment time-points served as primary parameter. The mean sum score for erythema and dryness was significantly lower for the hand rub with emollients (0.8 ± 2.4) in comparison with that for the hand rub without emollients (1.5 ± 3.5; P = 0.022; Wilcoxon signed rank test). A comparison of the atopic and non-atopic subjects revealed no significant difference for any of the products (P > 0.05; Mann,Whitney U -test). It is concluded that the addition of emollients to a propanol-based hand rub can significantly decrease irritant contact dermatitis under frequent-use conditions. [source]

Does elimination of placebo responders in a placebo run-in increase the treatment effect in randomized clinical trials?

DEPRESSION AND ANXIETY, Issue 1 2004
A meta-analytic evaluation
Abstract The use of a placebo run-in phase, in which placebo responders are withdrawn from a study before random assignment to treatment condition, has been criticized as favoring the active treatment in clinical trials. We compared the effect size of randomized, placebo-controlled clinical trials (in the treatment of depression with selective serotonin reuptake inhibitors [SSRIs]) that include a placebo run-in phase with those that do not, using a meta-analytic approach. This study differed from earlier meta-analytic studies in that it considered only SSRIs and included only studies using continuous measures of depression, allowing for a more refined assessment of effect size. An extensive literature search identified 43 datasets published between 1980 and 2000 comparing placebo with SSRI and using a continuous measure of depression (usually the Hamilton Depression Rating Scale). We included only studies of at least 6 weeks' duration focusing on treatment for primary acute major depression in adults 18,65 years of age. Studies focusing on depression in specific medical illnesses were not included. Analysis of efficacy was based on 3,047 subjects treated with an SSRI antidepressant and 3,740 subjects treated with a placebo. There was no statistically significant difference in effect size between the clinical trials that had a placebo run-in phase followed by withdrawal of placebo responders and those trials that did not. Despite the lack of a statistically significant difference between studies of withdrawing early placebo responders and those not using this procedure, this approach is likely to continue to be used widely because it produces large absolute effect sizes. It is recommended that future studies clearly describe these procedures and report the number of subjects dropped from the study for early placebo response and other reasons. Depression and Anxiety 19:10,19, 2004. 2004 Wiley-Liss, Inc. [source]

Estimating the Effects of a Time-Limited Earnings Subsidy for Welfare-Leavers

ECONOMETRICA, Issue 6 2005
David Card
In the Self Sufficiency Project (SSP) welfare demonstration, members of a randomly assigned treatment group could receive a subsidy for full-time work. The subsidy was available for 3 years, but only to people who began working full time within 12 months of random assignment. A simple optimizing model suggests that the eligibility rules created an "establishment" incentive to find a job and leave welfare within a year of random assignment, and an "entitlement" incentive to choose work over welfare once eligibility was established. Building on this insight, we develop an econometric model of welfare participation that allows us to separate the two effects and estimate the impact of the earnings subsidy on welfare entry and exit rates among those who achieved eligibility. The combination of the two incentives explains the time profile of the experimental impacts, which peaked 15 months after random assignment and faded relatively quickly. Our findings suggest that about half of the peak impact of SSP was attributable to the establishment incentive. Despite the extra work effort generated by SSP, the program had no lasting impact on wages and little or no long-run effect on welfare participation. [source]

AFTER-SCHOOL PROGRAM EFFECTS ON BEHAVIOR: RESULTS FROM THE 21ST CENTURY COMMUNITY LEARNING CENTERS PROGRAM NATIONAL EVALUATION

ECONOMIC INQUIRY, Issue 1 2008
SUSANNE JAMES-BURDUMY
This paper presents evidence on after-school programs' effects on behavior from the national evaluation of the U.S. Department of Education's 21st Century Community Learning Centers after-school program. Findings come from both of the study's components: (1) an elementary school component based on random assignment of 2,308 students in 12 school districts and (2) a middle school component based on a matched comparison design including 4,264 students in 32 districts. Key findings include higher levels of negative behavior for elementary students and some evidence of higher levels of negative behaviors for middle school students. (JEL I21) [source]

Computer-based psychological treatment for comorbid depression and problematic alcohol and/or cannabis use: a randomized controlled trial of clinical efficacy

ADDICTION, Issue 3 2009
Frances J. Kay-Lambkin
ABSTRACT Aims To evaluate computer- versus therapist-delivered psychological treatment for people with comorbid depression and alcohol/cannabis use problems. Design Randomized controlled trial. Setting Community-based participants in the Hunter Region of New South Wales, Australia. Participants Ninety-seven people with comorbid major depression and alcohol/cannabis misuse. Intervention All participants received a brief intervention (BI) for depressive symptoms and substance misuse, followed by random assignment to: no further treatment (BI alone); or nine sessions of motivational interviewing and cognitive behaviour therapy (intensive MI/CBT). Participants allocated to the intensive MI/CBT condition were selected at random to receive their treatment ,live' (i.e. delivered by a psychologist) or via a computer-based program (with brief weekly input from a psychologist). Measurements Depression, alcohol/cannabis use and hazardous substance use index scores measured at baseline, and 3, 6 and 12 months post-baseline assessment. Findings (i) Depression responded better to intensive MI/CBT compared to BI alone, with ,live' treatment demonstrating a strong short-term beneficial effect which was matched by computer-based treatment at 12-month follow-up; (ii) problematic alcohol use responded well to BI alone and even better to the intensive MI/CBT intervention; (iii) intensive MI/CBT was significantly better than BI alone in reducing cannabis use and hazardous substance use, with computer-based therapy showing the largest treatment effect. Conclusions Computer-based treatment, targeting both depression and substance use simultaneously, results in at least equivalent 12-month outcomes relative to a ,live' intervention. For clinicians treating people with comorbid depression and alcohol problems, BIs addressing both issues appear to be an appropriate and efficacious treatment option. Primary care of those with comorbid depression and cannabis use problems could involve computer-based integrated interventions for depression and cannabis use, with brief regular contact with the clinician to check on progress. [source]

Efficacy screening trials of paroxetine, pentoxifylline, riluzole, pramipexole and venlafaxine in cocaine dependence

ADDICTION, Issue 2005
Domenic A. Ciraulo
ABSTRACT Aims The two studies presented here were conducted to assess the efficacy of paroxetine, pentoxifylline, riluzole, venlafaxine and pramipexole as medications for the treatment of cocaine dependence. Design A multi-arm, modified blinded, placebo-controlled design was used. Setting The studies were conducted at the Boston VA Healthcare System and the Boston University School of Medicine Medication Development Research Unit (MDRU). Participants Participants met criteria for cocaine dependence during a 2-week screening period. Intervention Following random assignment to one of the treatment groups, subjects received active medication or placebo for 8 weeks in combination with cognitive behavioral counseling. In the first study the efficacy of the antidepressant paroxetine (20 mg daily), the phosphodiesterase inhibitor pentoxifylline (1200 mg daily) and the glutamate release inhibitor riluzole (100 mg daily) was assessed. The antidepressant venlafaxine (150 mg daily) and the dopamine agonist pramipexole (1.5 mg daily) were evaluated in the second study. Measurements Urine benzoylecgonine (BE) concentrations, self-report of cocaine use and global impression scores served as primary outcome measures. Secondary measures included assessments of cocaine craving and psychiatric functioning. Adverse events were monitored during the treatment period. Findings None of the active medications produced greater reductions in urine BE concentrations over the treatment period than did placebo. There were trends for BE levels to become reduced in the pentoxifylline group during the first 4 weeks of treatment and for Addiction Severity Index (ASI) drug composite scores to be lower in the pentoxyfylline group at end-point compared to the placebo group. Significant within-group reductions in reported cocaine use and craving were found for all treatment groups, but none of the active medications were superior to placebo on these measures. The accuracy of self-reported cocaine use declined over the study period. Overall, the active medications were well tolerated. Conclusions This study does not support the use of paroxetine, pentoxifylline, riluzole, venlafaxine or pramipexole for the treatment of cocaine dependence. However, these results need to be interpreted with caution because of the small size and lack of homogeneity of the experimental groups. [source]

Cognitive,behavioral treatment for alcohol dependence: a review of evidence for its hypothesized mechanisms of action

ADDICTION, Issue 10 2000
Jon Morgenstern
Objective. This review examined support for the hypothesis that cognitive-behavioral treatment (CBT) for alcohol dependence works through increasing cognitive and behavioral coping skills. Method. Ten studies were identified that examined the hypothesized mechanisms of action of CBT. These studies involved random assignment (or its near equivalent) of participants to CBT and at least one comparison condition. Results. Although numerous analyses of the possible causal links have been conducted to evaluate whether CBT works through increasing coping, the results indicate little support for the hypothesized mechanisms of action of CBT. Conclusions. Research has not yet established why CBT is an effective treatment for alcohol dependence. Negative findings may reflect methodological flaws of prior studies. Alternatively, findings may indicate one or more conceptual assumptions underlying CBT require revision. [source]

Do welfare-to-work programmes work for long?

FISCAL STUDIES, Issue 1 2004
David Greenberg
Abstract Evidence that welfare-to-work programmes in the USA succeed in boosting welfare recipients' earnings at modest cost has helped shape policy in Britain since 1997. So too has the belief that programmes that prioritise moving people into work quickly are more effective than ones that seek to enhance human capital. However, there is little evidence on how long the beneficial effects of programmes persist after individuals leave them. The analysis reported draws on the experience of 64 US welfare-to-work programmes that have all been evaluated using random assignment. It concludes that, on average, these programmes have a positive effect on participants' earnings for five to six years. The effects of ,work first' interventions are most marked early on and decline more rapidly than those of programmes emphasising human capital. Nevertheless, work first interventions typically increase earnings received over six years by more than two-and-a-half times that achieved by human capital approaches. [source]

Conventional versus resin-modified glass-ionomer cement for Class II restorations in primary molars.

INTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 1 2003
A 3-year clinical study
Summary. Objective. To compare the clinical performance of two glass-ionomer cements (GICs)for Class II restorations in primary molars: a conventional cement (Fuji II®) and a resin-modified cement (Vitremer®). Design. Split mouth and random assignment to the two materials were used for the majority of the molars. Sample and methods. Forty consecutive 4,7-year-old children were included. One operator made 115 restorations: 53 with Vitremer and 62 with Fuji II. The restorations were evaluated clinically, radiographically and from colour photographs. Results. The cumulative success rate of the Vitremer restorations was 94% and that of the Fuji II restorations 81%. The difference is statistically significant. The risk of a failed restoration was more than five times higher with Fuji II than with Vitremer as the restorative material. Of the 13 unsuccessful restorations, seven had lost their retention, four had secondary caries, and two were fractured. Conclusions. The resin-modified GIC offered advantages over the conventional GIC for restoring approximal caries in primary molars. [source]

Effects of interocclusal appliances on EMG activity during parafunctional tooth contact

JOURNAL OF ORAL REHABILITATION, Issue 6 2003
A. L. Roark
summary, To test the hypothesis that a flat plane interocclusal appliance affects the electromyographic (EMG) activity of the temporalis and masseter muscles in pain-free individuals, maxillary splints were fabricated for 20 individuals who reported no history, signs or symptoms of myofascial pain or arthralgia as determined by two trained, independent examiners. Subjects were instructed to establish light tooth contact, maximum clenching, and moderate clenching with/without the splint in place (as determined by random assignment) while EMG data from the left and right temporalis and masseter muscles were recorded. A 5-min biofeedback training session to relax the masticatory muscles was followed by a repetition of the tooth contact/clenching tasks with/without the splint in place. With the splint in place, the activity of the temporalis muscles decreased for all tasks, significantly for the left and right temporalis under maximal clenching and for the right temporalis under moderate clenching. In contrast, the activity of the masseter muscles increased under light and moderate clenching (significantly for the left masseter under moderate clenching) and decreased slightly under maximal clenching. The effectiveness of interocclusal appliances may be due to mechanisms other than redistribution of adverse loading. [source]

Beyond random assignment for internal validity and beyond social research for random assignment

JOURNAL OF POLICY ANALYSIS AND MANAGEMENT, Issue 1 2009
Laura Langbein
[source]

Do experimental and nonexperimental evaluations give different answers about the effectiveness of government-funded training programs?

JOURNAL OF POLICY ANALYSIS AND MANAGEMENT, Issue 3 2006
David H. Greenberg
This paper uses meta-analysis to investigate whether random assignment (or experimental) evaluations of voluntary government-funded training programs for the disadvantaged have produced different conclusions than nonexperimental evaluations. Information includes several hundred estimates from 31 evaluations of 15 programs that operated between 1964 and 1998. The results suggest that experimental and nonexperimental evaluations yield similar conclusions about the effectiveness of training programs, but that estimates of average effects for youth and possibly men might have been larger in experimental studies. The results also suggest that variation among nonexprimental estimates of program effects is similar to variation among experimental estimates for men and youth, but not for women (for whom it seems to be larger), although small sample sizes make the estimated differences somewhat imprecise for all three groups. The policy implications of the findings are discussed. © 2006 by the Association for Public Policy Analysis and Management [source]

Five-year effects of an anti-poverty program on marriage among never-married mothers

JOURNAL OF POLICY ANALYSIS AND MANAGEMENT, Issue 1 2006
Anna Gassman-Pines
Using data from an experimental evaluation of the New Hope project, an anti-poverty program that increased employment and income, this study examined the effects of New Hope on entry into marriage among never-married mothers. Among never-married mothers, New Hope significantly increased rates of marriage. Five years after random assignment, 21 percent of women assigned to the New Hope condition were married, compared to 12 percent of those assigned to the control group. The New Hope impact on marriage was robust to variations in model specification. The program also increased income, wage growth, and goal efficacy among never-married mothers, and decreased depression. In non-experimental analyses, income and earnings were associated with higher probability of marriage and material hardship was associated with lower probability of marriage. © 2006 by the Association for Public Policy Analysis and Management [source]

Does whole-school reform boost student performance?

JOURNAL OF POLICY ANALYSIS AND MANAGEMENT, Issue 1 2005
The case of New York City
Thousands of schools around the country have implemented whole-school reform programs to boost student performance. This paper uses quasi-experimental methods to estimate the impact of whole-school reform on students' reading performance in New York City, where various reform programs were adopted in dozens of troubled elementary schools in the mid-1990s. This paper complements studies based on random assignment by examining a broad-based reform effort and explicitly accounting for implementation quality. Two popular reform programs,the School Development Program and Success for All,were not found to significantly increase reading scores but might have been if they had been fully implemented. The More Effective Schools program was found to boost reading scores, but this effect seems to disappear when the program "trainers" leave the school. © 2005 by the Association for Public Policy Analysis and Management. [source]

Treatment Completion in a Brief Motivational Intervention in the Emergency Department: The Effect of Multiple Interventions and Therapists' Behavior

ALCOHOLISM, Issue 2007
Janette Baird
Background:, The aim of this study was to identify therapist behaviors during a brief motivational intervention (BMI) given to injured emergency department patients that predicted participant return for a second BMI session and 12-month alcohol-related outcomes. Method:, This was a secondary data analysis of a randomized controlled trial (n = 539) previously demonstrating that random assignment to a BMI and booster session resulted in a significant reduction of 12-month postintervention alcohol-related injuries and negative consequences relative to standard care. Results:, Participants who actually received 2 BMI sessions had significantly less alcohol-related negative consequences than those who received only 1 BMI session. Therapists who reported a higher focus on emotional support and low focus on participant drinking behaviors during the initial BMI session were more likely to have assigned participants return for the second BMI session. Conclusion:, The results of these secondary analyses show that compliance with a 2-session therapeutic intervention (BIB) predicted fewer negative alcohol-related consequences, and that therapists' supportive emotional emphasis during the first BMI session was important in predicting participants returning for the second MI session. [source]

Unipolar versus bipolar radiofrequency treatment of rhytides and laxity using a mobile painless delivery method

LASERS IN SURGERY AND MEDICINE, Issue 7 2008
Macrene Alexiades-Armenakas MD
Abstract Background Previous studies have shown that radiofrequency (RF) energy is a safe and effective treatment for rhytide-reduction. Objective This randomized, blinded, split-face study assesses the safety and efficacy of the unipolar versus bipolar handpieces on an RF device with a mobile delivery method for the treatment of rhytides and laxity using quantitative grading. Methods In this randomized, blinded, split-face design study, 10 subjects (aged 18,75 years) with a clinically observable excess of rhytides and laxity (minimum grade 2 out of 4) on the face received four treatments at 1-week intervals with random assignment of unipolar RF to one side and bipolar RF to the contralateral side. Each side received approximately four passes per treatment delivered in a mobile continuous manner. Results were evaluated by two blinded investigators of photographs employing a comprehensive 4-point grading scale at baseline, and 1- and 3-month follow-up visits after the final treatment. Results All subjects completed and responded to treatment. The blinded evaluations demonstrated the following mean percent improvements in grading scores of rhytides and laxity: for the unipolar side 6.0±4.6% and 4.6±4.8% versus the bipolar side 4.4±2.5 and 7.3±3.5%. The degree of improvement approached but did not achieve statistical significance for either handpiece, but demonstrated a trend toward improvement (P,=,0.5599 unipolar vs. 0.1108 bipolar). The treatment was painless (rated 0 out of 10 by all subjects) and side effects included minimal erythema which resolved within 1,3 hours. No crusting, dyspigmentation or scarring was observed. Conclusion This randomized, split-face study with blinded evaluations employing a quantitative grading scale demonstrated that minimal pass, mobile energy delivery serial treatments with either the unipolar or bipolar handpieces of a novel RF device appears to safe and painless. Each handpiece demonstrated minimal clinical efficacy which was not statistically significant, but with a trend toward improvement in rhytides and laxity of facial skin. Lesers Surg. Med. 40:446,453, 2008. © 2008 Wiley-Liss, Inc. [source]

A Drop in the Bucket: Randomized Controlled Trials Testing Reading and Math Interventions

LEARNING DISABILITIES RESEARCH & PRACTICE, Issue 2 2005
Pamela M. Seethaler
The purpose of this study was to determine the proportion of empirical studies published in the last 5 years in a sample of special education peer-reviewed journals that (1) assessed the effects of reading and math interventions with group designs and (2) used random assignment to treatment conditions to test those interventions. A hand search of articles from the Journal of Special Education, Exceptional Children, Learning Disabilities Research & Practice, the Journal of Learning Disabilities, and School Psychology Review yielded 806 relevant articles, of which 5.46 percent tested a reading or math intervention using a group design and 4.22 percent used random assignment. These findings indicate that randomized experimental designs, which offer the highest level of evidence of an intervention's efficacy, are underrepresented in the literature, at least in the area of reading and math interventions. [source]

Does Community Service Rehabilitate better than Short-term Imprisonment?: Results of a Controlled Experiment

THE HOWARD JOURNAL OF CRIMINAL JUSTICE, Issue 1 2000
Martin Killias
Community service, along with other new sanctions, has been recommended in many Western countries as an alternative to incarceration over many years. Despite a rich literature on evaluations of so-called alternative sanctions, random assignment has only exceptionally been used in this field, and (short-term) imprisonment has never been an option in such designs. The present study tried to assess the comparative effects of community service and prison sentences of up to 14 days, through a controlled experiment in Switzerland in which 123 convicts have been randomly assigned. The results show no difference with respect to later employment history and social and private life circumstances. However, re-arrest by the police was more frequent among those randomly assigned to prison than among those selected for community service. Prisoners also developed more unfavourable attitudes towards their sentence and the criminal justice system. [source]

Effects of a distance learning program on physicians' opioid- and benzodiazepine-prescribing skills

THE JOURNAL OF CONTINUING EDUCATION IN THE HEALTH PROFESSIONS, Issue 4 2006
Deana Midmer BScN
Abstract Introduction: Opioid misuse is common among patients with chronic nonmalignant pain. There is a pressing need for physicians to increase their confidence and competence in managing these patients. Methods: A randomized controlled trial of family physicians (N = 88) attending 1 of 4 continuing medical education events helped to determine the effectiveness of e-mail case discussions in changing physician behavior. Before random assignment, participants completed a pretest and attended a 3-hour didactic session on prescribing opioids and benzodiazepines. The intervention group participated in 10 weeks of e-mail case discussions, with designated participants responding to questions on cases. An addictions physician facilitated the discussion. Several months after the e-mail discussion, participants took part in a mock telephone consultation; a blinded researcher posing as a medical colleague asked for advice about 2 cases involving opioid and benzodiazepine prescribing. Using a checklist, the researcher recorded the questions asked and advice given by the physician. Results: On post-testing, both groups expressed greater optimism about treatment outcomes and were more likely to report using a treatment contract and providing advice about sleep hygiene. There were no significant differences between pretesting and post-testing between the groups on the survey. During the telephone consultation, the intervention group asked significantly more questions and offered more advice than the control group (odds ratio for question items, 1.27 [p = .03]; advice items, 1.33 [p = .01). Discussion: Facilitated by electronic mail and a medical expert, case discussion is an effective means of improving physician performance. Telephone consultation holds promise as a method for evaluating physicians' assessment and management skills. [source]

Evaluation of Omeprazole in the Treatment of Reflux Laryngitis: A Prospective, Placebo-Controlled, Randomized, Double-Blind Study,

THE LARYNGOSCOPE, Issue 12 2001
J. Pieter Noordzij MD
Abstract Objectives Proton-pump inhibitors are often recommended in the treatment of laryngitis secondary to gastric reflux. Despite prospective treatment studies reporting high efficacy, only one previous report has been placebo-controlled and blinded. The objective of this study was to determine the efficacy of omeprazole in treating proven reflux laryngitis. Study Design Prospective, placebo-controlled, randomized, double-blind clinical trial. Methods Fifty-three patients with one or more reflux laryngitis symptoms were recruited to undergo 24-hour dual-channel pH probe testing. Thirty patients with more than four episodes of laryngopharyngeal reflux were enrolled. By random assignment, 15 patients received 40 mg omeprazole twice a day and the other 15 received placebo for a period of 2 months. Symptoms (hoarseness, throat pain, lump in throat sensation, throat clearing, cough, excessive phlegm, dysphagia, odynophagia, and heartburn) and endoscopic laryngeal signs (erythema, edema, and mucus accumulation) were recorded initially, at 1 month, and 2 months. Results In general, most symptom scores improved over time for both the omeprazole and placebo groups. Hoarseness, when patients begin with low hoarseness symptom scores, and throat clearing improved significantly more in patients on omeprazole than in those on placebo during the 2-month study. Throat pain, lump in throat sensation, excessive phlegm, difficulty swallowing, pain with swallowing, and heartburn showed improvement in both treatment arms, signifying the possibility of a placebo effect. Endoscopic laryngeal signs did not change significantly over the course of the study for either treatment group. Conclusions A placebo effect appears to exist in the treatment of reflux laryngitis. However, hoarseness, when initially scored low, and throat clearing resulting from reflux laryngitis are effectively treated by omeprazole. [source]

Imputation Strategies for Missing Continuous Outcomes in Cluster Randomized Trials

BIOMETRICAL JOURNAL, Issue 3 2008
Monica Taljaard
Abstract In cluster randomized trials, intact social units such as schools, worksites or medical practices , rather than individuals themselves , are randomly allocated to intervention and control conditions, while the outcomes of interest are then observed on individuals within each cluster. Such trials are becoming increasingly common in the fields of health promotion and health services research. Attrition is a common occurrence in randomized trials, and a standard approach for dealing with the resulting missing values is imputation. We consider imputation strategies for missing continuous outcomes, focusing on trials with a completely randomized design in which fixed cohorts from each cluster are enrolled prior to random assignment. We compare five different imputation strategies with respect to Type I and Type II error rates of the adjusted two-sample t -test for the intervention effect. Cluster mean imputation is compared with multiple imputation, using either within-cluster data or data pooled across clusters in each intervention group. In the case of pooling across clusters, we distinguish between standard multiple imputation procedures which do not account for intracluster correlation and a specialized procedure which does account for intracluster correlation but is not yet available in standard statistical software packages. A simulation study is used to evaluate the influence of cluster size, number of clusters, degree of intracluster correlation, and variability among cluster follow-up rates. We show that cluster mean imputation yields valid inferences and given its simplicity, may be an attractive option in some large community intervention trials which are subject to individual-level attrition only; however, it may yield less powerful inferences than alternative procedures which pool across clusters especially when the cluster sizes are small and cluster follow-up rates are highly variable. When pooling across clusters, the imputation procedure should generally take intracluster correlation into account to obtain valid inferences; however, as long as the intracluster correlation coefficient is small, we show that standard multiple imputation procedures may yield acceptable type I error rates; moreover, these procedures may yield more powerful inferences than a specialized procedure, especially when the number of available clusters is small. Within-cluster multiple imputation is shown to be the least powerful among the procedures considered. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

DOES TEACHER QUALITY AFFECT STUDENT PERFORMANCE?

BULLETIN OF ECONOMIC RESEARCH, Issue 4 2009
EVIDENCE FROM AN ITALIAN UNIVERSITY
H52; I2 ABSTRACT In this paper, we analyse whether the characteristics of university teaching staff matter with regard to students' performance and interest in the discipline. We use data on about 1000 students enrolled on the first-level degree course in business and economics at a medium-sized Italian university. Thanks to the random assignment of students to different teaching classes during their first year, we are able to analyse the effect that teachers with different characteristics, in terms of experience and research productivity, produce both on students' performance, measured in terms of the grades obtained at subsequent examinations, and on courses chosen. Our results suggest that teacher quality has statistically significant effects on students' grades in subsequent courses. These effects are also robust after controlling for unobserved individual characteristics. On the other hand, we find less clear evidence when relating teacher quality to student involvement with a subject. It emerges that research productivity does not produce a statistically significant effect on the probability of a student undertaking additional courses in a subject, while more experienced teachers have a negative impact. However, also this effect does not become statistically significant when we run separate regressions for different disciplines. [source]

A Randomized Comparison Trial of Case-based Learning versus Human Patient Simulation in Medical Student Education

ACADEMIC EMERGENCY MEDICINE, Issue 2 2007
Lawrence R. Schwartz MD
Objectives Human patient simulation (HPS), utilizing computerized, physiologically responding mannequins, has become the latest innovation in medical education. However, no substantive outcome data exist validating the advantage of HPS. The objective of this study was to evaluate the efficacy of simulation training as compared with case-based learning (CBL) among fourth-year medical students as measured by observable behavioral actions. Methods A chest pain curriculum was presented during a one-month mandatory emergency medicine clerkship in 2005. Each month, students were randomized to participate in either the CBL-based or the HPS-based module. All students participated in the same end-of-clerkship chest pain objective structured clinical examination that measured 43 behaviors. Three subscales were computed: history taking, acute coronary syndrome evaluation and management, and cardiac arrest management. Mean total and subscale scores were compared across groups using a multivariate analysis of variance, with significance assessed from Hotelling's T2 statistic. Results Students were randomly assigned to CBL (n= 52) or HPS (n= 50) groups. The groups were well balanced after random assignment, with no differences in mean age (26.7 years; range, 22,44 years), gender (male, 52.0%), or emergency medicine preference for specialty training (28.4%). Self-ratings of learning styles were similar overall: 54.9% were visual learners, 7.8% auditory learners, and 37.3% kinetic learners. Results of the multivariate analysis of variance indicated no significant effect (Hotelling's T2 [3,98] = 0.053; p = 0.164) of education modality (CBL or HPS) on any subscale or total score difference in performance. Conclusions HPS training offers no advantage to CBL as measured by medical student performance on a chest pain objective structured clinical examination. [source]

Mindfulness-based stress reduction and attentional control

CLINICAL PSYCHOLOGY AND PSYCHOTHERAPY (AN INTERNATIONAL JOURNAL OF THEORY & PRACTICE), Issue 6 2007
Nicole D. Anderson
This study was designed to test the hypothesis that mindfulness involves sustained attention, attention switching, inhibition of elaborative processing and non-directed attention. Healthy adults were tested before and after random assignment to an 8-week Mindfulness-Based Stress Reduction (MBSR) course (n = 39) or a wait-list control (n = 33). Testing included measures of sustained attention, attention switching, Stroop interference (as a measure of inhibition of elaborative processing), detection of objects in consistent or inconsistent scenes (as a measure of non-directed attention), as well as self-report measures of emotional well-being and mindfulness. Participation in the MBSR course was associated with significantly greater improvements in emotional well-being and mindfulness, but no improvements in attentional control relative to the control group. However, improvements in mindfulness after MBSR were correlated with improvements in object detection. We discuss the implications of these results as they relate to the role of attention in mindfulness.,Copyright © 2007 John Wiley & Sons, Ltd. [source]

Analysis of multilocus fingerprinting data sets containing missing data

MOLECULAR ECOLOGY RESOURCES, Issue 2 2006
PHILIPP M. SCHLÜTER
Abstract Missing data are commonly encountered using multilocus, fragment-based (dominant) fingerprinting methods, such as random amplified polymorphic DNA (RAPD) or amplified fragment length polymorphism (AFLP). Data sets containing missing data have been analysed by eliminating those bands or samples with missing data, assigning values to missing data or ignoring the problem. Here, we present a method that uses random assignments of band presence,absence to the missing data, implemented by the computer program famd (available from http://homepage.univie.ac.at/philipp.maria.schlueter/famd.html), for analyses based on pairwise similarity and Shannon's index. When missing values group in a data set, sample or band elimination is likely to be the most appropriate action. However, when missing values are scattered across the data set, minimum, maximum and average similarity coefficients are a simple means of visualizing the effects of missing data on tree structure. Our approach indicates the range of values that a data set containing missing data points might generate, and forces the investigator to consider the effects of missing values on data interpretation. [source]