Dichotomous Data (dichotomous + data)

Distribution by Scientific Domains


Selected Abstracts


Fetal bradycardia due to intrathecal opioids for labour analgesia: a systematic review

BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 3 2002
Chahé Mardirosoff
Objective To evaluate fetal and maternal adverse effects of intrathecal opioid analgesia during labour. Data sources A systematic search was performed, in Medline, Embase, the Cochrane Library, bibliographies, and personal contact with authors, in any language, up to February 2001. Study selection Full reports on randomised comparisons of any analgesia with intrathecal opioid (experimental group) with any non-intrathecal opioid regimen (control group) during labour. Data extraction Dichotomous data from 24 trials (3513 women). Results With intrathecal opioids, there was a significant increase in the risk of fetal bradycardia: odds ratio 1.8 (95% confidence interval 1.0 to 3.1), number-needed-to-harm 28. The risk of caesarean section due to fetal heart rate abnormalities was similar (6.0%versus 7.8%). The incidence of pruritus was significantly higher with intrathecal opioids: relative risk 29.6 (95% CI 13.6 to 64.6), number-needed-to-harm 1.7. Conclusions Intrathecal opioids for labour increase the risk of fetal bradycardia and maternal pruritus. The risk of subsequent caesarean section is not increased. [source]


Some benefits of dichotomization in psychiatric and criminological research

CRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 2 2000
Professor David P. Farrington PhD FBA
Background The product-moment correlation r is widely used in criminology and psychiatry to measure strength of association. However, most criminological and psychiatric variables contravene its underlying assumptions. Aim To compare statistical measures of association based on dichotomous variables with the use of r. Method Explanatory variables for delinquency are investigated in the Pittsburgh Youth Study using a sample of 506 boys aged 13,14. Results Dichotomization does not necessarily cause a decrease in measured strength of associations. Conclusions about the most important explanatory variables for delinquency were not greatly affected by using dichotomous as opposed to continuous variables, by different dichotomization splits, or by using logistic versus OLS multiple regression. Non-linear relationships, interaction effects and multiple risk factor individuals were easily studied using dichotomous data. Conclusions Dichotomization produces meaningful findings that are easily understandable to a wide audience. Measures of association for dichotomous variables, such as the odds ratio, have many advantages and are often more realistic and meaningful measures of strength of relationship than the product-moment correlation r. Copyright © 2000 Whurr Publishers Ltd. [source]


Comparison of carbamazepine and lithium in treatment of bipolar disorder: A systematic review of randomized controlled trials,

HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 1 2009
Daniela Ceron-Litvoc
Abstract Objectives To review data from randomized controlled trials (RCTs) assessing the comparative efficacy of carbamazepine and lithium in treatment of acute manic and maintenance phase of bipolar disorder (BD). Design RCTs were identified through a search strategy that included: electronic databases, reference cross-checking, hand search of non-indexed publications, and book chapters on the treatment of BD comparing carbamazepine with lithium. Outcomes investigated were antimanic effect, trial withdrawal, relapse, hospitalization, need for rescue medication, and presence of adverse effects. Selection of studies and data analysis were performed independently by authors. Whenever possible, data from trials were combined through meta-analyses. Relative risks (RR) were estimated for dichotomous data. Results In acute mania, carbamazepine was similar to lithium on the following outcomes: trial withdrawal due to adverse effects, number of participants with at least one adverse effect, improvement in the Clinical Global Impression (CGI). In acute mania, carbamazepine was associated with fewer trial withdrawals. In maintenance treatment, carbamazepine was similar to lithium in relapses and hospitalization, but there were fewer trial withdrawals due to adverse effects on lithium. Conclusion This review suggests that carbamazepine might be comparable to lithium in terms of efficacy and safety, and therefore a valuable option in the treatment of both manic and maintenance phases. Copyright © 2008 John Wiley & Sons, Ltd. [source]


The clinical effectiveness of length of bed rest for patients recovering from trans-femoral diagnostic cardiac catheterisation

INTERNATIONAL JOURNAL OF EVIDENCE BASED HEALTHCARE, Issue 4 2008
Sek Ying Chair RN MBA PhD
Background, Cardiac catheterisation plays a vital role in the diagnosis and evaluation of cardiac conditions. The goal of management of patients after cardiac catheterisation is to reduce the risk of development of any local or prolonged vascular complications, in particular bleeding and haematoma formation at the puncture site. Bed rest and immobilisation of the affected leg are recommended practices to ensure adequate haemostasis at the femoral arterial puncture site and prevent complications. Objectives, The objective of this review was to present the best available evidence for the optimal length of bed rest after trans-femoral diagnostic cardiac catheterisation. The main outcome of interest was the incidence of bleeding and haematoma formation following varying periods of bed rest. Search strategy, We searched the following databases: CINAHL, Medline, Cochrane Library, Current Contents, EBSCO, Web of Science, Embase, British Nursing Index, Controlled clinical trials database, Google Scholar. Reference lists of relevant articles and conference proceedings were searched. We also contacted key organisations and researchers in the field. Selection criteria, All randomised and quasi-randomised controlled trials that compared the effects of different lengths of bed rest following trans-femoral diagnostic cardiac catheterisation on patient outcomes were considered for inclusion in the review. Data collection and analysis, Eligibility of the trials for inclusion in the review, details of eligible trials and the methodological quality of the trials were assessed independently by two reviewers. Odds ratios (OR) for dichotomous data and a weighted mean difference for continuous data were calculated with 95% confidence intervals (CI). Where synthesis was inappropriate, trials were considered separately. Main results, Eighteen trials involving a total of 4294 participants were included in the review. One trial included three treatment groups. In seven trials among 747 people there was no significant difference in the incidence of bleeding following six or less than 6 h of bed rest (OR 1.47; 95% CI 0.60, 3.64). Likewise, there was no significant difference in the incidence of bleeding following bed rest at other time periods. In eight trials involving 2272 patients there was no significant difference in the incidence of haematoma formation following 6 or less than 6 h of bed rest (OR 0.82; 95% CI 0.59, 1.16). Significantly fewer patients randomised to less than 6 h of bed rest complained of back pain. The odds of developing back pain at 4 (OR 24.60; 95% CI 1.29, 469) and 24 h (OR 2.47; 95% CI 1.16, 5.23) following coronary catheterisation was significantly higher among patients randomised to 6 compared with 3 h of bed rest. Authors' conclusions, There is evidence of no benefit relating to bleeding and haematoma formation in patients who have more than 3 h of bed rest following trans-femoral diagnostic cardiac catheterisation. However, there is evidence of benefit relating to decreased incidence and severity of back pain and cost-effectiveness following 3 h of bed rest. There is suggestive but inconclusive evidence of a benefit from bed rest for 2 h following trans-femoral cardiac catheterisation. Clinicians should consider a balance between avoiding increased risk of haematoma formation following 2,2.5 h of bed rest and circumventing back pain following more than 4 h of bed rest. [source]


Effectiveness of brief structured interventions on risk factor modification for patients with coronary heart disease: a systematic review

INTERNATIONAL JOURNAL OF EVIDENCE BASED HEALTHCARE, Issue 4 2007
Ritin Fernandez RN MN (Critical care) PhD Candidate
Abstract Background, The physical and psychosocial benefits of participation in cardiac rehabilitation following a coronary event have well been established. Despite these benefits there is strong evidence that participation in traditional cardiac rehabilitation programs remains low. Various models of cardiac rehabilitation have been implemented including the use of brief structured interventions to enable modification of coronary risk factors. Objectives, The objective of this review was to determine the effect of brief structured interventions on risk factor modification in patients with coronary heart disease. Search strategy, A literature search was performed using the following databases MEDLINE (1966,2006), CINAHL (1982,2006), EMBASE (1980,current) and up to the Cochrane Controlled Trials Register (Issue 2, 2006 of Cochrane Library). In addition, the reference lists of relevant trials and conference proceedings were also scrutinised. Company representatives, experts and investigators were contacted to elicit further information. Selection criteria, All randomised and quasi-randomised controlled trials that compared the effects of brief structured interventions on risk factor modification in patients with coronary heart disease were considered for inclusion in the review. Data collection and analysis, Eligibility of the trials for inclusion in the review, details of eligible trials and the methodological quality of the trials were assessed independently by two reviewers. Relative risks for dichotomous data and a weighted mean difference for continuous data were calculated with 95% confidence intervals. Where synthesis was inappropriate, trials were considered separately. Main results, Seventeen trials involving a total of 4725 participants were included in the final review: three trials compared the effects of brief structured interventions on diet modification; seven on smoking cessation; and seven on multiple risk factors. Two trials involving 76 patients compared brief structured intervention versus usual care for dietary modification. Although there was a tendency for more participants in the intervention arm to lose weight at the 12-week follow up and achieve target cholesterol levels at the 6-month follow up, these results were not statistically significant. Only one small trial involving 36 patients compared brief structured intervention and extensive intervention for dietary modification and demonstrated a significant reduction in the percentage of energy obtained from fat and saturated fat intake among participants receiving extensive intervention. However, no difference in fish, fruit and vegetable intake between the groups was evident. Six trials involving 2020 patients compared brief structured intervention versus usual care for smoking cessation. There was no difference in the smoking cessation rates at the 3- and 6-week follow up, however, there was evidence of a benefit of brief structured interventions for smoking cessation at the 3-, 6- and 12-month follow up. In the only trial that and compared brief structured intervention and extensive intervention for smoking cessation in 254 participants there was no clear difference of a likelihood of smoking cessation between the two groups. In the seven trials that compared brief structured intervention and usual care for multiple risk factor modification there was evidence of a benefit of the intervention on behavioural changes such as fat intake, weight loss and consequently on reduction in the body mass index, smoking cessation and physical activity among the participants. The findings concerning the effect on blood pressure, blood glucose levels and the lipid profile, however, remain inconclusive. Conclusions, There is suggestive but inconclusive evidence from the trials of a benefit in the use of brief interventions for risk factor modification in patients with coronary heart disease. This review, however, supports the concept that brief interventions for patients with coronary heart disease can have beneficial effects on risk factor modification and consequently on progression of coronary heart disease. Further trials using larger sample sizes need to be undertaken to demonstrate the benefits of brief structured intervention targeted at the modification of single or multiple risk factors. [source]


Meta-analysis: targeting the intestinal microbiota in prophylaxis for post-operative Crohn's disease

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 8 2010
G. A. DOHERTY
Aliment Pharmacol Ther,31, 802,809 Summary Background, Enteric bacteria play an important early role in the pathogenesis of Crohn's disease. Aim, To perform a meta-analysis of trials testing antibiotics or probiotics for prevention of post-operative recurrence of Crohn's disease. Methods, Review of all randomized controlled trials comparing antibiotics or probiotics with placebo in prevention of endoscopic or clinical recurrence of Crohn's disease after surgical resection. Fixed-effect meta-analysis was performed with dichotomous data summarized using relative risk with 95% confidence intervals, where appropriate. Results, Seven studies were identified as suitable for inclusion (two comparing antibiotics with placebo, five comparing probiotics with placebo). The use of nitroimidazole antibiotics (metronidazole, ornidazole) reduced the risk of clinical (RR 0.23; 95% CI 0.09,0.57, NNT = 4) and endoscopic (RR 0.44; 95% CI 0.26,0.74, NNT = 4) recurrence relative to placebo. However, these agents were associated with higher risk of adverse events (RR 2.39, 95% CI 1.5,3.7) and patient withdrawal. Probiotic administration was not associated with any significant difference in risk of recurrence compared with placebo. Conclusions, Nitroimidazole antibiotics are effective in the prevention of post-operative Crohn's disease recurrence, but their side-effects limit acceptability. Probiotics have failed to show efficacy for post-operative prophylaxis, but may merit further study. [source]