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Results for “Randomized controlled trials”

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PubMed1988

Prospective controlled randomized trial of prophylactic antiarrhythmic therapy in postmyocardial infarction patients with asymptomatic ventricular arrhythmias--study design and initial results.

In order to assess the effect of prophylactic antiarrhythmic therapy in asymptomatic patients with persistent complex ventricular ectopic activity after myocardial infarction, a prospective controlled trial was started in 1981 and is still ongoing. Until August 1986, 965 consecutive patients less than or equal to 70 hospitalized for acute myocardial infarction were screened without antiarrhythmic drugs by 24-h ECG before discharge from the hospital. In this group, 238 patients (28%) had ventricular arrhythmias Lown class III-IVb during at least 2 of 24 hours; they were randomly assigned to three treatment groups: (1) individualized antiarrhythmic therapy based on efficacy in multiple 24-h ECGs and drug level determinations (starting with mexiletine or quinidine; n = 79), (2) treatment with low-dose amiodarone (200-400 mg/day after a loading phase; n = 73), and (3) no antiarrhythmic therapy (n = 86). The three groups were comparable regarding age, gender, previous infarction, Q-wave infarction, ejection fraction, as well as incidence and severity of ventricular ectopic activity. Follow-up, including 24-h ECGs, was performed after 3, 6, and 12 months. Based on the results of this study which will be completed by the end of June 1988, it should be possible to estimate the benefit--or harm--of antiarrhythmic drug therapy as well as its cost in postmyocardial infarction patients with asymptomatic ventricular ectopic activity and to decide whether such treatment may improve survival.

Aged↗

PubMed1995

A model of regular geriatric follow-up by home visits to selected patients discharged from a geriatric ward: a randomized controlled trial.

The aim of this randomized controlled trial was to describe and evaluate a model of regular follow-up by home visits to selected elderly patients discharged from a geriatric ward. Ninety-seven patients were randomized to receive regular follow-up visits by a geriatric team at 1, 3, 8 and 16 weeks after discharge, and 96 patients to receive standard care. Based on the geriatric evaluation, medical and social adjustment was carried out, if indicated. Six months after discharge, significantly more patients in the intervention group were allocated to home help (p < 0.05), but only 42 (44%) were readmitted to a hospital, vs 62 (64%) in the control group (p < 0.005). Differences between the groups in mortality and nursing-home placement were not statistically significant. Regular follow-up home visits by a geriatric team after in-patient geriatric evaluation and management reduce the risk of hospital readmissions among highly selected frail geriatric patients.

Aged↗

PubMed2004

An observational study found that authors of randomized controlled trials frequently use concealment of randomization and blinding, despite the failure to report these methods.

BACKGROUND AND OBJECTIVE: Readers of randomized controlled trials (RCTs) commonly assume that what was not reported did not occur. We undertook an observational study to determine whether concealment of randomization or blinding was used in RCTs that failed to report these bias-reducing strategies. METHODS: We recorded the reporting of concealment of randomization and blinding in 105 RCTs. We subsequently contacted the authors and determined if they had used these methodological safeguards. RESULTS: We successfully obtained data from 98 authors. The authors in the full-text publications of these 98 RCTs failed to report the presence or absence of concealment of randomization in 55%, and the blinding status of participants in 26%, health care providers in 64%, data collectors in 84%, outcome assessors in 83%, and data analysts in 96%. In direct contact, authors frequently reported concealing randomization (96%; 95% confidence interval CI=87-100%), blinding participants (20%; 95% CI=7-41%), blinding health care providers (65%; 95% CI=52-77%), blinding data collectors (65%; 95% CI=53-75%), blinding outcome assessors (79%; 95% CI=69-87%), and blinding data analysts (50%; 95% CI=40-60%), despite not reporting the use of these methodological safeguards in their publications. CONCLUSIONS: Readers should not assume that bias-reducing procedures not reported in an RCT did not occur.

Bias↗

PubMed2005

Efficacy of mu-opioid agonists in the treatment of evoked neuropathic pain: Systematic review of randomized controlled trials.

UNLABELLED: Several reviews of randomized controlled trials (RCTs) have shown the efficacy of mu-opioids in reducing spontaneous neuropathic pain (NP). However, relatively little is known about their specific efficacy for evoked pain, which is a significant problem for many patients with NP. The present systematic review assesses the efficacy of opioid agonists for the treatment of evoked NP based upon published RCTs. We searched articles in any language using the MEDLINE database (1966 to December 2004), the Cochrane Central Register of Controlled Trials (4th quarter, 2004) and the reference lists of retrieved papers, employing search terms for RCTs, opioids and NP. Only RCTs in which opioid agonists were given to treat NP of any etiology, and evoked pain was assessed were included. Data were extracted by two independent investigators. Nine articles met inclusion criteria and were classified as short-term (less than 24h; n=7) or intermediate-term trials (4 weeks; n=2). Although the scarcity of retrieved data precluded formal meta-analysis of short-term trials, we found that the intensity of dynamic mechanical allodynia was significantly attenuated by opioids relative to placebo in all studies. In contrast, no consistent effects on the magnitude of static allodynia, the threshold for mechanical allodynia or the threshold or magnitude of heat allodynia were found. The threshold and magnitude of cold-induced allodynia generally responded positively to opioid treatments in patients with peripheral pain syndromes, but not central pain syndromes. Evoked pain was studied in only two intermediate-term trials, in both of which oxycodone was significantly superior to placebo. The results of the two trials were combinable for a meta-analysis that showed an overall 24 points difference in endpoint pain intensities between patients given opioids and those treated with placebo (95% CI -33 to -15; p<0.00001). IN CONCLUSION: short-term studies show that opioids can reduce the intensity of dynamic mechanical allodynia and perhaps of cold allodynia in peripheral NP. Insufficient evidence precludes drawing conclusions regarding the effect of opioids on other forms of evoked NP. A meta-analysis of intermediate-term studies demonstrates the efficacy of opioids over placebo for evoked NP. These findings are clinically relevant because dynamic mechanical allodynia and cold allodynia are the most prevalent types of evoked pain in NP.

Analgesics, Opioid↗

PubMed2004

Beyond randomized, controlled trials.

PURPOSE OF REVIEW: Most critical care physicians believe that randomized, controlled trials provide the best available evidence. This review contends that the importance of randomized, controlled trials was overemphasized and that they do not add more to knowledge and practice than physiologic and observational studies. In addition, protection of both patients and proxies may be less adequately ensured during randomized, controlled trials than during observational studies. RECENT FINDINGS: An analysis of the recent literature on critical care shows that conclusions from randomized, controlled trials are either disputable or do not affect existing practice. In addition, several papers reveal potential conflicts between randomized, controlled trials and ethical principles. SUMMARY: We may see in the future the twilight of randomized, controlled trials in critically ill patients because scientific, ethical, and sociologic substrata will be progressively lacking as will be funding.

Clinical Trials as Topic↗

PubMed2006

Effectiveness of a chlorhexidine dentifrice in orthodontic patients: a randomized-controlled trial.

This blind and randomized-controlled trial analysed chlorhexidine dentifrices in relation to dental plaque, gingivitis, bleeding, calculus and enamel extrinsic staining development. Volunteers in fixed orthodontic therapy used the following dentifrices: 1100 ppmF, NaF (group A, n=27); experimental, 1100 ppmF, NaF and chlorhexidine 0.95% (group B, n=28); and experimental, chlorhexidine 0.95% (group C, n=28). At baseline, after 6, 12 and 24 weeks, clinical examinations were carried out. The gingivitis, bleeding and plaque data were tested by anova and Tukey's post hoc tests. Stain and calculus data were analysed by Kruskal-Wallis and Dunn's post hoc tests (p<0.05). Plaque, gingivitis and bleeding scores improved in all three groups, but up to the 6 and 12 weeks examination the products containing chlorhexidine were statistically better. The chlorhexidine dentifrices significantly increased the mean of the stain index, although most of the patients did not notice the stains. The calculus index was not significantly modified. In summary, this study suggests that the use of dentifrices containing chlorhexidine seems to be effective for the treatment of gingivitis in orthodontic patients, although the intense motivating contact that the volunteers had with the researchers may have also played a role.

Adolescent↗

PubMed2004

Outcome measures in osteoarthritis: randomized controlled trials.

Accepted outcome measures in randomized controlled trials (RCTs) in osteoarthritis (OA) include patient-reported assessments of physical function and health-related quality of life (HRQOL). Available data can inform treatment decisions when statistically significant changes are viewed in terms of clinically important improvements. Patient-reported outcomes validated in OA include global assessments of pain, disease activity, and disease-specific and generic measures of physical function and HRQOL. Definitions of minimum clinically important differences (MCID) have been derived from RCTs with physical therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), and cyclooxygenase-2 selective agents. Definitions of MCID should serve only as guidelines based on mean changes in a treatment group, and do not necessarily reflect clinically meaningful improvements for an individual patient. They help to interpret data across treatments and patient populations. Definitions of MCID may differ for the type of intervention assessed; additional methodologic issues must be addressed when evaluating nonpharmacologic treatments. Based on RCTs in OA evaluating physical therapy, cyclooxygenase-2 agents, and NSAIDs, the Western Ontario and McMaster Osteoarthritis Index is valid, reliable, sensitive to change, and correlates closely with the generic Medical Outcomes Survey Short-Form 36 measure of HRQOL. When evaluating RCT data, understanding derivation and MCID values of outcome measures facilitates informed therapeutic decisions regarding therapeutic interventions.

Acupuncture↗

PubMed2000

Acupuncture for episodic tension-type headache: a multicentre randomized controlled trial.

A multicentre, randomized clinical trial was undertaken to test the hypothesis that acupuncture is more efficacious than sham control procedure in the prevention of episodic tension-type headache. Fifty subjects were randomized to receive a course of treatment with either brief acupuncture or a sham procedure. Subjects were followed up for 3 months. Changes in headache were assessed by daily diary, the primary outcome measure being the number of days with headache. No significant differences were found between the changes in the two groups for any measure at any time point. Results also show that patient blinding was successful. In conclusion, this study does not provide evidence that this form of acupuncture is effective in the prevention of episodic tension-type headache.

Acupuncture Therapy↗

PubMed2001

Adding ketamine to morphine for patient-controlled analgesia after major abdominal surgery: a double-blinded, randomized controlled trial.

UNLABELLED: In this double-blinded, randomized controlled trial we tested if the addition of ketamine to morphine for patient-controlled analgesia (PCA) resulted in improved analgesic efficacy and lower pain scores compared with morphine PCA alone after major abdominal surgery. Seventy-one patients were randomly allocated to receive either morphine 1 mg/mL (Group M) or morphine 1 mg/mL plus ketamine 1 mg/mL (Group MK) delivered via PCA after surgery. No other analgesics or regional blocks were permitted during the 48-h study period. Postoperatively there were no differences between the groups for subjective assessment of analgesic efficacy, pain scores at rest, and on movement, opioid consumption, or adverse events. Group MK patients performed worse in cognitive testing (P = 0.037). There was an increased risk of vivid dreaming in patients who received ketamine (relative risk = 1.8, 95% confidence interval 0.78-4.3). We conclude that small-dose ketamine combined with PCA morphine provides no benefit to patients undergoing major abdominal surgery. IMPLICATIONS: We performed a randomized, controlled trial comparing the use of ketamine and morphine with morphine alone to relieve pain after major abdominal surgery.Ketamine did not improve pain relief and merely increased side effects.

Abdomen↗

PubMed1984

Antibiotic prophylaxis in neurosurgery. A randomized controlled trial.

A randomized trial was performed to support the contention that prophylactic antibiotics can reduce the incidence of postoperative neurosurgical wound infections. The regime outlined by Malis was followed. Vancomycin and gentamicin were administered systemically just prior to surgery and streptomycin was added to the irrigating solution. Patients were randomly assigned to two groups: control and treated. The infection rate in the control group was 3.5% and in the treated group 0.5%.

Adult↗

PubMed1991

A comparison of sucralfate with placebo in the treatment of esophageal ulcers following therapeutic endoscopic sclerotherapy of esophageal varices--a prospective controlled randomized trial.

In 1984 Roark published the first report of a sucralfate treatment of esophageal ulcers after sclerotherapy. Because this was an uncontrolled trial we planned a prospective double-blind placebo-controlled study with 60 patients. After therapeutic paravariceal injection-sclerotherapy of esophageal varices, patients were randomly treated with sucralfate suspension or placebo. Time of treatment was limited to a maximum of 3 weeks and the dosage of sucralfate was 1 g q.i.d. (Ulcogant-Suspension). Healing was assessed by endoscopy at weekly intervals. Fifty-three patients (25 sucralfate, 28 placebo) were evaluable according to the protocol. No patient left the study because of side effects. At the start of the trial, the patients in the sucralfate group showed a larger ulcer area than the placebo group. There was a tendency to faster healing in the sucralfate group, especially in patients with deeper ulcerations. However, there was no significant difference in global healing between both treatment groups after 3 weeks. Sucralfate suspension may be of value in accelerating the healing process in esophageal ulcers after sclerotherapy, especially in patients with deep ulcers. These results should be confirmed in further trials, in which patients should be stratified with respect to their ulcer volume and severity of liver disease.

Aged↗

PubMedDate not supplied

What can randomized controlled trials tell us about nutrition and cancer prevention?

Randomized controlled trials are regarded as the most definitive of study designs. The randomized controlled trials that have tested nutritional factors for cancer prevention are reviewed. Trials that have tested the effects of nutrients given as high-dose supplements have been largely disappointing, typically showing either no or harmful effects. Possible benefits of vitamin E for prostate cancer prevention and selenium for prostate, colorectal, and lung cancer prevention have emerged only as secondary endpoints in trials conducted for other purposes; confirmatory new trials for these nutrients are now underway or are planned. The limitations of both past and current randomized controlled trials for studying diet-cancer relationships are discussed. The disappointing findings that have emerged from short-term studies of high-dose supplements cannot be interpreted as direct tests of the diet-cancer relationship because high-dose supplements cannot fully simulate the effects of whole foods on cancer risk. As we await findings from current and future trials, we should not forget that the ample evidence from observational epidemiologic research--suggesting that diets rich in fruits and vegetables can reduce the risk of many of the most common cancers--can provide a sound basis for nutritional recommendations aimed at reducing cancer risk.

Diet↗

PubMed2004

Patient-reported outcomes better discriminate active treatment from placebo in randomized controlled trials in rheumatoid arthritis.

BACKGROUND: Recent randomized controlled trials (RCTs) in rheumatoid arthritis (RA) have used patient- and physician-reported outcomes, ESR and/or CRP as components of ACR response criteria to assess efficacy. OBJECTIVES: Mean changes from baseline in patient- and physician-reported outcome measures, ESR and CRP were compared in two RCTs in patients with active RA. Comparisons between active and placebo treatment used mean percentage improvements and standard effect sizes (SESs). RESULTS: In both protocols, patient-reported assessments of disease activity, pain and physical function reflected little or no improvement with placebo, best discriminating between active and placebo therapy, as did ESR and CRP. CONCLUSION: Improvements in signs and symptoms of active RA in placebo RCTs appear to be best reflected by patient-reported measures of physical function, as long as reported changes in global assessments of disease activity and/or pain reflect similar benefit. Patient-reported outcome measures should be considered objective; treatment-associated changes are congruent with measures of inflammation, and appear less susceptible to the placebo response.

Antirheumatic Agents↗

PubMed2005

Comparison of the effects of pravastatin and atorvastatin on fracture incidence in the PROVE IT-TIMI 22 trial--secondary analysis of a randomized controlled trial.

Recent observational studies suggest that patients using statins have higher bone densities and lower fracture rates. However, this finding has not been supported by a secondary analysis of a large randomized controlled trial, assessing pravastatin. It has been suggested that the latter finding might be attributable to the failure of pravastatin, which is hydrophilic, to gain access to bone. The recently published TIMI 22 study, which compared pravastatin with more intensive therapy with the bone-active statin, atorvastatin, offers the possibility of re-assessing the effects of these agents, on fractures. This study assessed 4162 patients over a mean period of 24 months, and compared 40 mg of pravastatin daily with 80 mg of atorvastatin daily. There were 30 fractures in the pravastatin group and 31 in the atorvastatin group, producing a relative risk for any fracture of 1.02 (95% CI, 0.62-1.68) in the atorvastatin group. This study has sufficient fractures for a relative risk of fracture of 0.52 to be significant, which is of the order that has been observed in some of the observational studies. These data do not provide any support for the hypothesis that pravastatin and atorvastatin have different effects on fracture, and are consistent with the conclusions from the other controlled trials-that currently available statins do not impact on fracture risk.

Atorvastatin↗

PubMed1994

Review of 39 years of randomized controlled trials in the British Journal of General Practice.

BACKGROUND: Randomized controlled trials are being used increasingly to evaluate the effectiveness of health care interventions, including those in primary care. AIM: A study was undertaken to document the topic areas addressed by randomized controlled trials conducted in primary care and the methodological characteristics of these, based on a historical review of all trials published in the British Journal of General Practice (formerly the Research Newsletter and Journal of the Royal College of General Practitioners) between 1953 and 1991 inclusive. METHOD: Trials were identified by systematically hand searching all back issues. RESULTS: A total of 90 randomized controlled trials were identified, 78% of which were undertaken in general practice. The trials covered a wide range of topics; 62% examined pharmacological interventions, 21% non-pharmacological interventions, and 16% an intervention related to provision of an aspect of health service. Among the randomized controlled trials published there was a significant trend towards more reports on non-pharmacological trials in recent years (P < 0.001). The quality of trials, judged by the extent to which bias was controlled, varied considerably. Trials of pharmacological interventions generally controlled for selection bias at entry and at assessment of outcome more effectively than trials of non-pharmacological interventions. CONCLUSION: Some imaginative solutions to the logistic difficulties of conducting randomized trials in general practice were noted. These may serve as an incentive to those undertaking such studies in the future.

Community Health Services↗

PubMed2001

Growth hormone improves clinical status in prepubertal children with cystic fibrosis: results of a randomized controlled trial.

OBJECTIVES: We conducted a 1-year randomized controlled trial to test the hypothesis that growth hormone (GH) improves the clinical status of children with cystic fibrosis. STUDY DESIGN: Nineteen prepubertal children were randomized to control (NonTX, n = 9) or to daily injections of GH (0.3 mg/kg/wk) (GHTX, n = 10) for 1 year. Every 3 months height, weight, and lean tissue mass were measured. Caloric intake, resting energy expenditure, pulmonary function, and respiratory muscle strength were measured every 6 months, as were total number of hospitalizations and courses of outpatient intravenous antibiotics. RESULTS: The GHTX group had significantly greater height, height velocity (NonTX = 3.8 +/- 1.4 cm/y, GHTX = 8.1 +/- 2.4 cm/y; P =.002), weight, weight velocity (NonTX = 2.1 +/- 0.9 kg/y, GHTX = 4.5 +/- 1.1 kg/y; P =.004), and change in lean tissue mass (NonTX = 2.1 +/- 1.6 kg, GHTX = 4.7 +/- 1.7 kg; P =.01) analyzed by the Student t test. The GHTX group had significant improvement in delta forced vital capacity compared with the year before study, and respiratory muscle strength improved. The number of hospitalizations and outpatient intravenous antibiotic courses significantly decreased in the GHTX group but did not change in the NonTX group. No subject had development of cystic fibrosis-related diabetes. CONCLUSIONS: Results of the first randomized controlled trial of GH treatment in cystic fibrosis indicate that GH improves growth and clinical status.

Body Composition↗

PubMed2006

Comparison of reports of randomized controlled trials and systematic reviews in surgical journals: literature review.

OBJECTIVES: Randomized controlled trials and systematic reviews of such trials are the gold standard for assessing the effectiveness of interventions. There have been concerns about the anecdotal evidence underpinning many of the interventions used and introduced into surgical care. The American College of Surgeons has prioritized the need for more trials and systematic reviews of trials. To investigate the assertion that the methodological quality of studies conducted in surgery is in general poor and to assess the possible impact of new policy developments in the US, we sought to compare the number and proportion of published randomized controlled trials and systematic reviews in the leading two US and UK general surgical journals. Two reviewers systematically and independently hand searched all issues of these journals over a 12-month period to identify randomised controlled trials and systematic reviews. DESIGN: Systematic searching and independent abstraction of data from all volumes of the top two general surgical journals published in the USA and the UK in 2004. SETTING: 519 original reports in UK journals and 616 original reports in USA journals. MAIN OUTCOME MEASURES: Number and proportion of randomized controlled trials and systematic reviews. RESULTS: Overall, the proportion of randomized controlled trials in all four journals was 5.6% (95% confidence interval [CI] 4.4-7.0) and 5.2% (95% CI 4.1-6.7) for systematic reviews. For journals published in the UK 29/519 (5.6%) of the publications were reports of randomized controlled trials, and for the USA journals this figure was 34/616 (5.5%); odds ratio [OR]=0.99, 95%CI 0.6-1.6; P=0.96. Systematic reviews were significantly more commonly reported in the UK journals: UK 37/519 (7.1%) versus USA 22/616 (3.6%); OR=0.48, 95%CI 0.3-0.8; P<0.01. CONCLUSIONS: The concerns expressed almost a decade ago remain valid: there are still very few reports of randomized controlled trials and systematic reviews published in leading USA and UK surgical journals, with relatively little difference between these countries in the proportion of reported studies employing these designs. The American College of Surgeons initiative has yet to make an impact.

Biomedical Research↗

PubMed2003

Efficacy of dry extract of ivy leaves in children with bronchial asthma--a review of randomized controlled trials.

OBJECTIVES: To investigate if extracts from dried ivy leaves (Hedera helix L.) are effective in the treatment of chronic airway obstruction in children suffering from bronchial asthma. DESIGN: Systematic review of trials documented in the literature with re-analysis of original data. TRIALS: 5 randomized controlled trials investigating the efficacy of ivy leaf extract preparations in chronic bronchitis, 3 of which were conducted in children and met our selection criteria. One compared ivy leaf extract cough drops to placebo, one compared suppositories to drops and one tested syrup against drops. MAIN OUTCOME MEASURES: Body-plethysmographic and spirometric measures. RESULTS: Drops were significantly superior to placebo in reducing airway resistance (primary outcome measure; p = 0.04 two-sided) and descriptively superior in all other 'objective' measures. For syrup and suppositories, at least 54%, resp. 35% of the effect against placebo were preserved. CONCLUSIONS: The trials included in this review indicate that ivy leaf extract preparations have effects with respect to an improvement of respiratory functions of children with chronic bronchial asthma, but more far-reaching conclusions can hardly be drawn because of a meagre database, including the fact that only one primary trial included a placebo control. Further research, particularly into the long-term efficacy of the herbal extract, is needed.

Asthma↗