SEARCH · PubMed Health

Results for “Randomized controlled trials”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 937 records · Page 52Linked to original sources

PubMed2005

Randomized controlled trial of an energy conservation course for persons with multiple sclerosis.

OBJECTIVE: To assess the short-term efficacy and effectiveness of a six-week energy conservation course on fatigue impact, quality of life and self-efficacy for persons with multiple sclerosis (MS). METHODS: In this randomized controlled trial, we randomly assigned 169 persons with MS to an immediate intervention group or a delayed control group using a crossover design. The outcome measures: Fatigue Impact Scale, SF-36 Health Survey and Self-Efficacy for Performing Energy Conservation Strategies were measured before and after courses and no intervention control periods. We performed intent-to-treat analysis and compliers-only analyses using mixed effects analysis of variance models. RESULTS: Taking the energy conservation course had significant effects on reducing the physical and social subscales of Fatigue Impact Scale and on increasing the Vitality subscale of the SF-36 scores compared with not taking the course. Additional subscales were significant depending on methods of analyses. Self-Efficacy for Performing Energy Conservation Strategies Assessment increased significantly (P <0.05) postcourse compared to precourse. CONCLUSIONS: Results support the efficacy and effectiveness of the energy conservation course to decrease fatigue impact, and to increase self-efficacy and some aspects of quality of life.

Adult↗

PubMed1998

Sequential versus concomitant administration of ribavirin and interferon alfa-n3 in patients with chronic hepatitis C not responding to interferon alone: results of a randomized, controlled trial.

We conducted a three-arm, randomized trial in 96 patients with chronic hepatitis C who did not respond to interferon alfa to compare treatments. Group 1 (33 patients) received ribavirin alone (1,000 mg/daily for 6 months) followed by interferon alfa n-3 alone (3 MU thrice weekly for 6 months); group 2 (33 patients) received ribavirin plus interferon alfa n-3 for 6 months at the above doses; and group 3 (30 patients) received interferon alfa n-3 alone (3 MU thrice weekly for 6 months). At the end of treatment, 3 patients (10%) in group 1, 13 (41%) in group 2, and 5 (17%) in group 3 had normal alanine transaminase (ALT) levels (group 2 vs. groups 1 and 3, P = .008). After 6 months of follow-up, only 4 patients (12.5%) in group 2 still had normal ALT values (P = .03). At the end of therapy, hepatitis C virus (HCV) RNA was no longer detectable by polymerase chain reaction in 4 (13%), 9 (27%), and 2 (7%) patients, respectively, in groups 1, 2, and 3 (P = NS). Six months posttherapy, only 5 (15%) patients in group 2 were still HCV RNA negative (P = .02). At the time of follow-up liver biopsy, performed 6 months after the end of treatment, a significant improvement of the necroinflammatory scores was observed among group 2 patients (P = .01) but not in the other two groups. Side effects reflected the profile of each drug as monotherapy; mild hemolytic anemia was the most frequent side effect caused by ribavirin. In conclusion, concomitant administration of ribavirin and interferon alfa n-3 was significantly superior to the sequential schedule or interferon alfa n-3 monotherapy in inducing a sustained response in patients with chronic hepatitis C who had not responded to interferon alone. However, combination therapy at the dose and duration adopted in this study is capable of modifying the natural course of the disease in only a minority of these patients.

Adolescent↗

PubMed2001

ChlVPP alternating with PABlOE is superior to PABlOE alone in the initial treatment of advanced Hodgkin's disease: results of a British National Lymphoma Investigation/Central Lymphoma Group randomized controlled trial.

The purpose of this randomized trial was to compare the efficacy of 6 cycles of prednisolone, Adriamycin (doxorubicin), bleomycin, vincristine (Oncovin) and etoposide (PABlOE) with 3 cycles of PABIOE that alternate with 3 cycles of chlorambucil, vinblastine, procarbazine and prednisone (ChlVPP) in patients with advanced Hodgkin's disease. Between October 1992 and April 1996, 679 patients were entered onto the study. 41 of these did not match the protocol requirements on review and were excluded from further analysis, most of these being reclassified as NHL on histological review. Of the remaining 638 patients, 319 were allocated to receive PABIOE and 319 were allocated to receive ChlVPP/PABlOE. The complete remission (CR) rates were 78% and 64%, for ChlVPP/PABlOE and PABIOE respectively after initial chemotherapy (P< 0.0001). 124 patients were re-evaluated subsequently following radiotherapy to residual masses. The CR rates changed from 78% to 88% for ChlVPP/PABlOE and from 64% to 77% for PABlOE when re-evaluated in this manner (treatment difference still significant, P = 0.0002). The treatment associated mortality in the PABlOE arm was 2.2% (7 deaths), while there were no such deaths in the ChlVPP/PABlOE arm (P = 0.015). The failure-free survival was significantly greater in the ChlVPP/PABlOE arm (P< 0.0001) as was the overall survival (P = 0.01). The failure-free and overall survival rates at 3 years were 77% and 91% in the ChlVPP/PABlOE arm, compared with 58% and 85% in the PABIOE arm, respectively. These results indicate that ChlVPP alternating with PABIOE is superior to PABIOE alone as initial treatment for advanced Hodgkin's disease.

Adolescent↗

PubMed2005

The immunochemical faecal occult blood test leads to higher compliance than the guaiac for colorectal cancer screening programmes: a cluster randomized controlled trial.

INTRODUCTION: We conducted a cluster-randomized trial aimed at assessing the effect of the type of faecal occult blood, guaiac or immunochemical test on screening compliance. METHODS: We sampled 130 general practitioners (GPs) who consented to participate in the trial. We randomly allocated half of them to the guaiac (Hemo-Fec) and half to the immunochemical test (OC-Hemodia). We sampled 2/10 of the GPs' 50-75-year-old patients (n=7332) and randomly divided this population into half. One half was invited to be screened at the GP's office and the other to the nearest gastroenterology ward. The principal outcome was the percentage of returned tests. RESULTS: The immunochemical test had a compliance of 35.8% and the guaiac of 30.4% (relative risk [RR] 1.20; 95% confidence interval [CI] 1.02-1.44). The difference was mostly due to a higher probability of returning the sample: 93.8% and 88.6% for immunochemical and guaiac, respectively (RR 1.06; 95% CI 1.02-1.10). The guaiac test had a higher prevalence of positives (10.3% versus 6.3%, RR 0.603; 95% CI 0.433-0.837). There was a higher variability in the results obtained with the guaiac test compared with the immunochemical (F[1, 12] = 16.25; P=0.0017). CONCLUSIONS: Compliance is more likely with the immunochemical than the guaiac test, independent of the provider. Guaiac tests show a higher variability of the results among centres. The successful implementation of a screening programme requires a period of standardization of the test reading in order to avoid unexpected work overload for colonoscopy services.

Aged↗

PubMed2003

Multicenter randomized controlled trial for the treatment of ulcerative colitis with a leukocytapheresis column.

The administration of steroids is not always effective for the treatment of ulcerative colitis (UC). Their long-term use often causes adverse effects which sometimes result in their stoppage and acute exacerbation. Therefore, an alternative treatment is necessary in order to decrease steroid dosage and avoid the clinical problems associated with steroids. Methods The effectiveness and adverse effects of a leukocytapheresis (LCAP) were investigated in a controlled multicenter trial with randomized assignment of 76 active-stage UC patients in two groups. In the LCAP group (39 patients), LCAP weekly for 5 weeks as an intensive therapy was added to the on-going drug therapy, while steroids were maintained but not increased, and then LCAP was gradually reduced to once every 4 weeks as a maintenance therapy. In the high dose prednisolone (h-PSL) group (37 patients), PSL was added or increased 30 approximately 40 mg/day for moderately severe and 60 approximately 80 mg/day for severe patients and then gradually tapered. Findings The LCAP group showed a significantly higher effectiveness (74% vs. 38%; p=0.005) and lower incidence of adverse effects (24% vs. 68%; p<0.001). The patients were able to continue the trial for a longer period in the LCAP group than the h-PSL group (p=0.012). Clinical activity and endoscopic indexes showed the LCAP group had better improvements than the h-PSL group. Interpretation The results of the trial show that LCAP permits a reduction in total PSL dosage and is more effective and safer than high-dose PSL administration for intensive therapy, and LCAP may maintain remission longer than PSL.

Adult↗

PubMed2002

Unilateral versus bilateral neck exploration for primary hyperparathyroidism: a prospective randomized controlled trial.

OBJECTIVE: To compare unilateral and bilateral neck exploration for primary hyperparathyroidism in a prospective randomized controlled trial. SUMMARY BACKGROUND DATA: Based on the assumption that unilateral neck exploration for a solitary parathyroid adenoma should reduce operating time and morbidity, a variety of minimally invasive procedures have challenged the idea that bilateral neck exploration is the gold standard for the surgical treatment of primary hyperparathyroidism. However, to date, no open prospective randomized trial has been published comparing unilateral and bilateral neck exploration. METHODS: Ninety-one patients with the preoperative diagnosis of primary hyperparathyroidism were randomized to unilateral or bilateral neck exploration. Preoperative scintigraphy and intraoperative parathyroid hormone measurement guided the unilateral exploration. Gross morphology and frozen section determined the extent of parathyroid tissue resection in the bilateral group. The primary end-point was the use of postoperative medication for hypocalcemic symptoms. RESULTS: Eighty-eight patients (97%) were cured. Histology and cure rate did not differ between the two groups. Patients in the bilateral group consumed more oral calcium, had lower serum calcium values on postoperative days 1 to 4, and had a higher incidence of early severe symptomatic hypocalcemia compared with patients in the unilateral group. In addition, for patients undergoing surgery for a solitary parathyroid adenoma, unilateral exploration was associated with a shorter operative time. The cost for the two procedures did not differ. CONCLUSIONS: Patients undergoing a unilateral procedure had a lower incidence of biochemical and severe symptomatic hypocalcemia in the early postoperative period compared with patients undergoing bilateral exploration. Unilateral neck exploration with intraoperative parathyroid hormone assessment is a valid surgical strategy in patients with primary hyperparathyroidism with distinct advantages, especially for patients with solitary parathyroid adenoma.

Adenoma↗

PubMedDate not supplied

Effectiveness of telephone contact as an adjunct to a self-help program for smoking cessation: a randomized controlled trial in Spanish smokers.

This study evaluated the effect of telephone counseling as an adjunct to a self-help program for smoking cessation conducted through the mail. We obtained demographic and consumption information on those smokers who requested participation in the study. These participants (N = 200) were randomized into two study groups: (1) the standard self-help group (n = 100) (median age: 35.1 years; pretreatment consumption of 28.0 cigarettes/day); (2) the self-help group receiving additional multiple-contact telephone counseling (n = 100) (median age: 36.7 years; pretreatment consumption of 27.3 cigarettes/day). At the 12-month follow-up, the carbon monoxide in expired air was used to distinguish nonsmokers from smokers. Significant differences were found in the rates of continuous abstinence in both groups for each period evaluated. In the standard self-help group, the continuous abstinence rate at the 3-month follow-up was 21%, 18% at the 6-month follow-up, and 14% at the 12-month follow-up. The telephone counseling group yielded a 48% continuous abstinence rate at the 3-month follow-up, 40% at the 6-month follow-up, and 27% at the 12-month follow-up. The results of this randomized controlled trial show that telephone counseling was an effective aid for the smoking cessation program.

Adult↗

PubMed1999

Comparison of visual and computerized interpretation of nonstress test results in a randomized controlled trial.

OBJECTIVE: This study tested the null hypothesis that the number of fetal surveillance tests and perinatal outcomes would not differ statistically between pregnancies randomized to visual or computerized interpretation of antepartum nonstress test results. STUDY DESIGN: A prospective, randomized controlled trial was conducted, which required a sample size of 404 patients. By using a random-number table with assignment codes concealed in opaque envelopes, half of the patients were randomized to computerized interpretation of nonstress test results and half to standard visual interpretation of nonstress test results. The amount of antepartum testing and the perinatal outcome were measured and compared between the groups. Logistic regression analysis was used to control for maternal risk factors while morbidity differences between the 2 groups were assessed. RESULTS: The 2 randomized groups were similar at baseline, but the computerized interpretation group had significantly fewer biophysical profiles compared with the visual interpretation group (1.3 +/- 1.8 vs 1.9 +/- 2.1; P =.002). The patients in the computerized interpretation group spent less time per test than patients in the visual interpretation group (12 vs 20 minutes; P =.038). After the 5 pregnancies with congenital anomalies were excluded, the overall perinatal outcome was similar in the 2 groups. The computerized interpretation group, however, had a slightly lower proportion of infants who required >/=2 days of neonatal intensive care (7.4% vs 12.4%; P =.086; odds ratio, 0.56; 95% confidence interval, 0.29-1.09). The average number of neonatal intensive care days was also slightly lower in the computerized interpretation group (0.4 vs 0.9; P =.105). Neither of these variables was statistically significant. CONCLUSIONS: Computerized interpretation of nonstress test results is associated with fewer additional fetal surveillance examinations, less time spent in testing, and a similar length of stay in the neonatal intensive care unit compared with standard visual interpretation.

Adult↗

PubMed2005

Ineffectiveness of Lactobacillus GG as an adjunct to lactulose for the treatment of constipation in children: a double-blind, placebo-controlled randomized trial.

OBJECTIVE: To determine if Lactobacillus GG (LGG) is an effective adjunct to lactulose for treating constipation in children. STUDY DESIGN: Eighty-four children (2-16 years of age) with constipation (<3 spontaneous bowel movements [BMs] per week for at least 12 weeks) were enrolled in a double-blind, randomized placebo-controlled trial in which they received 1 mL/kg/day of 70% lactulose plus 10 9 colony-forming units (CFU) of LGG (experimental group, n = 43) or a placebo (control group, n = 41) orally twice daily for 12 weeks. The primary outcome measure was treatment success, and analyses were performed on an intention-to-treat basis. RESULTS: Treatment success, defined as >or=3 spontaneous BMs per week with no fecal soiling, was similar in the control and experimental groups at 12 weeks (28/41 [68%] vs 31/43 [72%], respectively; P = .7) and at 24 weeks (27/41 [65%] vs 27/42 [64%], respectively; P = 1.0]. Groups also did not differ in their mean number of spontaneous BMs per week or episodes of fecal soiling per week at 4, 8, and 12 weeks. Adverse events and overall tolerance did not differ between groups. CONCLUSION: LGG, as dosed in this study, was not an effective adjunct to lactulose in treating constipation in children.

Adolescent↗

PubMed1991

Conventional versus laparoscopic cholecystectomy and the randomized controlled trial. Cholecystectomy Study Group.

We considered using a randomized trial to assess the value of laparoscopic cholecystectomy in the treatment of symptomatic gallstones. The pros and cons for the timing of such a trial were in favour of not beginning the trial until surgeons learned to use the new procedure safely and effectively, and until key endpoints and outcome indices could be identified and assessed using valid measures. Instead an observational study was implemented to monitor the learning curve of surgeons as they mastered the laparoscopic equipment and procedures, and to assess the responses of the patients to the procedure. In the first 100 patients, the procedure proved to be as safe and feasible to use as conventional surgery, and there were strong benefits in terms of quicker recovery of the patients with less pain, discomfort, and a reduced length of hospital stay. The responses of the surgeons and the patients to the new procedure now place ethical constraints on the planning of a randomized controlled trial. Currently, comprehensive surveillance and monitoring of laparoscopic cholecystectomy is the only realistic method with which to assess the impact of this new technology in our clinic.

Adult↗

PubMed2001

Increase in echogenicity of echolucent carotid plaques after treatment with total triterpenic fraction of Centella asiatica: a prospective, placebo-controlled, randomized trial.

The aim of this study was to evaluate whether total triterpenic fraction of Centella asiatica (TTFCA), was effective in modulating collagen production over 12 months, by producing an increase in echogenicity in echolucent carotid plaques. Part I was a pilot study aimed at evaluating the effects of TTFCA on different types of plaques. Part II was a prospective, randomized, placebo-controlled trial aimed at evaluating the effects of TTFCA on hypoechoic-echolucent plaques. The sonographic examination of carotid plaques was made with high-resolution ultrasound. Capturing, digital image processing, and normalization were standardized, interobserver, intrascanner, gain-level variability were standardized using as reference blood (black) for the most echolucent parts of the plaque and the adventitia (white) as the most echogenic part. Normalization of echo texture was obtained and plaque characterization differentiated echo-texture of plaque associated with events and those that did not cause embolization, thrombosis, or cardiovascular events. After identifying plaques at higher risk, patients were treated with TTFCA (oral tablets, 60 mg, thrice daily for 12 months) to evaluate whether this compound, by modulating collagen synthesis, could increase the echogenicity and therefore the stability of echolucent plaques. Part II was aimed at evaluating the effects of TTFCA on hypoechoic-echolucent plaques. Asymptomatic patients with echolucent plaques (GSM<18) were treated with TTFCA (60 mg, oral tablets three times daily for 12 months) or with comparable placebo after informed consent. All patients were also treated with antiplatelet agents. In part 1, at inclusion the GSC in the hypoechoic group was 15 (range, 12-18) while in the hyperechoic group it was 26 (range, 24-31); at 6 months it was increased in the hypoechoic group and at 12 months the increase was significant (19.5; p<0.05). There was a minor increase in GSM in the hyperechoic group (30; ns). In part II in the treatment group there was a significant difference in GSM (increase) at 12 months (p<0.05), improvement in texture (p<0.05) and a nonsignificant decrease in stenosis. No changes were observed in the placebo group. Events were observed in 6.5% of patients in the TTFCA group and in 11% in the control group (p<0.05). In conclusion these observations suggest a positive action of TTFCA on the stabilization of hypoechoic, low-density carotid plaques.

Administration, Oral↗

PubMedDate not supplied

A randomized controlled trial of a physician-directed treatment program for low-income patients with high blood cholesterol: the Southeast Cholesterol Project.

OBJECTIVE: To assess the effectiveness of a cholesterol-lowering intervention designed to facilitate the management of hypercholesterolemia by primary care clinicians. DESIGN: Randomized controlled trial, with randomization of clinician-patient groups. SETTING: Twenty-one community and rural health centers in North Carolina and Virginia. PARTICIPANTS: Primary care clinicians (n = 42, 71% physicians) and the patients they enrolled with high cholesterol (n = 372). Twenty-two clinicians were randomized to give the special intervention (184 patients) and 20 to give usual care (188 patients). Two thirds of participating patients were women, 40% were African American, and 11% were Native American. INTERVENTION: A 90-minute tutorial to train clinicians how to use a structured assessment and treatment program (Food for Heart Program) consisting of a brief dietary assessment and three 5- to 10-minute dietary counseling sessions given by the primary care clinician, referral to a local dietitian if the low-density lipoprotein cholesterol (LDL-C) remained elevated at 4-month follow-up, and a prompt for the clinician to consider lipid-lowering medication based on the LDL-C at 7-month follow-up. MAIN OUTCOME MEASURES: Changes in total and LDL cholesterol at 4-month follow-up and averaged over a 1-year follow-up period (4-, 7-, and 12-month follow-up). RESULTS: At 4-month follow-up, total cholesterol decreased 0.33 mmol/L (12.6 mg/dL) in the intervention group and 0.21 mmol/L (8.3 mg/dL) in the control group: the difference was 0.11 mmol/L (4.2 mg/dL) (90% confidence interval [CI], -0.02 to 0.24 mmol/L [-0.7 to 9.1 mg/dL]). The average reduction during the 1-year follow-up period was 0.09 mmol/L (3.6 mg/dL) greater in the intervention group (90% CI, -0.01 to 0.19 mmol/L [-0.3 to 7.5 mg/dL]). Eight percent of intervention patients were taking lipid-lowering medication at follow-up visits compared with 15% of control patients. In a subgroup analysis restricted to the 89% of returnees who were not taking lipid-lowering medication, the reduction in total cholesterol at 4-month follow-up was 0.14 mmol/L (5.5 mg/dL) greater in the intervention group (95% CI, 0.01 to 0.28 mmol/L [0.3 to 10.7 mg/dL]); averaged over 1 year, it was 0.14 mmol/L (5.3 mg/dL) greater (95% CI, 0.03 to 0.24 mmol/L [1.2 to 9.4 mg/dL]). Changes in LDL-C were similar. CONCLUSIONS: Total cholesterol and LDL-C decreased more in the intervention group than in the control group. Overall, the difference in lipid reduction between groups was modest and of borderline statistical significance; among participants who did not take lipid-lowering medication during follow-up, the difference in lipid reduction between groups was larger. We conclude that primary care clinicians can be trained to give a cholesterol-lowering intervention to low-income patients that results in modest, short-term reductions in total cholesterol and LDL-C.

Cholesterol, LDL↗

PubMed2004

A meta-analysis of randomized controlled trials comparing endoscopic and open carpal tunnel decompression.

Controversy exists regarding the benefit of endoscopic carpal tunnel release versus open carpal tunnel release in terms of grip/pinch strength, scar tenderness, pain, return to work, reversible/irreversible nerve damage, and adverse effects. Although a number of randomized controlled trials and systematic reviews have been published on the subject, to date, no large definitive randomized controlled trial or meta-analysis has been performed comparing endoscopic to open carpal tunnel release. This meta-analysis was undertaken to address the effectiveness of endoscopic carpal tunnel release relative to open carpal tunnel release. Key outcome measures from 13 randomized controlled trials were extracted and statistically combined. Heterogeneity was observed in three of the outcomes (i.e., grip strength, pain, and return to work), but the causes of heterogeneity could not be explained because of insufficient detail in the reported studies. Using the Jadad et al. scale, nine of 13 studies were of low methodologic quality. The effect sizes were compared between the studies that were rated as high quality and the studies that were rated as low quality on the Jadad et al. scale. Similarly, the studies that were rated as high quality on the Gerritsen et al. scale were compared with those that were rated as low quality. No clinically significant difference in effect sizes was apparent between studies of high and low methodologic quality. This meta-analysis supports the conclusion that endoscopic carpal tunnel release is favored over the open carpal tunnel release in terms of a reduction in scar tenderness and increase in grip and pinch strength at a 12-week follow-up. With regard to symptom relief and return to work, the data are inconclusive. Irreversible nerve damage is uncommon in either technique; however, there is an increased susceptibility to reversible nerve injury that is three times as likely to occur with endoscopic carpal tunnel release than with open carpal tunnel release.

Absenteeism↗

PubMed2003

Termination of a randomized controlled trial of two vasectomy techniques.

Family Health International (FHI) and EngenderHealth conducted a multicenter, randomized controlled trial to evaluate a fascial interposition (FI) component of a vas occlusion procedure for male sterilization. A data monitoring committee (DMC) was established to provide independent review of the interim report. The DMC met to review the interim report after enrollment of 552 men. As planned, an estimate of the hazard ratio (HR) for successful vasectomy for the FI group versus the no-FI group controlling for age of the participant and level of experience of the surgeon was obtained for the interim report using Cox's proportional hazards regression. The main analysis comparing time to vasectomy success, defined as two consecutive azoospermic semen samples, was highly significant and met the prespecified level for stopping enrollment (HR=1.54, p<0.01). However, a troublesome age by vasectomy technique interaction became apparent in the analysis. FI was clearly beneficial for younger males. However, the trend for older men was not as clear. The DMC recommended continuing the trial to better study this interaction and obtain more data to clarify the effect of FI for older men. After consulting further with the DMC, the study statisticians presented the interim report to senior management at FHI. A meeting between FHI senior management and the DMC followed. After much deliberation, trial enrollment was terminated. Follow-up of participants already enrolled in the study continued as planned. This paper presents the issues involved in the decision to terminate the study.

Age Factors↗

PubMed2004

Control group selection in critical care randomized controlled trials evaluating interventional strategies: An ethical assessment.

BACKGROUND: Ethical concern has been raised with critical care randomized controlled trials in which the standard of care reflects a broad range of clinical practices. Commentators have argued that trials without an unrestricted control group, in which standard practices are implemented at the discretion of the attending physician, lack the ability to redefine the standard of care and might expose subjects to excessive harms due to an inability to stop early. OBJECTIVE: To develop a framework for analyzing control group selection for critical care trials. METHOD: Ethical analysis. RESULTS: A key ethical variable in trial design is the extent with which the control group adequately reflects standard care practices. Such a control group might incorporate either the "unrestricted" practices of physicians or a protocol that specifies and restricts the parameters of standard practices. Control group selection should be determined with respect to the following ethical objectives of trial design: 1) clinical value, 2) scientific validity, 3) efficiency and feasibility, and 4) protection of human subjects. Because these objectives may conflict, control group selection will involve trade-offs and compromises. Trials using a protocolized rather than an unrestricted standard care control group will likely have enhanced validity. However, if the protocolized control group lacks representativeness to standard care practices, then trials that use such groups will offer less clinical value and could provide less assurance of protecting subjects compared with trials that use unrestricted control groups. For trials evaluating contrasting strategies that do not adequately represent standard practices, use of a third group that is more representative of standard practices will enhance clinical value and increase the ability to stop early if needed to protect subjects. These advantages might come at the expense of efficiency and feasibility. CONCLUSION: Weighing and balancing the competing ethical objectives of trial design should be done for each trial.

Control Groups↗

PubMed1998

How reminders given to patients and physicians affected pap smear use in a health maintenance organization: results of a randomized controlled trial.

BACKGROUND: Despite its effectiveness as a method of controlling cervical carcinoma, the use of Pap smear testing remains incomplete, and its promotion in the primary care setting provides an important opportunity for intervention. METHODS: The authors conducted a randomized controlled trial that involved three sites of a health maintenance organization (HMO) serving an urban minority population. Their aim was to evaluate the impact of reminders given to patients and physicians on site visitation by patients and Pap smear use. Eligible women (n=5801) were randomly assigned to 1 of 4 intervention combinations (in which reminders were given to either the patient or the physician, to both, or to neither). If they were ineligible for patient reminder intervention, patients were randomized only to physician reminder intervention (the presence or absence of it). The letter of reminder mailed to the patient invited women due for Pap smears to visit the HMO site, and the reminder for physicians was a medical record notice that a Pap smear was due. Logistic and survival analyses were used to investigate the correlation of intervention status with visitation, interval of time to a visit, and Pap smear use. RESULTS: In the primary intent-to-treat analysis, there was no significant effect of either patient or physician reminder interventions on rates of visitation or Pap smear completion. The secondary efficacy analyses demonstrated no overall effect of either patient or physician reminders, but effects among subgroups of women at individual HMO sites were noted. At Site 3, there was an apparent increase in time to the next visit among the subgroup of women with a chronic illness (16 weeks with intervention vs. 9 weeks without). With the physician reminder, the odds that a Pap smear would be given during the study year were increased among women without a previous Pap smear at Site 1 (adjusted odds ratio=1.39) and those with a chronic illness at Site 2 (adjusted odds ratio=3.38). CONCLUSIONS: Reminders given to patients and physicians had a limited impact on visitation by patients to the HMO sites or Pap smear completion. Although some subgroups of women may benefit, the authors also observed a possibly unfavorable impact among other subgroups. These results emphasize the importance of identifying more effective interventions, targeting them to women most likely to benefit, and not overlooking the possibility that preventive intervention will have an unanticipated adverse effect.

Adolescent↗

PubMed1990

The n-of-1 randomized controlled trial: clinical usefulness. Our three-year experience.

OBJECTIVE: To review the feasibility and effectiveness of n-of-1 randomized controlled trials (n-of-1 trials) in clinical practice. DESIGN: Individual trials were double-blind, randomized, multiple crossover trials. The impact of n-of-1 trials was determined by eliciting physicians' plans of management and confidence in those plans before and after each trial. SETTING: Referral service doing n-of-1 trials at the requests of community and academic physicians. OBJECT of ANALYSIS: All trials were planned, started, and completed by the n-of-1 service. MEASURES OF OUTCOME: The proportion of planned n-of-1 trials that were completed and the proportion that provided a definite clinical or statistical answer. A definite clinical answer was achieved if an n-of-1 trial resulted in a high level of physician's confidence in the management plan. Specific criteria were developed for classifying an n-of-1 trial as providing a definite statistical answer. MAIN RESULTS: Seventy-three n-of-1 trials were planned in various clinical situations. Of 70 n-of-1 trials begun, 57 were completed. The reasons for not completing n-of-1 trials were patients' or physicians' noncompliance or patients' concurrent illness. Of 57 n-of-1 trials completed, 50 provided a definite clinical or statistical answer. In 15 trials (39% of trials in which appropriate data were available), the results prompted physicians to change their "prior to the trial" plan of management (in 11 trials, the physicians stopped the drug therapy that they had planned to continue indefinitely). CONCLUSION: We interpret the results as supporting the feasibility and usefulness of n-of-1 trials in clinical practice.

Adult↗

PubMed2006

Underrepresentation of renal disease in randomized controlled trials of cardiovascular disease.

CONTEXT: Patients with renal disease are at high risk for cardiovascular mortality. Determining which interventions best offset this risk remains a health priority. OBJECTIVE: To quantify the representation of patients with renal disease in randomized controlled trials for interventions proven efficacious for cardiovascular disease. DATA SOURCES: We searched MEDLINE for trials published from 1985 through 2005 in 11 major medical and subspecialty journals. STUDY SELECTION: Randomized controlled trials for chronic congestive heart failure and acute myocardial infarction of treatments that are currently listed as class I or II recommendations in the current American College of Cardiology/American Heart Association guidelines were included. DATA EXTRACTION: Two reviewers independently abstracted data on study and patient characteristics, renal measurements, outcomes, and prognostic features. DATA SYNTHESIS: A total of 153 trials were reviewed. Patients with renal disease were reported as excluded in 86 (56%) trials. Patients with renal disease were more likely to be excluded from trials that were multicenter; of moderate enrollment size; North American; that tested renin-angiotensin-aldosterone system antagonists and anticoagulants; and that tested chronic congestive heart failure. Only 8 (5%) original articles reported the proportion of enrolled patients with renal disease, and only 15 (10%) reported mean baseline renal function. While 81 (53%) trials performed subgroup analyses of some baseline characteristic in the original article, only 4 (3%) subgroup analyses of treatment stratified by renal disease were performed. CONCLUSION: Major cardiovascular disease trials frequently exclude patients with renal disease and do not provide adequate information on the renal function of enrollees or the effect of interventions on patients with renal disease.

Cardiovascular Diseases↗