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At least 307 records · Page 17Linked to original sources
PubMed2006

The feasibility of clinical endpoint trials in HIV infection in the highly active antiretroviral treatment (HAART) era.

BACKGROUND: Planning clinical-endpoint trials in patients with HIV remain difficult as long-term follow-up of many patients is required. Cohort studies of patients with HIV can provide key estimates of the likely disease progression, required sample size and follow-up. OBJECTIVES: To verify the assumptions used in designing ESPRIT, a large randomized clinical trial assessing the clinical benefit of interleukin-2 treatment in patients with HIV infection, to use EuroSIDA to mimic the inclusion criterion of ESPRIT in order to compare the observed event rate in ESPRIT with the projected rate in EuroSIDA, and to project the required length of ESPRIT. METHODS: Patients in EuroSIDA who satisfied the ESPRIT recruitment criteria were selected. Patients were followed from baseline to new AIDS or death. RESULTS: The incidence of clinical progression in the selected EuroSIDA patients (N = 4482) was 1.5 per 100 PYFU (95% CI 1.3-1.7), and did not increase with increasing time from baseline, contrary to what was assumed in the design of the ESPRIT trial. In ESPRIT (N = 4150), for which the comparative data remain blinded, the incidence was 1.1 per 100 PYFU (95% CI 0.9-1.3), with no increase over time. The average follow-up required to complete ESPRIT and accrue the 320 events required by protocol would be seven years, 10 months using the projected rates from the EuroSIDA study, and seven years, 11 months if the observed event rate in ESPRIT continued unchanged. LIMITATIONS: Differences between patients recruited to observational studies or clinical trials cannot always be adjusted for. CONCLUSIONS: Event rates in EuroSIDA were similar in the first two years to those used in the design of ESPRIT, but did not increase over time, leading to an increase in the expected duration of ESPRIT. Clinical endpoint trials in HIV infection remain feasible, and large cohort studies are critical to the planning and ongoing assessment of design assumptions in such trials. The underlying assumptions of the clinical trial should be re-examined to ensure the original trial assumptions remain valid.

Acquired Immunodeficiency Syndrome↗
PubMed2002

Truth survival in clinical research: an evidence-based requiem?

PURPOSE: Factors associated with the survival of truth of clinical conclusions in the medical literature are unknown. The authors hypothesized that conclusions derived from studies using better methodology should have a longer half-life. DATA SOURCES: MEDLINE and hand searches of journals with studies on cirrhosis and hepatitis. STUDY SELECTION: Original articles and meta-analyses published from 1945 to 1999 about cirrhosis or hepatitis in adults. DATA SYNTHESIS: In 2000, 285 of 474 conclusions (60%) were still considered to be true, 91 (19%) were considered to be obsolete, and 98 (21%) were considered to be false. The half-life of truth was 45 years. The 20-year survival of conclusions derived from meta-analysis was lower (57% +/- 10%) than that from nonrandomized studies (87% +/- 2%) (P < 0.001) or randomized trials (85% +/- 3%) (P < 0.001). The survival of conclusions was not different when studies of high methodologic quality were compared with those of low quality. In randomized trials, the 50-year survival rate was higher for 52 negative conclusions (68% +/- 13%) than for 118 positive conclusions (14% +/- 4%) (P < 0.001). CONCLUSIONS: Contrary to the authors' hypothesis, conclusions based on recognized, good methodology had no clear survival advantage. To better convince clinicians of the long-term utility of evidence-based medicine, better prognostic factors should be developed.

Clinical Trials as Topic↗
PubMed2001

[Is there progress in chemotherapy for breast cancer?].

Breast cancer is the most frequent type of cancer in women. The therapeutic approaches to breast cancer have developed rapidly over the past 20 years, due to the increasing knowledge about the biology of breast cancer. Therefore it was possible to increase response rates as well as the duration of response and survival in neoadjuvant, adjuvant, and palliative treatment. This paper gives a review of the current breast cancer trials. Effective new cytotoxic chemotherapy and hormonal therapy agents, as well as the identification of specific molecular abnormalities (HER2/neu) led to the development of targeted therapeutic interventions in the neoadjuvant, adjuvant, and palliative treatment of breast cancer. Increased understanding of the biology of breast cancer led to the development of rational therapeutic interventions, which are currently under active clinical development.

Algorithms↗
PubMedDate not supplied

Definitions of remission for rheumatoid arthritis and review of selected clinical cohorts and randomised clinical trials for the rate of remission.

Various definitions of remission in rheumatoid arthritis (RA) have been proposed. The ACR (American College of Rheumatology--formerly ARA, American Rheumatism Association) remission criteria are strict and include nonspecific symptoms such as fatigue. More recently remission according to the Disease Activity Index (DAS) and DAS28 has been described. However, patients who meet the DAS28 remission cut point of < 2.6 may nonetheless have tender and/or swollen joints. The ACR remission criteria are more rigorous than the requirement of DAS28 <2.6. Newer tools for evaluation of RA activity include the Simplified Disease Activity Index (SDAI) and Clinical Disease Activity Index (CDAI), and cut points for remission according to these new indices have been defined. However, all available remission criteria may ignore important aspects of RA, including physical function and radiographic damage.

Arthritis, Rheumatoid↗
PubMed1993

Arthrotec: a therapeutic option in the management of arthritis.

Arthrotec (Searle) is a new concept in NSAID therapy that provides powerful anti-inflammatory efficacy with enhanced upper GI safety. Arthrotec comprises an enteric-coated core of diclofenac sodium (50 mg) surrounded by a mantle of misoprostol (200 mcg). Two multicentre trials evaluated the efficacy of Arthrotec in rheumatoid arthritis (RA) and osteoarthritis (OA) patients who were randomised to receive either Arthrotec or diclofenac. The results of all arthritis assessments showed Arthrotec to be as effective as diclofenac in treating the signs and symptoms of RA and OA. Two endoscopic studies compared the antiarthritic efficacy and gastroduodenal safety of Arthrotec and diclofenac. In a 12-week study of RA patients, the antiarthritic efficacy of Arthrotec was equivalent to diclofenac; in addition, 60% fewer patients taking Arthrotec experienced ulcers than did those taking diclofenac (4.4% Arthrotec vs 11.1% diclofenac: P = 0.034). In a 4-week study of OA patients, Arthrotec's efficacy was equivalent to that of diclofenac and the Arthrotec group developed no ulcers, while 3.6% of the diclofenac group had ulcers (P = 0.015). In a trial conducted to compare the efficacy and upper gastroduodenal safety of Arthrotec with those of piroxicam and naproxen, patients with OA received either Arthrotec BID piroxicam 10 mg BID, or naproxen 375 BID for 4 weeks. Arthritis assessments showed Arthrotec to be at least as effective as piroxicam and naproxen in treating OA. Post-treatment endoscopy data indicated that gastroduodenal ulcers developed in 1.5% of patients receiving Arthrotec, 10.3% of patients receiving piroxicam, and 8.6% patients in the naproxen group.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1995

[Phase III studies of combined chemotherapy and radiation in locally advanced non-small-cell lung cancer and limited small-cell lung cancer].

Large phase III studies for lung cancer are reviewed. In an effort to improve survival results in locally advanced inoperable non-small-cell lung cancer (NSCLC), several studies have documented survival advantage for cisplatin + vinka alkaloid followed by radiotherapy (RT) when compared with RT alone. In SCLC, meta-analyses show that thoracic radiotherapy moderately improves survival in patients who are treated with combination chemotherapy. The optimum combination of chemotherapy and radiotherapy needs to be established.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Coronary anatomic and procedural characteristics of patients randomized to coronary angioplasty in the Bypass Angioplasty Revascularization Investigation (BARI).

The Bypass Angioplasty Revascularization Investigation (BARI) is a randomized multicenter clinical trial that compares a strategy of initial coronary angioplasty to initial coronary bypass surgery for patients with multivessel coronary artery disease. The purpose of this report is to describe the coronary anatomic characteristics of the 915 patients assigned to the angioplasty arm of the trial and the manner in which angioplasty was performed. Patients were eligible for BARI if they demonstrated multivessel coronary artery disease, had a clinical indication for revascularization, and were suitable for both coronary angioplasty and bypass surgery. Clinical and technical features of angioplasty procedures were systemically recorded. Coronary cineangiograms obtained before and during the angioplasty were interpreted by a central radiographic laboratory. Angioplasty was performed in 904 (98.8%) of the 915 patients assigned to that initial strategy. Of 6,530 coronary arterial lesions identified, 3,427 (52.5%) were significant (> 50% diameter reduction). The majority of patients had 2-6 significant lesions, with 3 being most common. Angioplasty was attempted in 92.2% of the lesions for which it was intended. Lesions most frequently attempted ranged between 50% and 79% in severity. Multilesion angioplasty was performed in 77.5% of patients and 69.7% had multivessel angioplasty. Factors that influenced whether a lesion was attempted included lesion severity, clinical significance, and complexity. For lesions presenting as total occlusions, a history of recent infarction and postinfarction angina favored attempting angioplasty. Patients assigned to the angioplasty arm of BARI had evidence of extensive multilesion and multivessel coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1996

The future of clinical research: from megatrials towards methodological rigour and representative sampling.

A powerful impetus behind the rise of the 'megatrial' (a large, simple, usually multi-centred randomized controlled trial analysed by 'intention to treat') has been the desire for ever-increasing precision in the measurement of therapeutic effectiveness. However, the demand for precision has been allowed to override other and more important methodological considerations. Megatrials have progressively abandoned the pursuit of scientifically rigorous experimentation, valid measurement and optimal epidemiological sampling in favour of recruiting and processing large number of subjects. This is a mistaken strategy which leads inevitably to error, because investigators are seeking a primarily statistical, rather than clinically or scientifically relevant, notion of exactness. We are now in a position to describe a clinical research strategy which offers many advantages over a megatrial-led approach. Research should be planned with an awareness that the validity and applicability of estimated is more important that their numerical precision, and that this requires both and unselected denominator population database of all incident cases, and maximally controlled randomized trials and other studies. The Population-Adjusted Clinical Epidemiology (PACE) strategy is suggested as exemplifying the twin principles of clinically useful research: rigorous science and representative epidemiology.

Confidence Intervals↗
PubMed2004

Alteplase: new indication. Inadequately assessed in ischaemic stroke.

(1) Alteplase is the first thrombolytic drug to be approved in France for the treatment of ischaemic stroke within three hours of symptom onset. (2) The clinical evaluation dossier contains nine placebo-controlled trials, of which six were relatively large. In the two NINDS trials (624 patients in total), treatment was started within the first three hours and it showed no survival benefit. Near-complete functional recovery was more frequent in the alteplase group than in the placebo group. In the two ECASS trials (620 and 800 patients) and the ATLANTIS trials (142 patients and 613 patients), treatment was started within the first six hours and it showed no significant benefit in terms of survival or functional recovery. (3) There are two meta-analyses of these trials. They confirm the lack of a survival benefit with alteplase. Using a combined endpoint, one meta-analysis showed that treating 1000 patients with alteplase prevented death or major disability (dependency) in 55 patients. The other meta-analysis underlined the importance of a short interval between the onset of symptoms and the beginning of treatment. (4) Intracranial haemorrhage is the most important adverse effect. One meta-analysis showed that alteplase caused 62 additional symptomatic intracranial haemorrhages (including 25 deaths) per 1000 treated patients. (5) Various retrospective subgroup analyses have tentatively identified subgroups of patients at a particularly high risk of adverse effects, but subgroup analyses provide only weak evidence. The patients most likely to benefit from alteplase, started within three hours of symptom onset, remain to be defined. (6) The current health infrastructure in France would allow only a small number of stroke patients to be treated with alteplase under the kind of conditions prevailing in clinical trials (imaging to confirm ischaemic stroke, and treatment very soon after the onset of symptoms). (7) In practice, there is a narrow margin between the wanted and unwanted effects of alteplase. This treatment should be used only by specialised teams and for strictly selected patients. Research must continue, particularly to identify those patients most likely to benefit from alteplase, and those most likely to be harmed in whom thrombolysis is contraindicated.

Brain Ischemia↗
PubMed2003

Optimizing lipid management in patients with acute coronary syndromes.

According to the Third Report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III), patients with low-density lipoprotein (LDL) cholesterol > or = 130 mg/dL should be discharged on lipid-lowering therapy. When LDL cholesterol levels are between 100 and 129 mg/dL, evaluation of ratios of LDL cholesterol/high-density lipoprotein (HDL) cholesterol or total cholesterol/HDL cholesterol may provide additional insight into a patient's risk status. Patients who were using statin therapy before admission for an acute coronary syndrome should be continued on lipid-lowering therapy. The American College of Cardiology/American Heart Association (ACC/AHA) 2002 guideline update for management of patients with unstable angina and non-ST-segment elevation myocardial infarction recommends statin therapy at discharge as a class I indication, level of evidence A. Furthermore, studies confirm that statin therapy begun early during hospitalization can prevent ischemic events in patients who are treated by an invasive strategy and those who are treated only by a medical strategy. However, studies suggest that patient compliance with a statin regimen after discharge is far from optimal. There are 2 programs available to help ensure that appropriate patients receive and continue taking lipid-lowering therapy. These programs are the Cardiac Hospitalization Atherosclerosis Management Program (CHAMP) and the Guidelines Applied in Practice (GAP).

Acute Disease↗
PubMed1994

Group education interventions for people with low back pain. An overview of the literature.

STUDY DESIGN: This study systematically reviewed the literature on group education for people with low back pain. Findings are considered in relation to parameters such as the characteristics of the study participants, the intervention, and the setting. OBJECTIVE: To make a recommendation regarding the effectiveness of group education as an intervention for people with low back pain. RESULTS: Based on a systematic search of the literature, 13 primary studies are cited; 6 of these were sufficiently well designed and executed for their findings to be considered. Of the four quality studies with chronic back pain subjects, only one found a positive short-term effect on one of the outcome measures considered (pain intensity). In the two studies with acute cases, group education was found by one of the studies to reduce pain duration and initial sick leave duration in the short term, but the intervention also included work-site visits. At 1 year of follow-up, there was no evidence in the six studies of clinically important benefits on any of the outcome measures. CONCLUSIONS: There is insufficient evidence to recommend group education for people with low back pain.

Adult↗
PubMed2004

The role of oral direct thrombin inhibitors in the prophylaxis of venous thromboembolism.

Venous thromboembolism, which is manifested as deep vein thrombosis (DVT) and pulmonary embolism (PE), represents a significant cause of death, disability, and discomfort. Two million people/year are affected by VTE, making it the third most common cardiovascular disease after coronary heart disease and stroke. The rationale for VTE prophylaxis stems from the clinically silent presentation of the disease and its prevalence among hospitalized patients. At greatest risk are patients undergoing major orthopedic surgery and those admitted to the intensive care unit with acute myocardial infarction, heart failure, ischemic stroke, respiratory disease, systemic infection, or other medical conditions that immobilize patients for 5 days or longer. Several anticoagulant regimens have been effective in reducing the risk of VTE after major orthopedic surgery. For patients undergoing total hip or knee replacement, treatment with adjusted-dose warfarin, low-molecular-weight heparins, or fondaparinux may be used. Warfarin, which has been around for more than 50 years, is the only oral anticoagulant available for VTE prophylaxis. Ximelagatran, a new low-molecular-weight oral prodrug of the direct thrombin inhibitor melagatran, has advantages over warfarin that may make it the drug of choice for prevention of VTE.

Administration, Oral↗