381,602 papers found

BACKGROUND: A 2013 meta-analysis observed a protective association between overweight body mass index (BMI) (vs. normal BMI) and all-cause mortality that was particularly strong in people aged ≥65. Estimates informing this meta-analysis were highly heterogeneous, and critics raised insufficient or inappropriate…

BACKGROUND: Overlapping meta-analyses on the same topic are now very common, and discordant results often occur. To explore why discordant results arise, we examined a common topic for overlapping meta-analyses- vitamin D supplements and fracture. METHODS AND FINDINGS: We identified 24 meta-analyses of vitamin D (with…

Spousal pairs permit assessment of determinants of diseases related to environment, because they share the same lifestyle and environment. The authors reviewed spouses' concordance for the major coronary risk factors. A search of the MEDLINE, PubMed, and EMBASE databases was performed. Seventy-one papers were selected…

The results of four similarly designed, randomized, double-blind, placebo-controlled studies conducted to evaluate ranitidine as prophylaxis for NSAID-associated damage are reviewed. A total of 673 patients receiving therapeutic dosages of NSAIDs for arthritic or musculoskeletal conditions also received either ranitidi…

The ability of computed tomography (CT) to detect mediastinal lymph node metastases from nonsmall cell bronchogenic lung cancer is highly controversial, as evidenced by reported accuracies ranging from 0.35 to 0.95 over the past eight years. We examined all studies on this matter published between January 1980 and Apri…

AIM: To assess the conclusiveness of the Cochrane Neonatal Reviews (CNRs). We tested the hypotheses that: 1) the majority of the reviews is inconclusive; 2) the majority of reviews recognizes the need for further studies; 3) the ability to reach a conclusion is dependent upon both the number of studies and the number o…

Electron microscopy offers a unique potentiality to visualize individual molecules. For the last 30 years it has been used to study the structure and the interactions of various biological macromolecules. The contribution of electron microscopy is important because of its capacity to demonstrate the existence of confor…

The power of the association between oral contraceptives and cervical cancer was analysed in all the papers published up to date. Fifty-three publications (from 48 studies) wer collected and graded as to quality using meta-analytical methods. Power achieved a figure of greater than or equal to 0.8 in a 24% of the assoc…

A review of 30 AIDS behavioral research studies revealed that almost half employed retrospective sexual activity assessment periods of 12 months or longer. The present study examined the correspondence between retrospective reports of sexual activity for 3 overlapping time-frames (past 2 weeks, past 3 months, and past…

The combined analysis of parallel double-blind studies of prescription anorectic drugs in 1973 showed 0.23 kg/wk more weight loss than placebo at the end of the studies. In 1985, the combined studies of phenylpropanolamine (PPA) and PPA with caffeine gave 0.27 kg/wk more weight loss than placebo, but since 1985, this d…

There are important scientific and pragmatic synergies between the medical decision making field and the emerging discipline of medical informatics. In the 1970s, the field of medicine forced clinically oriented artificial intelligence (AI) researchers to develop ways to manage explicit statements of uncertainty in exp…

We conducted an analysis of leukemia mortality and protracted exposure to low-dose ionizing radiation. We used data from seven published epidemiologic studies of nuclear workers that reported individual monitoring information for radiation exposure. We found 83 leukemia deaths among white males from a combined total of…

The close relationship between diabetes and hypertension has been recognized for decades. New information indicates that resistance to insulin action on glucose uptake in peripheral tissues is a common underlying mechanism in hypertension and diabetes. In prospective trials, the effects of antihypertensive agents on in…

In a re-analysis of eight case-control studies on Alzheimer's disease we explored several medical conditions that had previously been suggested as possible risk factors for Alzheimer's disease. History of hypothyroidism was increased in cases as compared to controls (relative risk 2.3; 95% confidence interval 1.0-5.4).…

Controversy prompted a systematic and critical review of original research articles to determine the prognosis of depression in the elderly. A search of three computer databases for articles published from January 1980 to May 1989 and of the bibliographies of articles located revealed 10 reports, involving 990 subjects…

Combination chemotherapy for advanced gastrointestinal malignancies remains unsatisfactory. Studies show a definite therapeutic advantage for folinic acid/5-fluorouracil (5-FU) regimen compared with single agent 5-FU given intravenously in the management of advanced colorectal cancer. Data on survival benefits vary. A…

We have analyzed 60 cases of intra-axial brain tumors associated with antecedent radiation therapy. These include four new cases. The patients had originally received radiation therapy for three reasons: (a) cranial irradiation for acute lymphoblastic leukemia (ALL), (b) definitive treatment of CNS neoplasia, and (c) t…

An overview of antihypertensive trials shows that, when absolute rather than relative measures of benefit are considered, a large benefit is derived from treating severe hypertension, whereas in mild hypertension the rate of prevented morbid events is relatively small. However, a greater benefit is observed when a mild…

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether the intraoperative use of surgical adhesives in patients undergoing lung resection would reduce the incidence and length of postoperative air leaks. The reported search strategy identified 261 pa…

The aim of the analysis was, in general, to find a way to summarise results of studies in search of exposure-response relationships and, in particular, to ask whether an exposure-response relationship can be ascertained for neurobehavioural studies on occupational mercury exposure. Eighteen studies dealing with human m…