This article proposes and evaluates a method to test for mediation in multilevel data sets formed when an intervention administered to intact groups is designed to produce change in individual mediator and outcome variables. Simulated data of this form were used to compare ordinary least squares (OLS) and two multilevel estimators of the mediated effect. OLS and multilevel standard error approx...

BACKGROUND Benchmarking Controlled Trial (BCT) is a concept which covers all observational studies aiming to assess impact of interventions or health care system features to patients and populations. AIMS To create and pilot test a checklist for appraising methodological validity of a BCT. METHODS The checklist was created by extracting the most essential elements from the comprehensive set...

This article explores how health inequalities are constructed as an object for policy intervention by considering four framings: politics, audit, evidence and treatment. A thematic analysis of 197 interviews conducted with local managers in England, Scotland and Wales is used to explore how these framings emerge from local narratives. The three different national policy regimes create contrasti...

The nature and magnitude of endemic waterborne disease are not well characterized in the United States. Epidemiologic studies of various designs can provide an estimate of the waterborne attributable risk along with other types of information. Community drinking water systems frequently improve their operations and may change drinking water treatment and their major source of water. In the Unit...

Lung cancer is the most common fatal malignancy in both men and women in the United Stares. In 1999, an estimated 171,600 patients will be diagnosed. Because the diagnosis is most commonly made in later stages, including presentations that manifest as distant metastasis, approximately 158,900 deaths will occur in 1999, if the current survival statistics continue. Today, lung cancer is the third...

Adults aged 65 years or older have been routinely and systematically excluded from research. With the number of older adults at a record high and growing faster than any other age group, there must be an increased priority on meeting the enrollment challenges so intervention studies are relevant to this population. The challenge centers around the complexity and heterogeneity of older adults, l...

Recent reports have called into question the reproducibility, validity and translatability of the preclinical animal studies due to limitations in their experimental design and statistical analysis. To this end, we implemented a matching-based modelling approach for optimal intervention group allocation, randomization and power calculations, which takes full account of the complex animal charac...

Functional near infrared spectroscopy (NIRS) is a non-invasive optical imaging technique used to monitor cerebral blood flow (CBF) and by proxy neuronal activation. The use of NIRS in nutritional intervention studies is a relatively novel application of this technique, with only a small, but growing, number of trials published to date. These trials-in which the effects on CBF following administ...

PURPOSE To present an overview of exercise interventions in cancer patients during and after treatment and evaluate dose-training response considering type, frequency, volume, and intensity of training along with expected physiological outcomes. METHODS The review is divided into studies that incorporated cardiovascular training, combination of cardiovascular, resistance, and flexibility trai...

BACKGROUND Clinical trials of interventions designed to prevent severe falciparum malaria in children require a clear endpoint. The internationally accepted definition of severe malaria is sensitive, and appropriate for clinical purposes. However, this definition includes individuals with severe nonmalarial disease and coincident parasitaemia, so may lack specificity in vaccine trials. Although...