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CONTEXT The evidence that breastfeeding improves cognitive development is based almost entirely on observational studies and is thus prone to confounding by subtle behavioral differences in the breastfeeding mother's behavior or her interaction with the infant. OBJECTIVE To assess whether prolonged and exclusive breastfeeding improves children's cognitive(More)
BACKGROUND The evidence that breastfeeding protects against obesity and a variety of chronic diseases comes almost entirely from observational studies, which have a potential for bias due to confounding, selection bias, and selective publication. OBJECTIVE We assessed whether an intervention designed to promote exclusive and prolonged breastfeeding(More)
RATIONALE Depression and anxiety are significant comorbid and potentially modifiable conditions in chronic obstructive pulmonary disease (COPD), but their effects on exacerbations are not clear. OBJECTIVES To investigate the independent effect of depression and anxiety on the risk of COPD exacerbations and hospitalizations. METHODS A multicenter(More)
BACKGROUND Over the past 30 years, eight major randomized controlled trials of breast cancer screening--with mammography and/or clinical breast examination--have been conducted. Results from several trials have been updated during the past year, and initial results of three other trials have been reported. PURPOSE The National Cancer Institute held an(More)
The hypothesis that patients with chronic obstructive pulmonary disease (COPD) have chronic inspiratory muscle fatigue was tested in an effectiveness trial in which negative pressure ventilation (NPV) was used to produce inspiratory muscle rest. In a double-blind study 184 patients with severe COPD were randomly allocated active or sham NPV treatment for a(More)
The purpose of our study was to examine the nutritional status of patients with severe chronic obstructive pulmonary disease (COPD) (mean predicted FEV1, 30 +/- 11%) and to explore its relationship to functional capacity. Functional capacity was evaluated by measuring peak oxygen consumption (VO2max) using an incremental cycle ergometry test, a 6-min walk(More)
We tested 46 fully vaccinated children in two day-care centers in Israel who were exposed to a fatal case of pertussis infection. Only two of five children who tested positive for Bordetella pertussis met the World Health Organization's case definition for pertussis. Vaccinated children may be asymptomatic reservoirs for infection.
This study had two primary aims: (1) to determine the usefulness of a telephone-administered health status questionnaire as an epidemiological survey instrument in groups at high risk for morbidity and disability; and (2) to evaluate the value of a telephone interview for making judgments about individual patient management. A structured telephone interview(More)
BACKGROUND Available evidence suggests that prolonged and exclusive breastfeeding is associated with lower infant weight and length by 6 to 12 months of age. This evidence, however, is based on observational studies, which are unable to separate the effects of feeding mode per se from selection bias, reverse causality, and the confounding effects of(More)
OBJECTIVE Pilot study to characterize treatment differences between patients treated in clinical trials and those treated in a clinical setting. Previous studies have shown higher survival rates for participants in trials of cancer therapy. This difference is observed even after rates are adjusted for important covariates such as age and stage of disease.(More)