Predictors of competing mortality to invasive breast cancer incidence in the Canadian National Breast Screening study.

Background: Evaluating the cost-effectiveness of breast cancer screening requires estimates of the absolute risk of breast cancer, which is modified by various risk factors. Breast cancer incidence, and thus mortality, is altered by the occurrence of competing events. More accurate estimates of competing risks should improve the estimation of absolute risk of breast cancer and benefit from breast cancer screening, leading to more effective preventive, diagnostic, and treatment policies.

Incidence of invasive breast cancer in the presence of competing mortality: the Canadian National Breast Screening Study.

Mortality due to causes other than breast cancer is a potential competing risk which may alter the incidence probability of breast cancer and as such should be taken into account in predictive modelling. We used data from the Canadian National Breast Screening Study (CNBSS), which consist of two randomized controlled trials designed to evaluate the efficacy of mammography among women aged 40-59. The participants in the CNBSS were followed up for incidence of breast cancer and mortality due to breast cancer and other causes; this allowed us to construct a breast cancer risk prediction model while taking into account mortality for the same study population.

Impact of hyperventilation on stimulus efficiency during the early phase of an electroconvulsive therapy course: a randomized double-blind study.

Objective: The question whether hyperventilation during electroconvulsive therapy (ECT) can improve stimulus efficiency is as yet unanswered.

Methods: Twenty-five consecutive consenting patients (N = 25) with major depression who were administered ECT entered into the study. Right unilateral ECT at thrice the threshold dose was administered using Mecta spECTrum 5000Q (Mecta Corp, Lake Oswego, Ore), with standard titration procedures and stimulus configurations.