Bounding Analyses of Age-Period-Cohort Effects.

For more than a century, researchers from a wide range of disciplines have sought to estimate the unique contributions of age, period, and cohort (APC) effects on a variety of outcomes. A key obstacle to these efforts is the linear dependence among the three time scales. Various methods have been proposed to address this issue, but they have suffered from either ad hoc assumptions or extreme sensitivity to small differences in model specification.

Endogenous Selection Bias: The Problem of Conditioning on a Collider Variable.

Endogenous selection bias is a central problem for causal inference. Recognizing the problem, however, can be difficult in practice. This article introduces a purely graphical way of characterizing endogenous selection bias and of understanding its consequences (Hernán et al.

Should an alternative to the Glasgow Coma Scale be taught to paramedic students?

Background: The accurate assessment of a patient's conscious state using the Glasgow Coma Scale (GCS) is an important skill for paramedics as it may determine the patient's initial and ongoing management. The objective of this study was to determine if undergraduate paramedic students from a large Australian University were able to accurately interpret a variety of conscious states.

Methods: A prospective double-blinded observational pilot study requiring students to interpret the conscious state of four adult patients using the GCS by viewing a simulation DVD package.

Cardiopulmonary resuscitation before defibrillation in the out-of-hospital setting: a literature review.

Background: Many studies over the past decade have investigated delaying initial defibrillation to perform cardiopulmonary resuscitation (CPR), as it has been associated with increased rates of restoration of spontaneous circulation and/or survival. Since 2006, a number of studies have investigated these procedures. The objective of this study was to undertake a literature review examining the commencement of CPR before defibrillation in the out-of-hospital setting.