Evaluation and Treatment of Iron Deficiency Anemia: A Gastroenterological Perspective

A substantial volume of the consultations requested of gastroenterologists are directed towards the evaluation of anemia. Since iron deficiency anemia often arises from bleeding gastrointestinal lesions, many of which are malignant, establishment of a firm diagnosis usually obligates an endoscopic evaluation. Although the laboratory tests used to make the diagnosis have not changed in many decades, their interpretation has, and this is possibly due to the availability of extensive testing in key populations. We provide data supporting the use of the serum ferritin as the sole useful measure of iron stores, setting the lower limit at 100 μg/l for some populations in order to increase the sensitivity of the test. Trends of the commonly obtained red cell indices, mean corpuscular volume, and the red cell distribution width can provide valuable diagnostic information. Once the diagnosis is established, upper and lower gastrointestinal endoscopy is usually indicated. Nevertheless, in many cases a gastrointestinal source is not found after routine evaluation. Additional studies, including repeat upper and lower endoscopy and often investigation of the small intestine may thus be required. Although oral iron is inexpensive and usually effective, there are many gastrointestinal conditions that warrant treatment of iron deficiency with intravenous iron

Forecast Evaluation of Explanatory Models of Financial Return Variability

A practice that has become widespread is that of comparing forecasts of financial return variability obtained from discrete time models against high frequency estimates based on continuous time theory. In explanatory financial return variability modelling this raises several methodological and practical issues, which suggests an alternative framework is needed. The contribution of this study is twofold. First, the finite sample properties of operational and practical procedures for the forecast evaluation of explanatory discrete time models of financial return variability are studied. Second, with basis in the simulation results a simple framework is proposed and illustrated

Assessing bettors' ability to process dynamic information: Policy implications

Regulation is often employed to encourage the provision of readily interpretable, explicitinformation to betting markets in an effort to promote their efficiency. This approach issupported by a considerable volume of laboratory-based research which suggests that individualsmake poor judgments in the face of implicit, dynamic information. This article investigates towhat extent horserace bettors, who have strong incentives to make good probability judgments,require the regulator’s protection from such hostile information environments. In particular, weexamine the accuracy of the subjective probabilities of bettors concerning 16,344 horses in 1671races. We find that bettors are skilled in adopting effective heuristics to simplify their dynamicinformation environment and, even in the face of restricted information, develop well-calibratedjudgments using outcome feedback. A number of factors that help bettors to achieve goodcalibration are identified and the implications for market regulation are discussed