This study puts paid to the idea that tight glycaemic control during on-pump cardiac surgery improves outcomes. In this trial it did the exact opposite.
Screening for colorectal cancer using guaiac-based tests for faecal occult blood has sometimes been pooh-poohed for its lack of sensitivity, but a better test is now available, based on quantitative immunochemical detection of human haemoglobin. In an Israeli cohort of patients with symptoms or at increased risk of colorectal neoplasia, the predictive characteristics were pretty good judged against the gold standard of colonoscopy: sensitivity 94%, specificity 87% for cancer, less for other significant neoplasia. How it would perform in whole-population screening is another matter.
How many doctors can immediately define sensitivity and specificity, and explain how these figures depend on the characteristics of the population studied? Most of us have acquired this knowledge from some kind of primer, and make occasional fumbling attempts to convey it to our patients when the need arises. Might they do better with a primer of their own? Apparently so, judging from this trial of such a document given to patients of high and low socioeconomic standing. But all it proved was that reading it gave them a bit more grasp of the principles, not that they were better able to make medical decisions.
Computerised prescribing systems commonly give warnings against prescribing cefalosporins to patients with a history of penicillin allergy, which we commonly ignore. Another drug with theoretical cross-reactivity is meropenem. This Italian study looked at skin tests to meropenem in penicillin-allergic subjects: 99% were negative.
In the UK, the periodic health evaluation has always been deeply unpopular. Here we consider ourselves quite busy enough, and resent patients coming in with their BUPA printouts expecting us to chase up borderline T-wave changes, slightly raised liver enzymes, highish triglycerides and all the rest; whereas in the USA, such endeavours are highly esteemed by patients and buoy up the health economy. A US systematic review of studies of the PHE comes out in favour, while carefully dodging any analysis of its individual elements.
Ann Intern Med 20 Feb 2007
