This Week in JAMA FREE

Patients with diabetic nephropathy often have high plasma homocysteine levels. In a randomized placebo-controlled trial, House and colleagues assessed whether high doses of B-vitamin therapy—an intervention known to lower homocysteine levels—could slow the progression of diabetic nephropathy. During a mean (SD) 31.9 (14.4) months of follow-up, the authors found that compared with placebo, high doses of B vitamin were associated with lower levels of homocysteine but a more rapid decline in renal function and higher rates of myocardial infarction and stroke.

The coronary artery calcium score has been shown to be associated with the risk of future coronary heart disease (CHD) events. In an analysis of data from the Multi-Ethnic Study of Atherosclerosis—a population-based cohort without known cardiovascular disease at baseline—Polonsky and colleagues Article found that adding the coronary artery calcium score to a prediction model based on traditional risk factors improved the classification of incident CHD risk and placed more individuals in the most extreme risk categories. In an editorial, Ioannidis and Tzoulaki Article define characteristics of clinically useful predictors of disease risk and discuss whether the coronary artery calcium score is ready for routine use.

To assess current global use of hematopoietic stem cell transplantation, Gratwohl and colleagues from the Worldwide Network for Blood and Marrow Transplantation analyzed data from a retrospective survey representing patients who received transplants in 2006 at 1327 centers in 71 participating countries. The authors found significant differences in transplant rates between countries and continental regions by indication and donor type. They also report macroeconomic factors including gross national income, governmental health care expenditures, and transplant team density that were associated with transplant rates.

Dinan and colleagues analyzed nationally representative Medicare claims for beneficiaries diagnosed with breast, colorectal, lung, or prostate cancer; leukemia; or non-Hodgkin lymphoma in 1999 through 2006 to assess changes in the use and cost of diagnostic imaging. The authors report that conventional radiograph rates decreased or remained the same during the period of study, whereas the use of other imaging techniques increased significantly and outpaced total cancer costs to Medicare.

Mr W is a 92-year-old retired college professor who lives with his wife in a community with little public transportation. He reports some memory loss and has greater difficulty determining driving routes. Recent neuropsychological testing is consistent with mild cognitive impairment. Carr and Ott Article summarize the literature on dementia and driving and discuss evidence-based assessment of fitness-to-drive and physicians' legal and ethical obligations. A commentary by Eby and Molnar Article discusses the role of physicians in evaluating patients' fitness to drive.

“What was his bedside manner like? Was he curious about interesting cases? How did he feel about the power of medicine to change people's lives? I had no answers for these questions.” From “Nana's Words.”

Widespread off-label prescribing of antipsychotic drugs continues despite serious concerns about the drugs' metabolic and cardiac risks.

Patient-centered medical homes: why now?

Join Roger Chou, MD, Wednesday, May 19, from 2 to 3 PM eastern time to discuss predicting whether low back pain may become persistent and disabling. To register, go to http://www.ihi.org/AuthorintheRoom.

How would you counsel a 42-year-old man with hypercholesterolemia who is considering whether to drink alcohol to improve his cardiovascular health? Go to www.jama.com to read the case, and submit your response, which may be selected for online publication. Submission deadline is May 23.

Dr DeAngelis summarizes and comments on this week's issue. Go to http://jama.ama-assn.org/misc/audiocommentary.dtl.

For your patients: Information about older drivers and cognitive impairment.