Annals of Internal Medicine tip sheet for April 17, 2012, issue

Early-stage chronic kidney disease (CKD) affects 11 percent of the U.S. population and becomes more prevalent with older age. Identifying CKD is important because the condition is strongly associated with diabetes, hypertension, and cardiovascular disease. Screening and monitoring for chronic kidney disease (CKD) could lead to earlier interventions that improve patient outcomes. Researchers reviewed published randomized, controlled trials to summarize the benefits and harms of screening for and monitoring and treatment of early-stage CKD in adults. The evidence showed no clear link between screening or monitoring and improved clinical outcomes. Evidence for CKD treatment benefit is strongest for angiotensin-converting enzyme inhibitors and angiotension II-receptor blockers. Evidence also shows treatment is most effective in patients with albuminuria combined with diabetes or cardiovascular disease. According to the authors of an accompanying editorial, new guidelines that are being developed based on this review are unlikely to recommend regular screening for CKD. However, the editorialists believe that physicians should consider individual patient risk factors as well as their own clinical experience and common sense to make screening and treatment decisions.

Low back pain is the most common reason people see a doctor. Approximately half of all cases of low back pain are neuropathic, meaning they are caused by nerve compression, inflammation, and/or injury. Identifying the source of back pain is important because classification informs treatment. Physicians commonly use steroid injections to treat lumbosacral radiculopathy, or compressed nerves in the back, but steroids can have dangerous effects. Etanercept injections have been considered to be another option for treatment for low back pain. Researchers conducted a randomized trial of 84 adults to evaluate whether epidural steroids, etanercept, or saline better improved pain and function in patients suffering from lumbosacral radiculopathy for less than six months. Participants received either two steroid injections, two etanercept injections, or two injections of saline (all mixed with bupivacaine) separated by two weeks. One month after the second injection, patients were asked to report leg pain and function. Leg pain was reduced more with steroids than etanercept or saline, but differences were modest and not statistically significant. Differences in back pain and function associated with steroids versus saline also were not statistically significant. Larger trials of longer duration are needed to establish benefits of epidural steroids for lumbosacral radiculopathy.

3. Preexposure Prophylaxis Effective, Cost Effective for HIV Prevention in Highest Risk Men Who Have Sex with Men

Up to 61 percent of new HIV cases each year occur among men who have sex with men (MSM), making them an important target for HIV prevention. In Clinical trials, preexposure chemophrophylaxis (PrEP) with antiretroviral drugs significantly reduced the risk for HIV infection in HIV-negative MSM, but at a considerable cost. Researchers used a computer model and published literature to estimate the effectiveness and cost-effectiveness of PrEP in MSM in the United States. PrEp was evaluated in both the general MSM population and in high-risk MSM and was assumed to reduce infection risk by 44 percent on the basis of clinical trial results. In a model, a strategy that targeted PrEP to the 20 percent of the MSM considered to be at highest risk for HIV (average of five sexual partners a year) prevented twice as many infections over the long term, and was more cost-effective than a strategy that provided PrEP to 20 percent of all HIV-negative MSM.