Blood pressure readings during clinical encounters are used to determine the adequacy of hypertension treatment and as measures of quality of care. In this secondary analysis of 444 veterans in a hypertension trial, blood pressure varied widely in the short term, whether measured in the home, clinic, or research setting. A single measurement was generally inadequate to correctly determine whether blood pressure was adequately controlled. These findings indicate that blood pressure management should not be based on a single measurement.

Multidetector computed tomography (MDCT) is frequently used to evaluate patients with suspected appendicitis, but systematic study of its performance in this setting is lacking. This retrospective analysis of records of 2871 patients who were referred for MDCT for suspected acute appendicitis showed that sensitivity, specificity, and negative and positive predictive values of MDCT were all above 93%. Potential harms of MDCT and alternative evaluation strategies, however, were not studied.

Patients with lymphangioleiomyomatosis (LAM) often have cystic lung disease, as well as angiomyolipomas and recurrent chylous effusions. Sirolimus can reduce the size of angiomyolipomas, but its use in treating cystic lung disease or chylous effusions has not been systematically studied. In this observational study of patients enrolled in a natural history study of LAM, pulmonary function declined before and improved during sirolimus therapy. Chylous effusions markedly decreased or resolved after therapy in patients who had them, and lung function stabilized in patients without effusions at baseline.

Tuberous sclerosis complex (TSC) is usually diagnosed when children present with skin lesions or seizures. Hamartomatous tumors may damage other organs later in life, but the clinical picture of TSC diagnosed in adulthood has not been well-described. This observational study found that most adult women with TSC had diagnostic findings that were unrecognized during childhood. In some patients, disease manifestations sufficient for diagnosis were not present until adulthood. Despite the absence of seizures or skin lesions in many adults with TSC, life-threatening pulmonary and renal complications could occur, suggesting that adult presentation does not necessarily indicate a less severe form of the disease.

This systematic review examined the sensitivity and specificity of thiopurine S-methyltransferase (TPMT) genotyping for TPMT enzymatic activity, whether pretesting reduces harm from thiopurine therapy, and the association of thiopurine toxicity with TPMT status in patients with chronic inflammatory diseases. Limited-quality evidence suggested imperfect and imprecise sensitivity but near-perfect specificity of genotyping for identifying patients with low and intermediate TPMT enzymatic activity. However, evidence was insufficient that TPMT pretesting improves patient outcomes compared with routine blood count monitoring in patients receiving thiopurines. More high-quality evidence on the utility and costs of routine TPMT pretesting is needed to guide its use.

This Update summarizes studies published in 2010 that the authors consider highly relevant to the practice of nephrology. Topics include chronic kidney disease, acute kidney injury, the role of diet in kidney stones, and genetic variations and kidney disease.

Conversations about end-of-life care options between physicians and patients can improve the quality of life of dying patients and help to relieve the emotional burden on surviving loved ones. The author discusses this topic in light of the political debate over end-of-life care. The author believes that one thing is clear: Achieving real reform requires addressing the entire span of life circumstances, including the end of life.

Efficacy, safety, and cost-effectiveness should guide the use of new drugs, but information about drugs' relative efficacy and safety is typically incomplete, even well after market entry. Market and other forces create a situation in which most new drugs are little better than their older counterparts. The authors propose policy changes for promoting more rapid adoption of truly innovative drugs, inhibiting reflexive adoption of products that do not offer innovation, and avoiding premature abandonment of established therapies.

In this issue, Powers and colleagues' analysis examined the effects of measuring blood pressure by 3 methods: during routine outpatient visits, during research study visits, and recorded at home. The editorial discusses the implications of the findings regarding the need to base decisions on average blood pressure measurements rather than on a single measurement.

In this issue, the articles by Taveira-DaSilva and colleagues and Seibert and coworkers reflect important progress in our understanding of the treatment of LAM and the relationship between LAM and TSC. The editorialist discusses these articles' findings, which highlight the challenges and benefits of correctly diagnosing TSC and LAM and the value of patient registries and natural history data in rare diseases.

In this issue, Booth and colleagues systematically review available evidence on testing TPMT enzymatic activity before starting thiopurine therapy. The editorialists discuss the article and examine the challenges contributing to the lack of evidence for application of biomarkers in most areas of medicine, especially pharmacogenomics.