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Purpose: A recent report linked methylphenidate (MPH) use in children to cytologic abnormalities in plasma lymphocytes, a possible cancer biomarker. The purpose of this study was to investigate the association of MPH use and childhood cancer risk., Methods: Using automated pharmacy databases and the SEER-affiliated cancer registry of the Kaiser Permanente Medical Care Program (KPMCP), we compared cancer rates at 18 sites among 35,400 MPH users who received it before age 20 to rates among KPMCP membership (age, sex, and calendar year standardized). Medical records of MPH exposed cancer cases were reviewed to identify the presence of established risk factors., Results: There were 23 cancers among MPH users, versus 20.4 expected (standardized morbidity ratio, SMR = 1.13, 95% confidence interval (0.72, 1.70)). Given the small number of cancers, site-specific SMR estimates were imprecise. Only one SMR was statistically significant at the p < 0.05 level, which given the number of comparisons is consistent with the absence of a true association at any site. MPH use was associated with increased risk of lymphocytic leukemia (SMR = 2.64 (1.14, 5.20)), based on eight observed cases). The medical records of these exposed cases did not reveal any lymphocytic leukemia risk factors (prior cancer, radiotherapy or chemotherapy, or Down syndrome)., Conclusions: Our results are consistent with no moderate or strong association between MPH use and cancer risk in children, although our ability to examine dose and duration of use or risk at specific sites was limited by small numbers. Further study of MPH use and lymphocytic leukemia risk is needed to determine whether our results are due to chance alone., (Copyright 2007 John Wiley & Sons, Ltd.)

Background: Control of blood pressure, low-density lipoprotein cholesterol (LDL-c), and A1c can lower the risk for diabetes complications. These quality indicators often are examined separately and weighted equally in performance measurement, potentially discarding important information., Objectives: We sought to create a composite indicator of the clinical benefit, or value, of diabetes risk factor control that appropriately weights the clinical importance of A1c, LDL-c, and blood pressure, and to test its usability for quality measurement., Methods: The combined value of control for 3 diabetes risk factors, measured by predicted quality-adjusted life years (QALYs), was compared in diabetes patients (n = 129,236 in 2001; n = 185,006 in 2003) in Kaiser Permanente Northern California across 16 medical center populations in 2001 and 2003 using hierarchical linear regression to adjust for case-mix differences. Patient-level QALYs, simulated from risk factor and case-mix variables in a Markov model, was the main outcome variable., Results: There was significant cross-sectional variability in average case-mix adjusted QALYs for diabetes patients across centers in 2003. QALYs increased from 2001 to 2003 as the result of improved risk factor control; longitudinal improvements in QALYs also showed variation across centers. Regression analyses demonstrated the greater impact of blood pressure versus LDL-c or A1c control on QALYs, and the greater value of risk factor control in those with poor versus near or in-control blood pressure., Conclusion: Using predicted QALYs to measure value holds promise as a sensitive composite indicator for quality measurement. Complex, evidence-based quality indicators such as these can potentially provide accurate and useful information to health plans, providers, and consumers.