Impact of the Baltimore Experience Corps Trial on cortical and hippocampal volumes.

INTRODUCTION: There is a substantial interest in identifying interventions that can protect and buffer older adults from atrophy in the cortex and particularly, the hippocampus, a region important to memory. We report the 2-year effects of a randomized controlled trial of an intergenerational social health promotion program on older men's and women's brain volumes. METHODS: The Brain Health Study simultaneously enrolled, evaluated, and randomized 111 men and women (58 interventions; 53 controls) within the Baltimore Experience Corps Trial to evaluate the intervention impact on biomarkers of brain health at baseline and annual follow-ups during the 2-year trial exposure. RESULTS: Intention-to-treat analyses on cortical and hippocampal volumes for full and sex-stratified samples revealed program-specific increases in volumes that reached significance in men only (P's ≤ .04). Although men in the control arm exhibited age-related declines for 2 years, men in the Experience Corps arm showed a 0.7% to 1.6% increase in brain volumes. Women also exhibited modest intervention-specific gains of 0.3% to 0.54% by the second year of exposure that contrasted with declines of about 1% among women in the control group. DISCUSSION: These findings showed that purposeful activity embedded within a social health promotion program halted and, in men, reversed declines in brain volume in regions vulnerable to dementia. CLINICAL TRIAL REGISTRATION: NCT0038.

Cognitive performance profiles by latent classes of drug use.

BACKGROUND AND OBJECTIVES: The relationship between substance use and cognitive deficits is complex and requires innovative methods to enhance understanding. The present study is the first to use LCA to examine associations of drug use patterns with cognitive performance. METHODS: Cocaine/heroin users (N = 552) completed questionnaires, and cognitive measures. LCA identified classes based on past-month drug use and adjusted for probabilities of group membership when examining cognitive performance. Latent indicators were: alcohol (ALC), cigarettes (CIG), marijuana (MJ), crack smoking (CS), nasal heroin (NH), injection cocaine (IC), injection heroin (IH), and injection speedball (IS). Age and education were included as covariates in model creation. RESULTS: Bootstrap likelihood ratio test (BLRT) supported a 5-class model. Prevalent indicators (estimated probability of over 50%) for each class are as follows: "Older Nasal Heroin/Crack Smokers" (ONH/CS, n = 166.9): ALC, CIG, NH, CS; "Older, Less Educated Polysubstance" (OLEP, n = 54.8): ALC, CIG, CS, IH, IC, and IS; "Younger Multi-Injectors" (MI, n = 128.7): ALC, CIG, MJ, IH, IC, and IS; "Less Educated Heroin Injectors" (LEHI, n = 87.4): CIG, IH; and "More Educated Nasal Heroin" users (MENH, n = ALC, CIG, NH. In general, all classes performed worse than established norms and older, less educated classes performed worse, with the exception that MENH demonstrated worse cognitive flexibility than YMI. DISCUSSION AND CONCLUSIONS: This study demonstrated novel applications of a methodology for examining complicated relationships between polysubstance use and cognitive performance. SCIENTIFIC SIGNIFICANCE: Education and/or nasal heroin use are associated with reduced cognitive flexibility in this sample of inner city drug users.

The Alzheimer's Disease Neuroimaging Initiative: Annual change in biomarkers and clinical outcomes.

BACKGROUND: The Alzheimer's Disease Neuroimaging Initiative Phase 1 (ADNI-1) is a multisite prospective study designed to examine potential cerebrospinal fluid and imaging markers of Alzheimer's disease (AD) and their relationship to cognitive change. The objective of this study was to provide a global summary of the overall results and patterns of change observed in candidate markers and clinical measures over the first 2 years of follow-up. METHODS: Change was summarized for 210 normal controls, 357 mild cognitive impairment, and 162 AD subjects, with baseline and at least one cognitive follow-up assessment. Repeated measures and survival models were used to assess baseline biomarker levels as predictors. Potential for improving clinical trials was assessed by comparison of precision of markers for capturing change in hypothetical trial designs. RESULTS: The first 12 months of complete data on ADNI participants demonstrated the potential for substantial advances in characterizing trajectories of change in a range of biomarkers and clinical outcomes, examining their relationship and timing, and assessing the potential for improvements in clinical trial design. Reduced metabolism and greater brain atrophy in the mild cognitive impairment at baseline are associated with more rapid cognitive decline and a higher rate of conversion to AD. Use of biomarkers as study entry criteria or as outcomes could reduce the number of participants required for clinical trials. CONCLUSIONS: Analyses and comparisons of ADNI data strongly support the hypothesis that measurable change occurs in cerebrospinal fluid, positron emission tomography, and magnetic resonance imaging well in advance of the actual diagnosis of AD.

A case for revisiting peer review: Implications for professional self-regulation and quality improvement.

BACKGROUND: Quality improvement in healthcare has often been promoted as different from and more valuable than peer review and other professional self-regulation processes. In spite of attempts to harmonize these two approaches, the perception of dichotomous opposition has persisted. A sequence of events in the troubled California prison system fortuitously isolated workforce interventions from more typical quality improvement interventions. Our objectives were to (1) evaluate the relative contributions of professional accountability and quality improvement interventions to an observed decrease in population mortality and (2) explore the organizational dynamics that potentiated positive outcomes. METHODS: Our retrospective mixed-methods case study correlated time-series analysis of mortality with the timing of reform interventions. Quantitative and qualitative evidence was drawn from court documents, public use files, internal databases, and other archival documents. RESULTS: Change point analysis reveals with 98% confidence that a significant improvement in age-adjusted natural mortality occurred in 2007, decreasing from 138.7 per 100,000 in the 1998-2006 period to 106.4 in the 2007-2009 period. The improvement in mortality occurred after implementation of accountability processes, prior to implementation of quality improvement interventions. Archival evidence supports the positive impact of physician competency assessments, robust peer review, and replacement of problem physicians. CONCLUSIONS: Our analysis suggests that workforce accountability provides a critical quality safeguard, and its neglect in scholarship and practice is unjustified. As with quality improvement, effective professional self-regulation requires systemic implementation of enabling policies, processes, and staff resources. The study adds to evidence that the distribution of physician performance contains a heterogeneous left skew of dyscompetence that is associated with significant harm and suggests that professional self-regulation processes such as peer review can reduce that harm. Beyond their responsibility for direct harm, dyscompetent professionals can have negative impacts on group performance. The optimal integration of professional accountability and quality improvement systems merits further investigation.