Propensity matched comparison of omaveloxolone treatment to Friedreich ataxia natural history data.

OBJECTIVE: The natural history of Friedreich ataxia is being investigated in a multi-center longitudinal study designated the Friedreich ataxia Clinical Outcome Measures Study (FACOMS). To understand the utility of this study in analysis of clinical trials, we performed a propensity-matched comparison of data from the open-label MOXIe extension (omaveloxolone) to that from FACOMS. METHODS: MOXIe extension patients were matched to FACOMS patients using logistic regression to estimate propensity scores based on multiple covariates: sex, baseline age, age of onset, baseline modified Friedreich Ataxia Rating scale (mFARS) score, and baseline gait score. The change from baseline in mFARS at Year 3 for the MOXIe extension patients compared to the matched FACOMS patients was analyzed as the primary efficacy endpoint using mixed model repeated measures analysis. RESULTS: Data from the MOXIe extension show that omaveloxolone provided persistent benefit over 3 years when compared to an untreated, matched cohort from FACOMS. At each year, in all analysis populations, patients in the MOXIe extension experienced a smaller change from baseline in mFARS score than matched FACOMS patients. In the primary pooled population (136 patients in each group) by Year 3, patients in the FACOMS matched set progressed 6.6 points whereas patients treated with omaveloxolone in MOXIe extension progressed 3 points (difference = -3.6; nominal p value = 0.0001). INTERPRETATION: These results suggest a meaningful slowing of Friedreich ataxia progression with omaveloxolone, and consequently detail how propensity-matched analysis may contribute to understanding of effects of therapeutic agents. This demonstrates the direct value of natural history studies in clinical trial evaluations.

Effects of donation frequency on U.S. source plasma donor health.

BACKGROUND: Plasma-derived medicinal products (PDMPs) are essential, life-saving medicines manufactured from plasma donated by healthy human volunteers. PDMPs are used to treat a range of rare, serious, and chronic conditions, often genetic in origin. Approximately 70% of the Source Plasma (SP) used for PDMP manufacturing comes from United States (US). The hypothesis of the study is that US donation frequency does not impair donor self-reported functional health and well-being. STUDY DESIGN AND METHODS: A total of 5608 SP donors from 14 US SP centers were enrolled in a cross-sectional study to assess self-reported health related quality of life (HRQoL) and well-being. By sex, donors were assigned to one of four groups, according to their frequency of SP donation in the 12 months before enrollment. The SF-36v2® Health Survey (SF-36v2) and a survey assessing the frequency of various health conditions that may be associated with impaired immune function over different time periods were used. RESULTS: There were no statistically significant differences in SF-36v2 scores between any of the donor frequency groups, compared with new donors after controlling for potential confounding and accounting for multiple comparisons among males and females. Cough, cold, occasional fatigue, and sore throat were the most reported health conditions or symptoms, but there was no clear difference among sex or frequency groups. DISCUSSION: The self-reported data in this study support the hypothesis that compensated donations at US FDA permitted frequencies and volumes are consistent with maintaining donor health. Compared with the general population, SP donors have comparable or better health than the general population.

A Multicenter Study of the Causes and Consequences of Optimistic Expectations About Prognosis by Surrogate Decision-Makers in ICUs.

OBJECTIVES: Optimistic expectations about prognosis by surrogate decision-makers in ICUs are common, but there are few data about the causes and clinical consequences. Our objective was to determine the causes of optimistic expectations about prognosis among surrogates and whether it is associated with more use of life support at the end of life. DESIGN: Prospective, multicenter cohort study from 2009 to 2012. SETTING: Twelve ICUs from multiple regions of the United States. SUBJECTS: The surrogates and physicians of 275 incapacitated ICU patients at high risk of death. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Surrogates and physicians completed a validated instrument assessing their prognostic expectations for hospital survival. We determined the proportion of surrogates with optimistic expectations, defined as a prognostic estimate that was at least 20% more optimistic than the physician's, then determined how frequently this arose from surrogates miscomprehending the physicians' prognosis versus holding more hopeful beliefs compared with the physician. We used multivariable regression to examine whether optimistic expectations were associated with length of stay, stratified by survival status, and time to withdrawal of life support among nonsurvivors. Overall, 45% of surrogates (95% CI, 38-51%) held optimistic expectations about prognosis, which arose from a combination of misunderstanding the physician's prognostic expectations and from holding more hopeful beliefs compared with the physician. Optimistic expectations by surrogates were associated with significantly longer duration of ICU treatment among nonsurvivors before death (ß coefficient = 0.44; 95% CI, 0.05-0.83; p = 0.027), corresponding to a 56% longer ICU stay. This difference was associated with a significantly longer time to withdrawal of life support among dying patients whose surrogates had optimistic prognostic expectations compared with those who did not (ß coefficient = 0.61; 95% CI, 0.16-1.07; p = 0.009). CONCLUSIONS: The prevalent optimism about prognosis among surrogates in ICUs arises both from surrogates' miscomprehension of physicians' prognostications and from surrogates holding more hopeful beliefs. This optimism is associated with longer duration of life support at the end of life.

A Randomized Trial of a Family-Support Intervention in Intensive Care Units.

BACKGROUND: Surrogate decision makers for incapacitated, critically ill patients often struggle with decisions related to goals of care. Such decisions cause psychological distress in surrogates and may lead to treatment that does not align with patients' preferences. METHODS: We conducted a stepped-wedge, cluster-randomized trial involving patients with a high risk of death and their surrogates in five intensive care units (ICUs) to compare a multicomponent family-support intervention delivered by the interprofessional ICU team with usual care. The primary outcome was the surrogates' mean score on the Hospital Anxiety and Depression Scale (HADS) at 6 months (scores range from 0 to 42, with higher scores indicating worse symptoms). Prespecified secondary outcomes were the surrogates' mean scores on the Impact of Event Scale (IES; scores range from 0 to 88, with higher scores indicating worse symptoms), the Quality of Communication (QOC) scale (scores range from 0 to 100, with higher scores indicating better clinician-family communication), and a modified Patient Perception of Patient Centeredness (PPPC) scale (scores range from 1 to 4, with lower scores indicating more patient- and family-centered care), as well as the mean length of ICU stay. RESULTS: A total of 1420 patients were enrolled in the trial. There was no significant difference between the intervention group and the control group in the surrogates' mean HADS score at 6 months (11.7 and 12.0, respectively; beta coefficient, -0.34; 95% confidence interval [CI], -1.67 to 0.99; P=0.61) or mean IES score (21.2 and 20.3; beta coefficient, 0.90; 95% CI, -1.66 to 3.47; P=0.49). The surrogates' mean QOC score was better in the intervention group than in the control group (69.1 vs. 62.7; beta coefficient, 6.39; 95% CI, 2.57 to 10.20; P=0.001), as was the mean modified PPPC score (1.7 vs. 1.8; beta coefficient, -0.15; 95% CI, -0.26 to -0.04; P=0.006). The mean length of stay in the ICU was shorter in the intervention group than in the control group (6.7 days vs. 7.4 days; incidence rate ratio, 0.90; 95% CI, 0.81 to 1.00; P=0.045), a finding mediated by the shortened mean length of stay in the ICU among patients who died (4.4 days vs. 6.8 days; incidence rate ratio, 0.64; 95% CI, 0.52 to 0.78; P<0.001). CONCLUSIONS: Among critically ill patients and their surrogates, a family-support intervention delivered by the interprofessional ICU team did not significantly affect the surrogates' burden of psychological symptoms, but the surrogates' ratings of the quality of communication and the patient- and family-centeredness of care were better and the length of stay in the ICU was shorter with the intervention than with usual care. (Funded by the UPMC Health System and the Greenwall Foundation; PARTNER ClinicalTrials.gov number, NCT01844492 .).

Procalcitonin-Guided Use of Antibiotics for Lower Respiratory Tract Infection.

BACKGROUND: The effect of procalcitonin-guided use of antibiotics on treatment for suspected lower respiratory tract infection is unclear. METHODS: In 14 U.S. hospitals with high adherence to quality measures for the treatment of pneumonia, we provided guidance for clinicians about national clinical practice recommendations for the treatment of lower respiratory tract infections and the interpretation of procalcitonin assays. We then randomly assigned patients who presented to the emergency department with a suspected lower respiratory tract infection and for whom the treating physician was uncertain whether antibiotic therapy was indicated to one of two groups: the procalcitonin group, in which the treating clinicians were provided with real-time initial (and serial, if the patient was hospitalized) procalcitonin assay results and an antibiotic use guideline with graded recommendations based on four tiers of procalcitonin levels, or the usual-care group. We hypothesized that within 30 days after enrollment the total antibiotic-days would be lower - and the percentage of patients with adverse outcomes would not be more than 4.5 percentage points higher - in the procalcitonin group than in the usual-care group. RESULTS: A total of 1656 patients were included in the final analysis cohort (826 randomly assigned to the procalcitonin group and 830 to the usual-care group), of whom 782 (47.2%) were hospitalized and 984 (59.4%) received antibiotics within 30 days. The treating clinician received procalcitonin assay results for 792 of 826 patients (95.9%) in the procalcitonin group (median time from sample collection to assay result, 77 minutes) and for 18 of 830 patients (2.2%) in the usual-care group. In both groups, the procalcitonin-level tier was associated with the decision to prescribe antibiotics in the emergency department. There was no significant difference between the procalcitonin group and the usual-care group in antibiotic-days (mean, 4.2 and 4.3 days, respectively; difference, -0.05 day; 95% confidence interval [CI], -0.6 to 0.5; P=0.87) or the proportion of patients with adverse outcomes (11.7% [96 patients] and 13.1% [109 patients]; difference, -1.5 percentage points; 95% CI, -4.6 to 1.7; P<0.001 for noninferiority) within 30 days. CONCLUSIONS: The provision of procalcitonin assay results, along with instructions on their interpretation, to emergency department and hospital-based clinicians did not result in less use of antibiotics than did usual care among patients with suspected lower respiratory tract infection. (Funded by the National Institute of General Medical Sciences; ProACT ClinicalTrials.gov number, NCT02130986 .).

Design and rationale of the Procalcitonin Antibiotic Consensus Trial (ProACT), a multicenter randomized trial of procalcitonin antibiotic guidance in lower respiratory tract infection.

BACKGROUND: Overuse of antibiotics is a major public health problem, contributing to growing antibiotic resistance. Procalcitonin has been reported to be commonly elevated in bacterial, but not viral infection. Multiple European trials found procalcitonin-guided care reduced antibiotic use in lower respiratory tract infection, with no apparent harm. However, applicability to US practice is limited due to trial design features impractical in the US, between-country differences, and residual safety concerns. METHODS: The Procalcitonin Antibiotic Consensus Trial (ProACT) is a multicenter randomized trial to determine the impact of a procalcitonin antibiotic prescribing guideline, implemented with basic reproducible strategies, in US patients with lower respiratory tract infection. DISCUSSION: We describe the trial methods using the Consolidated Standards of Reporting Trials (CONSORT) framework, and the rationale for key design decisions, including choice of eligibility criteria, choice of control arm, and approach to guideline implementation. TRIAL REGISTRATION: ClinicalTrials.gov NCT02130986 . Registered May 1, 2014.

Intrathecal 2-hydroxypropyl-ß-cyclodextrin decreases neurological disease progression in Niemann-Pick disease, type C1: a non-randomised, open-label, phase 1-2 trial.

BACKGROUND: Niemann-Pick disease, type C1 (NPC1) is a lysosomal storage disorder characterised by progressive neurodegeneration. In preclinical testing, 2-hydroxypropyl-ß-cyclodextrins (HPßCD) significantly delayed cerebellar Purkinje cell loss, slowed progression of neurological manifestations, and increased lifespan in mouse and cat models of NPC1. The aim of this study was to assess the safety and efficacy of lumbar intrathecal HPßCD. METHODS: In this open-label, dose-escalation phase 1-2a study, we gave monthly intrathecal HPßCD to participants with NPC1 with neurological manifestation at the National Institutes of Health (NIH), Bethesda, MD, USA. To explore the potential effect of 2-week dosing, three additional participants were enrolled in a parallel study at Rush University Medical Center (RUMC), Chicago, IL, USA. Participants from the NIH were non-randomly, sequentially assigned in cohorts of three to receive monthly initial intrathecal HPßCD at doses of 50, 200, 300, or 400 mg per month. A fifth cohort of two participants received initial doses of 900 mg. Participants from RUMC initially received 200 or 400 mg every 2 weeks. The dose was escalated based on tolerance or safety data from higher dose cohorts. Serum and CSF 24(S)-hydroxycholesterol (24[S]-HC), which serves as a biomarker of target engagement, and CSF protein biomarkers were evaluated. NPC Neurological Severity Scores (NNSS) were used to compare disease progression in HPßCD-treated participants relative to a historical comparison cohort of 21 NPC1 participants of similar age range. FINDINGS: Between Sept 21, 2013, and Jan 19, 2015, 32 participants with NPC1 were assessed for eligibility at the National Institutes of Health. 18 patients were excluded due to inclusion criteria not met (six patients), declined to participate (three patients), pursued independent expanded access and obtained the drug outside of the study (three patients), enrolled in the RUMC cohort (one patient), or too late for the trial enrolment (five patients). 14 patients were enrolled and sequentially assigned to receive intrathecal HPßCD at a starting dose of 50 mg per month (three patients), 200 mg per month (three patients), 300 mg per month (three patients), 400 mg per month (three patients), or 900 mg per month (two patients). During the first year, two patients had treatment interrupted for one dose, based on grade 1 ototoxicity. All 14 patients were assessed at 12 months. Between 12 and 18 months, one participant had treatment interrupted at 17 months due to hepatocellular carcinoma, one patient had dose interruption for 2 doses based on caregiver hardship and one patient had treatment interrupted for 1 dose for mastoiditis. 11 patients were assessed at 18 months. Between Dec 11, 2013, and June 25, 2014, three participants were assessed for eligibility and enrolled at RUMC, and were assigned to receive intrathecal HPßCD at a starting dose of 200 mg every 2 weeks (two patients), or 400 mg every two weeks (one patient). There were no dropouts in this group and all 3 patients were assessed at 18 months. Biomarker studies were consistent with improved neuronal cholesterol homoeostasis and decreased neuronal pathology. Post-drug plasma 24(S)-HC area under the curve (AUC8-72) values, an indicator of neuronal cholesterol homoeostasis, were significantly higher than post-saline plasma 24(S)-HC AUC8-72 after doses of 900 mg (p=0·0063) and 1200 mg (p=0·0037). CSF 24(S)-HC concentrations in three participants given either 600 or 900 mg of HPßCD were increased about two fold (p=0·0032) after drug administration. No drug-related serious adverse events were observed. Mid-frequency to high-frequency hearing loss, an expected adverse event, was documented in all participants. When managed with hearing aids, this did not have an appreciable effect on daily communication. The NNSS for the 14 participants treated monthly increased at a rate of 1·22, SEM 0·34 points per year compared with 2·92, SEM 0·27 points per year (p=0·0002) for the 21 patient comparison group. Decreased progression was observed for NNSS domains of ambulation (p=0·0622), cognition (p=0·0040) and speech (p=0·0423). INTERPRETATION: Patients with NPC1 treated with intrathecal HPßCD had slowed disease progression with an acceptable safety profile. These data support the initiation of a multinational, randomised, controlled trial of intrathecal HPßCD. FUNDING: National Institutes of Health, Dana's Angels Research Trust, Ara Parseghian Medical Research Foundation, Hope for Haley, Samantha's Search for the Cure Foundation, National Niemann-Pick Disease Foundation, Support of Accelerated Research for NPC Disease, Vtesse, Janssen Research and Development, a Johnson & Johnson company, and Johnson & Johnson.

Amyloid-Beta Deposition is Associated with Increased Medial Temporal Lobe Activation during Memory Encoding in the Cognitively Normal Elderly.

BACKGROUND: Much is unknown about changes that occur in the brain in the years preceding the cognitive and functional impairment associated with Alzheimer disease (AD). This period before mild cognitive impairment is present has been referred to as preclinical AD, and is thought to begin with amyloid-beta deposition and then progress to neurodegeneration and functional brain circuit alterations. Prior studies have shown that there is increased medial temporal lobe activation on functional magnetic resonance imaging (fMRI) early in the course of mild cognitive impairment. It is unknown, however, whether this altered fMRI activity precedes cognitive impairment. The purpose of this study is to address this question using Pittsburgh Compound-B (PiB) imaging and fMRI in a sample of cognitively normal older adults. METHODS: Forty-four cognitively normal older adults underwent both PiB imaging and fMRI with a face-name memory task: 21 were classified as PiB(+) and 23 were PiB(-). Additionally, thorough cognitive and neuropsychological test batteries were administered outside the scanner. The main outcome measure in this study is fMRI activation in the medial temporal lobe during a face-name memory-encoding task. RESULTS: PiB(+) subjects showed higher fMRI activation during the memory task in the hippocampus relative to PiB(-) participants. CONCLUSIONS: The increased medial temporal lobe activation in preclinical AD, observed in this study, may serve as an early biomarker of neurodegeneration. Future studies are needed to clarify whether this functional biomarker can stratify AD risk among PiB(+) older adults.

Pseudo maximum likelihood approach for the analysis of multivariate left-censored longitudinal data.

The linear mixed effects model based on a full likelihood is one of the few methods available to model longitudinal data subject to left censoring. However, a full likelihood approach is complicated algebraically because of the large dimension of the numeric computations, and maximum likelihood estimation can be computationally prohibitive when the data are heavily censored. Moreover, for mixed models, the complexity of the computation increases as the dimension of the random effects in the model increases. We propose a method based on pseudo likelihood that simplifies the computational complexities, allows a wide class of multivariate models, and that can be used for many different data structures including settings where the level of censoring is high. The motivation for this work comes from the need for a joint model to assess the joint effect of pro-inflammatory and anti-inflammatory biomarker data on 30-day mortality status while simultaneously accounting for longitudinal left censoring and correlation between markers in the analysis of Genetic and Inflammatory Markers for Sepsis study conducted at the University of Pittsburgh. Two markers, interleukin-6 and interleukin-10, which naturally are correlated because of a shared similar biological pathways and are left-censored because of the limited sensitivity of the assays, are considered to determine if higher levels of these markers is associated with an increased risk of death after accounting for the left censoring and their assumed correlation. Copyright © 2016 John Wiley & Sons, Ltd.

Prevalence of and Factors Related to Discordance About Prognosis Between Physicians and Surrogate Decision Makers of Critically Ill Patients.

IMPORTANCE: Misperceptions about prognosis by individuals making decisions for incapacitated critically ill patients (surrogates) are common and often attributed to poor comprehension of medical information. OBJECTIVE: To determine the prevalence of and factors related to physician-surrogate discordance about prognosis in intensive care units (ICUs). DESIGN, SETTING, AND PARTICIPANTS: Mixed-methods study comprising quantitative surveys and qualitative interviews conducted in 4 ICUs at a major US medical center involving surrogate decision makers and physicians caring for patients at high risk of death from January 4, 2005, to July 10, 2009. MAIN OUTCOMES AND MEASURES: Discordance about prognosis, defined as a difference between a physician's and a surrogate's prognostic estimates of at least 20%; misunderstandings by surrogates (defined as any difference between a physician's prognostic estimate and a surrogate's best guess of that estimate); differences in belief (any difference between a surrogate's actual estimate and their best guess of the physician's estimate). RESULTS: Two hundred twenty-nine surrogate decision makers (median age, 47 [interquartile range {IQR}, 35-56] years; 68% women) and 99 physicians were involved in the care of 174 critically ill patients (median age, 60 [IQR, 47-74] years; 44% women). Physician-surrogate discordance about prognosis occurred in 122 of 229 instances (53%; 95% CI, 46.8%-59.7%). In 65 instances (28%), discordance was related to both misunderstandings by surrogates and differences in belief about the patient's prognosis; 38 (17%) were related to misunderstandings by surrogates only; 7 (3%) were related to differences in belief only; and data were missing for 12. Seventy-five patients (43%) died. Surrogates' prognostic estimates were much more accurate than chance alone, but physicians' prognostic estimates were statistically significantly more accurate than surrogates' (C statistic, 0.83 vs 0.74; absolute difference, 0.094; 95% CI, 0.024-0.163; P = .008). Among 71 surrogates interviewed who had beliefs about the prognosis that were more optimistic than that of the physician, the most common reasons for optimism were a need to maintain hope to benefit the patient (n = 34), a belief that the patient had unique strengths unknown to the physician (n = 24), and religious belief (n = 19). CONCLUSIONS AND RELEVANCE: Among critically ill patients, discordant expectations about prognosis were common between patients' physicians and surrogate decision makers and were related to misunderstandings by surrogates about physicians' assessments of patients' prognoses and differences in beliefs about patients' prognoses.

A Comparison of Free-Standing versus Co-Located Long-Term Acute Care Hospitals.

BACKGROUND: Long-term acute care hospitals (LTACs) provide specialized treatment for patients with chronic critical illness. Increasingly LTACs are co-located within traditional short-stay hospitals rather than operated as free-standing facilities, which may affect LTAC utilization patterns and outcomes. METHODS: We compared free-standing and co-located LTACs using 2005 data from the United States Centers for Medicare & Medicaid Services. We used bivariate analyses to examine patient characteristics and timing of LTAC transfer, and used propensity matching and multivariable regression to examine mortality, readmissions, and costs after transfer. RESULTS: Of 379 LTACs in our sample, 192 (50.7%) were free-standing and 187 (49.3%) were co-located in a short-stay hospital. Co-located LTACs were smaller (median bed size: 34 vs. 66, p <0.001) and more likely to be for-profit (72.2% v. 68.8%, p = 0.001) than freestanding LTACs. Co-located LTACs admitted patients later in their hospital course (average time prior to transfer: 15.5 days vs. 14.0 days) and were more likely to admit patients for ventilator weaning (15.9% vs. 12.4%). In the multivariate propensity-matched analysis, patients in co-located LTACs experienced higher 180-day mortality (adjusted relative risk: 1.05, 95% CI: 1.00-1.11, p = 0.04) but lower readmission rates (adjusted relative risk: 0.86, 95% CI: 0.75-0.98, p = 0.02). Costs were similar between the two hospital types (mean difference in costs within 180 days of transfer: -$3,580, 95% CI: -$8,720 -$1,550, p = 0.17). CONCLUSIONS: Compared to patients in free-standing LTACs, patients in co-located LTACs experience slightly higher mortality but lower readmission rates, with no change in overall resource use as measured by 180 day costs.

Longitudinal assessment of neuroimaging and clinical markers in autosomal dominant Alzheimer's disease: a prospective cohort study.

BACKGROUND: The biomarker model of Alzheimer's disease postulates a dynamic sequence of amyloidosis, neurodegeneration, and cognitive decline as an individual progresses from preclinical Alzheimer's disease to dementia. Despite supportive evidence from cross-sectional studies, verification with long-term within-individual data is needed. METHODS: For this prospective cohort study, carriers of autosomal dominant Alzheimer's disease mutations (aged ≥21 years) were recruited from across the USA through referrals by physicians or from affected families. People with mutations in PSEN1, PSEN2, or APP were assessed at the University of Pittsburgh Alzheimer's Disease Research Center every 1-2 years, between March 23, 2003, and Aug 1, 2014. We measured global cerebral amyloid ß (Aß) load using (11)C-Pittsburgh Compound-B PET, posterior cortical metabolism with (18)F-fluorodeoxyglucose PET, hippocampal volume (age and sex corrected) with T1-weighted MRI, verbal memory with the ten-item Consortium to Establish a Registry for Alzheimer's Disease Word List Learning Delayed Recall Test, and general cognition with the Mini Mental State Examination. We estimated overall biomarker trajectories across estimated years from symptom onset using linear mixed models, and compared these estimates with cross-sectional data from cognitively normal control individuals (age 65-89 years) who were negative for amyloidosis, hypometabolism, and hippocampal atrophy. In the mutation carriers who had the longest follow-up, we examined the within-individual progression of amyloidosis, metabolism, hippocampal volume, and cognition to identify progressive within-individual changes (a significant change was defined as an increase or decrease of more than two Z scores standardised to controls). FINDINGS: 16 people with mutations in PSEN1, PSEN2, or APP, aged 28-56 years, completed between two and eight assessments (a total of 83 assessments) over 2-11 years. Significant differences in mutation carriers compared with controls (p<0·01) were detected in the following order: increased amyloidosis (7·5 years before expected onset), decreased metabolism (at time of expected onset), decreased hippocampal volume and verbal memory (7·5 years after expected onset), and decreased general cognition (10 years after expected onset). Among the seven participants with longest follow-up (seven or eight assessments spanning 6-11 years), three individuals had active amyloidosis without progressive neurodegeneration or cognitive decline, two amyloid-positive individuals showed progressive neurodegeneration and cognitive decline without further progressive amyloidosis, and two amyloid-positive individuals showed neither active amyloidosis nor progressive neurodegeneration or cognitive decline. INTERPRETATION: Our results support amyloidosis as the earliest component of the biomarker model in autosomal dominant Alzheimer's disease. Our within-individual examination suggests three sequential phases in the development of autosomal dominant Alzheimer's disease-active amyloidosis, a stable amyloid-positive period, and progressive neurodegeneration and cognitive decline-indicating that Aß accumulation is largely complete before progressive neurodegeneration and cognitive decline occur. These findings offer supportive evidence for efforts to target early Aß deposition for secondary prevention in individuals with autosomal dominant Alzheimer's disease. FUNDING: National Institutes of Health and Howard Hughes Medical Institute.

Incidental Cerebral Microbleeds and Cerebral Blood Flow in Elderly Individuals.

IMPORTANCE: Cerebral microbleeds (CMBs) are collections of blood breakdown products that are a common incidental finding in magnetic resonance imaging of elderly individuals. Cerebral microbleeds are associated with cognitive deficits, but the mechanism is unclear. Studies show that individuals with CMBs related to symptomatic cerebral amyloid angiopathy have abnormal vascular reactivity and cerebral blood flow (CBF), but, to our knowledge, abnormalities in cerebral blood flow have not been reported for healthy individuals with incidental CMBs. OBJECTIVE: To evaluate the association of incidental CMBs with resting-state CBF, cerebral metabolism, cerebrovascular disease, ß-amyloid (Aß), and cognition. DESIGN, SETTING, AND PARTICIPANTS: A cross-sectional study of 55 cognitively normal individuals with a mean (SD) age of 86.8 (2.7) years was conducted from May 1, 2010, to May 1, 2013, in an academic medical center in Pittsburgh; data analysis was performed between June 10, 2013, and April 9, 2015. INTERVENTIONS: 3-Tesla magnetic resonance imaging was performed with susceptibility-weighted imaging or gradient-recalled echo to assess CMBs, arterial spin labeling for CBF, and T1- and T2-weighted imaging for atrophy, white matter hyperintensities, and infarcts. Positron emission tomography was conducted with fluorodeoxyglucose to measure cerebral metabolism and Pittsburgh compound B for fibrillar Aß. Neuropsychological evaluation, including the Clinical Dementia Rating scale, was performed. MAIN OUTCOMES AND MEASURES: Magnetic resonance images were rated for the presence and location of CMBs. Lobar CMBs were subclassified as cortical or subcortical. Measurements of CBF, metabolism, and Aß were compared with the presence and number of CMBs with voxelwise and region-of-interest analyses. RESULTS: The presence of cortical CMBs was associated with significantly reduced CBF in multiple regions on voxelwise and region-of-interest analyses (percentage difference in global CBF, -25.3%; P = .0003), with the largest reductions in the parietal cortex (-37.6%; P < .0001) and precuneus (-31.8%; P = .0006). Participants with any CMBs showed a nonsignificant trend toward reduced CBF. Participants with cortical CMBs had a significant association with greater prevalence of infarcts (24% vs 6%; P = .047) and demonstrated a trend to greater prevalence of deficits demonstrated on the Clinical Dementia Rating scale (45% vs 19%; P = .12). There was no difference in cortical amyloid (measured by Pittsburgh compound B positron emission tomography) between participants with and without CMBs (P = .60). CONCLUSIONS AND RELEVANCE: In cognitively normal elderly individuals, incidental CMBs in cortical locations are associated with widespread reductions in resting-state CBF. Chronic hypoperfusion may put these people at risk for neuronal injury and neurodegeneration. Our results suggest that resting-state CBF is a marker of CMB-related small-vessel disease.

Dialyzer Reuse and Outcomes of High Flux Dialysis.

BACKGROUND: The bulk of randomized trial evidence for the expanding use of High Flux (HF) hemodialysis worldwide comes from two randomized controlled trials, one of which (HEMODIALYSIS, HEMO) allowed, while the other (Membrane Outcomes Permeability, MPO) excluded, the reuse of membranes. It is not known whether dialyzer reuse has a differential impact on outcomes with HF vs low flyx (LF) dialyzers. METHODS: Proportional Hazards Models and Joint Models for longitudinal measures and survival outcomes were used in HEMO to analyze the relationship between ß2-microglobulin (ß2M) concentration, flux, and reuse. Meta-analysis and regression techniques were used to synthesize the evidence for HF dialysis from HEMO and MPO. FINDINGS: In HEMO, minimally reused (< 6 times) HF dialyzers were associated with a hazard ratio (HR) of 0.67 (95% confidence interval, 95%CI: 0.48-0.92, p = 0.015), 0.64 (95%CI: 0.44 - 0.95, p = 0.03), 0.61 (95%CI: 0.41 - 0.90, p = 0.012), 0.53 (95%CI: 0.28 - 1.02, p = 0.057) relative to minimally reused LF ones for all cause, cardiovascular, cardiac and infectious mortality respectively. These relationships reversed for extensively reused membranes (p for interaction between reuse and flux < 0.001, p = 0.005) for death from all cause and cardiovascular causes, while similar trends were noted for cardiac and infectious mortality (p of interaction between reuse and flux of 0.10 and 0.08 respectively). Reduction of ß2M explained only 1/3 of the effect of minimally reused HF dialyzers on all cause mortality, while non-ß2M related factors explained the apparent attenuation of the benefit with more extensively reused dialyzers. Meta-regression of HEMO and MPO estimated an adjusted HR of 0.63 (95% CI: 0.51-0.78) for non-reused HF dialyzers compared with non-reused LF membranes. CONCLUSIONS: This secondary analysis and synthesis of two large hemodialysis trials supports the widespread use of HF dialyzers in clinical hemodialysis over the last decade. A mechanistic understanding of the effects of HF dialysis and the reuse process on dialyzers may suggest novel biomarkers for uremic toxicity and may accelerate membrane technology innovations that will improve patient outcomes.

Subjective Cognitive Complaints, Personality and Brain Amyloid-beta in Cognitively Normal Older Adults.

OBJECTIVE: Subjective cognitive complaints in otherwise normal aging are common but may be associated with preclinical Alzheimer disease in some individuals. Little is known about who is mostly likely to show associations between cognitive complaints and preclinical Alzheimer pathology. We sought to demonstrate associations between subjective complaints and brain amyloid-ß in cognitively normal older adults; and to explore personality factors as potential moderators of this association. DESIGN: Cross-sectional observational study. SETTING: Clinical neuroimaging research center. PARTICIPANTS: Community volunteer sample of 92 healthy older adults, screened for normal cognition with comprehensive neuropsychological evaluation. MEASUREMENTS: Subjective cognitive self-report measures included the Memory Functioning Questionnaire (MFQ), Cognitive Failures Questionnaire, and the Subjective Cognitive Complaint Scale. Personality was measured with the NEO Five Factor Inventory. Brain amyloid-ß deposition was assessed with Pittsburgh compound B (PiB)-PET imaging. RESULTS: One of three cognitive complaint measures, the MFQ, was associated with global PiB retention (standardized beta = -0.230, p = 0.046, adjusting for age, sex and depressive symptoms). Neuroticism moderated this association such that only high neuroticism individuals showed the predicted pattern of high complaint-high amyloid-ß association. CONCLUSION: Evidence for association between subjective cognition and brain amyloid-ß deposition in healthy older adults is demonstrable but measure-specific. Neuroticism may moderate the MFQ-amyloid-ß association such that it is observed in the context of higher trait neuroticism. Subjective cognitive complaints and neuroticism may reflect a common susceptibility toward psychological distress and negative affect, which are in turn risk factors for cognitive decline in aging and incident Alzheimer disease.

Association between hospitalization for pneumonia and subsequent risk of cardiovascular disease.

IMPORTANCE: The risk of cardiovascular disease (CVD) after infection is poorly understood. OBJECTIVE: To determine whether hospitalization for pneumonia is associated with an increased short-term and long-term risk of CVD. DESIGN, SETTINGS, AND PARTICIPANTS: We examined 2 community-based cohorts: the Cardiovascular Health Study (CHS, n = 5888; enrollment age, ≥65 years; enrollment period, 1989-1994) and the Atherosclerosis Risk in Communities study (ARIC, n = 15,792; enrollment age, 45-64 years; enrollment period, 1987-1989). Participants were followed up through December 31, 2010. We matched each participant hospitalized with pneumonia to 2 controls. Pneumonia cases and controls were followed for occurrence of CVD over 10 years after matching. We estimated hazard ratios (HRs) for CVD at different time intervals, adjusting for demographics, CVD risk factors, subclinical CVD, comorbidities, and functional status. EXPOSURES: Hospitalization for pneumonia. MAIN OUTCOMES AND MEASURES: Incident CVD (myocardial infarction, stroke, and fatal coronary heart disease). RESULTS: Of 591 pneumonia cases in CHS, 206 had CVD events over 10 years after pneumonia hospitalization. CVD risk after pneumonia was highest in the first year. CVD occurred in 54 cases and 6 controls in the first 30 days (HR, 4.07; 95% CI, 2.86-5.27); 11 cases and 9 controls between 31 and 90 days (HR, 2.94; 95% CI, 2.18-3.70); and 22 cases and 55 controls between 91 days and 1 year (HR, 2.10; 95% CI, 1.59-2.60). Additional CVD risk remained elevated into the tenth year, when 4 cases and 12 controls developed CVD (HR, 1.86; 95% CI, 1.18-2.55). In ARIC, of 680 pneumonia cases, 112 had CVD over 10 years after hospitalization. CVD occurred in 4 cases and 3 controls in the first 30 days (HR, 2.38; 95% CI, 1.12-3.63); 4 cases and 0 controls between 31 and 90 days (HR, 2.40; 95% CI, 1.23-3.47); 11 cases and 8 controls between 91 days and 1 year (HR, 2.19; 95% CI, 1.20-3.19); and 8 cases and 7 controls during the second year (HR, 1.88; 95% CI, 1.10-2.66). After the second year, the HRs were no longer statistically significant. CONCLUSIONS AND RELEVANCE: Hospitalization for pneumonia was associated with increased short-term and long-term risk of CVD, suggesting that pneumonia may be a risk factor for CVD.

Longer lithium exposure is associated with better white matter integrity in older adults with bipolar disorder.

OBJECTIVES: Bipolar disorder (BD) is associated with cognitive dysfunction and structural brain abnormalities. In human and non-human studies, lithium has been related to neuroprotective and neurotrophic effects. We explored whether lithium treatment is related to better brain integrity and cognitive function in older adults with BD. METHODS: We examined cognitive and neuroimaging data in 58 individuals with BD [mean (standard deviation) age = 64.5 (9.8) years] and 21 mentally healthy comparators (controls) of similar age and education. Subjects received comprehensive neurocognitive assessment and structural brain imaging, examining total gray matter volume, overall white matter integrity (fractional anisotropy), and total white matter hyperintensity burden. RESULTS: In comparison to controls, subjects with BD had worse overall cognitive performance, lower total gray matter volume, and lower white matter integrity. Among subjects with BD, longer duration of lithium treatment was related to higher white matter integrity after controlling for age and vascular disease burden, but not with better cognitive performance. CONCLUSIONS: Lithium treatment appears to be related to better brain integrity in older individuals with BD, in particular, in those who take lithium long-term. While intriguing, these findings need to be confirmed in a larger sample.

A likelihood ratio test for nested proportions.

For policy and medical issues, it is important to know if the proportion of an event changes after an intervention is administered. When the later proportion can only be calculated in a portion of the sample used to compute the previous proportion, the two proportions are nested. The motivating example for this work comes from the need to test whether admission rates in emergency departments are different between the first and a return visit. Here, subjects who contribute to the admission rate at the return visit must be included in the first rate and also return, but not vice versa. This conditionality means that existing methods, including the basic test of equality of two proportions, longitudinal data analysis methods, and recurrent event approaches are not directly applicable. Currently, researchers can only explore this question by the use of descriptive statistics. We propose a likelihood ratio test to compare two nested proportions by using the product of conditional probabilities. This test accommodates the conditionality, subject dependencies, and cluster effects and can be implemented in SAS PROC NLMIXED allowing for the proposed method to be readily used in an applied setting. Simulation studies showed that our approach provides unbiased estimates and reasonable power. Moreover, it generally outperforms the two-sample proportion z-test, in the presence of heterogeneity, and the Cochran-Mantel-Haenszel test. An example based on readmission rates through an emergency department is used to illustrate the proposed method.

Amyloid, neurodegeneration, and small vessel disease as predictors of dementia in the oldest-old.

OBJECTIVE: To examine the association between brain structural changes and ß-amyloid deposition, and incident dementia in 183 elderly subjects without dementia (mean age 85.5 years) 2 years later. METHODS: Subjects had a brain structural MRI scan and a PET scan with (11)C-labeled Pittsburgh compound B (PiB) in 2009, and were evaluated clinically in 2011. RESULTS: At baseline evaluation, of the 183 participants (146 cognitively normal [CN]); 37 mild cognitive impairment [MCI]), 139 (76%) were PiB+, had small hippocampal volume (<25th percentile), or had high white matter lesion (WML) volume (>75th percentile). Two years later, 111 (61%) were classified as CN, 51 (28%) as MCI, and 21 (11%) as dementia. At baseline, 51% of the CN participants and 67.5% of the MCI cases were PiB+. Thirty percent of the CN and 51% of the MCI cases had small hippocampi, and 24% of the CN and 40.5% of the MCI cases had abnormal WMLs. Of the 21 participants who progressed to dementia, 20 (95%) had at least one imaging abnormality. Only 3 (14%) were only PiB+, 1 (5%) had only small hippocampi, 1 (5%) had only WMLs, 1 (5%) was biomarker negative, and the other 16 had various pairs of imaging abnormalities. Continuous variables of PiB retention, left and right hippocampal volume, and WML volume were independent predictors of dementia in a logistic regression analysis controlling for age, sex, education level, and Mini-Mental State Examination scores. CONCLUSIONS: The prevalence of ß-amyloid deposition, neurodegeneration (i.e., hippocampal atrophy), and small vessel disease (WMLs) is high in CN older individuals and in MCI. A combination of 2 or 3 of these factors is a powerful predictor of short-term incidence of dementia.

Regional amyloid burden and intrinsic connectivity networks in cognitively normal elderly subjects.

Although previous studies demonstrated decreased functional connectivity in the default mode network in the cognitively normal older adults with amyloid burden, effects of amyloid burden in the other large-scale intrinsic connectivity networks are not yet clear. The aim of this study was to investigate the distinctive association pattern of amyloid-ß deposition on the three large-scale intrinsic connectivity networks (the default mode network, salience network and central executive network) in older adults with normal cognition. Fifty-six older adults with normal cognition underwent functional magnetic resonance imaging and were dichotomized using 11C-labelled Pittsburgh compound B positron emission tomography imaging into subjects with (PiB+; n=27) and without (PiB-; n=29) detectable amyloid burden. We found that the functional connectivities of (i) the default mode network were greater; (ii) the salience network were not different; and (iii) the central executive network were lower in the Pittsburgh compound B positive group, compared with the Pittsburgh compound B negative group. Anterior cingulate cortex Pittsburgh compound B retention was negatively correlated with the functional connectivities of the posterior default mode network, and positively correlated with fronto-parietal functional connectivity (within the central executive network) in the Pittsburgh compound B positive group. The anti-correlation strength between the default mode network and the central executive network was negatively correlated with the anterior cingulate cortex Pittsburgh compound B levels. Additionally, significant group × episodic memory interactions with functional connectivities in the posterior default mode network, and the frontal default mode network were observed. Our results of aberrant default mode network functional connectivity and distinctive correlation patterns between the Pittsburgh compound B retention in the anterior cingulate cortex and functional connectivities in the default mode network and central executive network in the Pittsburgh compound B positive group might reflect a detrimental effect of amyloid retention on functional changes in the course of Alzheimer's disease progression.