Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 105
Filter
Add more filters

Publication year range
1.
J Stat Plan Inference ; 222: 149-159, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36467464

ABSTRACT

When no single outcome is sufficient to capture the multidimensional impairments of a disease, investigators often rely on multiple outcomes for comprehensive assessment of global disease status. Methods for assessing covariate effects on global disease status include the composite outcome and global test procedures. One global test procedure is the O'Brien's rank-sum test, which combines information from multiple outcomes using a global rank-sum score. However, existing methods for the global rank-sum do not lend themselves to regression modeling. We consider sensible regression strategies for the global percentile outcome (GPO), under the transformed linear model and the monotonic index model. Posing minimal assumptions, we develop estimation and inference procedures that account for the special features of the GPO. Asymptotics are established using U-statistic and U-process techniques. We illustrate the practical utilities of the proposed methods via extensive simulations and application to a Parkinson's disease study.

2.
Transfusion ; 60(5): 922-931, 2020 05.
Article in English | MEDLINE | ID: mdl-32358836

ABSTRACT

BACKGROUND: There have been no prior investigations of the cost effectiveness of transfusion strategies for trauma resuscitation. The Pragmatic, Randomized, Optimal Platelet and Plasma Ratios (PROPPR) study was a Phase III multisite, randomized trial in 680 subjects comparing the efficacy of 1:1:1 transfusion ratios of plasma and platelets to red blood cells with the 1:1:2 ratio. We hypothesized that 1:1:1 transfusion results in an acceptable incremental cost-effectiveness ratio, when estimated using patients' age-specific life expectancy and cost of care during the 30-day PROPPR trial period. STUDY DESIGN AND METHODS: International Classification of Diseases, Ninth Revision codes were prospectively collected, and subjects were matched 1:2 to subjects in the Healthcare Utilization Program State Inpatient Data to estimate cost weights. We used a decision tree analysis, combined with standard costs and estimated years of expected survival to determine the cost effectiveness of the two treatments. RESULTS: The 1:1:1 group had higher overall costs for the blood products but were more likely to achieve hemostasis and decreased hemorrhagic death by 24 hours (p = 0.006). For every 100 patients treated in the 1:1:1 group, eight more achieved hemostasis than in the 1:1:2 group. At 30 days, the total hospital cost per 100 patients was $5.6 million in the 1:1:1 group compared with $5.0 million in the 1:1:2 group. For each 100 patients, the 1:1:1 group had 218.5 more years of life expectancy. This was at a cost of $2994 per year gained. CONCLUSION: The 1:1:1 transfusion ratio in severely injured hemorrhaging trauma patients is a very cost-effective strategy for increasing hemostasis and decreasing trauma deaths.


Subject(s)
Blood Transfusion/economics , Blood Transfusion/methods , Adolescent , Adult , Blood Cell Count/economics , Blood Platelets/cytology , Blood Transfusion/mortality , Blood Transfusion/statistics & numerical data , Cost-Benefit Analysis , Erythrocyte Count , Erythrocyte Transfusion/economics , Erythrocyte Transfusion/methods , Erythrocyte Transfusion/mortality , Erythrocyte Transfusion/statistics & numerical data , Erythrocytes/cytology , Female , Hemorrhage/blood , Hemorrhage/mortality , Hemorrhage/therapy , Hospital Mortality , Humans , Length of Stay/economics , Length of Stay/statistics & numerical data , Male , Middle Aged , Plasma/cytology , Platelet Transfusion/economics , Platelet Transfusion/methods , Platelet Transfusion/mortality , Platelet Transfusion/statistics & numerical data , Resuscitation/mortality , Resuscitation/statistics & numerical data , Young Adult
3.
Clin Trials ; 17(6): 627-636, 2020 12.
Article in English | MEDLINE | ID: mdl-32838555

ABSTRACT

BACKGROUND: Cluster randomized trials are designed to evaluate interventions at the cluster or group level. When clusters are randomized but some clusters report no or non-analyzable data, intent-to-treat analysis, the gold standard for the analysis of randomized controlled trials, can be compromised. This article presents a very flexible statistical methodology for cluster randomized trials whose outcome is a cluster-level proportion (e.g. proportion from a cluster reporting an event) in the setting where clusters report non-analyzable data (which in general could be due to nonadherence, dropout, missingness, etc.). The approach is motivated by a previously published stratified randomized controlled trial called, "The Randomized Recruitment Intervention Trial (RECRUIT)," designed to examine the effectiveness of a trust-based continuous quality improvement intervention on increasing minority recruitment into clinical trials (ClinicalTrials.gov Identifier: NCT01911208). METHODS: The novel approach exploits the use of generalized estimating equations for cluster-level reports, such that all clusters randomized at baseline are able to be analyzed, and intervention effects are presented as risk ratios. Simulation studies under different outcome missingness scenarios and a variety of intra-cluster correlations are conducted. A comparative analysis of the method with imputation and per protocol approaches for RECRUIT is presented. RESULTS: Simulation results show the novel approach produces unbiased and efficient estimates of the intervention effect that maintain the nominal type I error rate. Application to RECRUIT shows similar effect sizes when compared to the imputation and per protocol approach. CONCLUSION: The article demonstrates that an innovative bivariate generalized estimating equations framework allows one to implement an intent-to-treat analysis to obtain risk ratios or odds ratios, for a variety of cluster randomized designs.


Subject(s)
Intention to Treat Analysis/methods , Patient Selection , Randomized Controlled Trials as Topic/methods , Bias , Cluster Analysis , Computer Simulation , Data Interpretation, Statistical , Humans , Intention to Treat Analysis/statistics & numerical data , Linear Models , Minority Groups , Odds Ratio , Randomized Controlled Trials as Topic/statistics & numerical data , Research Design , Treatment Outcome
5.
Clin Trials ; 14(3): 286-298, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28545336

ABSTRACT

BACKGROUND: Racial/ethnic minority groups remain underrepresented in clinical trials. Many strategies to increase minority recruitment focus on minority communities and emphasize common diseases such as hypertension. Scant literature focuses on minority recruitment to trials of less common conditions, often conducted in specialty clinics and dependent on physician referrals. We identified trust/mistrust of specialist physician investigators and institutions conducting medical research and consequent participant reluctance to participate in clinical trials as key-shared barriers across racial/ethnic groups. We developed a trust-based continuous quality improvement intervention to build trust between specialist physician investigators and community minority-serving physicians and ultimately potential trial participants. To avoid the inherent biases of non-randomized studies, we evaluated the intervention in the national Randomized Recruitment Intervention Trial (RECRUIT). This report presents the design of RECRUIT. Specialty clinic follow-up continues through April 2017. METHODS: We hypothesized that specialist physician investigators and coordinators trained in the trust-based continuous quality improvement intervention would enroll a greater proportion of minority participants in their specialty clinics than specialist physician investigators in control specialty clinics. Specialty clinic was the unit of randomization. Using continuous quality improvement, the specialist physician investigators and coordinators tailored recruitment approaches to their specialty clinic characteristics and populations. Primary analyses were adjusted for clustering by specialty clinic within parent trial and matching covariates. RESULTS: RECRUIT was implemented in four multi-site clinical trials (parent trials) supported by three National Institutes of Health institutes and included 50 associated specialty clinics from these parent trials. Using current data, we have 88% power or greater to detect a 0.15 or greater difference from the currently observed control proportion adjusting for clustering. We detected no differences in baseline matching criteria between intervention and control specialty clinics (all p values > 0.17). CONCLUSION: RECRUIT was the first multi-site randomized control trial to examine the effectiveness of a trust-based continuous quality improvement intervention to increase minority recruitment into clinical trials. RECRUIT's innovations included its focus on building trust between specialist investigators and minority-serving physicians, the use of continuous quality improvement to tailor the intervention to each specialty clinic's specific racial/ethnic populations and barriers to minority recruitment, and the use of specialty clinics from more than one parent multi-site trial to increase generalizability. The effectiveness of the RECRUIT intervention will be determined after the completion of trial data collection and planned analyses.


Subject(s)
Biomedical Research/methods , Minority Groups , Patient Selection , Research Design , Healthcare Disparities/ethnology , Humans , Multicenter Studies as Topic , National Institutes of Health (U.S.) , Pilot Projects , Quality Improvement , Referral and Consultation , United States
6.
Crit Care Med ; 44(5): 926-33, 2016 May.
Article in English | MEDLINE | ID: mdl-26765498

ABSTRACT

OBJECTIVE: To investigate ICU utilization and hospital outcomes of oncological patients admitted to a comprehensive cancer center. DESIGN: Observational cohort study. SETTING: The University of Texas MD Anderson Cancer Center. PATIENTS: Consecutive adults with cancer discharged over a 20-year period. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The Cochran-Armitage test for trend was used to evaluate ICU utilization and hospital mortality rates by primary service over time. A negative binomial log linear regression model was fitted to the data to investigate length of stay over time. Among 387,306 adult hospitalized patients, the ICU utilization rate was 12.9%. The overall hospital mortality rate was 3.6%: 16.2% among patients with an ICU stay and 1.8% among non-ICU patients. Among those admitted to the ICU, the mean (SD) admission Sequential Organ Failure Assessment score was 6.1 (3.8) for all ICU patients: 7.3 (4.4) for medical ICU patients and 4.9 (2.8) for surgical ICU patients. Hematologic disorders were associated with the highest hospital mortality rate in ICU patients (42.8%); metastatic disease had the highest mortality rate in non-ICU patients (4.2%); sepsis, pneumonia, and other infections had the highest mortality rate for all inpatients (8.5%). CONCLUSIONS: This study provides a longitudinal view of ICU utilization rates, hospital and ICU length of stay, and severity-adjusted mortality rates. Although the data arise from a single institution, it encompasses a large number of hospital admissions over two decades and can serve as a point of comparison for future oncological studies at similar institutions. More studies of this nature are needed to determine whether consolidation of cancer care into specialized large-volume facilities may improve outcomes, while simultaneously sustaining appropriate resource utilization and reducing unnecessary healthcare costs.


Subject(s)
Cancer Care Facilities/statistics & numerical data , Hospital Mortality , Intensive Care Units/statistics & numerical data , Adult , Aged , Cohort Studies , Female , Humans , Length of Stay , Longitudinal Studies , Male , Middle Aged , Organ Dysfunction Scores
7.
Mov Disord ; 31(12): 1865-1873, 2016 12.
Article in English | MEDLINE | ID: mdl-27943473

ABSTRACT

OBJECTIVE: Assess MDS-UPDRS items for gender-, age-, and race/ethnicity-based differential item functioning. BACKGROUND: Assessing differential item functioning is a core rating scale validation step. For the MDS-UPDRS, differential item functioning occurs if item-score probability among people with similar levels of parkinsonism differ according to selected covariates (gender, age, race/ethnicity). If the magnitude of differential item functioning is clinically relevant, item-score interpretation must consider influences by these covariates. Differential item functioning can be nonuniform (covariate variably influences an item-score across different levels of parkinsonism) or uniform (covariate influences an item-score consistently over all levels of parkinsonism). METHODS: Using the MDS-UPDRS translation database of more than 5,000 PD patients from 14 languages, we tested gender-, age-, and race/ethnicity-based differential item functioning. To designate an item as having clinically relevant differential item functioning, we required statistical confirmation by 2 independent methods, along with a McFadden pseudo-R2 magnitude statistic greater than "negligible." RESULTS: Most items showed no gender-, age- or race/ethnicity-based differential item functioning. When differential item functioning was identified, the magnitude statistic was always in the "negligible" range, and the scale-level impact was minimal. CONCLUSIONS: The absence of clinically relevant differential item functioning across all items and all parts of the MDS-UPDRS is strong evidence that the scale can be used confidently. As studies of Parkinson's disease increasingly involve multinational efforts and the MDS-UPDRS has several validated non-English translations, the findings support the scale's broad applicability in populations with varying gender, age, and race/ethnicity distributions. © 2016 International Parkinson and Movement Disorder Society.


Subject(s)
Parkinson Disease/diagnosis , Parkinson Disease/epidemiology , Psychometrics/methods , Severity of Illness Index , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Parkinson Disease/ethnology , Reproducibility of Results , Societies, Medical/standards
8.
Clin Trials ; 13(6): 592-596, 2016 12.
Article in English | MEDLINE | ID: mdl-27573636

ABSTRACT

BACKGROUND: Communicating with trial participants is an important aspect of study conduct, relevant for informed consent and respect for participants. Group teleconferences are one means to convey information to trial participants. We used group teleconferences during an ongoing large-scale clinical trial to communicate important trial updates. METHODS: The National Institute of Neurological Disorders and Stroke Exploratory Trials in Parkinson's Disease Longitudinal Study-1 trial studied creatine for treatment of early-stage Parkinson's disease. A total of 1741 participants enrolled at 45 sites in the United States and Canada to take part in a double-blind randomized trial of 5 years of treatment with creatine versus placebo. The study leadership held two teleconferences with study participants and their caregivers after each of two pre-specified interim analyses, for a total of four teleconferences. Each agenda included a presentation by study leadership followed by an open question and answer period. Teleconference recordings were made available to all site personnel and trial participants. Recordings were reviewed and abstracted for themes and topics of the presentations, participant questions, and discussion. Number of participants, connection time for each participant, number of questions, and caller connection time were summarized using descriptive statistics. After the first teleconferences, participants who remained on the call until the end were invited to complete a voluntary, four-question survey about the teleconference process. During the second teleconferences, participants were notified of premature study closure. RESULTS: There were 258 callers for the first pair of teleconferences and 604 callers for the second pair of teleconferences. Study leaders answered more than 110 questions from study participants and caregivers across all calls. The most frequently asked question themes related to study drug, Parkinson's disease, side effects, future research, and data analysis. The initial teleconferences were well received by participants. Based on responses to the post-call survey, 98% (118/121) of participants found the call useful, 91% (115/127) were interested in future similar calls, 88% stated the call made them more likely to continue in the study (112/128), and 85% (90/106) were satisfied overall with study communications. CONCLUSION: Teleconferences provide a convenient way to communicate with trial participants and can be used during the conduct of clinical trials to convey study progress and other information. For multi-site trials, teleconferences enable participants to engage directly with study leadership and to ask questions. Survey respondents were highly satisfied with the group teleconference experience. Future research is needed to determine whether teleconferences improve participants' satisfaction with clinical trial participation and improve retention.


Subject(s)
Clinical Trials as Topic , Communication , Information Dissemination , Multicenter Studies as Topic , Research Subjects , Telecommunications , Canada , Creatine/therapeutic use , Double-Blind Method , Humans , Informed Consent , Longitudinal Studies , Parkinson Disease/drug therapy , Patient Participation , Randomized Controlled Trials as Topic , United States
9.
Mov Disord ; 30(12): 1632-8, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25649812

ABSTRACT

This study was undertaken to define the number of missing values permissible to render valid total scores for each Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part. To handle missing values, imputation strategies serve as guidelines to reject an incomplete rating or create a surrogate score. We tested a rigorous, scale-specific, data-based approach to handling missing values for the MDS-UPDRS. From two large MDS-UPDRS datasets, we sequentially deleted item scores, either consistently (same items) or randomly (different items) across all subjects. Lin's Concordance Correlation Coefficient (CCC) compared scores calculated without missing values with prorated scores based on sequentially increasing missing values. The maximal number of missing values retaining a CCC greater than 0.95 determined the threshold for rendering a valid prorated score. A second confirmatory sample was selected from the MDS-UPDRS international translation program. To provide valid part scores applicable across all Hoehn and Yahr (H&Y) stages when the same items are consistently missing, one missing item from Part I, one from Part II, three from Part III, but none from Part IV can be allowed. To provide valid part scores applicable across all H&Y stages when random item entries are missing, one missing item from Part I, two from Part II, seven from Part III, but none from Part IV can be allowed. All cutoff values were confirmed in the validation sample. These analyses are useful for constructing valid surrogate part scores for MDS-UPDRS when missing items fall within the identified threshold and give scientific justification for rejecting partially completed ratings that fall below the threshold.


Subject(s)
Disability Evaluation , Parkinson Disease/diagnosis , Research Design , Severity of Illness Index , Societies, Medical/standards , Adult , Aged , Aged, 80 and over , Databases, Factual/statistics & numerical data , Female , Humans , Male , Middle Aged , Parkinson Disease/physiopathology , Reproducibility of Results
10.
Transfusion ; 55(6): 1331-9, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25823522

ABSTRACT

BACKGROUND: The Pragmatic, Randomized Optimal Platelets and Plasma Ratios (PROPPR) trial was a randomized clinical trial comparing survival after transfusion of two different blood component ratios for emergency resuscitation of traumatic massive hemorrhage. Transfusion services supporting the study were expected to provide thawed plasma, platelets, and red blood cells within 10 minutes of request. STUDY DESIGN AND METHODS: At the 12 Level 1 trauma centers participating in PROPPR, blood components transfused and delivery times were tabulated, with a focus on universal donor (UD) plasma management. The adequacy of site plans was assessed by comparing the bedside blood availability times to study goals and the new American College of Surgeons guidelines. RESULTS: Eleven of 12 sites were able to consistently deliver 6 units of thawed UD plasma to their trauma-receiving unit within 10 minutes and 12 units in 20 minutes. Three sites used blood group A plasma instead of AB for massive transfusion without complications. Approximately 4700 units of plasma were given to the 680 patients enrolled in the trial. No site experienced shortages of AB plasma that limited enrollment. Two of 12 sites reported wastage of thawed AB plasma approaching 25% of AB plasma prepared. CONCLUSION: Delivering UD plasma to massively hemorrhaging patients was accomplished consistently and rapidly and without excessive wastage in high-volume trauma centers. The American College of Surgeons Trauma Quality Improvement Program guidelines for massive transfusion protocol UD plasma availability are practicable in large academic trauma centers. Use of group A plasma in trauma resuscitation needs further study.


Subject(s)
Blood Component Transfusion , Hemorrhage/therapy , Multicenter Studies as Topic/statistics & numerical data , Plasma , Randomized Controlled Trials as Topic/statistics & numerical data , Wounds and Injuries/complications , ABO Blood-Group System/blood , Blood Banks/statistics & numerical data , Blood Component Transfusion/statistics & numerical data , Blood Preservation , Cryopreservation , Female , Hemorrhage/etiology , Humans , Male , Resuscitation , Time Factors , Trauma Centers/statistics & numerical data , United States , Blood Banking/methods
11.
Stat Med ; 34(27): 3577-89, 2015 Nov 30.
Article in English | MEDLINE | ID: mdl-26123093

ABSTRACT

Continuous time Markov chain (CTMC) models are often used to study the progression of chronic diseases in medical research but rarely applied to studies of the process of behavioral change. In studies of interventions to modify behaviors, a widely used psychosocial model is based on the transtheoretical model that often has more than three states (representing stages of change) and conceptually permits all possible instantaneous transitions. Very little attention is given to the study of the relationships between a CTMC model and associated covariates under the framework of transtheoretical model. We developed a Bayesian approach to evaluate the covariate effects on a CTMC model through a log-linear regression link. A simulation study of this approach showed that model parameters were accurately and precisely estimated. We analyzed an existing data set on stages of change in dietary intake from the Next Step Trial using the proposed method and the generalized multinomial logit model. We found that the generalized multinomial logit model was not suitable for these data because it ignores the unbalanced data structure and temporal correlation between successive measurements. Our analysis not only confirms that the nutrition intervention was effective but also provides information on how the intervention affected the transitions among the stages of change. We found that, compared with the control group, subjects in the intervention group, on average, spent substantively less time in the precontemplation stage and were more/less likely to move from an unhealthy/healthy state to a healthy/unhealthy state.


Subject(s)
Bayes Theorem , Feeding Behavior , Health Behavior , Markov Chains , Models, Psychological , Aged , Empirical Research , Female , Humans , Linear Models , Male , Middle Aged , Surveys and Questionnaires
12.
Cerebrovasc Dis ; 40(5-6): 293-300, 2015.
Article in English | MEDLINE | ID: mdl-26513489

ABSTRACT

BACKGROUND: There are very limited prospective data on the significance of persistent antiphospholipid antibodies (aPL) and recurrent thrombo-occlusive events (TOEs). We investigated the prognostic value of (1) 2 newer aPL assays, (2) an aPL portfolio and (3) persistent aPL positivity following stroke. METHODS: A total of 1,770 subjects from the APASS-WARSS study underwent further aPL testing for antibodies to phosphatidylserine (aPS) and anti-ß2-glycoprotein-I (anti-ß2GPI) from stored sera. Follow-up aPL status was also tested in a subset of subjects. Primary analysis was based on time to any TOE (ischemic stroke, myocardial infarction, transient ischemic attack, deep vein thrombosis, pulmonary embolism or systemic arterial occlusion)/death at 2 years. Cox proportional hazard analyses assessed whether aPL independently related to outcome. RESULTS: Persistent anti-ß2GPI decreased the time to TOE/death after adjustment for potential confounders (hazards ratio (HR) 2.86, 95% CI 1.21-6.76, p = 0.017). When persistent anti-ß2GPI was combined with another persistently positive aPL, time to TOE/death was also reduced (HR 3.79, 95% CI 1.18-12.14, p = 0.025). Neither persistent anticardiolipin antibodies nor persistent aPS alone nor a single positive anti-ß2GPI nor aPS was associated with decreased time to TOE/death. No single positive aPL, portfolio of baseline aPL or any persistent aPL increased the rate of TOE/death. CONCLUSIONS: Rates of TOE/death were not influenced by aPL results at baseline or follow-up. Persistent anti-ß2GPI alone, and with persistent second aPL, was independently associated with decreased time to TOE/death. Persistent aPL, an aPL portfolio and newer aPL in ischemic stroke patients are not helpful in predicting an increased rate of recurrent TOEs.


Subject(s)
Antibodies, Antiphospholipid/blood , Thrombophilia/epidemiology , Thrombosis/etiology , Aged , Antiphospholipid Syndrome/complications , Antiphospholipid Syndrome/immunology , Autoantigens/immunology , Brain Ischemia/etiology , Confounding Factors, Epidemiologic , Double-Blind Method , Female , Follow-Up Studies , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Myocardial Infarction/etiology , Phosphatidylserines/immunology , Pulmonary Embolism/etiology , Recurrence , Risk Factors , Thrombophilia/blood , Thrombophilia/immunology , beta 2-Glycoprotein I/immunology
13.
JAMA ; 313(5): 471-82, 2015 Feb 03.
Article in English | MEDLINE | ID: mdl-25647203

ABSTRACT

IMPORTANCE: Severely injured patients experiencing hemorrhagic shock often require massive transfusion. Earlier transfusion with higher blood product ratios (plasma, platelets, and red blood cells), defined as damage control resuscitation, has been associated with improved outcomes; however, there have been no large multicenter clinical trials. OBJECTIVE: To determine the effectiveness and safety of transfusing patients with severe trauma and major bleeding using plasma, platelets, and red blood cells in a 1:1:1 ratio compared with a 1:1:2 ratio. DESIGN, SETTING, AND PARTICIPANTS: Pragmatic, phase 3, multisite, randomized clinical trial of 680 severely injured patients who arrived at 1 of 12 level I trauma centers in North America directly from the scene and were predicted to require massive transfusion between August 2012 and December 2013. INTERVENTIONS: Blood product ratios of 1:1:1 (338 patients) vs 1:1:2 (342 patients) during active resuscitation in addition to all local standard-of-care interventions (uncontrolled). MAIN OUTCOMES AND MEASURES: Primary outcomes were 24-hour and 30-day all-cause mortality. Prespecified ancillary outcomes included time to hemostasis, blood product volumes transfused, complications, incidence of surgical procedures, and functional status. RESULTS: No significant differences were detected in mortality at 24 hours (12.7% in 1:1:1 group vs 17.0% in 1:1:2 group; difference, -4.2% [95% CI, -9.6% to 1.1%]; P = .12) or at 30 days (22.4% vs 26.1%, respectively; difference, -3.7% [95% CI, -10.2% to 2.7%]; P = .26). Exsanguination, which was the predominant cause of death within the first 24 hours, was significantly decreased in the 1:1:1 group (9.2% vs 14.6% in 1:1:2 group; difference, -5.4% [95% CI, -10.4% to -0.5%]; P = .03). More patients in the 1:1:1 group achieved hemostasis than in the 1:1:2 group (86% vs 78%, respectively; P = .006). Despite the 1:1:1 group receiving more plasma (median of 7 U vs 5 U, P < .001) and platelets (12 U vs 6 U, P < .001) and similar amounts of red blood cells (9 U) over the first 24 hours, no differences between the 2 groups were found for the 23 prespecified complications, including acute respiratory distress syndrome, multiple organ failure, venous thromboembolism, sepsis, and transfusion-related complications. CONCLUSIONS AND RELEVANCE: Among patients with severe trauma and major bleeding, early administration of plasma, platelets, and red blood cells in a 1:1:1 ratio compared with a 1:1:2 ratio did not result in significant differences in mortality at 24 hours or at 30 days. However, more patients in the 1:1:1 group achieved hemostasis and fewer experienced death due to exsanguination by 24 hours. Even though there was an increased use of plasma and platelets transfused in the 1:1:1 group, no other safety differences were identified between the 2 groups. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01545232.


Subject(s)
Blood Component Transfusion/methods , Exsanguination/therapy , Shock, Hemorrhagic/therapy , Wounds and Injuries/therapy , Blood Platelets , Erythrocytes , Exsanguination/etiology , Exsanguination/mortality , Female , Hemostasis , Humans , Male , Plasma , Shock, Hemorrhagic/etiology , Wounds and Injuries/complications , Wounds and Injuries/mortality
14.
JAMA ; 313(6): 584-93, 2015 Feb 10.
Article in English | MEDLINE | ID: mdl-25668262

ABSTRACT

IMPORTANCE: There are no treatments available to slow or prevent the progression of Parkinson disease, despite its global prevalence and significant health care burden. The National Institute of Neurological Disorders and Stroke Exploratory Trials in Parkinson Disease program was established to promote discovery of potential therapies. OBJECTIVE: To determine whether creatine monohydrate was more effective than placebo in slowing long-term clinical decline in participants with Parkinson disease. DESIGN, SETTING, AND PATIENTS: The Long-term Study 1, a multicenter, double-blind, parallel-group, placebo-controlled, 1:1 randomized efficacy trial. Participants were recruited from 45 investigative sites in the United States and Canada and included 1741 men and women with early (within 5 years of diagnosis) and treated (receiving dopaminergic therapy) Parkinson disease. Participants were enrolled from March 2007 to May 2010 and followed up until September 2013. INTERVENTIONS: Participants were randomized to placebo or creatine (10 g/d) monohydrate for a minimum of 5 years (maximum follow-up, 8 years). MAIN OUTCOMES AND MEASURES: The primary outcome measure was a difference in clinical decline from baseline to 5-year follow-up, compared between the 2 treatment groups using a global statistical test. Clinical status was defined by 5 outcome measures: Modified Rankin Scale, Symbol Digit Modalities Test, PDQ-39 Summary Index, Schwab and England Activities of Daily Living scale, and ambulatory capacity. All outcomes were coded such that higher scores indicated worse outcomes and were analyzed by a global statistical test. Higher summed ranks (range, 5-4775) indicate worse outcomes. RESULTS: The trial was terminated early for futility based on results of a planned interim analysis of participants enrolled at least 5 years prior to the date of the analysis (n = 955). The median follow-up time was 4 years. Of the 955 participants, the mean of the summed ranks for placebo was 2360 (95% CI, 2249-2470) and for creatine was 2414 (95% CI, 2304-2524). The global statistical test yielded t1865.8 = -0.75 (2-sided P = .45). There were no detectable differences (P < .01 to partially adjust for multiple comparisons) in adverse and serious adverse events by body system. CONCLUSIONS AND RELEVANCE: Among patients with early and treated Parkinson disease, treatment with creatine monohydrate for at least 5 years, compared with placebo did not improve clinical outcomes. These findings do not support the use of creatine monohydrate in patients with Parkinson disease. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00449865.


Subject(s)
Antiparkinson Agents/therapeutic use , Creatine/therapeutic use , Parkinson Disease/drug therapy , Aged , Antiparkinson Agents/adverse effects , Creatine/adverse effects , Creatine/blood , Disease Progression , Double-Blind Method , Drug Therapy, Combination , Female , Follow-Up Studies , Humans , Male , Medication Adherence , Middle Aged , Treatment Outcome
15.
Clin Trials ; 11(2): 187-94, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24686108

ABSTRACT

BACKGROUND: The Final Rule regulations were developed to allow exception from informed consent (EFIC) to enable clinical trial research in emergency settings where major barriers exist for informed consent. There is little known evidence of the effect of the Final Rule in minority enrollment in clinical trials, particularly in traumatic brain injury (TBI) trials. A clinical trial funded by the National Institute of Neurological Disorders and Stroke was conducted to study the effects of erythropoietin on cerebral vascular dysfunction and anemia in subjects with TBI. There were periods of time when EFIC was and was not available for enrollment into the study. PURPOSE: To explore the effect of EFIC availability on TBI trial enrollment of minority versus non-minority subjects. METHODS: Minority status of screened (n = 289) and enrolled (n = 191) TBI subjects was determined for this study. We tested for the presence of a minority and EFIC availability interaction in a multiple logistic regression model after controlling for EFIC and minority group main effects and other covariates. RESULTS: An interaction between the availability of EFIC minority and non-minority enrollment was not detected (odds ratio = 1.22; 95% confidence interval (CI) = 0.29-5.16). LIMITATIONS: Our study was conducted at a single site, and the CI for the EFIC and minority interaction term was wide. Therefore, a small interaction effect cannot be ruled out. CONCLUSION: EFIC increased the odds of being enrolled regardless of minority status.


Subject(s)
Clinical Trials as Topic/methods , Cultural Diversity , Ethnicity/statistics & numerical data , Informed Consent , Minority Groups/statistics & numerical data , Patient Selection , Adult , Black or African American/statistics & numerical data , Anemia/complications , Anemia/drug therapy , Asian/statistics & numerical data , Brain Injuries/complications , Brain Injuries/drug therapy , Cerebrovascular Disorders/complications , Cerebrovascular Disorders/drug therapy , Erythropoietin/therapeutic use , Female , Hematinics/therapeutic use , Hispanic or Latino/statistics & numerical data , Humans , Logistic Models , Male , Middle Aged , Odds Ratio , United States , White People/statistics & numerical data
16.
JAMA ; 312(1): 36-47, 2014 Jul 02.
Article in English | MEDLINE | ID: mdl-25058216

ABSTRACT

IMPORTANCE: There is limited information about the effect of erythropoietin or a high hemoglobin transfusion threshold after a traumatic brain injury. OBJECTIVE: To compare the effects of erythropoietin and 2 hemoglobin transfusion thresholds (7 and 10 g/dL) on neurological recovery after traumatic brain injury. DESIGN, SETTING, AND PARTICIPANTS: Randomized clinical trial of 200 patients (erythropoietin, n = 102; placebo, n = 98) with closed head injury who were unable to follow commands and were enrolled within 6 hours of injury at neurosurgical intensive care units in 2 US level I trauma centers between May 2006 and August 2012. The study used a factorial design to test whether erythropoietin would fail to improve favorable outcomes by 20% and whether a hemoglobin transfusion threshold of greater than 10 g/dL would increase favorable outcomes without increasing complications. Erythropoietin or placebo was initially dosed daily for 3 days and then weekly for 2 more weeks (n = 74) and then the 24- and 48-hour doses were stopped for the remainder of the patients (n = 126). There were 99 patients assigned to a hemoglobin transfusion threshold of 7 g/dL and 101 patients assigned to 10 g/dL. INTERVENTIONS: Intravenous erythropoietin (500 IU/kg per dose) or saline. Transfusion threshold maintained with packed red blood cells. MAIN OUTCOMES AND MEASURES: Glasgow Outcome Scale score dichotomized as favorable (good recovery and moderate disability) or unfavorable (severe disability, vegetative, or dead) at 6 months postinjury. RESULTS: There was no interaction between erythropoietin and hemoglobin transfusion threshold. Compared with placebo (favorable outcome rate: 34/89 [38.2%; 95% CI, 28.1% to 49.1%]), both erythropoietin groups were futile (first dosing regimen: 17/35 [48.6%; 95% CI, 31.4% to 66.0%], P = .13; second dosing regimen: 17/57 [29.8%; 95% CI, 18.4% to 43.4%], P < .001). Favorable outcome rates were 37/87 (42.5%) for the hemoglobin transfusion threshold of 7 g/dL and 31/94 (33.0%) for 10 g/dL (95% CI for the difference, -0.06 to 0.25, P = .28). There was a higher incidence of thromboembolic events for the transfusion threshold of 10 g/dL (22/101 [21.8%] vs 8/99 [8.1%] for the threshold of 7 g/dL, odds ratio, 0.32 [95% CI, 0.12 to 0.79], P = .009). CONCLUSIONS AND RELEVANCE: In patients with closed head injury, neither the administration of erythropoietin nor maintaining hemoglobin concentration of greater than 10 g/dL resulted in improved neurological outcome at 6 months. The transfusion threshold of 10 g/dL was associated with a higher incidence of adverse events. These findings do not support either approach in this setting. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00313716.


Subject(s)
Anemia/therapy , Brain Injuries/complications , Erythrocyte Transfusion/adverse effects , Erythropoietin/administration & dosage , Hemoglobins/analysis , Adult , Anemia/complications , Anemia/etiology , Brain Injuries/therapy , Erythrocyte Transfusion/methods , Female , Glasgow Outcome Scale , Humans , Male , Middle Aged , Neurologic Examination , Persistent Vegetative State , Reference Values , Severity of Illness Index , Thromboembolism/chemically induced , Treatment Outcome , Young Adult
17.
Mov Disord ; 28(5): 668-70, 2013 May.
Article in English | MEDLINE | ID: mdl-23408503

ABSTRACT

BACKGROUND: Formulas were developed to define tremor dominant (TD) and postural instability/gait difficulty (PIGD) phenotypes of Parkinson's Disease (PD) using the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS). TD and PIGD designations, based on the original Unified Parkinson's Disease Rating Scale (UPDRS), provided useful designations for classifying different phenotypes of PD. With the advent of the MDS-UPDRS, a valid set of calculations for these phenotypes is needed. METHODS: UPDRS and MDS-UPDRS scores were collected on 877 PD patients. TD/PIGD scores were calculated using the UPDRS formula for all patients. Comparable TD and PIGD items from the MDS-UPDRS were used to calculate new ratios. Data were analyzed using receiver operating characteristic models. RESULTS: The new MDS-UPDRS TD/PIGD ratios accounted for a significant area under the curve compared with the UPDRS classification. Optimal sensitivity and specificity were obtained with MDS-UPDRS cutoff scores of ≥1.15 for TD classification and ≤0.90 for PIGD. CONCLUSIONS: The development of comparable and valid PIGD and TD scores from the MDS-UPDRS provides a clear method for clinicians and researchers to transition from the original UPDRS to the new MDS-UPDRS in categorizing patients with different clinical phenotypes. © 2013 Movement Disorder Society.


Subject(s)
Gait Disorders, Neurologic/diagnosis , Gait Disorders, Neurologic/etiology , Parkinson Disease/complications , Postural Balance/physiology , Sensation Disorders/diagnosis , Sensation Disorders/etiology , Disability Evaluation , Female , Humans , Male , Neurologic Examination , ROC Curve , Severity of Illness Index , Tremor
18.
Mov Disord ; 27(10): 1239-42, 2012 Sep 01.
Article in English | MEDLINE | ID: mdl-22886777

ABSTRACT

The aim of this study was to develop formulas to convert the UPDRS to Movement Disorder Society (MDS)-UPDRS scores. The MDS-UPDRS is a revision of the UPDRS with sound clinimetric properties. Reliable formulas to recalculate UPDRS scores into MDS-UPDRS equivalents are pivotal to the practical transition and definitive adoption of the MDS-UPDRS. UPDRS and MDS-UPDRS scores were collected on 875 PD patients. A developmental sample was used to regress UPDRS scores on corresponding MDS-UPDRS scores based on three H & Y groupings (I/II, III, and IV/V). Regression weighting factors and intercept terms provided formulas for UPDRS conversions to be tested in a validation sample. Concordance between the true MDS-UPDRS Part scores and those derived from the formulas was compared using Bland-Altman's plots and Lin's concordance coefficient (LCC). Significant concordance between UPDRS-estimated MDS-UPDRS scores was achieved for Parts II (Motor Experiences of Daily Living) (LCC = 0.93) and III (Motor Examination) (LCC = 0.97). The formulas resulted in mean differences between the true MDS-UPDRS and estimated MDS-UPDRS scores of less than 1 point for both Parts II and III. Concordance was not achieved for Parts I and IV (Non-motor Experiences of Daily Living and Complications of Therapy). Formulas allow archival UPDRS Parts II and III individual patient data to be accurately transferred to MDS-UPDRS scores. Because Part I collects data on much more extensive information than the UPDRS, and because Part IV is structured differently in the two versions, old ratings for these parts cannot be converted. © 2012 Movement Disorder Society.


Subject(s)
Disability Evaluation , Movement Disorders/physiopathology , Parkinson Disease/diagnosis , Severity of Illness Index , Societies, Scientific/standards , Algorithms , Calibration , Female , Humans , Male , Parkinson Disease/complications
19.
Clin Trials ; 9(2): 188-97, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22496398

ABSTRACT

BACKGROUND: Failure to include participants of diverse race and ethnicity (i.e. those other than European Caucasian, non-Hispanic) in clinical trials impedes the safe development of new therapies given the potential for racial/ethnicity-related variations in treatment response. Increasing diversity is problematic for low prevalence diseases, where most community-based approaches do not reach those with the disease. PURPOSE: Increase racial/ethnic diversity of participants in a Parkinson's disease therapeutic trial. METHODS: We incorporated a randomized Ancillary Trial into the multisite National Institute of Neurologic Disorders and Stroke Exploratory Trials in Parkinson's Disease Long-Term Study 1. Movement disorders clinics already participating in long-term trial 1 were eligible and were the unit of randomization and analysis. At least 14% of adult residents over age 55 and living within 30 miles of the eligible site were from a diverse population, or there was a near-by zip code with a highly diverse population. Eligible sites also agreed to be randomized. The intervention was designed to increase community physicians' trust in long-term trial 1 investigators and address recruitment barriers in diverse populations. Primary outcomes included percentage of participants from diverse racial/ethnic groups enrolled in long-term trial 1, and qualitative findings from key informant interviews of the Ancillary Trial investigators and coordinators at the end of the trial. RESULTS: The Ancillary Trial stopped early for lack of efficacy, conditional power less than 1%. The 17 intervention sites had 12.6% diverse participants compared to 15.6% in 15 control clinics; odds ratio 0.82 (95% confidence interval = 0.32-2.16). In key informant interviews, high enrollers of diverse participants reported more use of existing physician relationships, untargeted community outreach, and extensive efforts to overcome participants' barriers. Low enrollers reported more use of patients in their practices and placed more responsibility for low enrollment on prospective participants. LIMITATIONS: The Ancillary Trial included only those with Parkinson's disease. Whether our findings generalize to trials in other low prevalence diseases is unknown. CONCLUSIONS: Increasing diversity in Parkinson's disease clinical trials requires new paradigms for trial investigator and coordinator interactions with community physicians and prospective trial participants.


Subject(s)
Clinical Trials as Topic , Parkinson Disease/ethnology , Patient Selection , Random Allocation , Humans , Interviews as Topic , Middle Aged , Sample Size , United States
20.
Lancet ; 375(9727): 1695-703, 2010 May 15.
Article in English | MEDLINE | ID: mdl-20472172

ABSTRACT

BACKGROUND: Early administration of intravenous recombinant tissue plasminogen activator (rt-PA) after ischaemic stroke improves outcome. Previous analysis of combined data from individual patients suggested potential benefit beyond 3 h from stroke onset. We re-examined the effect of time to treatment with intravenous rt-PA (alteplase) on therapeutic benefit and clinical risk by adding recent trial data to the analysis. METHODS: We added data from ECASS III (821 patients) and EPITHET (100 patients) to a pool of common data elements from six other trials of alteplase for acute stroke (2775 patients). We used multivariate logistic regression to assess the relation of stroke onset to start of treatment (OTT) with treatment on favourable 3-month outcome (defined as modified Rankin score 0-1), mortality, and occurrence and outcome of clinically relevant parenchymal haemorrhage. The presence of an arterial occlusion was inferred from the patient's symptoms and absence of haemorrhage or other causes of ischaemic stroke. Vascular imaging was not a requirement in the trials. All patients with confirmed OTT within 360 min were included in the analysis. FINDINGS: Treatment was started within 360 min of stroke onset in 3670 patients randomly allocated to alteplase (n=1850) or to placebo (n=1820). Odds of a favourable 3-month outcome increased as OTT decreased (p=0.0269) and no benefit of alteplase treatment was seen after around 270 min. Adjusted odds of a favourable 3-month outcome were 2.55 (95% CI 1.44-4.52) for 0-90 min, 1.64 (1.12-2.40) for 91-180 min, 1.34 (1.06-1.68) for 181-270 min, and 1.22 (0.92-1.61) for 271-360 min in favour of the alteplase group. Large parenchymal haemorrhage was seen in 96 (5.2%) of 1850 patients assigned to alteplase and 18 (1.0%) of 1820 controls, with no clear relation to OTT (p=0.4140). Adjusted odds of mortality increased with OTT (p=0.0444) and were 0.78 (0.41-1.48) for 0-90 min, 1.13 (0.70-1.82) for 91-180 min, 1.22 (0.87-1.71) for 181-270 min, and 1.49 (1.00-2.21) for 271-360 min. INTERPRETATION: Patients with ischaemic stroke selected by clinical symptoms and CT benefit from intravenous alteplase when treated up to 4.5 h. To increase benefit to a maximum, every effort should be taken to shorten delay in initiation of treatment. Beyond 4.5 h, risk might outweigh benefit. FUNDING: None.


Subject(s)
Fibrinolytic Agents/administration & dosage , Stroke/drug therapy , Tissue Plasminogen Activator/administration & dosage , Fibrinolytic Agents/adverse effects , Humans , Infusions, Intravenous , Injections, Intravenous , Intracranial Hemorrhages/chemically induced , Randomized Controlled Trials as Topic , Recombinant Proteins/administration & dosage , Time Factors , Tissue Plasminogen Activator/adverse effects , Treatment Outcome
SELECTION OF CITATIONS
SEARCH DETAIL