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1.
Math Med Biol ; 38(4): 474-489, 2021 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-34697633

RESUMEN

Sodium dodecyl sulphate (SDS), a commonly used laundry surfactant, has been known to cause some damage to epithelial cells in skin. Further, independent experiments have shown that a single laundry wash with rinsing leaves a residue of around 10% of the chemicals used in a wash cycle. A realistic nonlinear system of partial differential equations is developed for coupled water and solute transport through a drying porous medium when the solute has a mobile state (monomers) as well as an immobile state (micelles). An accurate finite difference scheme is developed and tested against known exact solutions of the nonlinear porous medium equation for transport of water and against known conservation laws. It shows that at the end of atmosphere-controlled stage 1 of drying when little water remains, the concentration of SDS near the drying surface, where it may contact skin, is commonly an order of magnitude higher than its initial value. The problem is exacerbated by successive regular wash cycles and by higher evaporation rates in electronic dryers. The numerical solutions show the partitioning between the two phases of SDS.


Asunto(s)
Irritantes , Difusión , Porosidad
2.
Eur J Neurol ; 22(1): 37-43, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23607783

RESUMEN

BACKGROUND AND PURPOSE: Although Parkinson's disease (PD) is characterized by typical motor manifestations, non-motor symptoms (NMS) are an outstanding part of the disease. At present, several specific instruments for assessment of NMS are available. The objective of our study was to determine the performance of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS): Part I - Non-Motor Aspects of Experiences of Daily Living (nM-EDL) compared with the Non-Motor Symptoms Scale (NMSS). METHODS: To this purpose, 434 consecutive patients with PD were included in an international, observational, cross-sectional study. The association between scores of both scales was determined by the Spearman rank correlation coefficient. Equations for transformation of total score of a scale to the other were constructed from weighted regression models and both, transformed and observed score, contrasted by means of the Lin's Concordance Correlation Coefficient (LCCC) and Bland-Altman plot. RESULTS: As a whole, the prevalence of the NMS according to each scale was quite similar, and most of the correlations between their corresponding components were high (r(S) > 0.60). The total score correlation of the MDS-UPDRS Part I with the NMSS was high (r(S) = 0.81). Concerning the transformed scores, estimated scores only partially approach the observed ones (sharing about 60-64% of the variance) because residual variance increased with increasing magnitudes of the scores, i.e. the most severe patients (Bland-Altman plot; LCCC < 0.60 for severe patients). CONCLUSIONS: (i) MDS-UPDRS Part I (nM-EDL) and NMSS showed a strong convergent validity; (ii) however, transformed scores using the equations from weighted regression models showed that for patients with the most severe NMS they are not concordant.


Asunto(s)
Actividades Cotidianas , Enfermedad de Parkinson/diagnóstico , Psicometría/instrumentación , Índice de Severidad de la Enfermedad , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad
3.
Eur J Neurol ; 21(3): 519-24, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24447695

RESUMEN

BACKGROUND AND PURPOSE: The Movement Disorder Society sponsored version of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) is a comprehensive instrument for assessing Parkinson's disease (PD). The present study was aimed at determining the relationships between MDS-UPDRS components and health-related quality of life (HRQoL) evaluations in PD patients. METHODS: An international, multicenter, cross-sectional study was carried out of 435 PD patients assessed with the MDS-UPDRS, Hoehn and Yahr (HY), Clinical Impression Severity for PD, EQ-5D and PD Questionnaire - eight items (PDQ-8). Spearman's rank correlation coefficients, exploratory factor analysis and multiple linear regression models (dependent variables EQ-5D and PDQ-8) were performed. RESULTS: The participants' age was 66.71 ± 10.32 years (51.5% men). PD duration was 8.52 ± 6.14, and median HY was 2 (range 1-5). The correlation between the EQ-5D index and the MDS-UPDRS ranged from -0.46 (Part IV) to -0.72 (Part II) and for the PDQ-8 index from 0.47 (Part III) to 0.74 (Part II). In multiple regression models with the MDS-UPDRS domains as independent variables, the main determinant for both the EQ-5D index and the PDQ-8 was Part II followed by Part I. After factorial grouping of the cardinal PD manifestations embedded in the MDS-UPDRS Parts III and IV for inclusion into multiple regression models, a factor formed by M-EDL, nM-EDL and fluctuations was the main determinant for both the EQ-5D and PDQ-8 indexes. CONCLUSIONS: The MDS-UPDRS component most tightly related with the HRQoL measures was a combination of motor and non-motor experiences of daily living.


Asunto(s)
Enfermedad de Parkinson/diagnóstico , Enfermedad de Parkinson/psicología , Calidad de Vida/psicología , Índice de Severidad de la Enfermedad , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Humanos , Cooperación Internacional , Masculino , Persona de Mediana Edad , Análisis de Regresión
4.
Parkinsonism Relat Disord ; 18(7): 837-41, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22542094

RESUMEN

BACKGROUND: We sought to define the frequency of falls in early PD and assess potential risk factors for falls in this population. METHODS: We analyzed the data from two randomized, placebo controlled trials (NET-PD FS1 and FS-TOO) of 413 individuals with early PD over 18 months of follow-up in FS1 and 12 months in FS-TOO. Falls were defined as any report of falls on the UPDRS or the adverse event log. We assessed the frequency of falls overall and by age. The relationship between prespecified fall risk markers and the probability of falling was assessed using logistic and multiple logistic regression. A hurdle Poisson model was used to jointly model the probability of remaining fall-free and the number of falls. RESULTS: During the follow-up period, 23% of participants fell, and 11% were habitual fallers. In a multiple logistic regression model, age, baseline UPDRS Falling score, and baseline PDQ-39 scores were associated with subsequent fall risk (p < 0.001). Similarly, in a hurdle Poisson regression model, age, baseline UPDRS falling item, and baseline PDQ-39 were all significantly related to the probability of falling, but only UPDRS falling >0 was associated with the number of falls. CONCLUSION: Falls are frequent and are associated with impaired quality of life, even in early PD. Current standard rating scales do not sufficiently explain future fall risk in the absence of a prior fall history. New assessment methods for falls and postural instability are required to better evaluate this important problem in clinical trials and clinical practice.


Asunto(s)
Accidentes por Caídas , Enfermedad de Parkinson/fisiopatología , Equilibrio Postural/fisiología , Accidentes por Caídas/estadística & datos numéricos , Estudios de Seguimiento , Humanos , Incidencia , Modelos Logísticos , Examen Neurológico , Medición de Riesgo , Factores de Riesgo , Encuestas y Cuestionarios
6.
Neurology ; 66(5): 628-33, 2006 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-16534099

RESUMEN

Many agents are being considered for treatment of Parkinson disease (PD). Given the large number of agents and the limited resources to evaluate new agents, it is essential to reduce the likelihood of advancing ineffective agents into large, long-term Phase III trials. Futility design methodology addresses this goal. The authors describe how a single-arm Phase II futility study uses a short-term outcome to compare a treatment group response to a predetermined hypothesized or historically based control response. The authors present advantages and limitations of futility designs along with examples derived from the data archive of a large Phase III efficacy study of treatments to delay PD progression, the Deprenyl And Tocopherol Antioxidative Therapy Of Parkinsonism (DATATOP) trial. Using the same control progression rate and treatment effect assumptions used to power the original DATATOP trial, the authors calculated the number of subjects needed to conduct two 12-month futility studies. DATATOP was designed to enroll 800 patients. Using data on 124 consecutive subjects randomized into each of the DATATOP treatment groups, the authors identified tocopherol as futile and deprenyl as worthy of further study. Using Phase II information, DATATOP could have been simplified from a 2 x 2 factorial design to a comparison of deprenyl vs placebo. While not testing efficacy, futility designs provide a strategy for discarding treatments unlikely to be effective in Phase III. A limitation is the dependence on historical data or hypothesized outcomes for untreated controls. Futility studies may decrease the time to identify treatments unworthy of further pursuit and reduce subjects' exposure to futile treatments.


Asunto(s)
Antiparkinsonianos/uso terapéutico , Enfermedad de Parkinson/tratamiento farmacológico , Ensayos Clínicos como Asunto , Ensayos Clínicos Fase II como Asunto/normas , Ensayos Clínicos Fase III como Asunto/normas , Humanos , Inutilidad Médica , Reproducibilidad de los Resultados , Proyectos de Investigación
7.
Transplant Proc ; 36(10): 3212-9, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15686731

RESUMEN

BACKGROUND: As bone marrow transplantation (BMT) increases, the availability of suitable donors becomes critical, especially for African Americans, who require a large donor pool to find a suitable match. Previous studies indicated willingness to donate marrow may be a barrier for achieving a large donor pool. METHODS: We conducted a random-sample, statewide telephone survey of 421 Caucasians and 408 African Americans in South Carolina to determine if racial differences in willingness to donate bone marrow exist. We assessed a general level of willingness, asking, "Will you be willing to be a marrow donor?" We assessed an additional level of willingness, asking, "Are you willing to be contacted about bone marrow donation?" RESULTS: We detected no racial differences in general willingness to donate (Caucasians 34%, African Americans 32%, P=.52), although there was a difference in willingness to be contacted to sign-up for the registry (Caucasians 18.3%, African Americans 11%, P=.003). African Americans were more aware that better matches occur within the same race (P <.0001). Caucasians were more knowledgeable about the registry (P <.0001). Younger, more highly educated respondents indicated a greater willingness to be donors. In both races, fear of pain was the most common reason for unwillingness to donate, and it was significantly higher in African Americans. CONCLUSION: Our study suggests reported lack of general willingness does not explain the racial disparities in BMT. Many who expressed willingness to donate were not willing to be contacted to sign up for the registry, especially African Americans. Education and adequate pain control may improve minority recruitment.


Asunto(s)
Actitud Frente a la Salud , Población Negra , Células de la Médula Ósea/citología , Conocimientos, Actitudes y Práctica en Salud , Donadores Vivos , Población Blanca , Adulto , Escolaridad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sistema de Registros , South Carolina , Encuestas y Cuestionarios
9.
Neurology ; 59(5): 669-74, 2002 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-12221155

RESUMEN

BACKGROUND: Hyperglycemia during acute ischemic stroke may augment brain injury, predispose to intracerebral hemorrhage (ICH), or both. METHOD: To analyze the relationship between admission glucose level and clinical outcomes from acute ischemic stroke, the authors performed multivariate regression analysis with the National Institute of Neurological Disorders and Stroke recombinant tissue plasminogen activator (rt-PA) Stroke Trial data. Neurologic improvement was defined as improvement on the NIH Stroke Scale by 4 or more points from baseline to 3 months, or a final score of zero. Favorable outcome was defined as both Glasgow Outcome score of 1 and Barthel Index 95 to 100 at 3 months. Symptomatic ICH was defined as CT-documented hemorrhage temporally related to clinical deterioration within 36 hours of treatment. Potential confounding factors were controlled, including acute treatment (rt-PA or placebo), age, baseline NIH Stroke Scale score, history of diabetes mellitus, stroke subtype, and admission blood pressure. RESULTS: There were 624 patients enrolled within 3 hours after stroke onset. As admission glucose increased, the odds for neurologic improvement decreased (odds ratio [OR] = 0.76 per 100 mg/dL increase in admission glucose, 95% CI 0.61 to 0.95, p = 0.01). The relation between admission glucose and favorable outcome depended on admission mean blood pressure (MBP): as admission MBP increased, the odds for favorable outcome related to increasing admission glucose levels progressively decreased (p = 0.02). As admission glucose increased, the odds for symptomatic ICH also increased (OR = 1.75 per 100 mg/dL increase in admission glucose, 95% CI 1.11 to 2.78, p = 0.02). Admission glucose level was not associated with altered effectiveness of rt-PA. CONCLUSIONS: In patients with acute ischemic stroke, higher admission glucose levels are associated with significantly lower odds for desirable clinical outcomes and significantly higher odds for symptomatic ICH, regardless of rt-PA treatment. Whether this represents a cause and effect relationship remains to be determined.


Asunto(s)
Glucemia , Fibrinolíticos/administración & dosificación , Accidente Cerebrovascular/sangre , Accidente Cerebrovascular/tratamiento farmacológico , Activador de Tejido Plasminógeno/administración & dosificación , Humanos , Hiperglucemia/complicaciones , Hiperglucemia/diagnóstico , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Accidente Cerebrovascular/complicaciones , Resultado del Tratamiento
10.
JAMA ; 286(22): 2830-8, 2001 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-11735758

RESUMEN

CONTEXT: The prevalence and clinical significance of early ischemic changes (EICs) on baseline computed tomography (CT) scan of the head obtained within 3 hours of ischemic stroke are not established. OBJECTIVE: To determine the frequency and significance of EIC on baseline head CT scans in the National Institute of Neurological Disorders and Stroke (NINDS) rt-PA (recombinant tissue plasminogen activator) Stroke Trial. DESIGN AND SETTING: The original study, a randomized controlled trial, took place from January 1991 through October 1994 at 43 sites, during which CT images were obtained within 3 hours of symptom onset and prior to the initiation of rt-PA or placebo. For the current analysis, detailed reevaluation was undertaken after October 1994 of all baseline head CT scans with clinical data available pretreatment (blinded to treatment arm). PATIENTS: Of 624 patients enrolled in the trial, baseline CT scans were retrieved and reviewed for 616 (99%). MAIN OUTCOME MEASURES: Frequency of EICs on baseline CT scans; association of EIC with other baseline variables; effect of EICs on deterioration at 24 hours (>/=4 points increase from the baseline National Institutes of Health Stroke Scale [NIHSS] score); clinical outcome (measured by 4 clinical scales) at 3 months, CT lesion volume at 3 months, death at 90 days; and symptomatic intracranial hemorrhage (ICH) within 36 hours of treatment. RESULTS: The prevalence of EIC on baseline CT in the combined rt-PA and placebo groups was 31% (n = 194). The EIC was significantly associated with baseline NIHSS score (rho = 0.23; P<.001) and time from stroke onset to baseline CT scan (rho = 0.11; P =.007). After adjusting for baseline variables, there was no EIC x treatment interaction detected for any clinical outcome, including deterioration at 24 hours, 4 clinical scales, lesion volume, and death at 90 days (P>/=.25), implying that EIC is unlikely to affect response to rt-PA treatment. After adjusting for NIHSS score (an independent predictor of ICH), no EIC association with symptomatic ICH at 36 hours was detected in the group treated with rt-PA (P>/=.22). CONCLUSIONS: Our analysis suggests that EICs are prevalent within 3 hours of stroke onset and correlate with stroke severity. However, EICs are not independently associated with increased risk of adverse outcome after rt-PA treatment. Patients treated with rt-PA did better whether or not they had EICs, suggesting that EICs on CT scan are not critical to the decision to treat otherwise eligible patients with rt-PA within 3 hours of stroke onset.


Asunto(s)
Isquemia Encefálica/diagnóstico por imagen , Activadores Plasminogénicos/uso terapéutico , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/tratamiento farmacológico , Activador de Tejido Plasminógeno/uso terapéutico , Anciano , Humanos , Hemorragias Intracraneales/diagnóstico por imagen , Modelos Logísticos , Persona de Mediana Edad , Distribución de Poisson , Proteínas Recombinantes , Riesgo , Índice de Severidad de la Enfermedad , Accidente Cerebrovascular/fisiopatología , Análisis de Supervivencia , Factores de Tiempo , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
11.
Ann Neurol ; 49(6): 736-44, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11409425

RESUMEN

We used stored plasma samples from 409 patients in the National Institute of Neurological Diseases and Stroke (NINDS) tissue plasminogen activator (t-PA) Stroke Trial to examine the relationship between an apolipoprotein (Apo) E2 or an Apo E4 phenotype and a favorable outcome 3 months after stroke, the risk of intracerebral hemorrhage, and the response to intravenous t-PA therapy. For the 27 patients with an Apo E2 phenotype who were treated with t-PA, the odds ratio (OR) of a favorable outcome at 3 months was 6.4 [95% confidence interval (CI) 2.7-15.3%] compared to the 161 patients without an Apo E2 phenotype who were treated with placebo. The 190 patients treated with t-PA who did not have an Apo E2 phenotype also had a greater, though less pronounced, likelihood of a favorable outcome (OR 2.0, 95% CI 1.2-3.2%) than patients without an Apo E2 phenotype treated with placebo. For the 31 patients with an Apo E2 phenotype treated with placebo, the OR of a favorable 3 month outcome was 0.8 (95% CI 0.4-1.7%) compared to the 161 patients without an Apo E2 phenotype treated with placebo. This interaction between treatment and Apo E2 status persisted after adjustment for baseline variables previously associated with 3 month outcome, for differences in the baseline variables in the two treatment groups and in the Apo E2-positive and -negative groups, and for a previously reported time-to-treatment x treatment interaction (p = 0.03). Apo E4 phenotype, present in 111 (27%) of the 409 patients, was not related to a favorable 3 month outcome, response to t-PA, 3 month mortality, or risk of intracerebral hemorrhage. We conclude that the efficacy of intravenous t-PA in patients with acute ischemic stroke may be enhanced in patients who have an Apo E2 phenotype, whereas the Apo E2 phenotype alone is not associated with a detectable benefit on stroke outcome at 3 months in patients not given t-PA. In contrast to prior studies of head injury and stroke, we could not detect a relationship between Apo E4 phenotype and clinical outcome.


Asunto(s)
Apolipoproteínas E/genética , Hemorragia Cerebral/genética , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/genética , Activador de Tejido Plasminógeno/uso terapéutico , Anciano , Anciano de 80 o más Años , Apolipoproteína E2 , Apolipoproteína E4 , Apolipoproteínas E/sangre , Hemorragia Cerebral/sangre , Hemorragia Cerebral/tratamiento farmacológico , Hemorragia Cerebral/patología , Distribución de Chi-Cuadrado , Método Doble Ciego , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Oportunidad Relativa , Fenotipo , Placebos , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios Retrospectivos , Accidente Cerebrovascular/sangre , Accidente Cerebrovascular/patología , Tasa de Supervivencia , Factores de Tiempo , Activador de Tejido Plasminógeno/sangre , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
12.
Stat Med ; 20(13): 1891-901, 2001 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-11427947

RESUMEN

In clinical trials, when a single outcome is not sufficient to describe the underlying concept of interest, it may be necessary to compare treatment groups on multiple correlated outcomes. A global test based on a logit link function provides an estimate of the odds ratio for assessing a common treatment effect among correlated binary outcomes. In this paper we extend the use of generalized estimating equations (GEE) to calculate a common relative risk from correlated binary outcomes based on a log link function. In the context of global tests, we discuss the equivalence and difference between logit and log links and their estimates. We also derive a formula for calculating a common risk difference between two treatment groups based on multiple correlated binary outcomes with categorical covariates, assuming the asymptotic equivalency between the logit and log-linear links. We discuss the statistical tools to be used in choosing between the logit and log links when models on different links yield contrasting results. Examples using data from the NINDS t-PA Stroke Trials are provided. We conclude, in a study of correlated binary outcomes, that the choice of the logit or log link could be based on a comparison of goodness-of-link.


Asunto(s)
Oportunidad Relativa , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Accidente Cerebrovascular/tratamiento farmacológico , Resultado del Tratamiento , Evaluación de Medicamentos/métodos , Humanos , Modelos Logísticos , National Institutes of Health (U.S.) , Riesgo , Activador de Tejido Plasminógeno/uso terapéutico , Estados Unidos
13.
Cancer Epidemiol Biomarkers Prev ; 10(1): 35-43, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11205487

RESUMEN

Risk perception may be an important motivator of health-related behaviors. To develop effective risk communication messages, it is important to understand both the patterns of association between perceived risk and health-related behaviors as well as the correlates of risk perception. Very little is known about whether correlates of risk perception are similar in cross-sectional data compared with prospective data. Furthermore, there are scant data on consistency of correlates of risk perception across groups who vary in objective medical risk. If correlates differ, it would underscore the need to tailor intervention messages based on subgroup characteristics as well as increase awareness of the limitations of basing intervention messages only on cross-sectional data. We analyzed data on a subset of 5042 employees who participated in The Next Step Trial, a randomized health promotion trial to encourage colorectal cancer screening and dietary change. We restricted our analysis to only those automotive workers who were white, male, and did not have colorectal cancer (4477/5042) and who returned surveys both at baseline (2,684/4,477) and at year 2 of follow-up (1955/2684). Initial analyses detected interactions between a history of polyps and several of the other covariates. Therefore, univariate and multivariable analyses were conducted separately for men with and without a personal history of colorectal polyps. Within each of the four subgroups (those with or without polyps in the baseline or follow-up analyses), we examined associations between perceived risk measured at baseline (cross-sectional analyses) and at year 2 of follow-up (prospective analyses) in relation to intervention group status, demographic, medical history, psychosocial, and worksite characteristics measured at baseline. To assess the predictive ability of the models, we computed sensitivity and specificity as measures of each model's ability to correctly classify men into their respective subgroup. Although there was no association between perceived risk and intervention group status in the four subgroups analyzed, we included intervention group status as a covariate in all analyses. At baseline (cross-sectional analyses) among men with and without a history of polyps, perceived risk was positively associated with family history of colorectal polyps or cancer, family support for screening, and worry about being diagnosed with colorectal cancer. In addition, for men without polyps, perceived risk was positively associated with being a current smoker. At year 2 of follow-up (prospective analyses) for men with and without polyps, perceived risk at year 2 was positively associated with family history and baseline perceived risk and was negatively associated with having a normal screening examination or no examinations during the trial. In addition, for men with polyps, perceived risk was positively associated with belief in the salience and coherence of screening and with intention to be screened and was negatively associated with access to screening at the worksite. Specificity was higher than sensitivity in three of four subgroups and was >65% in all subgroups. Except for family history, messages to influence perceived risk would emphasize different factors, depending on whether associations were based on baseline or follow-up data and depending on whether men reported a personal history of polyps. For example, although intervention messages using baseline data would emphasize the same factors for men with or without polyps, messages based on follow-up data would emphasize psychosocial characteristics, such as salience and coherence of screening and intention for men with a history of polyps but not for men without. Our findings support the need to delineate subgroups in the study population to target and tailor health-related messages based on respondent characteristics. Our findings also underscore the need to base health-related messages on prospective data as well as cross-sectional data to better address health-related beliefs and behaviors.


Asunto(s)
Neoplasias Colorrectales/etiología , Conductas Relacionadas con la Salud , Conocimientos, Actitudes y Práctica en Salud , Adulto , Anciano , Automóviles , Pólipos del Colon/complicaciones , Estudios Transversales , Predisposición Genética a la Enfermedad , Humanos , Industrias , Masculino , Persona de Mediana Edad , Ocupaciones , Educación del Paciente como Asunto , Percepción , Factores de Riesgo
14.
Neurology ; 55(11): 1649-55, 2000 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-11113218

RESUMEN

BACKGROUND: The National Institute of Neurological Disorders and Stroke (NINDS) rt-PA Stroke Study showed a similar percentage of intracranial hemorrhage and good outcome in patients 3 months after stroke treatment given 0 to 90 minutes and 91 to 180 minutes after stroke onset. At 24 hours after stroke onset more patients treated 0 to 90 compared to 91 to 180 minutes after stroke onset had improved by four or more points on the NIH Stroke Scale (NIHSS). The authors performed further analyses to characterize the relationship of onset-to-treatment time (OTT) to outcome at 3 months, early improvement at 24 hours, and intracranial hemorrhage within 36 hours. METHODS: Univariate analyses identified potentially confounding variables associated with OTT that could mask an OTT-treatment interaction. Tests for OTT-treatment interactions adjusting for potential masking confounders were performed. An OTT-treatment interaction was considered significant if p < or = 0.10, implying that treatment effectiveness was related to OTT. RESULTS: For 24-hour improvement, there were no masking confounders identified and there was an OTT-treatment interaction (p = 0.08). For 3-month favorable outcome, the NIHSS met criteria for a masking confounder. After adjusting for NIHSS as a covariate, an OTT-treatment interaction was detected (p = 0.09): the adjusted OR (95% CI) for a favorable 3-month outcome associated with recombinant tissue-type plasminogen activator (rt-PA) was 2.11 (1.33 to 3.35) in the 0 to 90 minute stratum and 1.69 (1.09 to 2.62) in the 91 to 180 minute stratum. In the group treated with rt-PA, after adjusting for baseline NIHSS, an effect of OTT on the occurrence of intracranial hemorrhage was not detected. CONCLUSIONS: If the NINDS rt-PA Stroke Trial treatment protocol is followed, this analysis suggests that patients treated 0 to 90 minutes from stroke onset with rt-PA have an increased odds of improvement at 24 hours and favorable 3-month outcome compared to patients treated later than 90 minutes. No effect of OTT on intracranial hemorrhage was detected within the group treated with rt-PA, possibly due to low power.


Asunto(s)
Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/fisiopatología , Activador de Tejido Plasminógeno/uso terapéutico , Método Doble Ciego , Humanos , Pronóstico , Proteínas Recombinantes/uso terapéutico , Factores de Tiempo
15.
Neurology ; 55(7): 952-9, 2000 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-11061250

RESUMEN

BACKGROUND: Physicians are often asked to predict outcome after acute stroke. Very little information is available that can reliably predict the likelihood of severe disability or death. OBJECTIVE: To develop a practical method for predicting a poor outcome after acute ischemic stroke. METHODS: Data from the placebo arms of Parts 1 and 2 of the National Institute of Neurological Disorders and Stroke rt-PA [recombinant tissue plasminogen activator] Stroke Trial were used to identify variables that could predict a poor outcome, defined as moderately severe disability, severe disability, or death (Modified Rankin Scale score >3) 3 months after stroke. RESULTS: Baseline variables that predicted poor outcome were the NIH Stroke Scale (NIHSS) >17 plus atrial fibrillation, yielding a positive predictive value (PPV) of 96% (95% CI, 88 to 100%). The best predictor at 24 hours was NIHSS >22, yielding a PPV of 98% (95% CI, 93 to 100%). The best predictor at 7 to 10 days was NIHSS >16, yielding a PPV of 92% (95% CI, 85 to 99%). CONCLUSIONS: Patients with a severe neurologic deficit after acute ischemic stroke, as measured by the NIHSS, have a poor prognosis. During the first week after acute ischemic stroke, it is possible to identify a subset of patients who are highly likely to have a poor outcome. These findings require confirmation in a separate study.


Asunto(s)
Accidente Cerebrovascular/fisiopatología , Anciano , Femenino , Humanos , Masculino , Modelos Neurológicos , Placebos , Valor Predictivo de las Pruebas , Pronóstico , Sensibilidad y Especificidad
16.
Stroke ; 31(10): 2335-41, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11022060

RESUMEN

BACKGROUND AND PURPOSE: We sought to identify the most powerful binary measures of the treatment effect of tissue plasminogen activator (tPA) in the National Institute of Neurological Disorders and Stroke (NINDS) rTPA Stroke Trial. METHODS: Using the Classification and Regression Tree (CART) algorithm, we evaluated binary cut points and combination of binary cut points with the 4 clinical scales and head CT imaging measures in the NINDS tPA Stroke Trial at 4 times after treatment: 2 hours, 24 hours, 7 to 10 days, and 3 months. The first analysis focused on detecting evidence of "early activity" of tPA with the use of outcome measures derived from the 2-hour and 24-hour clinical and radiographic measures. The second analysis focused on longer-term outcome and "efficacy" and used outcome measures derived from 7- to 10-day and 3-month measures. After identifying the cut points with the ability to classify patients into the tPA and placebo groups using part I data from the trial, we then used data from part II of the trial to validate the results. RESULTS: Of the 5 most powerful outcome measures for early activity of tPA, 4 involved the National Institutes of Health Stroke Scale (NIHSS) score at 24 hours or changes in the NIHSS score from baseline to 24 hours. The best overall single outcome measure was an NIHSS score

Asunto(s)
Algoritmos , Ensayos Clínicos como Asunto/métodos , Modelos Estadísticos , Accidente Cerebrovascular/tratamiento farmacológico , Activador de Tejido Plasminógeno/uso terapéutico , Biomarcadores , Interpretación Estadística de Datos , Humanos , Oportunidad Relativa , Valor Predictivo de las Pruebas , Tamaño de la Muestra , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Accidente Cerebrovascular/clasificación , Accidente Cerebrovascular/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
17.
Health Educ Behav ; 27(1): 112-25, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10709796

RESUMEN

This report, based on 1,795 participants in the Next Step Trial, examines how a dietary intervention program affected mediating factors for dietary change. The model tested whether intervention increased predisposing (skills, knowledge, and beliefs) and enabling (social support and norms) factors for change and advanced participants into action and maintenance stages of change. The intervention significantly increased both predisposing factors for dietary change and the likelihood of moving into or remaining in action and maintenance stages of change. Changes in predisposing and enabling factors and stage of change at follow-up (regardless of stage at baseline) were associated with significant dietary change. Changes in mediating variables explained between 34% and 55% of the effects of the dietary intervention. These results support the value of measuring mediating factors as part of dietary intervention evaluations and suggest that interventions that target norms and eating environments in addition to skills and knowledge may further increase intervention effectiveness.


Asunto(s)
Conducta Alimentaria/psicología , Conductas Relacionadas con la Salud , Educación en Salud/organización & administración , Conocimientos, Actitudes y Práctica en Salud , Neoplasias/prevención & control , Ciencias de la Nutrición/educación , Servicios de Salud del Trabajador/organización & administración , Adulto , Causalidad , Grasas de la Dieta , Fibras de la Dieta , Estudios de Seguimiento , Frutas , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Programas y Proyectos de Salud , Encuestas y Cuestionarios , Verduras
18.
Arthritis Rheum ; 42(9): 1879-88, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10513802

RESUMEN

OBJECTIVE: To evaluate global statistical tests (GSTs) of treatment effectiveness for rheumatoid arthritis (RA) trials measuring multiple outcomes. METHODS: Using outcome measures from American College of Rheumatology (ACR) core set variables available in 3 RA trials, GSTs were calculated using the O'Brien ranking procedure and a procedure for binary data. GSTs take correlations among outcomes into account. Power calculations using 1 trial data set provide comparisons of GSTs and ACR criteria for improvement. RESULTS: Spearman correlations among outcomes ranged from 0.21 to 0.73. Erythrocyte sedimentation rate had the lowest correlation with other outcomes in all 3 trials. Within a trial, joint swelling and joint tenderness or patient and physician assessment had the highest correlations, depending on the trial. Results were consistent with results using the ACR criteria, although the GST was more powerful. CONCLUSION: GSTs are a useful tool for comparing treatment effects across multiple clinically meaningful outcome measures. The GST allows easy inclusion of validated, reliable new measures that are not a part of ACR criteria, such as quality of life, and can be computed with or without selecting a cutoff point defining patient improvement. GSTs should be considered for rheumatic disease treatment trials.


Asunto(s)
Artritis Reumatoide/terapia , Sedimentación Sanguínea , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Evaluación de Resultado en la Atención de Salud , Encuestas y Cuestionarios , Resultado del Tratamiento
19.
Stroke ; 30(8): 1528-33, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10436095

RESUMEN

BACKGROUND AND PURPOSE: Ischemic changes identified on CT scans performed in the first few hours after stroke onset, which are thought to possibly represent early cytotoxic edema and development of irreversible injury, may have important implications for subsequent treatment. However, insecurity and conflicting data exist over the ability of clinicians to correctly recognize and interpret these changes. We performed a detailed review of selected baseline CT scans from the NINDS rt-PA Stroke Trial to test agreement among experienced stroke specialists and other physicians on the presence of early CT ischemic changes. METHODS: Seventy baseline CT scans from the NINDS Stroke Trial were read and classified for the presence or absence of various early findings of ischemia by 16 individuals, including NINDS trial investigators, other neurologists, other emergency medicine physicians, and radiology or stroke fellows. CT scans included normal scans and scans from patients who later developed symptomatic intracranial hemorrhage, as well as scans on which the NINDS rt-PA Stroke Trial neuroradiologist identified clear-cut early CT changes. For each CT finding, kappa-statistics were used to assess the proportion of agreement beyond chance. RESULTS: kappa-Values (95% confidence interval [CI]) ranged from 0.20 (-0.20, 0.61) (fair agreement) to 0.41 (0.37, 0.45) (moderate agreement) among the 16 viewers, and the kappa-value was only 0.39 (0.29, 0.49) (fair) in answer to the question "do early CT changes involve more than one third of the MCA [middle cerebral artery] territory?" There was substantial variability within each specialty group and between groups. kappa-Values were only fair to moderate even among physicians experienced in selecting and treating acute stroke patients with rtPA. Observed agreement ranged from 68% to 85%. Physicians agreed on the finding of early CT changes involving >33% of the MCA territory 77% of the time, although the kappa-value of 0.39 suggested only moderate agreement beyond chance. CONCLUSIONS: There is considerable lack of agreement, even among experienced clinicians, in recognizing and quantifying early CT changes. Improved methods of recognizing and quantifying early ischemic brain damage are needed.


Asunto(s)
Trastornos Cerebrovasculares/diagnóstico por imagen , Fibrinolíticos/uso terapéutico , Activador de Tejido Plasminógeno/uso terapéutico , Tomografía Computarizada por Rayos X , Trastornos Cerebrovasculares/tratamiento farmacológico , Intervalos de Confianza , Método Doble Ciego , Fibrinolíticos/administración & dosificación , Humanos , Inyecciones Intravenosas , Variaciones Dependientes del Observador , Proteínas Recombinantes , Reproducibilidad de los Resultados , Activador de Tejido Plasminógeno/administración & dosificación , Resultado del Tratamiento
20.
J Adv Nurs ; 30(2): 425-30, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10457245

RESUMEN

Nurses' perceptions in caring for persons with diabetes have been little studied. To address this gap in the literature, a sample of nurses from a large Mid-western health care system were surveyed on nurses' perceptions of: (i) problems encountered in the care of patients with diabetes; (ii) problems encountered by patients and/or family member(s) in diabetes management; and (iii) nurses' suggested solutions. A randomly selected list of 200 registered nurses obtained from the health system's Department of Human Resources included inpatient, outpatient, emergency department, medical centre and home health care nurses. The sample was stratified to include 25% inpatient and 75% outpatient nurses. Of the 200 surveys mailed, 136 were returned (68% response rate). Twenty-four per cent of the 136 nurses reported they did not provide care for patients with diabetes. Of 103 nurses providing care to patients with diabetes, 98% were female, 91% were Caucasian, 76% were between the ages of 30 and 49 years, 57% worked in outpatient settings, 35% worked in primary care, and 42% had a bachelor's degree or higher. Of those with practice guidelines, 84% found the practice guidelines helpful. These nurses also perceived that they, as nurses, needed more education to improve their care of diabetes patients; few nurses believed it was within the scope of their practice to change treatment regimens. The perception of most nurse respondents was that acceptance of diabetes, knowledge deficits and non-compliance were primary patient problems in the management of diabetes. Nurses' perceptions of solutions to the problems centred on education of nurses and patients, and reinforcement of the importance of follow-up care.


Asunto(s)
Diabetes Mellitus/enfermería , Conductas Relacionadas con la Salud , Adulto , Continuidad de la Atención al Paciente , Estudios Transversales , Diabetes Mellitus/psicología , Educación en Enfermería , Femenino , Humanos , Masculino , Persona de Mediana Edad , Medio Oeste de Estados Unidos , Cooperación del Paciente
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