RESUMEN
We discuss the computation of randomization tests for clinical trials of two treatments when the primary outcome is based on a regression model. We begin by revisiting the seminal paper of Gail, Tan, and Piantadosi (1988), and then describe a method based on Monte Carlo generation of randomization sequences. The tests based on this Monte Carlo procedure are design based, in that they incorporate the particular randomization procedure used. We discuss permuted block designs, complete randomization, and biased coin designs. We also use a new technique by Plamadeala and Rosenberger (2012) for simple computation of conditional randomization tests. Like Gail, Tan, and Piantadosi, we focus on residuals from generalized linear models and martingale residuals from survival models. Such techniques do not apply to longitudinal data analysis, and we introduce a method for computation of randomization tests based on the predicted rate of change from a generalized linear mixed model when outcomes are longitudinal. We show, by simulation, that these randomization tests preserve the size and power well under model misspecification.
Asunto(s)
Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Algoritmos , Bioestadística , Simulación por Computador , Humanos , Modelos Lineales , Estudios Longitudinales , Modelos Estadísticos , Método de Montecarlo , Distribución Aleatoria , Análisis de Regresión , Estadísticas no Paramétricas , Análisis de SupervivenciaRESUMEN
Family physicians traditionally have played an integral role in delivering babies as a component of the comprehensive care they provide for women. The proportion of family physicians who report providing any maternity care continues to decrease. This trend is particularly concerning because family physicians are the most widely distributed specialty and are essential to health care access in rural areas.
Asunto(s)
Accesibilidad a los Servicios de Salud , Necesidades y Demandas de Servicios de Salud , Servicios de Salud Materna/estadística & datos numéricos , Obstetricia/estadística & datos numéricos , Médicos de Familia/estadística & datos numéricos , Atención a la Salud , Femenino , Humanos , Servicios de Salud Materna/normas , Obstetricia/normas , Salud Rural , Estados UnidosRESUMEN
Despite continued growth of the primary care workforce, profound maldistribution persists among providers available for the care of children. Family physicians (FPs) spend, on average, approximately 10% of their total practice time caring for children; however, given that, among physician specialties, FPs are geographically distributed most evenly across the US population, the self-reported decline in the share of FPs caring for children should be disturbing to policymakers, especially with the looming insurance expansion in 2014.