Search results for "Time trends"
showing 7 items of 37 documents
Time Trends in the Joint Distributions of Income and Age
2001
We propose a method of analyzing time changes of joint income-age densities. Change is decomposed into time invariant components which act on the densities as deformations with time varying strength. The functional form of these components is estimated non parametrically from cross sectional data. The method is applied to analyze British household data on income and age for the years 1968–95. It is learned that for the young and middle aged there is a trend towards increasing inequality, while during the early eighties there seems to occur a reversal in the evolution of the income distribution for the old.
Tendencia temporal y variaciones geográficas de la prevalencia de síntomas de rinitis alérgica en escolares de 6-7 años de ocho áreas españolas, segú…
2005
Antecedentes: Se presenta la fase III del estudio ISAAC (International Study of Asthma and other Allergies in Childhood) en escolares de 6-7 años de ocho áreas españolas para estimar la tendencia temporal y variaciones geográficas de los síntomas de rinitis alérgica. Material y método: Se comparan las prevalencias de síntomas de rinitis alérgica entre la fase I y fase III, efectuadas entre los años 1993-1994 y 2001-2002, mediante un cuestionario estandarizado y validado según metodología ISAAC, cumplimentado por los padres de los escolares. Participaron ocho centros de Asturias, Barcelona, Bilbao, Cartagena, Castellón, Madrid, Pamplona y Valencia. Se empleó la regresión de Poisson en el aná…
Time trends of technology mediated communication with friends among bullied and not bullied children in four Nordic countries between 2001 and 2010
2016
Background Friends are important in childhood and adolescence, especially to bullied children. Technology mediated communication (TMC) could be used both to develop and maintain friendship. The present study examined (1) trends in the use of TMC with friends between 2001 and 2010; (2) possible differences between bullied and not bullied children and (3) differences between children with few close friends and children with several close friends. Methods Data were obtained from three waves of the serial cross-sectional Health Behaviour in School-Aged Children survey conducted in Denmark, Finland, Iceland and Sweden during 2001/2002, 2005/2006 and 2009/2010. The total sample consisted of 65 95…
Evolución temporal de la prevalencia de síntomas de rinitis alérgica en escolares de 13-14 años de 8 áreas españolas entre 1993-1994 y 2001-2002 segú…
2004
Fundamento y objetivo Estimar la evolucion temporal de la prevalencia de sintomas de rinitis alergica y sus variaciones geograficas. Pacientes y metodo Durante 2001-2002 se efectuo la tercera fase del estudio ISAAC, cuyos resultados se compararon con los de la primera fase (1993-1994). Este estudio transversal incluyo a 30.046 escolares de 13-14 anos en 9 centros (Asturias, Barcelona, Bilbao, Cartagena, Castellon, Madrid, Pamplona, Valencia y Valladolid). Se empleo un cuestionario sobre sintomas de rinitis cumplimentado por los escolares en colegios e institutos con una participacion entre el 100 y el 75,8%. Se emplearon modelos de regresion de Poisson para estudiar la evolucion. Resultados…
Trends over Time in Dental Caries status in Urban and Rural Thai Children.
2017
Background Historically, the prevalence of dental caries was higher in urban areas than rural areas of Thailand. This study aim to examine the time trends in caries status in children in Thailand. Material and Methods Linear regression was used to examine trend of dental caries prevalence and mean number of teeth with caries, filled and missing due to caries (dmft/DMFT) in urban and rural, of 3-, 5-6 and 12-year olds from seven Thailand National Oral Health Surveys conducted approximately every 5 years from 1977 to 2012. Results There were declines in the caries prevalence and mean dmft/DMFT in every age group. Significant results were observed in the mean dmft of 3 year-olds and the mean D…
Time trends, sociodemographic and health factors associated with discharge and length of stay of hospitalised patients with sickle cell disease in Gh…
2021
ObjectivePatients with sickle cell disease (SCD) are prone to multiple episodes resulting in frequent hospital visits. We determined the time trends, sociodemographic and health factors associated with length of stay (LoS) for patients with SCD in Ghana.Design, participants, settingWe retrospectively analysed SCD hospitalisation records of 22 680 patients from a nationwide database of the Ghana Health Service from 2012 to 2017.Outcome measuresFactors associated with LoS were estimated using Cox regression, while the cumulative incidence of being discharged alive was estimated with in-hospital death as a competing risk.ResultsPatients admitted for SCD over 6 years constituted 22 680 (0.8%) o…
Changes in food habits amongst Norwegian adolescents in 2016 and 2019 according to gender and socioeconomic status
2021
Background: Monitoring dietary habits is important in order to identify risk groups and as a basis for targeted public health initiatives. Objective: To study trends in consumption of selected foods and beverages from 2016 to 2019 amongst Norwegian adolescents according to gender and parental education. Design: Repeated cross-sectional study amongst 25,996 adolescents, aged 14–17 years old. Consumption of selected food and beverages was measured by an online food frequency questionnaire and general linear models were applied to estimate changes in dietary habits. Results: Between 2016 and 2019, we observed a reduced frequency of consumption of vegetables (from 4.7 to 4.4 times/week), fruit …