The impact of attrition on the representativeness of cohort studies of older people

Background: There are well-established risk factors, such as lower education, for attrition of study participants. Consequently, the representativeness of the cohort in a longitudinal study may deteriorate over time. Death is a common form of attrition in cohort studies of older people. The aim of this paper is to examine the effects of death and other forms of attrition on risk factor prevalence in the study cohort and the target population over time

Calculating total health service utilisation and costs from routinely collected electronic health records using the example of patients with irritable bowel syndrome before and after their first gastroenterology appointment

INTRODUCTION: Health economic models are increasingly important in funding decisions but most are based on data, which may therefore not represent the general population. We sought to establish the potential of real-world data available within the Clinical Practice Research Datalink (CPRD) and linked Hospital Episode Statistics (HES) to determine comprehensive healthcare utilisation and costs as input variables for economic modelling. METHODS: A cohort of patients with irritable bowel syndrome (IBS) who first saw a gastroenterologist in 2008 or 2009, and with 3 years of data before and after their appointment, was created in the CPRD. Primary care, outpatient, inpatient, prescription and colonoscopy data were extracted from the linked CPRD and HES. The appropriate cost to the NHS was attached to each event. Total and stratified annual healthcare utilisation rates and costs were calculated before and after the gastroenterology appointment with distribution parameters. Absolute differences were calculated with 95 % confidence intervals. RESULTS: Total annual healthcare costs over 3 years increase by £935 (95 % CI £928–941) following a gastroenterology appointment for IBS. We derived utilisation and cost data with parameter distributions stratified by demographics and time. Women, older patients, smokers and patients with greater comorbidity utilised more healthcare resources, which generated higher costs. CONCLUSIONS: These linked datasets provide comprehensive primary and secondary care data for large numbers of patients, which allows stratification of outcomes. It is possible to derive input parameters appropriate for economic models and their distributions directly from the population of interest

Chinatown 2.0: El difícil florecimiento de una zona comercial de temática étnica

En la pintoresca zona de canales de Ámsterdam, Zeedijk y sus alrededores, los empresarios chinos han estampado su presencia en lo que parece el Chinatown local. Desde principios de los 90´s, los empresarios y sus organizaciones hicieron campaña por el reconocimiento oficial de Zeedijk como un distrito solo étnico y por el apoyo gubernamental a la mejora de “lo chino”. Siguiendo lo que opinan Hackworth y Rekers (2005), argumentamos que este caso desafía la comprensión tradicional de los paisajes comerciales étnicos. En contraste con la ortodoxia actual, nos hemos acercado ante todo al Chinatown de Ámsterdam como un espacio económico temático. Aquí chinos y otros empresarios compiten por una parte del mercado y por el derecho a reivindicar la identidad de la zona. ¿Cuál es el desarrollo histórico de Zeedijk, cómo los empresarios chinos y sus asociaciones impulsaron el Chinatown y negociaron “lo chino” públicamente, y cómo respondieron los actores institucionales gubernamentales y no gubernamentales a esos intentos