GPS technology has made it possible to evaluate the performance of outdoor advertising campaigns in an objective manner. Given the GPS trajectories of a sample of test persons over several days, their passages with arbitrary poster campaigns can be calculated. However, inference is complicated by the early dropout of persons. Other than in most demonstrations of spatial data mining algorithms w...

Reports an error in "Meta-analysis of dropout in treatments for posttraumatic stress disorder" by Zac E. Imel, Kevin Laska, Matthew Jakupcak and Tracy L. Simpson (Journal of Consulting and Clinical Psychology, 2013[Jun], Vol 81[3], 394-404). There are two errors in the Results section. Each is described alongside the corrected results. Corrections did not influence interpretation of the results...

In many clinical trials with longitudinal outcome data, a common situation is where some patients withdraw or dropout from the trial before completing the measurement schedule. In most cases reasons for dropout is related to the subsequent outcome, hence missingess is informative or non-ignorable. Failure to take appropriate account of such missing data can lead to biased estimation of treatmen...

AIM This paper aims to assess the dropout rate in different age groups through the example of the large cardiac rehabilitation centre affiliated with the Institute of Sports Medicine, University of Caxias do Sul. MATERIAL AND METHODS A historic cohort study comprising the following groups: Non-Old < 65 (n = 141); Young-Old 65-74 (n = 128); and Middle-Old 75-84 years old (n = 57). The exercise...

BACKGROUND Dropout (DO) is common in the treatment of eating disorders (EDs), but the reasons for this phenomenon remain unclear. This study is an extensive review of the literature regarding DO predictors in EDs. METHODS All papers in PubMed, PsycINFO and Cochrane Library (1980-2009) were considered. Methodological issues and detailed results were analysed for each paper. After selection acc...

One of the Millennium Development Goals is to ensure universal access to primary education by 2015. However, primary school dropout remains a challenge in many developing countries. While official statistics in China report aggregated primary school dropout of only 0.2 %, almost no independent, survey-based studies have sought to verify these dropout rates in rural areas. The primary objective ...

In many longitudinal studies, the response process is correlated with observation times and dropout. We propose a joint modeling for analysis of longitudinal data with informative observation times and dropout. We specify a semiparametric linear regression model for the longitudinal process, and accelerated time models for the observation and the dropout processes, while leaving the distributio...

The most outstanding event in the Spanish education system in the past two decades has been the overall improvement of enrolment in all educational levels. However, the primary school dropout rate in Spain is relatively high, and the evidence indicates that being a dropout is a permanent condition. This is the first study on dropouts in Spain, and it uses individual-level data from the Living a...

BACKGROUND Electronic surveys are convenient, cost effective, and increasingly popular tools for collecting information. While the online platform allows researchers to recruit and enroll more participants, there is an increased risk of participant dropout in Web-based research. Often, these dropout trends are simply reported, adjusted for, or ignored altogether. OBJECTIVE To propose a concep...

BACKGROUND High school dropout is of major concern in the western world. Our aims were to estimate the risk of school dropout in adolescents following chronic somatic disease, somatic symptoms, psychological distress, concentration difficulties, insomnia or overweight and to assess to which extent the family contributes to the association between health and school dropout. METHODS A populatio...