“
“In this study, we explored different statistical

approaches to identify the best algorithm to predict EQ-5D utility scores from the NEI-VFQ 25 in patients with age-related macular degeneration (AMD).

Ordinary least squares (OLS), Tobit, and censored least absolute deviation (CLAD) approaches were compared using cross-sectional data (primary dataset, n = 151) at screening from a phase I/II clinical trial in patients with AMD. Three models were specified in this study: full (includes all 12 dimensions of the NEI-VFQ 25), short (includes only the general health dimension and the composite score), and reduced model (using stepwise regression). To evaluate the predictive accuracy of the models, the mean absolute prediction

error (MAPE), mean error, and root means squared error were calculated using in-sample cross-validation (within FK228 the primary dataset) and out-of-sample validation using an independent dataset (n = 393). The model that provided the lowest prediction errors was chosen as the best model.

In-sample cross-validation and out-of-sample validation consistently demonstrated that, compared to other approaches, heteroscedasticity-adjusted OLS produced the lowest MAPE (mean values were 0.1400, selleck chemical 0.1593, respectively) for the full model, while CLAD performed best for the short and reduced models (mean values were 0.1299, 0.1483,

respectively). The normality and homoscedasticity assumptions of both OLS and Tobit were rejected. CLAD, however, can accommodate these particular violations.

The CLAD-short model is recommended for producing the EQ-5D utility scores when only the NEI-VFQ 25 data are available.”
“Objectives: To compare selleck kinase inhibitor epidemiological aspects of young (15 to 49 years old) and older (more than 50 years old) AIDS patients.

Methods: We analyzed 511,633 AIDS cases notified to the Brazilian Ministry of Health in the period of 1980-2008 looking at sex, age ranges, educational level and exposure category. Patients were divided into three age groups: under 15, from 15 to 49 and over 50 years old. Using a comparative approach, we analyzed data with regard to category of exposure, education (expressed in years of schooling), and sex ratio among younger (15-49) and older adults (over 50 years old). Time series data were log-transformed and normalized, and the temporal trend was evaluated.

Results: AIDS incidence is increasing among people over 50 years old in Brazil, with those older than 50 being responsible for 9.64 % of AIDS cases. There was no significant difference between educational level and gender (p = 0.468), but there was a significant difference in exposure category with a lower proportion of injecting drug users amongst the older group.