title: [Developing a predictive model for the caregiver strain index].
abstract: BACKGROUND
  Patient homecare with multiple morbidities is an increasingly common occurrence. The caregiver strain index is tool in the form of questionnaire that is designed to measure the perceived burden of those who care for their families. The aim of this study is to construct a diagnostic nomogram of informal caregiver burden using data from a predictive model.
  
  
  METHODS
  The model was drawn up using binary logistic regression and the questionnaire items as dichotomous factors. The dependent variable was the final score obtained with the questionnaire but categorised in accordance with that in the literature. Scores between 0 and 6 were labelled as "no" (no caregiver stress) and at or greater than 7 as "yes". The version 3.1.1R statistical software was used. To construct confidence intervals for the ROC curve 2000 boot strap replicates were used.
  
  
  RESULTS
  A sample of 67 caregivers was obtained. A diagnosing nomogram was made up with its calibration graph (Brier scaled = 0.686, Nagelkerke R2=0.791), and the corresponding ROC curve (area under the curve=0.962).
  
  
  RESULTS
  The predictive model generated using binary logistic regression and the nomogram contain four items (1, 4, 5 and 9) of the questionnaire. R plotting functions allow a very good solution for validating a model like this. The area under the ROC curve (0.96; 95% CI: 0.994-0.941) achieves a high discriminative value. Calibration also shows high goodness of fit values, suggesting that it may be clinically useful in community nursing and geriatric establishments.
authors: Unidad de Gestión Clínica Polígono Sur-Las Letanías, Distrito Sanitario de Atención Primaria, Sevilla, España.
authors: Margarita
authors: M
authors: Álvarez-Tello
authors: Departamento de Enfermería, Facultad de Enfermería, Fisioterapia y Podología, Universidad de Sevilla, Sevilla, España.
authors: Rosa
authors: R
authors: Casado-Mejía
authors: Unidad de Metodología y Evaluación de la Investigación, Fundación Pública Andaluza para la Gestión de la Investigación en Salud de Sevilla (FISEVI), Hospital Universitario Virgen del Rocío, Sevilla, España.
authors: Juan Manuel
authors: JM
authors: Praena-Fernández
authors: Centro de Salud Esperanza Macarena, Unidad de Investigación Distrito Sanitario de Atención Primaria, Sevilla, España; CIBER de la Fisiopatología de la Obesidad y de la Nutrición, Instituto de Salud Carlos III, Madrid, España. Electronic address: 106mayorque104@gmail.com.
authors: Manuel
authors: M
authors: Ortega-Calvo
mesh_terms: D017028:Caregivers; D017281:Cost of Illness; D005192:Family Health; D005260:Female; D005544:Forecasting; D006801:Humans; D008297:Male; D049451:Nomograms; D013315:Stress, Psychological / Q000175:diagnosis*
keywords: Atención primaria de salud; Caregivers; Cuidador; Enfermería de atención primaria; Logistic models; Modelos logísticos; Primary care nursing; Primary health care