“Reporting biases in self-assessed physical and cognitive health status of older Europeans,” by Sonja Spitzer and Daniela Weber (PLoS ONE 14(10): e0223526. doi.org/10.1371/journal.pone.0223526, XML, HTML, and .pdf format, 22p.).
journals.plos.org/plosone/article?id=10.1371/journal.pone.0223526