1. Andersson, L. B., Marcusson, J., & Wressle, E. (2014). Health-related quality of life and activities of daily living in 85-year-olds in Sweden. Health & Social Care in the Community, 22(4), 368–374. https://doi.org/10.1111/hsc.12088.
2. Bilotta, C., Bowling, A., Casè, A., Nicolini, P., Mauri, S., Castelli, M., & Vergani, C. (2010). Dimensions and correlates of quality of life according to frailty status: A cross-sectional study on community-dwelling older adults referred to an outpatient geriatric service in Italy. Health and Quality of Life Outcomes, 8, 56. https://doi.org/10.1186/1477-7525-8-56.
3. Bilotta, C., Bowling, A., Nicolini, P., Case, A., Pina, G., Rossi, S. V., & Vergani, C. (2011). Older people’s quality of life (OPQOL) scores and adverse health outcomes at a one-year follow-up. A prospective cohort study on older outpatients living in the community in Italy. Health and Quality of Life Outcomes, 9, 72.
4. Boggatz, T. (2016). Quality of life in old age—A concept analysis. International Journal of Older People Nursing, 11(1), 55–69. https://doi.org/10.1111/opn.12089.
5. Börsch-Supan, A., & Jürges, H. (2005). The survey of health, and retirement in Europe—Methodology. Mannheim: Mannheim Research Institute for the Economics of Ageing.