Health status and its socio-economic covariates in the older population in Poland - the assumptions and methods of the nationwide, cross-sectional PolSenior2 survey

Population ageing constitutes an increasing medical, social, and economic burden worldwide. Optimal senior policy should be based on well-assessed knowledge on the prevalence and control of age-related diseases, multimorbidity, disabilities, and their social determinants. The objective of this paper is to describe the assumptions, methods, and sampling procedures of the PolSenior2 survey, which was aimed at characterising the health status of old and very-old adults in Poland. The project was conducted in the period 2018-2019 as a cross-sectional survey of a representative sample of people aged 60 years and over. Subjects were selected using three-stage stratified and proportional random sampling in seven equally sized ( = 850) age groups. The study protocol consisted of face-to-face interviews, specific geriatric scales and tests, and anthropometric and blood pressure measurements performed by well-trained nurses at participants homes as well as blood and urine sample laboratory tests. In the Polsenior2 study a group of 5987 subjects underwent the questionnaire parts of the survey, and almost all ( = 5823) agreed to blood or urine sample collection. In recent decades several studies focused on various aspects of elderly health and life conditions had been carried out in Poland and Central and Eastern Europe. However, none of them is so complex and has covered so many issues as PolSenior2, which is the largest study devoted to the health status of older persons in Poland and one of the largest and the most comprehensive in Europe. The results of the study will help to improve health policy targeted at the elderly population in Poland.