We would like to give a special thanks to all participating nursing homes including patients,staff and physicians who made this study possible.BSH would like to thank the G.C.Rieber Foundation and the Norwegian Government for supporting our work at the Centre for Elderly and Nursing Home Medicine,University of Bergen,Norway.Statistician Dagrun Slettebo at the Biostatistics and Data analysis core facility (BIOS),University of Bergen,carried out parts of the work.We would also like to thank Irene Aasmul,Torstein Habiger,and Tony Elvegaard for helping with implementation of the study and data collection.This study was sponsored by the Norwegian Research Council,Oslo,Norway (Sponsor's Protocol Code:222113/H10) and Rebekka Ege Hegermann's Legat,Bergen,Norway (R.E.Hegermann's Endowment).The sponsors had no say in the study concept and design,acquisition of subjects,analysis and interpretation of data and preparation of the manuscript.The authors declare no conflicts of interests.All authors contributed substantially in setting the aims and drafting the manuscript.All authors approved the final version. （BIOS）