BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20251105T182605EST-7432X91EBz@132.216.98.100 DTSTAMP:20251105T232605Z DESCRIPTION:Title: Developing a New Rank-Based Quantile Regression Methodol ogy for Monitoring the Prevalence of Osteoporosis.\n\nIn osteoporosis stud ies\, quantiles of the distribution of bone mineral density (BMD) and thei r relationship with risk factors such as age\, family history\, gender\, e tc.\, are important. Low BMD is associated with higher probability of leg and pelvis fractures due to falls and causes significant public health iss ues\, especially in elderly women\, leading to high medical cost\, inabili ty to live independently\, and even risk of death. In this study\, we use a large cohort study in the Canadian province of Manitoba and develop a ne w methodology to monitor the prevalence of osteoporosis using more efficie nt and cost-efficient follow-ups. We propose to use expert knowledge and/o r suitable measurements from the base-line study to design follow-up sampl e selection procedures that are based on ranks. We obtain the ranks by com paring a patient with a small number of other patients\, randomly selected from the study cohort. We propose a new check-function to incorporate the rank information associated with selected (nominated) samples in the esti mation process. Strategies are given to design proper follow-up studies fo r a given population quantile. Numerical studies show that rank-based quan tile regression models are more efficient than those based on simple rando m sampling (SRS) for analyzing upper/lower tail quantiles of the distribut ion of BMD. Among other results\, we observe that in some cases\, our prop osed method requires about one‐tenth of the sample used in SRS to estimate the lower/upper tail conditional quantiles with comparable mean squared e rrors. This is a dramatic reduction in time and cost compared with the usu al approach and is very efficient to design better follow-ups in large coh ort studies.\n DTSTART:20181120T203000Z DTEND:20181120T213000Z LOCATION:Room 24\, Purvis Hall\, CA\, QC\, Montreal\, H3A 1A2\, 1020 avenue des Pins Ouest SUMMARY:Prof. Mohammad Jafari Jozani (University of Manitoba) - (SPECIAL SE MINAR) URL:/mathstat/channels/event/prof-mohammad-jafari-joza ni-university-manitoba-special-seminar-291799 END:VEVENT END:VCALENDAR