title: The idea of uniform change: is it time to revisit a central tenet of Rose's "Strategy of Preventive Medicine"?
abstract: A mean-centric view of populations, whereby a change in the mean of a health variable at the population level is assumed to result in uniform change across the distribution, is a core component of Geoffrey Rose's concept of the "population strategy" to disease prevention. This idea also has a critical role in Rose's observation that individuals who are considered abnormal or sick (the rightward tail of the distribution) and those who are considered normal (the center) are very closely related, and that true preventive medicine must focus on shifting the normal or average. In this Perspective, we revisit these core tenets of Rose's concept of preventive medicine after providing an overview of the key concepts that he developed. We examine whether these assumptions apply to population changes in body mass index (BMI) and show that there is considerable evidence of a widening of the BMI distribution in populations over time. We argue that, with respect to BMI, the idea of using statistical measures of a population solely on the basis of means and the assumption that populations are coherent entities that change uniformly over time may not fully capture the true nature of changes in the population. These issues have important implications for how we assess and interpret the health of populations over time with implications for the balance between universal and targeted strategies aimed at improving health.
authors.affiliation: Department of Medicine, University of Toronto, Toronto, Canada.|Li Ka Shing Knowledge Institute and Division of General Internal Medicine, St. Michael's Hospital, Toronto, Canada.|Harvard Center for Population and Development Studies, Cambridge, MA.
authors.forename: Fahad
authors.identifier: 0000-0001-9195-7286
authors.initials: F
authors.lastname: Razak
authors.affiliation: Medical Research Council Integrative Epidemiology Unit and.|School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom; and.
authors.forename: George
authors.identifier: 0000-0002-1407-8314
authors.initials: G
authors.lastname: Davey Smith
authors.affiliation: Harvard Center for Population and Development Studies, Cambridge, MA; svsubram@hsph.harvard.edu.|Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, MA.
authors.forename: S V
authors.initials: SV
authors.lastname: Subramanian
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002149:Energy Intake; D005260:Female; D006293:Health Promotion; D054624:Health Status Disparities; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D011315:Preventive Medicine / Q000592:standards*; D011322:Primary Prevention; D012307:Risk Factors; D012959:Socioeconomic Factors; D055815:Young Adult
keywords: Geoffrey Rose; dispersion; high risk; inter-individual inequality; population strategy; sick populations; uniform change