Département de Médecine et Santé Communautaires ALCOHOL USE IN COMMUNITY-DWELLING OLDER PERSONS AGED 65 TO 70 YEARS : CROSS-SECTIONAL AND LONGITUDINAL ASSOCIATION WITH FRAILTY , GAIT PERFORMANCE AND HEALTH CARE USE

Background: Frailty is a relatively new geriatric concept referring to an increased vulnerability to stressors. Various definitions have been proposed, as well as a range of multidimensional instruments for its measurement. More recently, a frailty phenotype that predicts a range of adverse outcomes has been described. Understanding frailty is a particular challenge both from a clinical and a public health perspective because it may be a reversible precursor of functional dependence. The Lausanne cohort Lc65+ is a longitudinal study specifically designed to investigate the manifestations of frailty from its first signs in the youngest old, identify medical and psychosocial determinants, and describe its evolution and related outcomes. Methods/Design: The Lc65+ cohort was launched in 2004 with the random selection of 3054 eligible individuals aged 65 to 70 (birth year 1934–1938) in the non-institutionalized population of Lausanne (Switzerland). The baseline data collection was completed among 1422 participants in 2004–2005 through questionnaires, examination and performance tests. It comprised a wide range of medical and psychosocial dimensions, including a life course history of adverse events. Outcomes measures comprise subjective health, limitations in activities of daily living, mobility impairments, development of medical conditions or chronic health problems, falls, institutionalization, health services utilization, and death. Two additional random samples of 65–70 years old subjects will be surveyed in 2009 (birth year 1939–1943) and in 2014 (birth year 1944–1948). Discussion: The Lc65+ study focuses on the sequence "Determinants → Components → Consequences" of frailty. It currently provides information on health in the youngest old and will allow comparisons to be made between the profiles of aging individuals born before, during and at the end of the Second World War. Published: 18 August 2008 BMC Geriatrics 2008, 8:20 doi:10.1186/1471-2318-8-20 Received: 11 July 2008 Accepted: 18 August 2008 This article is available from: http://www.biomedcentral. com/1471-2318/8/20 © 2008 Santos-Eggimann et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. BMC Geriatrics 2008, 8:20 http://www.biomedcentral. com/1471-2318/8/20 Page 2 of 10 (page number not for citation purposes) Background Health and social security systems of industrialized countries are confronted with aging populations and must solve problems related to functional dependence over a wide scale resulting from an epidemic of chronic diseases. This unprecedented situation has prompted researchers to focus their efforts on studying relationships between chronic diseases and the development of disability [1,2], and documenting and forecasting related needs for chronic care. Functional dependency, however, mostly concerns the oldest old population, while demographic trends and population health over the next 30 years will be determined not only by the evolution of longevity, but also by the aging of the large cohort generated by the postWorld War II baby-boom. Health and health care needs of this youngest old population have been less well studied. Baby-boomers will be affected by the consequences of cumulated chronic diseases in two decades from now, and preventing disability in this cohort should be considered a public health priority. A logical approach is to study aging individuals not yet affected by disability. The concept of frailty [3,4] is of particular interest in this regard. A better understanding of the pathway leading from health to frailty and to disability is necessary for preventive intervention. Despite a large volume of recent publications on the subject, and a variety of models, definitions and criteria [5], frailty is still an evolving concept [3,6-8]. There is nevertheless a consensus view that considers frailty as a multidimensional geriatric syndrome with biological, physiological and psychosocial components, and as a state of increasing vulnerability and loss of adaptability to stress [5,9]. Rather than a dichotomous characteristic separating older subjects into two distinct subgroups, it is viewed as a progressive loss of capacity to adapt to complexity and to environmental stressors [10], and as a decline in the ability of an individual to withstand illness without loss of function (functional homeostasis) [11,12]. Campbell and Buchner [13] described frailty as a condition or syndrome which results from a multi-system reduction in reserve capacity to the extent that a number of physiological systems are close to, or past, the threshold of symptomatic clinical failure. The detection and quantification of frailty in epidemiological studies necessitate some operational definition of this concept. The frailty model proposed by Fried et al. is one of the most frequently used and seems of particular interest for research since it integrates a description of a measurable frailty phenotype within a theoretical concept of causation, manifestations and consequences [14,15]. In this model, the clinical syndrome of frailty is influenced by diseases and by declines in physiologic function and reserve, and it results in adverse outcomes that range from falls to death. The Fried et al. phenotype relies on five items: unintentional weight loss or sarcopenia, weakness as measured by grip strength, poor endurance resulting in self-reported exhaustion, slowness as measured by walking speed, and self-reported low physical activity. It was developed in the context of the longitudinal Cardiovascular Health Study and validated in the Women's Health and Aging Studies [16]. At this stage of knowledge, the phenotype described by Fried et al. seems the most concrete as well as the most agreed upon way to detect frailty. Its frequency has been estimated in a few studies [16-21]. However, despite a consensus on its pertinence, several concerns about this phenotype could be raised. First, this phenotype likely neglects some important dimensions of frailty, as it contains mostly physical characteristics, even though the inclusion of self-reported exhaustion, which is frequently associated with depression, already indicates a contribution of mental health to the frailty syndrome [22]. The Fried phenotype will probably evolve to include additional dimensions such as cognitive and psychological characteristics. Second, the clinical applicability of this phenotype has been questioned and simplified versions need to be developed [23]. Third, there is much debate on the role of psychosocial and economic characteristics in the frailty syndrome. Key components of several multidimensional models of frailty, such as economic vulnerability, may act as determinants, as enhancers, or as outcomes of frailty. Finally, despite a growing body of literature, the chronology and temporal relationships between the different determinants of frailty remain largely speculative. Improving our knowledge of frailty is particularly appealing because frailty may expose individuals to an increased risk of a range of adverse outcomes and constitute a reversible precursor of functional loss in old age [24,25]. Falls, injuries, acute illnesses, repeated use of emergency services, hospitalizations, disability, and death have been found to be associated with sub-clinical diseases and frailty [15,26-31]. As a result, frailty also appears to be a powerful indicator of health status and of health care needs of aging populations. From a public health perspective, the early detection and prevention of frailty may influence the progression of disability in aging populations [32]. This, however, requires improvements in our understanding of the "Determinants → Components → Consequences" sequence that characterizes age-related frailty. Rationale and aims of the Lc65+ study The rationale for undertaking the Lc65+ study is the paucity of longitudinal epidemiological data specifically collected to improve our understanding of frailty as 1) a phenomenon resulting from various psychosocial and medical influences, 2) a manifestation of abnormal BMC Geriatrics 2008, 8:20 http://www.biomedcentral. com/1471-2318/8/20 Page 3 of 10 (page number not for citation purposes) decline in old age, and 3) a cause of evolution towards adverse outcomes, particularly functional decline and a high level of health services utilization. The ultimate goal of the Lc65+ study is to open the field toward developing and testing interventions to potentially reverse the frailty pathway. This study will provide essential information to shape individual and community-based preventive interventions, taking into account the opinions of frail older individuals and their caring environment, and recognizing the evolution of health and expectations across population groups born before, during and after the Second World War. The specific aims of the Lc65+ cohort are to investigate: a) the sequence of the physical and mental health manifestations of frailty (phenotype); b) the relationship between subjective health and objective manifestations of frailty (perception); the extent to which frail individuals perceive their entry and progressions in the spiral of frailty is an essential question in public health, particularly for the quantification of frailty as a major indicator of health in aging populations, since survey data often rely essentially on self-reported data. c) the trajectories and transitions between levels of frailty (natural history); d) the environmental, medical and psychosocial determinants or other predictive factors for frailty (risk factors); e) the effect of frailty on the risk of falls, functional impairments or dependency, secondary morbidity, health services utilizati