The distinguishing features of age are both physical and mental.  The signs of aging are so different from the signs of middle age that jurist Richard Posner suggests that an individual moving into old age can be considered different “time-sharing” people of the same identity. :86–7 Unlike previous examples, which showed limitations for the use of therapy in the elderly, one statement limited the use of therapy only to “older” patients (preferably younger patients). Subgroup analysis to compare age definitions of hip fractures and non-hip fracture studies Although no significant differences in the range of reported definitions of an older adult were observed when examining the different research groups (region of development, orthopaedic subspecialty and level of evidence), some populations within these groups were very small, so there is a risk of type II error in our results. Clinical practice guidelines are important tools, but they are often criticized for being insensitive to needs and/or limited applicability to the elderly patient population.51 The results of this study confirm this, as the guidelines reviewed did not contain a complete or practical definition of the term “elderly” either qualitatively or quantitatively. The age-based historical definitions of “senior,” as presented in three guidelines, do not provide a snapshot of a patient`s actual health status and unique needs. As a result, these recommendations have limited capacity to assist health professionals in making decisions. A patient`s unique characteristics, such as impaired drug handling, physical/functional and cognitive functions, level of comorbidity, polypharmacy, social status and quality of life, should be considered in clinical guidelines. Current guidelines refer only to these issues superficially, without adequate definition or support, and some continue to use relatively arbitrary definitions of ageing based on chronological age. 80 studies with the search strategy were identified that met the eligibility criteria and were analysed in this study. A total of 271,470 patients were included in the selected orthopaedic research. A total of 76 (95%) of the studies defined age in relation to chronological age only.
There were 4 studies (5%) that, as part of their objectives, indicated the intention to investigate an intervention in an elderly population, but did not explain what their definition of an older person was in the methodology. The demographic description of the research in terms of development region, orthopaedic subspecialty and level of evidence is presented in Table 1. The chronological definitions of an older person are presented in Fig. 2. The most commonly used age to define an older person was 65 years and this was found in 38 (47.5%) of the studies. Medical research often defines a person as older if they are 65 or older, but the definition of old age by chronology alone has its limitations. In addition, the potential variability in definitions of old age can confuse the interpretation of collective evidence in a particular area of research. Our research objectives were (1) to assess published orthopaedic research and determine whether there is variability in the proposed definitions of an older person, and (2) to determine whether there is variability within the important research subset of hip fractures. A defined research protocol was used within PubMed, EMBASE and The Cochrane Library, which identified orthopaedic research articles published in 2012 to investigate an intervention in an older population. 80 studies involving 271,470 patients were identified and analysed. Four (5%) studies were unable to define their older population.
The remaining 76 (95%) all look at old age solely on the basis of chronology. Definitions of a senior ranged from 50 to 80 years of age and older. The most common age used to define an elderly person was 65, but this accounted for only 38 (47.5%) of studies. Orthopaedic research seems to favour the definition of old age by chronology alone, and there is considerable heterogeneity between these definitions. This can blur the interpretation of the evidence base in areas of orthopaedic research that focus on elderly patients. The results of this study underscore the importance of future orthopaedic research using validated measures of frailty index to make population descriptions more consistent and clinically relevant in elderly patients. The statements in only two guidelines implied or explicitly stated that there was a limited evidence base for the use of drug therapy in older adults and therefore did not provide practical advice to support clinical decision-making. The main objective of this survey study was to evaluate published orthopaedic research and determine what definitions were proposed by an older adult and whether there was variability in the proposed definitions. The secondary objective of this study was to conduct subgroup analyses in the field of hip fracture research. This area of orthopedics primarily treats elderly patients with high mortality rates, and therefore a well-defined population is essential for clinicians to apply research findings effectively and appropriately in their practice. Every person – in every country in the world – should have the opportunity to live a long and healthy life. Nevertheless, the environment in which we live can be beneficial to health or harmful to it.
The environment has a major impact on our behaviour and exposure to health risks (e.g. air pollution or violence), our access to services (e.g. health care and social services) and the opportunities that ageing brings. In 2011, the United Nations proposed a human rights convention that would specifically protect older persons.  The increasing number of people living between the ages of 80 and 90 in developed countries has strained public welfare systems and has also led to an increase in the incidence of diseases such as cancer and dementia, rarely seen in pre-modern times. When the U.S. Social Security program was created, people over the age of 65 made up only about 5% of the population, and the average life expectancy of a 65-year-old in 1936 was about 5 years, while in 2011 it could often be between 10 and 20 years. Other problems that may arise from a growing population include the growing demand for health care and a growing demand for various types of services.  Seniors are often defined as those 65 years of age or older (Crews & Zavotka, 2006). In advanced economies, this subgroup is growing rapidly, accounting for nearly 15 per cent of their population (Crews, 2005).
As the population of older citizens increases, the social and economic pressure to care for them increases proportionately (Crews, 2005). Nevertheless, a large proportion of people over the age of 65 are healthy and live independently (Crews and Zavotka, 2006). Therefore, the definition of old age by chronology in medical research or economic evaluations of health may have its limitations.