Heterogeneity of the definition of elderly age in current orthopaedic research

Sabharwal et al. SpringerPlus (2015) 4:516 DOI 10.1186/s40064-015-1307-x Open Access RESEARCH Heterogeneity of the definition of elderly age in current orthopaedic research Sanjeeve Sabharwal1*, Helen Wilson2, Peter Reilly1 and Chinmay M. Gupte1 Abstract Medical research often defines a person as elderly when they are 65 years of age or above, however defining elderly age by chronology alone has its limitations. Moreover, potential variability in definitions of elderly age can make interpretation of the collective body of evidence within a particular field of research confusing. Our research goals were to (1) evaluate published orthopaedic research and determine whether there is variability in proposed definitions of an elderly person, and (2) to determine whether variability exists within the important research sub-group of hip fractures. A defined search protocol was used within PubMed, EMBASE and the Cochrane Library that identified orthopaedic research articles published in 2012 that stated within their objective, intent to examine an intervention in an elderly population. 80 studies that included 271,470 patients were identified and subject to analysis. Four (5 %) studies failed to define their elderly population. The remaining 76 (95 %) studies all defined elderly age by chronology alone. Definitions of an elderly person ranged from 50 to 80 years and above. The most commonly used age to define an elderly person was 65, however this accounted for only 38 (47.5 %) of studies. Orthopedic research appears to favor defining elderly age by chronology alone, and there is considerable heterogeneity amongst these definitions. This may confuse interpretation of the evidence base in areas of orthopaedic research that focus on elderly patients. The findings of this study underline the importance of future research in orthopaedics adopting validated frailty index measures so that population descriptions in older patients are more uniform and clinically relevant. Keywords: Orthopaedics, Elderly age, Methodology, Frailty Background The World Aging Report published by United Nations in 2013 stated that population aging is unprecedented, enduring and has profound global socio-economic implications (United Nations 2013, Department of Social Affairs, Population). The impact of an older population demographic on healthcare spending can be seen in the United Kingdom’s National Health Service (NHS), where between 2007 and 2008, the average value for NHS services for retired households was £5200 compared to £2800 for non-retired households (Cracknell 2010). In the past, archaic medical beliefs often meant that healthcare professionals held negative attitudes towards caring for elderly patients, however in the twenty first century *Correspondence: 1 Department of Trauma and Orthopaedics, St Mary’s Hospital, Ground Floor, Salton House, South Wharf Road, London W2 1NY, UK Full list of author information is available at the end of the article ageist attitudes are increasingly challenged (Lovell 2006), and there is growing awareness of the need for clinical research and treatment focused on the elderly population (Hempenius et al. 2013). Persisting deficiencies in the care received by elderly patients underline the need for an improving standard of care (Wilkinson 2010). Research focus on treatment interventions in the elderly may relate to differences in clinical outcome as well healthcare expenditure compared to a younger population (Hamel et al. 2005; Yang et al. 2003). Although mortality rates inevitably increase with advancing age (Yang et al. 2003), clinical research has delivered improved clinical outcomes for these patients across a wide range of medical sub-specialties (Nishihata et al. 2013; Partridge et al. 2014). In orthopaedic surgery, focus on an ageing population is especially relevant owing to the association of advanced age with chronic musculoskeletal conditions, such as osteoarthritis, as well as an increased incidence of fragility fractures © 2015 Sabharwal et al. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Sabharwal et al. SpringerPlus (2015) 4:516 Page 2 of 7 (Woolf and Pfleger 2003). Furthermore, an evolving understanding of how age related loss of muscle mass and function, or sarcopenia, correlates with conditions such as osteoporosis draws attention to the importance of physiological measures of ageing in musculoskeletal medicine (Matthews et al. 2011). Although many countries consider a person to be elderly when they have reached 65 years of age, this view is often disputed because of improving life expectancy, quality of life and level of function within an aged population (Sanderson and Scherbov 2008). Some organisations suggest using the age at which entitlement to state pensions commences, however definitions of an elderly population are multidimensional and often accommodate factors such as chronology, change in social role and change of capabilities (United Nations 2012). The complexity of defining elderly age means that examining the treatment benefits in an aged population has the potential to be challenging to clinicians practicing evidence based medicine. The key issue is whether the definition of an elderly person is uniform when examining specific areas of clinical practice, or whether it is variable, and hence produces uncertainty in interpreting the available body of evidence. The primary objective of this survey study was to evaluate published orthopaedic research and determine what the proposed definitions of an elderly person were, and whether there was variability in the proposed definitions. The secondary objective of this study was to perform sub-group analysis within the field of hip fracture research. This area of orthopaedics deals primarily with older patients with high mortality rates, and therefore a well-defined population is key to clinicians applying the findings of research effectively and appropriately to their practice. Inclusion and exclusion criteria Methods Results There were 80 studies identified using the search strategy that met the eligibility criteria and were subject to analysis in this study. A total of 271,470 patients were included in the selected orthopaedic research. A total of 76 (95 %) of studies defined elderly age in relation to chronological age alone. There were 4 (5 %) studies that stated within their objectives an intention to examine an intervention within an elderly population, however failed to explain what their definition of an elderly person was in the methodology. Demographic description of the research in relation to region of development, ortho (...truncated)