Framework for Individualised Physical Exercise Training for Older Adults in an Outpatient Setting

Population projections indicate substantial global population growth and a shift towards an ageing population. Currently, the ratio between working-age and older dependent populations is approximately 4:1 in Europe. However, this is expected to be 2:1 by the year 2050, indicating a severe change in the composition of societies.1,2 As more people live longer, a higher proportion of older adults will also experience living longer with chronic health disorders impairing their physical functioning. This will increase the pressure on the current framework for welfare, as expected healthcare needs will increase accordingly. Roughly 120,000 older adults in Denmark will additionally be in contact with the healthcare system from 2019-2025.3 A considerable proportion is offered physical rehabilitation by law in outpatient settings to achieve habitual or best possible physical ability. Consensus exists among researchers and health professionals about the necessity and beneficial effects of physical exercise training for older adults.4 However, the proportion of older adults commencing regular physical exercise training remains low, accelerating secondary ageing. Consequently, innovative planning of physical exercise training is warranted. Older adults constitute a heterogeneous group with individual exercise preferences, which challenges the more generic approach of offering the same training modalities to all older adults. One of the methods to overcome these challenges and harvest the beneficial effects of physical exercise training is through "individualisation” by targeting improvements in specific health indicators. This PhD thesis presents a framework for individualising physical exercise training in older adults in outpatient settings and aims to:

1) Describe the development of individualised physical exercise training (IPET) based on objective health indicators for older adults in an outpatient setting.
2) Investigate older adults' allocation into training categories derived from the IPET approach for planning training.
3) Investigate the internal consistency and construct validity of the Short Musculoskeletal Function Assessment (SMFA) questionnaire in a heterogeneous sample of older individuals to understand how the SMFA reflects different levels of the International Classification of Functioning, Disability, and Health (ICF).
4) Present a study protocol for a randomised controlled trial (RCT) that investigates whether IPET in combination with protein-enriched yoghurts can improve (both in the short- and long-term) the degree of self-reported dysfunction in older adults referred to municipality-based rehabilitation compared to usual care alone, or in combination with protein-enriched yoghurts.
The outcomes of this PhD thesis were that: 1) An individualised physical exercise training (IPET) intervention was developed using an iterative approach entailing literature searches, discussions with health professionals from an outpatient setting, and practical testing (Paper I). 2) Older adults in outpatient settings showed different needs for physical exercise training, supporting the
implementation of IPET (Paper I). Likewise, the feasibility of health indicators selected to plan IPET is excellent, demonstrating high completion rates in older adults (Paper I). 3) The SMFA demonstrated adequate internal consistency and construct validity to assess self-reported health status in older adults, primarily
considering items covering physical health status (Paper II). Further, the SMFA should not be implemented as a stand-alone tool since it only captures parts of commonly used clinical outcome measures (Paper II). 4) Several older adults have commenced participation in a multi-centre three-armed, single-blinded RCT, testing the effect of IPET intervention in combination with supplementation of protein-enriched yoghurts (Paper III).