As outlined in previous chapters, falls are not random events and are associated with multiple risk factors. Fall risk increases in line with the cumulative effect of impairments, making a multi-factorial risk assessment important. A risk assessment should include tests with proven validity and reliability in the relevant setting and population, and linked to appropriate, evidence-based interventions to reduce fall risk. This chapter discusses the relevance and role of fall risk screening and assessment and provides information about validated tools that can be used to measure fall risk in the community, hospitals, and residential aged care.

Chapter 2 outlined how human balance is dependent on the interactions of multiple sensory, motor, and integrative systems. This chapter focuses on age-related changes in key sensory and motor systems involved in balance control, and the associations between impairments in these systems and falls in older people. Specific topics of review include vision, somatosensory and vestibular acuity, and muscle strength, power, and endurance.

The vast amount of literature on the many risk factors for falls and the various intervention options can make interpretation and implementation of the evidence difficult. This chapter overviews the research findings presented in previous chapters to assist the reader to integrate this information and use it to guide their own research and/or practice. It concludes with a brief review of select research issues that need to be addressed in the future.

In this chapter, we have brought together the findings from published studies cited in Chapters 1 to 14 that have addressed fall risk in older people. We have rated the major socio-demographic, physiological, psychological, health, and environmental factors that have been posited as important fall risk factors according to the strength of the published evidence associating that factor with falls, using the following four-level rating system:

In this chapter, we examine the epidemiology of falls in older people. We review the major studies that have described the incidence of falls, the locations where falls occur, and falls sequelae. We also examine the costs required to treat and manage fall-related injuries. Before addressing these issues, however, it is helpful to briefly discuss three important methodological considerations that are relevant to all research studies of falls in older people: how falls are defined, how falls are counted, and what constitutes an older person.

As indicated in Chapter 4, there is good evidence that important visual functions including poor contrast sensitivity, deficient depth perception, and visual field loss increase the risk of falls and fall-related fractures in older people. Some visual impairments are amenable to intervention by surgery or refractive correction, and accordingly several randomized controlled trials have investigated visual interventions as a fall prevention strategy. This chapter provides summaries of these trial findings as well as a complementary study that evaluated the roles of exercise and home safety programmes for older people with visual impairment.

Medications have long been implicated as an iatrogenic cause of falls and fractures, with a number of epidemiological and prospective cohort studies providing support for a link between medications and falls. This chapter will discuss the pharmacology of ageing and the potential physiological mechanisms by which medications may impact on postural stability. Specific drug classes will be highlighted where there is evidence to support a causal link between drug use and falls, and the concept of optimization of prescribing will be explored.

Drugs and ageing

Ageing is not a clearly defined single entity but more the result of a combination of anatomical, biochemical and physiological changes that occur with time. There are alterations to the physiological reserve capacity of the human body that can lead to marked haemodynamic and biochemical compromise even with the mildest of external stressor, e.g. a urinary tract infection.

The ageing process can be associated with an alteration of the body's ability to absorb, metabolize, distribute and excrete drugs (pharmacokinetics) as well as an alteration of the drug effect at its intended target site (pharmacodynamics). Changes with age are seen in body composition, with a reduction in total body water and lean body mass and a relative increase in body fat, which impact on the pharmacokinetics of a given drug. Advancing age can also be associated with an increase in the number of disease processes, which can impact on the body's ability to deal with and respond to drugs.