Prospects for the future and implications for future studies

If the observed trends in this study continue, the number of fall-induced injuries of older adults will substantially increase during the coming decades. This is even the case with the declining incidence of fall-induced injuries because our older population at risk is expanding rapidly in the near future. The problem is especially alarming in TBIs and cervical spine injuries since the incidence of these injuries increased during the entire study period without signs of levelling off. The only exception might be hip fractures: if the declining fracture incidence continues, the annual number of these injuries might even slightly decrease in the coming decades.

Thus, it is the combination of high injury incidence and sharply increasing population at risk that makes the fall injury problem so severe in our older population. The only way to limit the number of these injuries is to decline its incidence further by effectively preventing falls and subsequent injuries.

In addition to the increasing numerical burden of these injuries, treatment of the patients may become more demanding in the future. First, the average age of the patients with a fall-induced injury increased between 1970 and 2012. Older adults with TBI have been reported to have more in-hospital procedures (such as imaging and surgery) and more likely to require continued medical care than their younger counterparts (Dams-O'Connor et al. 2013). Second, the increasing number of multiple pre-existing medical comorbidities and polypharmacy among older adults makes TBI and other fall injuries more difficult to diagnose and treat. This is likely to increase the risk for secondary complications (Dams-O'Connor et al.

2013). It has also been suggested that the current tendency to support older people to remain in their own homes longer could result in exposing them to a greater risk of sustaining a fall-related injury (Watson and Mitchell 2011).

Many of fall injuries could be prevented. The US Public Health Service has estimated that two-thirds of deaths due to falls are potentially preventable (Rubenstein 2006). It has also been estimated that one third of hip fractures could be prevented with exercise (Sievänen et al. 2014). As we now have evidence-based information about effective fall prevention programs, they need larger implementation (Karinkanta et al. 2010). The challenge is how to assure the full and effective use of the programs in practice (Fixsen et al. 2011). In Finland, a recent publication of The Ministry of Social Affairs and Health stated that the national target is to reduce the number of severe and fatal home and leisure accidents by 25% by the year 2025 (The Ministry of Social Affairs and Health 2013). It was stated further that the need and possibilities for national-level TBI prevention will be clarified (The Ministry of Social Affairs and Health 2013).

Related to this, a recent video analysis of head impacts during authentic falls of older persons suggested that backward rotation of the body during the descent phase of the fall could protect the head, but hand impact as protective response appeared ineffective (Schonnop et al. 2013). Thus, improving upper-limb strength and teaching falling techniques were suggested to reduce fall-related head impacts in older adults (Schonnop et al. 2013). Since there is a gender difference in the profile of fall-induced injuries, a question has been raised if strategies for injury prevention are more difficult to implement to men than women (Jamieson and Roberts-Thomson 2007).

Recurring falls and secondary hip fractures are common in the elderly population (Lönnroos et al. 2007). Because the causes and risk factors of the index fall remain too often uninvestigated, the patient is likely to stay at high risk for future falls and injuries. This calls for effective implementation of the secondary

strategies of fall prevention in Finland and elsewhere (Salter et al. 2006; Salonoja et al. 2010).

Further studies are needed to confirm the observations of this thesis and elaborate the reasons for the changes in the profile of fall-induced injuries and differences between genders in fall-induced deaths. Complementary detailed investigation of deaths certificates would be of interest. This would reveal more information on the circumstances of fall-induced deaths, and the specific injury types and details of the fatal falls. The gender differences in the specific injuries the deceased received in the fall accident would be valuable information.

For now, the Finnish OCDS are very reliable, but challenge in the future is to maintain the high medical and medico-legal autopsy rates and thus the quality in detecting the causes of death. Autopsies are of great importance since there is a 10% probability that medical autopsy will change the perception of the cause of death among hospitalized patients (Lindsberg and Karjalainen-Lindsberg 2003).

Autopsies are also important for educational purposes.

The alarming rise in TBI of older adults is worthy of further research: a more detailed analysis of hospitalized patients, diagnoses confirmed with CT or MRI imaging, and sub-mechanisms of falls would be of interest. More detailed information on patient characteristics (such as comorbidities, medications, alcohol consumption, living arrangements, length of hospitalization, and treatment) might suggest reasons for the increase in incidence. In addition, it would be useful to identify the mechanisms and risk factors of fall-induced cervical spine injuries of our elderly adults and have more precise information on the treatment practices and outcomes of these injuries.