The effects of habitual functional training on physical functioning in patients after hip fracture: the protocol of the HIPFRAC study

Hip fracture (a fracture of the upper part of the femur), is a worldwide health problem in old age [1, 2]. World-wide, there are approximately 1.7 million hip fractures each year. The highest rates are seen in North America and Europe [1]. In Norway (with 4.7 million inhabitants), about 9000 patients are hospitalized and operated for hip fractures annually. This is among the highest reported hip fracture incidence rates in the world [1‐3], even though the hip fracture rates in Norway have declined during the past 15 years. Nevertheless, the forecasted growing number of older people might cause an increase in the absolute number of fractures. This may lead to a substantial, societal, economic and public health burden [4]. Hip fracture is a serious event; one out of every four patients die within one year. Survivors often report severe pain and loss of physical functioning [3].

In a systematic review it was estimated that 42% of survivors after hip fracture did not return to their pre-fracture level of physical functioning, and 35% became incapable of walking independently after the fracture [5]. Moreover, 50% of those able to walk without a walking device before the fracture became permanently dependent on a walking device, and 50% of survivors had persistent loss of independence in daily activities after the fracture [6, 7]. Long-lasting mobility limitations after hip fracture may lead to prolonged physical disability, increased fall risk and new injuries, and 15% of the patients will become permanently institutionalized [7]. Altogether, these impairments cause considerable suffering. Therefore, strategies for hip fracture rehabilitation to enhance the patients’ recovery of physical functioning and prevent future falls is an urgent health care challenge. With such serious consequences, prevention and treatment of fractures to improve outcomes are crucial.

In Norway, the mean length of hospital stay (LOS) after hip fracture surgery is 5–6 days [8]. An increasingly shorter LOS is in line with international studies showing that aging patients are discharged from the hospital “quicker and sicker” [9, 10]. After discharge, most of the patients in Norway are transferred to short-term stays in nursing homes in primary health care before they are able to return to home.

Functional training, such as walking and transfers, ought to be an important part of the rehabilitation after hip fracture. Nevertheless, research indicates that rehabilitation strategies after hip fracture vary [11‐13]. Experts agree that for better survival rate and for improvement of pain, quality of life and physical functioning, early assisted ambulation should begin while the patients are in hospital [10‐12]. According to a systematic review and two Cochrane reviews [14‐16], there are no set guidelines for best practice training programs after discharge from hospital. To maintain the continuity in rehabilitation, we have an assumption that it is of utmost importance to continue and progress the functional training during the sub-acute phase while the patients are at short-term stays in nursing homes. However, in the nursing homes the resources of physiotherapists and nursing staff seem to be limited, and the nursing staff involved may only to a small extent be focused upon enhancement of the patients’ physical functioning. These assumptions are supported by a study that examined the nurses’ experiences and attitudes towards rehabilitation after hip fractures [17]. The nurses working in the nursing homes, as opposed to the nurses at the hospital, seemed to be less concerned with their role and participation in the patients’ rehabilitation process [17]. Therefore, the possible discontinuity in the rehabilitation efforts during short-term stays may have a negative impact on the patients’ recovery of physical functioning.

Progressive resistance training is found effective in improving physical functioning in the frail elderly [18] and in patients after hip fracture surgery [13, 19]. However, progressive resistance training may be difficult to carry out in the sub-acute phase, partly because of limited recourses, and partly because of the patients’ pain and health condition after surgery. An option may therefore be to continue and progress the functional training started during hospital stay, such as training in walking and further on repetitive sit-to-stands, as part of the daily habitual routine during their short-term stays in the nursing homes [20]. This type of functional training may be motivational and easily recognizable to the patients, and it can also be carried out by the nursing staff with only initial guiding from a physiotherapist. There seems to be lack of knowledge on the effect of additional functional training, incorporated as part of the habitual daily routine during short-term stays, on the patients’ immediate and long term recovery of physical functioning and activity level after hip fracture, compared to usual care alone.

We expect that the intervention described in this protocol will have positive impact on the physical functioning measured by SPPB. The tailored intervention will have potential to promote evidence-based decision-making and empower patients with hip fracture to remain in charge of their own lives. We rely on a systematic approach which corresponds with the guidance on developing and evaluating RCTs [25, 26].

This protocol creates a plan for the investigators to follow. Several issues related to the quality of the study have to be discussed, such as internal and external validity. Internal and external validity relates to whether the results drawn from the study can be trusted and generalized into other contexts. Examples of methodological issues that may influence internal validity in a pragmatic RCT include random allocation, blinding, outcome measures, sample size, drop-outs, statistical methods, and the participants’ adherence to the intervention.

In the present study we are particularly concerned with the outcome measures and the participants’ adherence to the program. A standard set for the measurement of outcomes in patients with hip fracture has been identified [46]. In line with their recommendations we chose to focus on mobility, level of activity, and health-related quality of life measures, and also include some other outcomes, such as pain, fear of falling, number of falls, complications and mortality rate. The intervention is designed to increase the amount of physical activity, which in turn may increase the patients’ physical functioning, such as their ability to move around. Therefore, the primary outcome is physical functioning measured by the SPPB. The SPPB has also been used in prior research to measure effects of interventions on physical functioning. In one study the SPPB was used to examine the effect of comprehensive geriatric care, compared to orthopedic care, in the acute postoperative phase during hospital stay [22]. The SPPB was responsive and able to reveal a difference between the groups even a few days after surgery. Our primary outcome measure is therefore considered to be sensitive to change, responsive and also used in other comparable studies. Our results may therefore be comparable to others, and this will strengthen the validity of the study.

Other outcome measures are also important to apply to give a broad picture of the patients’ health and life situation after hip fracture. The self-reported measurements of activity level and fear of falling will add information on how the patients themselves consider their present activity level and concerns related to future falls. Registration of home care services will give a picture of their ability to manage daily activities. Furthermore, in EQ-5D-5 L the patients’ health-related quality of life, including depression and anxiety, will reveal other important aspects of the recovery of physical functioning after hip fracture. In the present study both performance-based and self-reported outcome measures are used. The different measurements will strengthen the study as they are complementing each other in terms of measuring the functional status in a broad sense [47]. To maximize the test-retest reliability, the assessors are experienced physiotherapists who are properly trained in testing before the inclusion starts.

Gait and balance are important aspects of mobility in everyday life. Moreover, research has shown that functional exercises, which involve shifts between positions with weight-bearing over a changing base of support, are important to improve gait and balance in older people and thereby reduce the fall risk [48, 49]. There is a close association between mortality rate and level of physical functioning, such as mobility [50], which underlines the importance of increased physical activity for the patients with hip fracture. Prior studies have focused on the effect of functional-, strength- and balance exercises several months after hip fracture [13, 16, 29]. To our knowledge, little research has been done on the effect of easily adoptable functional exercises while the patients are at short-term stays in a nursing home after hip fracture. This is a period when the patients have just started their recovery process, but are still vulnerable and in need of support to improve further. In general, exercises are believed to depend on certain intensity with respect to repetitions and exercise duration time to exert their effects. In the meta-analysis of Diong et al [13] they found that the interventions with the best effects were delivered later in the recovery course and with longer duration than the present one. Therefore, it will be interesting to examine whether our functional training intervention, performed 4 times daily for 2 weeks in the early sub-acute phase, is of sufficient length and intensity to exert an effect.

To further take care of the internal validity of the study, an apparent challenge is the adherence to the program. That is whether the patients are capable of adhering to the program and whether the nurses will adhere and keep on initiating the program despite their already heavy workload. We assume that the nurses may get a busier working schedule during the first days of the patients’ short-term stays, but thereafter their workload may be reduced, as the patients get stronger, more mobile and possibly will manage to do functional activities and the functional training by themselves. Even so, adherence to the program is of utmost importance and a challenge that will require motivational efforts from all persons involved.

External validity or generalizability is another important issue to discuss. In this study we include patients who are living at home before the fracture, but are in need of short-term stays after discharge from hospital before they are able to return to home. Those returning directly to home after discharge from hospital are excluded. Also those who are physically or mentally too impaired to manage the training intervention and completing the measurements are excluded from participating. Therefore, the results can only be generalized to a similar group and neither to the healthiest who return directly to home, nor to those that were institutionalized before the fracture.

The present experimental intervention is considered to be a complex intervention. A complex intervention in health care is defined according to the number of interacting components involved [51]. The outline for the arguments in this protocol is organized according to the guidelines of the Medical Research Council (MRC) guidance on how to develop and evaluate complex interventions [51]. According to the new Medical Research Council guidance, certain issues have to be taken into account when reporting such interventions. The different components within the interventions, how the intervention is tailored to the local context, and how the intervention is implemented are all important factors to describe in detail. A description of these elements may broaden the understanding of possible other active components within the intervention and thereby add knowledge to factors that may have contributed to the eventual effect [26]. These issues are taken into consideration and elaborated on when reporting on the effects from the randomized controlled trial, but are not included in this protocol.

Running intervention studies for multi-diseased fracture patients with low functional capacity is challenging with regards to data collection. Nevertheless, it is important to run such studies to be able to develop interventions that may improve wellbeing and minimise functional decline in these patients. Prior studies have often used small samples and a pragmatic choice of interventions [13]. The present study has, due to its large sample size and theoretically based intervention, the potential to generate new knowledge that may improve the design of future activity programs for patients with hip fracture. It is our hope that knowledge drawn from this study may contribute to fill the gap between hospital, primary health care and home in the rehabilitation of the frail elderly after hip fracture.