Conceptual Framework for an Episode of Rehabilitative Care After Surgical Repair of Hip Fracture

Abstract

Researchers face a challenge when evaluating the effectiveness of rehabilitation after a surgical procedure for hip fracture. Reported outcomes of rehabilitation will vary depending on the end point of the episode of care. Evaluation at an inappropriate end point might suggest a lack of effectiveness leading to the underuse of rehabilitation that could improve outcomes. The purpose of this article is to describe a conceptual framework for a continuum-care episode of rehabilitation after a surgical procedure for hip fracture. Definitions are proposed for the index event, end point, and service scope of the episode. Challenges in defining the episode of care and operationalizing the episode, and next steps for researchers are discussed. The episode described is intended to apply to all patients eligible for entry to rehabilitation after hip fracture and includes most functional recovery end points. This framework will provide a guide for rehabilitation researchers when designing and interpreting evaluations of the effectiveness of rehabilitation after hip fracture. Evaluation of all potential care episodes facilitates transparency in reporting of outcomes, enabling researchers to determine the true effectiveness of rehabilitation after a surgical procedure for hip fracture.

Background

Hip Fracture and Rehabilitation

A projected 4.5 million people will fracture their hip in 2050.¹ The injury has been dubbed the “hip attack” due to its clinical severity and adverse outcomes.² In spite of treatment, 30% of patients die within 1 year.³ Among survivors, 25% to 50% need assistance in walking or never walk again, and 22% transition from independent living to long-term care.^4–6 These adverse outcomes reflect the interplay among characteristics of patients, their injury, and their access to medical care, surgery, and rehabilitation.^7,8

Rehabilitation assists “individuals who experience disability to achieve and maintain optimal functioning in interaction with their environment.”⁹ Patients describe access to and delivery of rehabilitation as key to their ability to recover after hip fracture.^10–14 However, the most effective rehabilitation remains unclear.^15–22 This is evidenced by limited National Institute for Health and Care Excellence (NICE) guidance,²³ the absence of recent Cochrane systematic reviews, the conclusion of insufficient evidence to recommend practice change from earlier Cochrane reviews,^19–22 and the need for national audit of rehabilitation after hip fracture.²⁴ NICE and the authors of the Cochrane systematic reviews recommended research questions and priority areas for future research on rehabilitation after hip fracture (Tab. 1).

Table 1.

Research Questions and Priority Areas for Future Research on Rehabilitation After Hip Fracture^a

Source	Research Question/Priority Area
NICE 2017	What is the clinical effectiveness and cost-effectiveness of additional intensive physical therapy and/or occupational therapy (eg, progressive resistance training) after hip fracture?
NICE 2017	Do patients who live permanently in a care/nursing home and are admitted to hospital with a fractured hip have equal access to multidisciplinary rehabilitation as patients admitted from their own homes?
Smith et al (2015)22; Handoll et al (2011)20	Identify the optimal model of rehabilitation after hip fracture to improve outcomes for patients with dementia
Handoll et al (2011)20	Identify the optimal method to enhance long-term mobility after hip fracture
Handoll et al (2009)21; Handoll et al (2011)20	Determine whether differing responses to rehabilitation occur among different subgroups of patients with hip fracture
Crotty et al (2010)19	Identify the optimal timing, duration, setting, and administrating discipline(s) of rehabilitation after hip fracture across care settings
Handoll et al (2009)21	Determine the effectiveness and cost-effectiveness of multidisciplinary rehabilitation overall, rather than evaluate its component parts

^aRecommended by the National Institute for Health and Care Excellence and Cochrane Systematic Review authors.

Episode of Care

There is currently no framework that specifies the appropriate start, duration, and end point of rehabilitation after hip fracture. Therefore, rehabilitation researchers face a challenge when designing and interpreting evaluations of the effectiveness of rehabilitation after surgical repair of hip fracture. In particular, evaluation at an inappropriate end point could suggest lack of effectiveness leading to the underuse of rehabilitation that could improve outcomes.²⁵

Since the early 1960s, researchers have used episodes of care to identify and evaluate a set of services provided to treat a clinical condition.²⁶ This episode of care is often embedded in a broader episode of illness, which can include multiple episodes of care as well as environmental and cultural dimensions of the illness.²⁵ Researchers must define 3 key elements when constructing an episode of care—the index event (start), scope of services, and end point (acute- or continuum-care) (Tab. 2). These 3 elements are customized based on the nature of a health condition under examination and the aim of a research study.²⁵

Table 2.

Definition, Purpose, and Example of Hip Fracture Surgery for Terms Used in the Construction of Episodes of Care

Term	Definition	Purpose	Example: Hip Fracture Surgery
Episode of care	A set of health services provided to treat a clinical condition26	To evaluate health services provided to treat a clinical condition	Acute inpatient health care services following admission for hip fracture surgery
Index event	The event that triggers the start of an episode of care	To define the point from which services are considered by an evaluation	Admission to acute inpatient care
		To identify the population for the evaluation
End point	The event that triggers the end of an episode of care	To define the point after which services are no longer considered by an evaluation	Discharge from acute inpatient care
		To define the point for measuring outcomes of the services
Scope of services	Services considered part of treatment for a clinical condition	The service scope will depend on the needs of individual patients, the exposurea-outcome relationship under evaluation, and available data	Surgical repair of hip fracture completed during acute inpatient stay
Episode of illness	Health care, environmental, and cultural dimensions of a clinical condition. Can include multiple episodes of care25	To describe the trajectory of health, environmental, and cultural dimensions of a clinical condition	Malnutrition
Acute care episode	Tracks patients from acute inpatient admission to discharge	To evaluate services received during acute inpatient stay	Follows patients with hip fracture from acute inpatient admission to acute inpatient discharge
Continuum care episode	Follows patients through an array of health services spanning different levels and intensity of care	To evaluate all services related to the index event	Follows patients with hip fracture from acute inpatient admission to postacute services (eg, until 6-wk outpatient orthopedic follow-up)

^aIntervention or independent variable of interest.

In the current context, the episode of care reflects services related to rehabilitation after a surgical procedure for hip fracture. Yet, there is no framework outlining an appropriate index event, scope of services, and end point of the episode of care. Previous studies of rehabilitation after hip fracture surgery have predominantly adopted an acute-care episode, using discharge from hospital as the episode end point.²¹ This approach restricts outcomes to those that occur in hospital, implying that rehabilitation ends at the point of discharge despite the fact that most patients go on to receive postacute rehabilitation. Further, discharge from acute care is often driven by reducing acute length of hospital stay rather than rehabilitation outcome.²⁷ For these reasons, a continuum-care episode that follows patients through an array of health services, spanning different levels and intensity of care ending with a rule or time window, could be a more appropriate means to capture the true outcome of rehabilitation after a surgical procedure for hip fracture. Continuum-care episodes have been successfully defined for other fields of specialist rehabilitation (eg, cardiac and stroke rehabilitation).^28,29

Therefore, the purpose of this article is to describe a conceptual framework for a continuum-care episode of rehabilitation after hip fracture. We propose definitions for the index event, service scope, and end point of the episode. This framework will provide a guide for researchers when designing and interpreting evaluations of the effectiveness of rehabilitation after hip fracture.

Conceptual Framework

Index Event

A surgical procedure to repair hip fracture is the index event that triggers the start of the care episode (Fig. 1). The selection of surgery as the index event, rather than the fracture itself, excludes between 2% and 6% of patients who do not undergo a surgical procedure after hip fracture.^30,31 In higher-income countries, nonsurgical patients are often nonambulatory or deemed unfit for surgery.^32,33 These patients are often treated palliatively with a focus on quality of life and symptom control, and with different expected outcomes than patients treated surgically.^33,34

Figure 1.

Conceptual framework for rehabilitation continuum-care episode after a surgical procedure for hip fracture. The asterisk (*) indicates readmission for complications, readmission for revision surgery, or the start of a new unrelated episode of care.

End Point

The end point of a rehabilitation continuum-care episode can be triggered by a decision rule, a predetermined time window, or a health care event.²⁵

Decision rule

A logical episode end point is recovery from hip fracture. Recovery can be categorized as from fracture, or functional.³⁵ Recovery from fracture is achieved with fixation and bone healing, or arthroplasty.³⁶ Functional recovery is less clearly defined. Early studies described functional recovery in the context of survival, whereby recovery is considered an alternative to death.³⁷ In this case, recovery from fracture and functional recovery can be used interchangeably for an episode end point. However, ensuring survival to fracture repair is not the only important end point, especially for older adults who value the quality as well as quantity of survival time.³⁸ A similar construct was operationalized for quantifying the burden of disease in the form of the Disability-Adjusted Life Year (DALY)—the sum of years of life lost due to premature death and years of life lost due to disability.³⁹ In the current context, to ensure value from rehabilitation, a functional recovery end point should reflect survival as well as additional dimensions of recovery.

Patients, caregivers, and therapists describe additional dimensions of functional recovery as getting back to normal or back to baseline (Fig. 1).⁴⁰ Therapists often adopt a traditional biomedical model to define return to baseline as the attainment of prefracture physical dimensions of function (gait, balance, activities of daily living) (Fig. 2).^35,41,42 Patients and caregivers adopt a more personal definition, which incorporates the importance to individuals of functioning well physically, instrumentally, cognitively, affectively, and socially (Fig. 2).^35,43,44 This is consistent with the World Health Organization (WHO) approach to healthy aging as having the functional ability to be or to do what the individual has reason to value.⁴⁵ Further, Griffiths et al reported that patients with hip fracture considered functional recovery as “stable mobility (without falls or fear of falls) for valued activities.”⁴⁴

Figure 2.

Defining “back to baseline” from the perspective of the patient and caregiver, and of the therapist.

In current practice, patients often achieve a level of functional recovery better than simply avoiding death but not back to baseline.^4–6 It is not clear whether failure to attain baseline function is due to access and delivery of medical care, surgical care, and rehabilitation, or to characteristics of the patient and their injury.^8,46  Back to baseline might not be a feasible end point where characteristics of the patients and their injuries limit recovery. Indeed, some patients report they do not expect to return to their baseline function.^43,47 In this case rehabilitation can be considered a readaptive process, where the patient adapts his or her set of values to a different, more restricted life situation—their new baseline.⁴⁸

Time window

Completion of a predefined time window could trigger the end of a rehabilitation continuum-care episode. The time window can be defined as completion of a fixed period from the episode index event. This end point is commonly used for evaluation of clinical effectiveness and cost-effectiveness that seeks to compare outcomes across locations that have different discharge practices.²⁵ However, the optimal duration of this period is unclear. In the United States, a new episode of care, the Surgical Hip and Femur Fracture Treatment Model, took effect in January 2018. Under this episode, providers pay for acute inpatient hospital services and postacute services within 90 days.⁴⁹ The 90-day window was selected after cost evaluation indicated “significant services related to the clinical condition that is the focus of the model [hip fracture] occurred during days 31–90.”⁴⁹ However, patterns of recovery vary by dimensions of functional recovery (physical, instrumental, cognitive, affective, and social).³⁵ Recovery of most dimensions shows a lessening of dependence in the first 6–12 months.³⁵ Therefore, the United Kingdom's NICE guideline and the Canadian National Hip Fracture Toolkit support a longer window of 12 months, suggesting that changes in patients’ health state after 12 months are no longer influenced by their hip fracture.^23,50

The time window can also be defined as completion of a fixed period where no improvement in patient function is observed. This end point is sometimes described as reached recovery potential or a plateau in recovery. A US survey noted that more than 50% of physical therapists fail to use standardized outcome measures to inform their care plan.⁵¹ Therefore, for many patients, a plateau end point can be motivated by a therapist's previous experience or by finite health care resources rather than an objective measure of recovery.^43,52–54 However, in nonclinical populations, a performance plateau does not indicate lack of capacity for further gain.⁵⁵ Indeed, an observed plateau can be a temporary cessation in recovery rather than an outcome (eFig. 1, available at https://academic.oup.com/ptj).⁵² This plateau can be overcome by changes in the dose, timing, and composition of rehabilitation that the therapist can offer.⁵² For older adults, a plateau can also reflect functional gains mitigated by declining function associated with other diseases or aging.⁴⁶ Therefore, termination of rehabilitation could lead to accelerated decline for these patients. To minimize harm from potential underuse of rehabilitation, a follow-up reassessment should be scheduled for patients whose episode is ended after failure to overcome an objectively measured plateau despite changes in rehabilitation parameters.^28,29

Alternatively, a time window can be defined by a clean period where no services related to the episode are provided. This period can be defined by local protocol and is more consistent with episodes for chronic conditions whereby patients enter symptom-free periods or periods of remission.²⁵

Health care events

A patient's death will trigger the end of a rehabilitation continuum-care episode. Other health care events that trigger the end of a rehabilitation continuum-care episode include: a transfer to palliative care, readmission to hospital for complications, readmission for revision surgery, or the start of a new unrelated episode of care (Fig. 1).⁵⁶ The assessment, treatment, and management of these health care events is prioritized over rehabilitation after hip fracture. Patients might enter a new continuum-care episode of rehabilitation following their health care event, and the occurrence of a health care event might influence the chance of functional recovery. Indeed, mortality is higher following a second hip fracture.⁵⁶ Therefore, this episode should be defined by the health care event or as a subsequent rehabilitation episode.

Scope of Services

A Cochrane systematic review points to the need to evaluate all components of rehabilitation together rather than separately.²¹ The continuum-care episode of rehabilitation supports the inclusion of all relevant health care services following a surgical procedure for hip fracture, which can be delivered across multiple care settings and by numerous individual providers. The specific scope of services, settings, and providers will depend on the exposure (intervention/independent variable)-outcome relationship under evaluation, available data, and the needs of individual patients as they relate to services.²⁵ Here, we discuss acute and postacute rehabilitation services as well as secondary prevention services delivered during rehabilitation.

Access to acute rehabilitation is more homogeneous than to other components of the rehabilitation care episode in that all patients who undergo a surgical procedure for hip fracture in higher-income countries enter the rehabilitation service by default, irrespective of treating country. Although most patients in high-income countries will receive early mobilization and daily physical therapy during their inpatient stay,^23,57 additional processes and duration of the service can vary. Indeed, the average postoperative acute length of stay was 5 days in the United States compared with 34 days in Japan.⁵⁸ The episode ends during acute rehabilitation only if patients are transferred to palliative care, die in hospital, or recover their baseline function. Most patients’ episode will progress to some form of postacute rehabilitation services (Fig. 3).

Figure 3.

Expanded service scope of conceptual framework for continuum-care episode of rehabilitation after a surgical procedure for hip fracture.

Access to postacute rehabilitation is more heterogeneous in that services and patients selected for entry vary by treating location. Evidence from the United States, England, and Canada suggests there is variation, even within a single health region, in the proportion of patients that are immediately discharged to each postacute service, such as inpatient rehabilitation, outpatient rehabilitation, home-based rehabilitation, or long-term care rehabilitation (Fig. 3).^59–63 Depending on their recovery status, patients can transition between several postacute services as they progress toward the end of their continuum-care episode of rehabilitation. In one Canadian province, Pitzul et al noted 49 distinct postacute patient pathways in the first year postfracture.⁶³ Moreover, these pathways are frequently changing in response to health care reform (eg, restructuring of primary health care services⁶⁴). The variation coupled with changing postacute pathways presents substantial challenges for researchers when attempting to evaluate the effectiveness of postacute rehabilitation after surgical procedures for hip fracture.

Secondary prevention services are incorporated into the continuum-care episode after hip fracture surgery. Processes of secondary prevention can begin within the acute care setting. Postacute services can include fracture liaison services (services who case-find patients with fragility fractures at risk of osteoporosis and second hip fracture),^65–67 falls clinics,^68,69 or the prescription of osteoporosis medication.⁷⁰ A truly comprehensive episode might even include services beyond those delivered by health care providers. For example, it could be ideal to also include social care services that enable increased physical activity in the community.

Discussion

Main Findings

The extent to which outcomes of surgical procedures for hip fracture can be attributed to rehabilitation depends on the scope and end point of the episode. Here, we describe a conceptual framework for constructing a rehabilitation continuum-care episode. We identify the surgical procedure as the index event. We identify several independent potential end points. We suggest episode end points of baseline, no improvement in recovery, 1-year postoperative, or a health care event, whichever comes first (Fig. 1). We suggest service scope should incorporate acute rehabilitation, postacute rehabilitation, and secondary prevention.

Operationalizing the Framework

The index event, service scope, and end points time frame and health care event can be operationalized using existing data sources (Tab. 3). For the additional end points, baseline and no improvement in recovery proxy measures in existing data sources include return to preadmission residence and presence of a long-term follow-up reassessment, respectively (Tab. 3).

Table 3.

Element, Conceptual, and Operational Frameworks for Episode of Rehabilitation After Hip Fracture

Element	Conceptual Framework	Operational Framework
Index event	Surgery for hip fracture	Procedure code for surgery after hip fracture
End point	(i) Baseline	Return to preadmission residence (proxy)
		Need to identify core outcome set inclusive of patient-reported outcome and experience measures
	(ii) Time frame	One year after the procedure date
	(iii) No improvement in recovery	Presence of long-term follow-up reassessment (proxy)
		Need to determine duration of fixed period with no improvement in recovery after the episode is ended
	(iv) Health care event	Code for death, transfer to palliative care, or admission to acute care
Service scope	Acute and postacute rehabilitation, and secondary prevention	Unique patient identifier to link data from the index event acute hospital stay to postacute rehabilitation and secondary prevention services

We describe the multifaceted nature of back to baseline as an episode end point. There is a need to determine how best to measure the physical, instrumental, cognitive, affective, and social dimensions of this end point. There is no consensus on a core outcome set for evaluation of current and/or new interventions after hip fracture. In 2014, Haywood et al recommended 5 core outcome measures—mortality, pain, activities of daily living, mobility, and quality of life—as a minimum for all hip fracture trials.⁷¹ They recommended single-item measures of mortality and mobility (indoor/outdoor walking status), and the EQ-5D as a measure of health-related quality of life.⁷¹ This is less comprehensive than the 12 core outcomes for evaluation of orthogeriatric comanagement for hip fractures—mortality, pain, activities of daily living (Barthel Index), mobility (Parker Mobility Score and the Timed Up and Go), quality of life, length of stay, time to surgery, complications, readmission rate, medication use, place of residence, and costs.⁷² Consensus could lie somewhere between the 2 recommendations to avoid an undue burden of assessment while collecting sufficient data for evaluation. However, there is a need for consensus among rehabilitation researchers with respect to appropriate standardized outcome measures for activities of daily living and mobility. Indeed, a recent randomized feasibility study of rehabilitation after hip fracture reported a ceiling effect for the Barthel Index.⁷³

It is difficult to objectively determine whether patients achieve “back to baseline” because objective baseline measures are rarely available. Moreover, we highlighted that back to baseline might not be a feasible end point for all patients after hip fracture. For those who do not achieve baseline status it is often unclear whether this relates to characteristics of the patient or the clinical effectiveness of rehabilitation. We suggest that patient/caregiver-reported outcome measures, as well as patient/caregiver-reported experience measures, should be incorporated into the evaluation of rehabilitation after surgical procedures for hip fracture.⁷⁴ These measures will help to assess patients along 2 dimensions: (1) satisfaction with outcome and rehabilitation experience; and (2) a more objective view on degree of returning to baseline status. We might cautiously interpret that those who failed to reach baseline status and were dissatisfied with their outcome received ineffective rehabilitation.

The end point no improvement in recovery presents even greater challenges. It is not clear whether it is feasible to define the end of an episode of care for rehabilitation after a fixed period for all patients following hip fracture. There is large heterogeneity in the characteristics of patients and their injuries at baseline. This can lead to differing responses to rehabilitation among different subgroups of patients with hip fracture.^20,21

Next Steps

Since the early 1960s, researchers have used episodes of care to frame analyses of administrative and registry data.²⁶ External bodies standardize collection of these data, which occurs at regular intervals. Researchers have no (or limited) control over which data are collected. Historically, most of these databases have not included data related to rehabilitation exposures and outcomes, limiting their utility for rehabilitation research. Exposures focused predominantly on structures such as composition of the multidisciplinary team and staffing levels, and outcomes included length of stay and discharge destination.^59,75 In 2010, Porter argued that “achieving high value for patients must become the overarching goal of health care delivery.”³⁸ Since this time, national registries have begun to incorporate rehabilitation process exposures such as timing of first mobilization, and outcomes including the Cumulated Ambulation Score and the EQ-5D.^31,76 In 2018, a national audit of physical therapy after hip fracture demonstrated variation in the frequency, type, and duration of rehabilitation, as well as community waiting times and handover, across services in the United Kingdom.²⁴ We anticipate an increase in the availability of rehabilitation process and outcome measures in administrative and registry data in the future.

This article represents a step to prepare researchers for future evaluations of these data. It also provides clinicians with an understanding of the implications of framework selection for interpreting evaluation of these data. If operationalized, the care episode will enable evaluation of the effectiveness of rehabilitation after surgical procedures for hip fracture across the continuum care episode. Finally, the framework will help rehabilitation researchers to better design and implement evaluations to address evidence gaps highlighted by NICE and Cochrane systematic reviews.^19–23

The framework focuses on the end point of a rehabilitation continuum-care episode. It does not include interim end points during this episode, ie, end points for acute care, inpatient rehabilitation, long-term care, or outpatient or home-based rehabilitation. Further, the focus of the episode is functional recovery. However, other outcomes beyond this episode end point, such as immobility-related complications, are also important. Optimizing these outcomes often requires interplay between rehabilitation and environmental interventions.

Conclusion

To conclude, we constructed a continuum-care episode to guide rehabilitation researchers when designing and interpreting evaluations of rehabilitation after hip fracture. The episode described includes all patients eligible for entry to rehabilitation after hip fracture and most functional recovery end points. Evaluation of all potential care episodes facilitates transparency in reporting of outcomes, enabling researchers to determine the true effectiveness of rehabilitation after hip fracture surgery.

Author Contributions and Acknowledgments

Concept/idea/research design: K.J. Sheehan, T.O. Smith, F.C. Martin, A. Johansen, A. Drummond, L. Beaupre, J. Magaziner, I.D. Cameron, I. Price, C. Sackley

Writing: K.J. Sheehan, T.O. Smith, F.C. Martin, A. Johansen, A. Drummond, L. Beaupre, J. Magaziner, J. Whitney, A. Hommel, I.D. Cameron, I. Price, C. Sackley

Project management: K.J. Sheehan

Providing facilities/equipment: C. Sackley

Providing institutional liaisons: K.J. Sheehan, C. Sackley

Clerical/secretarial support: K.J. Sheehan

Consultation (including review of manuscript before submitting): K.J. Sheehan, T.O. Smith, F.C. Martin, A. Johansen, A. Drummond, L. Beaupre, J. Magaziner, J. Whitney, A. Hommel, I.D. Cameron, I. Price, C. Sackley

We thank Professor Christopher McKevitt for his thoughtful review and discussion of our conceptual framework.

Funding

There are no funders to report for this submission.

Disclosures and Presentations

The authors completed the ICJME Form for Disclosure of Potential Conflicts of Interest and reported no conflicts of interest. Toby Smith is supported by funding from the National Institute for Health Research (NIHR) Oxford Health Biomedical Research Centre. The views expressed are those of the author(s) and not necessarily those of the NIHR. Part of this manuscript was orally presented at the Fragility Fracture Network 2018, July 5, 2018, Dublin, Ireland.