Conditions that affect the hip joint range in pathology and can affect people of all ages with surgeries on the joint being one of the most common surgical procedures in the developed world.1 Recent developments in data collection on such interventions have been thrust to the forefront of value-based healthcare and the implementation of patient-reported outcome measurements (PROMs) has escalated in this field in particular.2
The inclusion of PROMs in patient journeys has yielded enhancements in the PROMs themselves, but also in care pathways, patient involvement and has facilitated aggregated results in the form of registries to better inform healthcare professionals on best practices.
With PROMs being well established in the field of orthopedics, we are aiming to contribute to a better understanding of what is currently in use in management of hip pathologies, if there are right choices and how they can be enhanced to fully integrate them into everyday clinical use.
The plague of hip pain
Hip-related pain is a well-recognised complaint amongst the elderly, however it can also affect young and middle-aged active adults. People experiencing hip-related disorders commonly report pain and reduced functional capacity, including difficulties in executing activities of daily living which in turn affects their social and mental well-being.3
Chronic hip joint pain leads to limitations in walking, sitting and standing thus restricting the ability to work or perform everyday tasks.4,5 Osteoarthritis (OA) of the hip can cause groin pain on walking (which may radiate to the knee), stiff and limited movements, a fixed flexion deformity as well as true leg length discrepancy and is regarded as one of the most common causes of total hip arthroplasty (THA).6 OA is one of the 10 most disabling diseases in developed countries. Worldwide estimates are that 10% of men and 18% of women aged over 60 years have symptomatic OA, including moderate and severe forms.7 The benefits of management of OA of the hip include relief of pain and improved function resulting in improvements in quality of life.8
Nevertheless, the problem spans across age groups, children and young adults can experience chronic hip joint pain and dysfunction due to conditions such as developmental hip dysplasia, Perthe’s disease, femoroacetabular impingement (FAI) and slipped upper femoral epiphysis. Patients most commonly report a sharp or achy pain located in the anterior groin or radiating down towards the knee.4, 9, 10 Without adequate management, the causative factors contributing to a patient’s pain may progress to avascular necrosis or OA, which is a leading cause of reduced quality of life and loss of function in elderly people thereby resulting in tremendous costs.11 A challenge exists between rising costs and insufficient quality of care which will only grow due to demographic change.
Whilst corrective hip surgery or total hip replacements can prove revolutionary in alleviating symptoms and enhancing mobility, the adequate management of complications remain challenging. This includes deep infection (usually Staphylococcus epidermidis) complicating 0.5% of hip and knee replacements. Moreover, dislocation or instability of the joint, abductor muscle disruption and periprosthetic failure are among other complications that can arise following surgical intervention in the joint.12 Considering this, effective monitoring of a patient’s pain and function of the joint throughout their health journey (both clinically and self-reported) proves invaluable in optimising treatment and individualising care to ultimately conquer the plague of hip pain.
Total Hip Arthroplasty
Significant advances in surgical treatments have provided effective options to reduce the pain and disability associated with certain musculoskeletal conditions. Joint replacement surgery (hip and knee replacement) is considered the most effective intervention for severe OA, reducing pain and disability and restoring some patients to near normal function.13 In 2007, The Lancet lauded THA as ‘‘the operation of the century’’ and is one of the most frequently performed surgeries in Western Europe with continuous improvements in surgical techniques, devices and care pathways.13, 14
Joint replacement is a recommended intervention if disability is significant and conservative management is ineffective.15, 16 THA (total hip arthroplasty) is a surgical procedure in which the hip joint is replaced by a prosthetic implant.
Why use PROMs?
Patient-reported outcome measures (PROMs) have been broadly recognized as essential when moving to a patient-centered care model. They quantify treatment impact in three major categories: global health-related quality-of-life (HRQoL), pain, and disease-specific disability.
According to the European Medicines Agency (EMA) a Patient-Reported Outcome (PRO) “includes any outcome evaluated directly by the patient himself or herself” and “can be measured by self-report, generally in the form of a questionnaire, or by interview, provided that the interviewer records only the patient’s response”.17 They encompass single dimensional and multidimensional measures of symptoms, health-related quality of life, health status, adherence to treatment and satisfaction with treatment.18
PROMs are the corresponding instruments used to measure PROs and specify questions, survey time points and measuring scales. They are developed and validated according to scientific standards. PROMs encompass different focuses including: generic health-related (e.g. Medical Outcomes Survey Short Form-36), disease/diagnosis speciﬁc (e.g. Western Ontario and McMaster Universities Osteoarthritis Index WOMAC), or regionally speciﬁc, (e.g. Oxford Hip Score (OHS)).19 Usually, a combination of generic and disease-specific PROMs are implied to encompass a holistic understanding of all dimensions that matter to patients with a specific condition.
The true power in a PROM is its ability to distill the specific reason a patient seeks care by isolating their symptoms and monitoring their progress through the whole cycle of care including formerly invisible data points after discharge from hospital. Achieving genuine integration of PROs into routine clinical practice not only remains the most optimal way to derive instructive information from the patient‘s vantage point, but can also tailor their care to achieve enhanced results based on the patient experience. Such an amalgamation of practice has been framed as being positive for patients, clinicians and the health system as a whole, with them being considered as a basic clinical activity in medical guidelines.20
Why are PROMs relevant for hip care?
PROMs are essential to accurately examine and compare the effects of different treatments on disability in those with hip disorders. With improved general health and increased life span, expectations on physical activity and function by the elderly have risen. This has thus raised the standard of outcome after surgical hip interventions.21
The World Health Organization (WHO) has defined patient centeredness as a “fundamental characteristic for the quality of healthcare”.22 Patient centeredness can be improved through the collection and analysis of functional outcomes and quality of life reported by patients. Currently, PROMs are considered a necessary aspect of medical treatment evaluation which is underlined by their increasing and extended use in national and international registries.23 – 25
PROMs are frequently used and recommended to support clinical decision-making, health policies and reimbursement processes.26 For example, as part of the quality measurement and assurance, the indication and outcome quality of patients with hip and knee prostheses must be measured in the publicly commissioned hospitals on behalf of the Health Department of the Canton of Zurich since mid-2019. More specifically, every patient who receives an elective and primary artificial hip or knee joint is questioned by the hospital about their current state of health using a standardised form before and one year after the surgery.27
Utilising PROMs to identify preoperative threshold scores enables surgeons to quantify the severity of patient symptoms and improve indications for surgery. Thus, PROs can provide individual physicians and the orthopedic community with data that, when combined with relevant clinical measures, improve the ability to risk-stratify patients into those more likely to improve following surgery and those who are less likely to benefit.28
A combination of improved surgical techniques and aging populations with expectations for high quality of life have led to a surge in surgical interventions on the hip, especially in Europe and the United States.29 With increasing surgeries, comes a greater need to effectively monitor patients for post-operative complications and joint function improvement.
PROMs for the hip
The growing popularity of therapeutic hip interventions over the past number of years continues to drive outcome-related research. A number of validated PRO questionnaires are currently in use for patients with hip disorders.30 Below are the most prominent PROMs used in patient care in those experiencing hip pathologies.
|Oxford Hip Score (OHS)||Preferred for large-scale studies and joint-specific|
|UCLA Activity Score||Brevity and simplicity makes it attractive to combine with generic health measures|
|Forgotten Joint Score-12 (FJS-12)||Focused documentation of symptoms post-operatively from THA|
|Modified Harris Hip Score (mHHS)||Reliably assessed functional outcomes post-operatively|
|Hip Disability and Osteoarthritis Outcome Score (HOOS)||HOOS incorporates questions from the WOMAC|
- Oxford Hip Score
The OHS was originally developed in 1996, but updated in 2007 and is among the most commonly used PROMs in the field of hip arthroplasty.31, 32 The essential goal of the OHS is to assess physical aspects in terms of pain and function in patients undergoing THA surgery, including walking, dressing, climbing the stairs and sleeping.
Whilst it has proven valuable in the evaluation of THA patients, the OHS demonstrates good predictive ability to identify when a hip THA referral will be deemed nonsurgical rather than surgical by the surgeon during the first consultation, and that OHS thresholds can effectively screen out a large proportion of nonsurgical referrals.33 This in turn preserves health resources and augments the ability to streamline patients towards the most suitable management options.
Compared to other PROMs such as HOOS, the OHS is a relatively short 12-item questionnaire with a recall period of 4 weeks. As it is a concise, reproducible and extensively referenced tool within orthopaedic literature it is a desired instrument for large scale studies.34 The advantages of this measurement are compounded by its highly sensitive change in patients undergoing primary THA and revision surgeries as well as being suitable to use with generic PROMs like SF-36 and the disease-specific WOMAC. Nevertheless a hindrance of the OHS is the inclusion of double-barreled questions, meaning there is more than one claim in each question which can lead to confusion amongst patients on how to answer some questions.35
Pre-consultation OHS has demonstrated a good ability to predict when a primary THA referral will be deemed nonsurgical in a surgeon’s clinic. Multiple OHS thresholds can effectively screen out nonsurgical referrals.33, 36
- UCLA Activity Score
The University of California Los Angeles activity score was developed in 1984 and includes 10 statements that cover the range of activity states from being “wholly inactive, dependent on others and cannot leave residence” to “regularly participating in impact sports”.37, 38
The UCLA activity rating is a single question measure of a patient’s overall activity level. The patient selects 1 of 10 distinct activity levels, 1 being the least and 10 the most active. A study by Zahiri et al indicates that both the UCLA activity score and the investigator visual analog scale (VAS) are valid for routine activity assessment in the clinical setting.39 A limitation of the UCLA activity rating is the categorical nature of the descriptions for the 10 activity levels, making the UCLA activity rating scale insensitive to the frequency and intensity of an activity.
- Forgotten Joint Score-12 (Hip)
The Forgotten Joint Score measures the patient’s ability to forget the artificial hip joint in everyday life with the aim to measure PRO joint disorders The FJS covers the patients’ perception, i.e. the awareness rather than the pain itself as compared to the OHS.35
The 12-item FJS was primarily designed to chart the symptoms of patients postoperatively.40, 41 It is a more finely-tuned tool to distinguish patients with good to excellent outcomes following THA. The high internal consistency of FJS indicates that the items of the instrument consistently cover the construct of joint awareness.35
- Modified Harris Hip Score (mHHS)
Derived from the Harris Hip Score, the mHHS comprises 8 items covering 8 areas: pain, limp, support, distance walked, stairs, putting on shoes/socks, sitting and ease of use of public transportation.42
The HHS includes a physician’s physical examination component which has a high interobserver variability.43 While the original HHS includes both patient-administered and surgeon-administered sections, an exclusively patient-administered version of the HHS i.e. the modified HHS (mHHS), has since been developed. The mHHS has been shown to have excellent concordance with the original HHS.44, 45 The mHHS has been used to assess functional outcome of THA and does not contain as much variability as the HHS as the subjective physician-administered physical function aspect is not included.46
- Hip Disability and Osteoarthritis Outcome Score (HOOS)
The HOOS is a PROM used to evaluate the postoperative healing of THA patients. This tool was derived from the Western Ontario and MacMaster Universities Osteoarthritis Index (WOMAC), which also measures outcomes in OA and following THA. As many patients eligible for THR have expectations of more demanding physical functions than required for activities of daily living, HOOS has 2 additional dimensions: hip-related quality of life and sport and recreation.47
Comprising 40 items, HOOS was constructed to assess patient-relevant outcomes in five separate subscales (pain, symptoms, activity of daily living, sport and recreation function and hip related quality of life).47
The pioneering study that launched HOOS found that Sport and Recreation Function and Hip Related Quality of Life were highly responsive with an average age of 73 years at surgery (range 53–85), with the responsiveness being highest for those younger than 66 years. These dimensions are usually associated with a younger population but appear to be important also for the older.47 Thus, HOOS is regarded as being more valuable for more active and younger patients than WOMAC. Moreover, it has the added bonus that a WOMAC score can be derived from it and so it is suitable for use over short and long-term time intervals to assess changes induced by treatment, primary or post-traumatic OA.48
Despite the advantages associated with HOOS being plentiful, the 10 – 15 minutes it takes to complete can prove challenging for some patients and so issues of compliance arise in its collection. Learnings from this have led to the development of HOOS-JR, a shortened, validated version of HOOS in 2015 which increased patient engagement.49 Whilst validated and frequently used, there are disadvantages to its joint- and side-specific nature. For example, a patient with bilateral hip OA and unilateral knee OA would complete three surveys. For longitudinal tracking, three surveys would be required at each follow-up time point. Whereas, a measure such as the Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS PF) covers all joints on both sides.50
Which PROM or PROM combination is best?
A comprehensive review by Browne et al favored the OHS (used alongside European Quality of Life Questionnaire 5D (EQL-5D)) as primary outcome measures of choice to be used in a national audit of hip and knee replacement surgery (NHS PROMS programme) with thanks to the reliability and ease of use of such PROMs.51 However, the Hip Outcome Score (HOS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the modified Harris Hip Score (mHHS) were the most commonly reported PROMs utilised according to the literature.52, 53
However, in order to acquire robust information to aid healthcare advancement for the patient and wider system, validity and responsiveness of the PROM must be verified through numerous studies in clinical practice.54 A lack of standardization can lead to variation in the analysis of results and could result in two near-identical studies being analysed in different ways, leading to potential differences in data interpretation.55
Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines and to summarise feasibility aspects of the tools (eg, time to complete, fee payable, training required). Disease or region-specific PROMs are rarely used on their own to capture the entirety of a patient’s disease, therapeutic or surgical experience. It is not possible to capture the entirety of a patient’s disease by only using one PROM and that a combination of disease and generic problems are best applied. It is commonplace to include “generic” PROMs in the implementation of PROMs within various patient cohorts. The EQ-5D, WOMAC, and VAS questionnaires were the most commonly reported generic, disease-specific, and domain-specific PROMs, respectively as was elucidated by Sørensen et al.56 Whereas, Harris et al., noted that the generic measure Short-Form-12 (SF-12) performed best in their studies.52
Nevertheless, the pivotal factor for success in PROMs usage is the way in which it is integrated into the clinical routine and opting for open, connected and flexible digital solutions to do this is more beneficial.57, 58
PROM integration in conservative therapy
Conservative therapy approaches are, for most cases, the first-line options for musculoskeletal pain conditions according to clinical guidelines (primarily due to the greater costs and risks associated with surgery).59 – 61 As such determining the efficacy of non-surgical treatments for hip pain is critical.
Physiotherapy has the potential to reduce the burden of hip pain, with current evidence guiding physiotherapist-led treatments to target modifiable impairments i.e. strength, range of motion, functional task performance and neuromuscular control.62 A recent systematic review and meta-analysis of physiotherapist-led interventions for hip-related pain conducted by Kemp et al., aimed to report the effectiveness of improving pain and function in young and middle-aged adults.62 The review illuminated different PROMs used at different time points making data pooling and comprehensive conclusions difficult to derive.62 Whilst data suggests that physiotherapist-led intervention may aid hip pain and function definitive, comprehensive evidence remains lacking. Therefore consistency in their use across studies would truly prove informative when conducting meta-analysis from which evidence-based patient management guidelines can be drawn from.
PROMs and hip surgery
With the enhanced uptake of PROMs in clinical practice, it is prudent to develop a detailed understanding of their responsiveness to surgery such that implementation can be executed in a responsible, cost-effective,and mutually beneficial manner for all stakeholders and of course, patients.63, 64
The inclusion of PROMs collection of patients pre and post-operatively has long been cited to flag potential complications earlier, reduce morbidity, reduce revision-rates and improve the quality of care patients receive through enhanced care team communication feedback loops.65
The department of Orthopedics at Radboudumc, the Netherlands established a clinical registry in the mid-1990s to collect routine data of clinical and patient-reported health outcomes of patients after total hip and knee replacement. The study showed that the functional status of a large cohort of patients significantly improved after total hip and knee replacement, based on routine patient-reported and clinical data collection and aided the prediction of those with poorer outcomes at earlier stages.66 The feasibility of the routine collection of PRO data in patients with total hip and knee replacement was illustrated here and that the use of PRO data provides opportunities for continuous quality improvement.66
Sports, the hip and PROMs
A large number of athletes present with hip pain and functional disability related to FAI.67 Hip surgery aims to treat the intra-articular pathologies resulting from FAI e.g. articular cartilage lesions and labral tears, that may cause hip pain. The objectives of hip surgery are to reduce hip pain, improve hip function and allow the patient to return to their sport activities as well as reduce the degenerative changes within the joint.68, 69
The importance of sports participation also applies to the non-athlete as more and more people want to preserve their mobility for longer to improve their quality of life.70 Patient expectations are being heightened – monitoring post-surgical PROs in patients informs surgical techniques and what intervention works best for particular cohorts in order to meet their expectations.71
PROMoting Quality - applying PROMs to optimise care pathways
PROMoting Quality is a multidisciplinary project whose aim is to demonstrate that the application of PROMs helps patients achieve better postoperative outcomes in knee and hip arthroplasties through the investigation for cost-effectiveness and the early detection of post-surgical complications in >8,000 patients.72 As part of the investigation, participating healthcare providers integrated PROMs-collection software into their respective IT infrastructures, while concurrently aligning with clinical routines and patient journeys.73 The collaboration of insurers, healthcare providers, IT providers and most importantly, patients are taking information derived from PROMs inclusion in orthopaedic surgery to the next level – deriving new insights as well as encouraging more widespread use. To date, patients have provided 9,000 responses to follow-up questionnaires (1, 3, and 6 months post-discharge), resulting in a return rate of 85%. Depending on the follow-up month, 15 – 30% of patients in the intervention group have triggered alerts. Concurrently 30% of patients have engaged in conversations regarding their PROMs with their post-treatment physicians. Additionally, surveys among study assistants report time-saving and robust digital workflows with high acceptance rates of PROM-based interventions among the physicians involved.73
Like PROMoting Quality, the drive to conduct thorough research in the field of PROMs can be seen in efforts by the Organization for Economic Cooperation and Development (OECD). The PaRIS Initiative – a study of the systematic collection of PROMs in patients undergoing elective hip, shoulder, elbow and knee arthroplasty aspired to investigate the temporal trend of PROMs in relation to the type of prosthesis and the type of surgical intervention. The PaRIS-IOR study is a prospective, single site, cohort study that consists of the administration of PROMs questionnaires to patients on the list for elective arthroplasty with the HOOS-PS listed as the hip-related PROM of choice for this study.74 With the number of hip, knee and shoulder arthroplasties continuing to rise worldwide, such research initiatives are pivotal to help healthcare systems and patients acknowledge that PROMs are not merely a nice “add-on” to care pathways, but prove invaluable to realise the best possible patient outcomes and complete patient data.75
Promoting advancements – measuring progress
Our society is aging and with advancing treatment methodologies the expectations towards improving quality of life and with this a new understanding of quality is being sought. In accordance with this the use of PROMs are on the rise along with efforts to improve and qualitatively assess the value-based reimbursement nature of its use to further integrate their usage in healthcare. Nevertheless, PROMs have to be regarded not simply as a single quality measure, but a first and essential step towards a holistic and patient centred healthcare system. PROMs are playing an ever-increasing role in bringing patients and doctors closer together for a treatment.
With the above in mind, Heartbeat Medical provides the technology and expertise to enable healthcare decision-makers to efficiently measure and compare PROs. With our platform and network, our customers can ensure that treatments, devices, drugs and care pathways meet the expectations of patients regarding their quality of life. Heartbeat Medical helps to merge the physicians’ knowledge of PROMs with an actionable and supportive digital infrastructure that will allow care teams to sustainably change individual treatment experience and systemic healthcare outcomes.
Connecting with patients before and after their interventions adds to the clinical history and enables enhanced monitoring ong after they have left the direct care of their medical team. Maintaining insight into the patients’ pain, range of movement and quality of life helps to track treatment and recovery and enables early intervention if it is required to achieve the best outcomes both for the patient and physician.