EDITORIAL
The use of patient-reported outcomes after routine arthroplasty BEYOND THE WHYS AND IFS O. Rolfson, H. Malchau From Massachusetts General Hospital, Harvard Medical School, Massachusetts, United States
O. Rolfson, MD, PhD, Orthopaedic Surgeon Swedish Hip Arthroplasty Register, Centre of Registers Västra Götaland, SE-413 45 Gothenburg, Sweden. H. Malchau, MD, PhD, Orthopaedic Surgeon, Professor Sahlgrenska University Hospital, SE-431 80 Mölndal, Sweden. Correspondence should be sent to Dr Med O. Rolfson; e-mail: [email protected] ©2015 The British Editorial Society of Bone & Joint Surgery doi10.1302/0301-620X.97B5. 35356 $2.00 Bone Joint J 2015;97-B:578–81.
578
The limitations and benefits of patient-reported outcome measures, in defining the merits of arthroplasty surgery, are discussed. Cite this article: Bone Joint J 2015;97-B:578–81.
There are many programmes collecting and monitoring patient-reported outcome measures (PROMs) for arthroplasty surgery.1-4 PROMs are meant to complement traditional outcome measures such as local complications, general adverse events and re-operations or revisions. It is generally accepted that pain relief and improved function are the principal aims of joint replacement. However, clinician-based tests are biased and not considered appropriate for the description of the patients’ perception of their state of health. Despite many limitations, such as their bounded nature and difficulty with interpretation, PROMs represent the best objective measurement of the information being sought. Thus, the debate is not primarily why or if we should measure PROMs, but rather how, when and what to measure, and how to interpret the results. The introduction of the concept of value-based health care, where decisions on how best to deliver health-care are based on what adds value to the patient’s life,5 are dependent on PROMs. While revision surgery and major adverse events are rare complications, between 11% and 20% of patients who undergo arthroplasty of the hip or knee have inadequate pain relief, limited function or dissatisfaction with the outcome.6-10
What are PROMs? By definition, any report of a patient’s health status, that comes directly from them without interpretation by others is considered a patientreported outcome.11 PROMs are thus used as standardised instruments, designed to measure particular phenomena or constructs of individuals’ health states in defined populations.11 Apart from the confusing terminology, cross-sectional PROMs do not generate true outcomes. In order to do so it takes longitudinal measures, before and at intervals after an intervention or along the course of disease process.
Improvement or absolute level of function, pain, and health status? The greatest capacity for improvement following arthroplasty lies with patients with the most severe symptoms pre-operatively.12,13 However, patients with severely affected states of health generally do not reach the levels of health achieved in those with less severe symptoms before surgery.12,13 Furthermore, the bounded nature of instruments often limits their ability to discriminate between good and excellent outcomes. Consequently, when evaluating outcomes from the patients’ perspective, one has to consider the change as well as the absolute level of pain, function and healthrelated quality of life. Naturally, there is a strong association between pre- and postoperative PROMs. Concentrating on the absolute change from before to after arthroplasty, may lead to incorrect conclusions about the quality of health-care providers. From both patients’ and societal perspectives it is desirable to strive to preserve as much function as possible and to prevent suffering during the course of disease. Arthroplasty providers, surgeons and researchers should therefore be encouraged to engage in how the care of patients, who eventually may benefit from arthroplasty, is being organised from the early onset of symptoms until the arthroplasty has been performed. What is a difference? It is commonly questioned whether changes in PROMs represent clinically relevant differences. Ideally, every measure should be interpreted by defining the threshold for change that all patients actually perceive as an improvement or deterioration. This has turned out to be precarious and not straightforward to determine. A plethora of methodologies exist for this purpose and there is no consensus THE BONE & JOINT JOURNAL
THE USE OF PATIENT-REPORTED OUTCOMES AFTER ROUTINE ARTHROPLASTY
on which to use.14 The minimum important difference (MID) calculated for a specific PROM differs depending on the methodology used, the nature of the intervention being studied, the characteristics of the population studied, and it differs within the range of the instrument.14-17Considering all concerns about universal thresholds of MID, there are reasons to plead for great caution when applying such values. The main approach which is recommended when comparing providers involves routine statistical testing. However, when investigating small differences between providers it may be informative to supply proportional data on patients improving or deteriorating using well-established thresholds for MIDs.
Are samples enough? Arthroplasty is art, not industry. In addition to requiring skilled craftsmanship, many delicate considerations and decisions have to be made during treatment. Samples may be useful for research purposes or to get a general perception of the outcomes in a health care system. Even though procedures for arthroplasty may be standardised, each patient and operation is unique. It could therefore be argued that quality assurance must include all patients being treated. Patient satisfaction complements PROMs Besides measures addressing health status, there are other useful ways of assessing the success of treatment such as satisfaction, fulfilment of expectations and the willingness to repeat or to recommend to others. This inter-related group of measures are by definition not true PROMs. Nevertheless, satisfaction and similar measures are clearly associated with changes in PROMs as well as the patient’s experience of the delivery of care and may indicate how well a provider managed to engage the patient in shared decision-making and to set realistic expectations on outcomes.18-20 In cases where true PROMs by inherent limitations fail to determine the success of treatment, measures of satisfaction may be useful complements. This corroborates the current use of such additional measures in some of the existing large-scale PROM programmes in arthroplasty surgery. PROMs for prioritisation Commendable attempts to develop tools, including but not limited to PROMs, for the prioritisation and referral of individual patients have been made.21 It is not a simple task to identify equitably those who have the greatest needs and who will benefit the most. A combination of a clinicianbased assessment of priority and PROMs is reasonably equitable and effective. However, it has been shown that single score thresholds in PROMs are not suitable for prioritising access to care.22 However, aggregated, such data may be helpful in understanding differences in indications and referral patterns over time, and between different regions and individual providers.23 Ideally, PROMs should aid the patient and the care giver to make a shared decision VOL. 97-B, No. 5, MAY 2015
579
about the care rather than dictate pathways in clinical practice by applying thresholds. Unfortunately, there is still limited evidence on the effectiveness of such use in clinical practice.
Some providers do better than others Variation in the quality of care must be analysed in order to make improvements. Regardless of case-mix, there are differences in PROMs between providers that cannot solely be explained by differences in comorbidities and demography.24,25 It could be argued that routine PROMs should not be used before the efficacy of such initiatives has been established. Even though costly overall, the total expenditure for such a programme is trivial compared with all direct and indirect costs associated with end-stage hip and knee disease and arthroplasty. Moreover, it is not farfetched to draw parallels to the presumptive, but not proven, benefits of arthroplasty registers on revision rates. Having among the lowest reported revision rates in the world, Sweden’s tradition of transparency and public reporting are proposed to have been an effective stimulus to clinical improvement, and adherence to evidence-based methods. After more than a decade of nation-wide collection of PROMs in Sweden, a significant trend of improvement in outcomes has been reported.24,26 Case-mix differences between care-givers It is essential when analysing outcome to include differences in case-mixes between care givers. As the collection of casemix variables in addition to PROMs increases the burden on patients and health-care providers, these must be carefully balanced in order to obtain adequate response rates. However, it is not easy to determine if and how extensive or precise factors such as diagnosis at the time of arthroplasty, previous interventions, bodily constitution, comorbidities, socioeconomic status, ethnicity, physical function, and personality characteristics should be included in the adjustment of models of case-mix. Regardless of the case-mix variables which are used, for the sake of transparency and comprehensiveness, open reporting of both adjusted and unadjusted results of PROMs is encouraged. As outlined above, a key feature of the case-mix adjustment is the inclusion of the preoperative PROMs as a determinant of outcome. Reimbursement on results Even though cumbersome, the question of how to use PROMs data in reimbursement models needs to be addressed. The transition is inevitable and crucial; current methods of payment do not incentivise the combination of improvement of quality and cost control. It has been argued that the orthopaedic community should provide guidance and leadership in the transition from fee-for-service to value-based payment methods. Should the orthopaedic community fail to do so, the alternative is for other stakeholders to define and weight components used to assess outcomes in orthopaedic care.27
580
O. ROLFSON, H. MALCHAU
What have we learnt from PROMs in routine arthroplasty health care? First, the mere act of measuring PROMs has confirmed that joint replacement is an effective treatment of end-stage hip or knee joint diseases in general, and has shed light on an important minority of patients who do not improve as expected or express dissatisfaction with the outcome.7,20 Secondly, several patient-related determinants such as emotional health,28-30 the presence of coexisting low back pain31 and other medical conditions which impair mobility,32,33 socioeconomic status,34 and obesity35 have been identified as being associated with patient-reported outcomes. These variables should not exclude patients from joint replacement but should be considered in shared decision-making in order to ensure realistic expectations. Thirdly, the existing PROMs have revealed an association between surgical factors, such as surgical approach, and outcome.36,37 In addition, registry data have demonstrated low function after hip replacement to be a risk factor of subsequent revision.38 However, considering the high volume of literature on PROMs in joint replacement from both registry and clinical studies, it is discouraging to realise how little is published on how PROMs are used in clinical practice to improve on results. Start the transformation Although not comprehensively discussed, we now face several challenges with the routine PROMs programmes beyond the issues of why and if they are indicated. It has been claimed that PROMs could help transform health care.39 An impressive amount of research on the association between PROMs and factors such as patient demography,7,33,40 comorbidities,32,33,35,41 socioeconomic status34 and surgical techniques35-37 has been published. However, there are only a few reports 24,26,42 on the benefits of using PROMs in clinical practice to improve outcome. The good examples are sought. It is time to start the transformation in clinical practice. Author contribution O. Rolfson: Literature research and writing manuscript H. Malchau: Conception and critically reviewing manuscript. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. This article was primary edited by G. Scott and first proof edited by J. Scott.
References 1. Franklin PD, Allison JJ, Ayers DC. Beyond joint implant registries: a patient-centered research consortium for comparative effectiveness in total joint replacement. JAMA 2012;308:1217–1218. 2. Rolfson O, Dahlberg LE, Kärrholm J, Garellick G. Patient-reported outcomes in the Swedish Hip Arthroplasty Register. J Bone Joint Surg [Br] 2011;93-B-7:867–875. 3. Rolfson O, Rothwell A, Sedrakyan A, et al. Use of patient-reported outcomes in the context of different levels of data. J Bone Joint Surg [Am] 2011;93 (suppl 3):66– 71. 4. No authors listed. Department of Health: Guidance on the routine collection of Patient-Reported Outcome Measures (PROMs) for the NHS in England 2009/10. http:/ /www.dh.gov.uk/ (date last accessed 16 February 2015). 5. Porter ME. What is value in health care? N Engl J Med 2010;363:2477–2481.
6. Dunbar MJ, Richardson G, Robertsson O. I can't get no satisfaction after my total knee replacement: rhymes and reasons. Bone Joint J 2013;95-B (Suppl A):148–152. 7. Rolfson O, Kärrholm J, Dahlberg LE, Garellick G. Patient-reported outcomes in the Swedish Hip Arthroplasty Register: results of a nationwide prospective observational study. J Bone Joint Surg [Br] 2011;93-B:867–875. 8. Nam D, Nunley RM, Barrack RL. Patient dissatisfaction following total knee replacement: a growing concern? Bone Joint J 2014;96-B (11 Supple A):96–100. 9. Drexler M, Dwyer T, Chakravertty R, Farno A, Backstein D. Assuring the happy total knee replacement patient. Bone Joint J 2013;95-B (11Suppl A):120–123. 10. Judge A, Cooper C, Williams S, Dreinhoefer K, Dieppe P. Patient-reported outcomes one year after primary hip replacement in a European Collaborative Cohort. Arthritis Care Res (Hoboken) 2010;62:480–488. 11. No authors listed. Guidance for industry: patient-reported outcome measures: use in medical product development to support labeling claims: draft guidance. Health Qual Life Outcomes 2006;4:79. 12. Matthias Vogl, Rainer Wilkesmann, Christian Lausmann, Matthias Hunger, Werner Plötz. The impact of preoperative patient characteristics on health states after total hip replacement and related satisfaction thresholds: a cohort study. Health Qual Life Outcomes 2014;12:108. 13. Greene ME, Rolfson O, Garellick G, Gordon M, Nemes S. Improved statistical analysis of pre- and post-treatment patient-reported outcome measures (PROMs): the applicability of piecewise linear regression splines. Qual Life Res 2015;24:567–573. 14. King MT. A point of minimal important difference (MID): a critique of terminology and methods. Expert Rev Pharmacoecon Outcomes Res 2011;11:171–184. 15. Hays RD, Farivar SS, Liu H. Approaches and recommendations for estimating minimally important differences for health-related quality of life measures. COPD 2005;2:63–67. 16. Walters SJ, Brazier JE. Comparison of the minimally important difference for two health state utility measures: EQ-5D and SF-6D. Qual Life Res 2005;14:1523–1532. 17. Paulsen A, Roos EM, Pedersen AB, Overgaard S. Minimal clinically important improvement (MCII) and patient-acceptable symptom state (PASS) in total hip arthroplasty (THA) patients 1 year postoperatively. Acta Orthop 2014;85:39–48. 18. Hamilton DF, Lane JV, Gaston P, et al. What determines patient satisfaction with surgery? A prospective cohort study of 4709 patients following total joint replacement. BMJ Open 2013;3:3–4. 19. Baker PN, van der Meulen JH, Lewsey J, Gregg PJ, National Joint Registry for England and Wales. The role of pain and function in determining patient satisfaction after total knee replacement. Data from the National Joint Registry for England and Wales. J Bone Joint Surg [Br] 2007;89-B:893–900. 20. Baker PN, Rushton S, Jameson SS, et al. Patient satisfaction with total knee replacement cannot be predicted from pre-operative variables alone: A cohort study from the National Joint Registry for England and Wales. Bone Joint J 2013;95B:1359–1365. 21. De Coster C, McMillan S, Brant R, et al. The Western Canada Waiting List Project: development of a priority referral score for hip and knee arthroplasty. J Eval Clin Pract 2007;13:192–196. 22. Judge A, Arden NK, Kiran A, et al. Interpretation of patient-reported outcomes for hip and knee replacement surgery: identification of thresholds associated with satisfaction with surgery. J Bone Joint Surg [Br] 2012;94-B:412–418. 23. Lofvendahl S, Bizjajeva S, Ranstam J, Lidgren L. Indications for hip and knee replacement in Sweden. J Eval Clin Pract 2011;17:251–260. 24. Garellick G, Kärrholm J, Rogmark C, Rolfson O. Swedish Hip Arthroplasty Register Annual Report 2012. http://www.shpr.se/en/ (date last accessed 16 February 2015). 25. Neuburger J, Cromwell DA, Hutchings A, Black N, van der Meulen JH. Funnel plots for comparing provider performance based on patient-reported outcome measures. BMJ Qual Saf 2011;20:1020–10206. 26. Garellick G, Kärrholm J, Lindahl H, et al . Swedish Hip Arthroplasty Register Annual Report 2013. http://www.shpr.se/en/ (date last accessed 26 February 2015). 27. Andrawis JP, Chenok KE, Bozic KJ. Health policy implications of outcomes measurement in orthopaedics. Clin Orthop Relat Res 2013;471:3475–3481. 28. Franklin PD, Li W, Ayers DC. The Chitranjan Ranawat Award: functional outcome after total knee replacement varies with patient attributes. Clin Orthop Relat Res 2008;466:2597–2604. 29. Rolfson O, Dahlberg LE, Nilsson JA, Malchau H, Garellick G. Variables determining outcome in total hip replacement surgery. J Bone Joint Surg [Br] 2009;91B:157–161. 30. Clement ND, MacDonald D, Burnett R. Primary total knee replacement in patients with mental disability improves their mental health and knee function: a prospective study. Bone Joint J 2013;95-B:360–366.
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THE USE OF PATIENT-REPORTED OUTCOMES AFTER ROUTINE ARTHROPLASTY
31. Clement ND, MacDonald D, Simpson AH, Burnett R. Total knee replacement in patients with concomitant back pain results in a worse functional outcome and a lower rate of satisfaction. Bone Joint J 2013;95-B:1632–1639. 32. Ayers DC, Li W, Oatis C, Rosal MC, Franklin PD. Patient-reported outcomes after total knee replacement vary on the basis of preoperative coexisting disease in the lumbar spine and other nonoperatively treated joints: the need for a musculoskeletal comorbidity index. J Bone Joint Surg [Am] 2013;95-A:1833–1837. 33. Gordon M, Frumento P, Skoldenberg O, et al. Women in Charnley class C fail to improve in mobility to a higher degree after total hip replacement. Acta Orthop 2014;85:335–341. 34. Greene ME, Rolfson O, Nemes S, et al. Education attainment is associated with patient-reported outcomes: findings from the Swedish Hip Arthroplasty Register. Clin Orthop Relat Res 2014;472:1868–1876. 35. Jameson SS, Mason JM, Baker PN, et al. The impact of body mass index on patient reported outcome measures (PROMs) and complications following primary hip arthroplasty. J Arthroplasty 2014;29:1889–1898. 36. Lindgren JV, Wretenberg P, Karrholm J, Garellick G, Rolfson O. Patientreported outcome is influenced by surgical approach in total hip replacement: a study of the Swedish Hip Arthroplasty Register including 42,233 patients. Bone Joint J 2014;96-B:590–596.
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37. Jameson SS, Mason J, Baker P, et al. A comparison of surgical approaches for primary hip arthroplasty: a cohort study of patient reported outcome measures (PROMs) and early revision using linked national databases. J Arthroplasty 2014;29:1248–1255. 38. Devane P, Horne G, Gehling DJ. Oxford hip scores at 6 months and 5 years are associated with total hip revision within the subsequent 2 years. Clin Orthop Relat Res 2013;471:3870–3874. 39. Black N. Patient reported outcome measures could help transform healthcare. BMJ 2013;346:167. 40. Gordon M, Greene M, Frumento P, et al Age- and health-related quality of life after total hip replacement: decreasing gains in patients above 70 years of age. Acta Orthop 2014;85:244–249. 41. Greene ME, Rolfson O, Gordon M, Garellick G, Nemes S. Standard Comorbidity Measures Do Not Predict Patient-reported Outcomes 1 Year After Total Hip Arthroplasty. Clin Orthop Relat Res 2015.(Epub ahead of print). 42. Ovretveit J, Keller C, Hvitfeldt Forsberg H, et al. Continuous innovation: developing and using a clinical database with new technology for patient-centred care--the case of the Swedish quality register for arthritis. Int J Qual Health Care 2013;25:118– 124.
The use of patient-reported outcomes after routine arthroplasty BEYOND THE WHYS AND IFS O. Rolfson, H. Malchau From Massachusetts General Hospital, Harvard Medical School, Massachusetts, United States
O. Rolfson, MD, PhD, Orthopaedic Surgeon Swedish Hip Arthroplasty Register, Centre of Registers Västra Götaland, SE-413 45 Gothenburg, Sweden. H. Malchau, MD, PhD, Orthopaedic Surgeon, Professor Sahlgrenska University Hospital, SE-431 80 Mölndal, Sweden. Correspondence should be sent to Dr Med O. Rolfson; e-mail: [email protected] ©2015 The British Editorial Society of Bone & Joint Surgery doi10.1302/0301-620X.97B5. 35356 $2.00 Bone Joint J 2015;97-B:578–81.
578
The limitations and benefits of patient-reported outcome measures, in defining the merits of arthroplasty surgery, are discussed. Cite this article: Bone Joint J 2015;97-B:578–81.
There are many programmes collecting and monitoring patient-reported outcome measures (PROMs) for arthroplasty surgery.1-4 PROMs are meant to complement traditional outcome measures such as local complications, general adverse events and re-operations or revisions. It is generally accepted that pain relief and improved function are the principal aims of joint replacement. However, clinician-based tests are biased and not considered appropriate for the description of the patients’ perception of their state of health. Despite many limitations, such as their bounded nature and difficulty with interpretation, PROMs represent the best objective measurement of the information being sought. Thus, the debate is not primarily why or if we should measure PROMs, but rather how, when and what to measure, and how to interpret the results. The introduction of the concept of value-based health care, where decisions on how best to deliver health-care are based on what adds value to the patient’s life,5 are dependent on PROMs. While revision surgery and major adverse events are rare complications, between 11% and 20% of patients who undergo arthroplasty of the hip or knee have inadequate pain relief, limited function or dissatisfaction with the outcome.6-10
What are PROMs? By definition, any report of a patient’s health status, that comes directly from them without interpretation by others is considered a patientreported outcome.11 PROMs are thus used as standardised instruments, designed to measure particular phenomena or constructs of individuals’ health states in defined populations.11 Apart from the confusing terminology, cross-sectional PROMs do not generate true outcomes. In order to do so it takes longitudinal measures, before and at intervals after an intervention or along the course of disease process.
Improvement or absolute level of function, pain, and health status? The greatest capacity for improvement following arthroplasty lies with patients with the most severe symptoms pre-operatively.12,13 However, patients with severely affected states of health generally do not reach the levels of health achieved in those with less severe symptoms before surgery.12,13 Furthermore, the bounded nature of instruments often limits their ability to discriminate between good and excellent outcomes. Consequently, when evaluating outcomes from the patients’ perspective, one has to consider the change as well as the absolute level of pain, function and healthrelated quality of life. Naturally, there is a strong association between pre- and postoperative PROMs. Concentrating on the absolute change from before to after arthroplasty, may lead to incorrect conclusions about the quality of health-care providers. From both patients’ and societal perspectives it is desirable to strive to preserve as much function as possible and to prevent suffering during the course of disease. Arthroplasty providers, surgeons and researchers should therefore be encouraged to engage in how the care of patients, who eventually may benefit from arthroplasty, is being organised from the early onset of symptoms until the arthroplasty has been performed. What is a difference? It is commonly questioned whether changes in PROMs represent clinically relevant differences. Ideally, every measure should be interpreted by defining the threshold for change that all patients actually perceive as an improvement or deterioration. This has turned out to be precarious and not straightforward to determine. A plethora of methodologies exist for this purpose and there is no consensus THE BONE & JOINT JOURNAL
THE USE OF PATIENT-REPORTED OUTCOMES AFTER ROUTINE ARTHROPLASTY
on which to use.14 The minimum important difference (MID) calculated for a specific PROM differs depending on the methodology used, the nature of the intervention being studied, the characteristics of the population studied, and it differs within the range of the instrument.14-17Considering all concerns about universal thresholds of MID, there are reasons to plead for great caution when applying such values. The main approach which is recommended when comparing providers involves routine statistical testing. However, when investigating small differences between providers it may be informative to supply proportional data on patients improving or deteriorating using well-established thresholds for MIDs.
Are samples enough? Arthroplasty is art, not industry. In addition to requiring skilled craftsmanship, many delicate considerations and decisions have to be made during treatment. Samples may be useful for research purposes or to get a general perception of the outcomes in a health care system. Even though procedures for arthroplasty may be standardised, each patient and operation is unique. It could therefore be argued that quality assurance must include all patients being treated. Patient satisfaction complements PROMs Besides measures addressing health status, there are other useful ways of assessing the success of treatment such as satisfaction, fulfilment of expectations and the willingness to repeat or to recommend to others. This inter-related group of measures are by definition not true PROMs. Nevertheless, satisfaction and similar measures are clearly associated with changes in PROMs as well as the patient’s experience of the delivery of care and may indicate how well a provider managed to engage the patient in shared decision-making and to set realistic expectations on outcomes.18-20 In cases where true PROMs by inherent limitations fail to determine the success of treatment, measures of satisfaction may be useful complements. This corroborates the current use of such additional measures in some of the existing large-scale PROM programmes in arthroplasty surgery. PROMs for prioritisation Commendable attempts to develop tools, including but not limited to PROMs, for the prioritisation and referral of individual patients have been made.21 It is not a simple task to identify equitably those who have the greatest needs and who will benefit the most. A combination of a clinicianbased assessment of priority and PROMs is reasonably equitable and effective. However, it has been shown that single score thresholds in PROMs are not suitable for prioritising access to care.22 However, aggregated, such data may be helpful in understanding differences in indications and referral patterns over time, and between different regions and individual providers.23 Ideally, PROMs should aid the patient and the care giver to make a shared decision VOL. 97-B, No. 5, MAY 2015
579
about the care rather than dictate pathways in clinical practice by applying thresholds. Unfortunately, there is still limited evidence on the effectiveness of such use in clinical practice.
Some providers do better than others Variation in the quality of care must be analysed in order to make improvements. Regardless of case-mix, there are differences in PROMs between providers that cannot solely be explained by differences in comorbidities and demography.24,25 It could be argued that routine PROMs should not be used before the efficacy of such initiatives has been established. Even though costly overall, the total expenditure for such a programme is trivial compared with all direct and indirect costs associated with end-stage hip and knee disease and arthroplasty. Moreover, it is not farfetched to draw parallels to the presumptive, but not proven, benefits of arthroplasty registers on revision rates. Having among the lowest reported revision rates in the world, Sweden’s tradition of transparency and public reporting are proposed to have been an effective stimulus to clinical improvement, and adherence to evidence-based methods. After more than a decade of nation-wide collection of PROMs in Sweden, a significant trend of improvement in outcomes has been reported.24,26 Case-mix differences between care-givers It is essential when analysing outcome to include differences in case-mixes between care givers. As the collection of casemix variables in addition to PROMs increases the burden on patients and health-care providers, these must be carefully balanced in order to obtain adequate response rates. However, it is not easy to determine if and how extensive or precise factors such as diagnosis at the time of arthroplasty, previous interventions, bodily constitution, comorbidities, socioeconomic status, ethnicity, physical function, and personality characteristics should be included in the adjustment of models of case-mix. Regardless of the case-mix variables which are used, for the sake of transparency and comprehensiveness, open reporting of both adjusted and unadjusted results of PROMs is encouraged. As outlined above, a key feature of the case-mix adjustment is the inclusion of the preoperative PROMs as a determinant of outcome. Reimbursement on results Even though cumbersome, the question of how to use PROMs data in reimbursement models needs to be addressed. The transition is inevitable and crucial; current methods of payment do not incentivise the combination of improvement of quality and cost control. It has been argued that the orthopaedic community should provide guidance and leadership in the transition from fee-for-service to value-based payment methods. Should the orthopaedic community fail to do so, the alternative is for other stakeholders to define and weight components used to assess outcomes in orthopaedic care.27
580
O. ROLFSON, H. MALCHAU
What have we learnt from PROMs in routine arthroplasty health care? First, the mere act of measuring PROMs has confirmed that joint replacement is an effective treatment of end-stage hip or knee joint diseases in general, and has shed light on an important minority of patients who do not improve as expected or express dissatisfaction with the outcome.7,20 Secondly, several patient-related determinants such as emotional health,28-30 the presence of coexisting low back pain31 and other medical conditions which impair mobility,32,33 socioeconomic status,34 and obesity35 have been identified as being associated with patient-reported outcomes. These variables should not exclude patients from joint replacement but should be considered in shared decision-making in order to ensure realistic expectations. Thirdly, the existing PROMs have revealed an association between surgical factors, such as surgical approach, and outcome.36,37 In addition, registry data have demonstrated low function after hip replacement to be a risk factor of subsequent revision.38 However, considering the high volume of literature on PROMs in joint replacement from both registry and clinical studies, it is discouraging to realise how little is published on how PROMs are used in clinical practice to improve on results. Start the transformation Although not comprehensively discussed, we now face several challenges with the routine PROMs programmes beyond the issues of why and if they are indicated. It has been claimed that PROMs could help transform health care.39 An impressive amount of research on the association between PROMs and factors such as patient demography,7,33,40 comorbidities,32,33,35,41 socioeconomic status34 and surgical techniques35-37 has been published. However, there are only a few reports 24,26,42 on the benefits of using PROMs in clinical practice to improve outcome. The good examples are sought. It is time to start the transformation in clinical practice. Author contribution O. Rolfson: Literature research and writing manuscript H. Malchau: Conception and critically reviewing manuscript. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. This article was primary edited by G. Scott and first proof edited by J. Scott.
References 1. Franklin PD, Allison JJ, Ayers DC. Beyond joint implant registries: a patient-centered research consortium for comparative effectiveness in total joint replacement. JAMA 2012;308:1217–1218. 2. Rolfson O, Dahlberg LE, Kärrholm J, Garellick G. Patient-reported outcomes in the Swedish Hip Arthroplasty Register. J Bone Joint Surg [Br] 2011;93-B-7:867–875. 3. Rolfson O, Rothwell A, Sedrakyan A, et al. Use of patient-reported outcomes in the context of different levels of data. J Bone Joint Surg [Am] 2011;93 (suppl 3):66– 71. 4. No authors listed. Department of Health: Guidance on the routine collection of Patient-Reported Outcome Measures (PROMs) for the NHS in England 2009/10. http:/ /www.dh.gov.uk/ (date last accessed 16 February 2015). 5. Porter ME. What is value in health care? N Engl J Med 2010;363:2477–2481.
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