Do patient-reported outcome scores better identify outlier surgical practice compared with revision rates for total knee arthroplasty?
DOI:
https://doi.org/10.2340/17453674.2025.44037Keywords:
Arthroplasty, Knee, StatisticsAbstract
Background and purpose: The New Zealand Joint Registry provides surgeon-level feedback on revision rate and Oxford scores for primary total knee replacement (TKR). Potential outliers are identified using revision rate. Using patient-reported outcome measures to identify outliers, alongside revision rate, could provide a more comprehensive understanding of surgeons’ results. We aimed to evaluate using Oxford scores compared with revision rates to identify potential outliers.
Methods: A registry-based prospective longitudinal cohort design was used. The association between surgeon mean Oxford score at 6 months and revision rate at 2 years, within 5 years, and within 10 years was evaluated using the Pearson correlation coefficient. Funnel and scatter plots were used to compare potential outliers for both measures using control limit and centile outlier thresholds respectively. All TKR in the registry prior to 31 December 2021, performed for any indication, were included.
Results: There was a weak negative association between mean Oxford score at 6 months and revision rate at 2 years, within 5 years, and within 10 years using the Pearson correlation coefficient. Funnel plot control limits identified similar numbers of outliers for 6-month Oxford score and revision rate, however, there here was minimal overlap in outliers identified using the 2 methods. There was also minimal overlap in outliers using centile thresholds.
Conclusion: Correlation between Oxford score at 6 months and revision rates is weaker at the surgeon level compared with the patient level. Mean Oxford score identifies different potential outliers compared with revision rates with minimal overlap. This has implications for reporting surgeon-level outcomes, raising questions regarding the most appropriate measure of surgical performance following TKR.
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Lingard M C H, Willis J, Frampton C M A, Hooper G J. Survey of New Zealand arthroplasty surgeon on surgeon-level outcome reporting. Arthroplasty 2023; 38(11): 2254-8. doi: 10.1016/j.arth.2023.05.069. DOI: https://doi.org/10.1016/j.arth.2023.05.069
Lingard M C H, Teo Y, Frampton C M A, Hooper G J. Effect of surgeon-specific feedback on surgical outcomes: a systematic review of the literature. ANZ J Surg 2023; 94: 47-56. doi: 10.1111/ans.18772. DOI: https://doi.org/10.1111/ans.18772
Tay M L, Monk A P, Frampton C M, Hooper G J, Young S W. Associations of the Oxford Knee Score and knee arthroplasty revision at long-term follow-up. ANZ J Surg 2023; 93(1-2): 310-15. doi: 10.1111/ans.18286. DOI: https://doi.org/10.1111/ans.18286
Von Elm E, Altman D G, Egger M, Pocock S J, Gotzsche P C, Vandenbroucke J P, Strobe Initiative. Strengthening the reporting of observational studies in epidemiology (STROBE) statement: guidelines for reporting observational studies. BMJ 2007; 335(7624): 806-8. doi: 10.1136/bmj.39335.541782.AD. DOI: https://doi.org/10.1136/bmj.39335.541782.AD
Rahardja R, Allen R, Frampton C M, Morris A J, McKie J, Young S W. Completeness and capture rate of publicly funded arthroplasty procedures in the New Zealand Joint Registry. ANZ J Surg 2020; 90(12): 2543-8. doi: 10.1111/ans.16385. DOI: https://doi.org/10.1111/ans.16385
Dawson J, Fitzpatrick R, Murray D, Carr A. Questionnaire on the perceptions of patients about total knee replacement. J Bone Joint Surg Br 1998; 80(1): 63-9. doi: 10.1302/0301-620x.80b1.7859. DOI: https://doi.org/10.1302/0301-620X.80B1.0800063
New Zealand Joint Registry. Twenty-two year report January 1999 to December 2020. New Zealand Joint Registry. December 2021. Available from: https://www.nzoa.org.nz/sites/default/files/NZJR_22_Year_Report_Final.pdf [accessed 15/09/2022].
Weldring T, Smith S M S. Patient-reported outcomes (PROs) and patient-reported outcome measures (PROMs). Health Serve Insights 2013; 6: 61-8. doi: 10.4137/HSI.S11093. DOI: https://doi.org/10.4137/HSI.S11093
Rothwell A G, Hooper G J, Hobbs A, Frampton C M. An analysis of the Oxford hip and knee scores and their relationship to early revision in the New Zealand Joint Registry. J Bone Joint Surg Br 2010; 92(3): 413-18. doi: 10.1302/0301-620X.92B3.22913. DOI: https://doi.org/10.1302/0301-620X.92B3.22913
Boyce M B, Browne J P, Greenhalgh J. Surgeon’s experiences of receiving peer benchmarked feedback using patient-reported outcome measures: a qualitative study. Implementation Sci 2014; 9: 84. doi: 10.1186/1748-5908-9-84. DOI: https://doi.org/10.1186/1748-5908-9-84
Hamilton D F, Giesinger J M, Giesinger K. It is merely subjective opinion that patient-reported outcome measures are not objective tools. Bone Joint Res 2017; 6(12): 665-6. doi: 10.1302/2046-3758.612.BJR-2017-0347. DOI: https://doi.org/10.1302/2046-3758.612.BJR-2017-0347
Kluzek S, Dean B, Wartolowska K A. Patient-reported outcome measures (PROMs) as proof of treatment efficacy. BMJ Evid Based Med 2022; 27(3): 153-5. doi: 10.1136/bmjebm-2020-111573. DOI: https://doi.org/10.1136/bmjebm-2020-111573
Black N, Varaganum M, Hutchings A. Relationship between patient reported experience (PREMs) and patient reported outcomes (PROMs) in elective surgery. BMJ Qual Saf 2014; 23(7): 534-42. doi: 10.1136/bmjqs-2013-002707. DOI: https://doi.org/10.1136/bmjqs-2013-002707
Hahn E A, Cella D, Chassany O, Fairclough D L, Wong G Y, Hays R D. Precision of health-related quality-of-life data compared with other clinical measures. Mayo Clin Proc 2007: 82(10): 1244-54. doi: 10.4065/82.10.1244. DOI: https://doi.org/10.4065/82.10.1244
Murray D W, Fitzpatrick R, Rogers K, Pandit H, Beard D J, Carr A J, et al. The use of the Oxford hip and knee scores. J Bone Joint Surg Br 2007; 89(8): 1010-14. doi: 10.1302/0301-620X.89B8.19424. DOI: https://doi.org/10.1302/0301-620X.89B8.19424
Harris K, Dawson J, Gibbons E, Lim C R, Beard D J, Fitzpatrick R, et al. Systematic review of measurement properties of patient-reported outcome measures used in patients undergoing hip and knee arthroplasty. Patient Relat Outcome Meas 2016; 7: 101-8. doi: 10.2147/PROM.S97774. DOI: https://doi.org/10.2147/PROM.S97774
Hamilton D F, Loth F L, Giesinger J M, Giesinger K, MacDonald D J, Patton J T, et al. Validation of the English Language Forgotten Joint Score-12 as an outcome measure for total hip and knee arthroplasty in a British population. Bone Joint J 2017; 99(2): 218-24. doi: 10.1302/0301-620X.99B2.BJJ-2016-0606.R1. DOI: https://doi.org/10.1302/0301-620X.99B2.BJJ-2016-0606.R1
Zhu M, Ravi S, Frampton C, Luey C, Young S. New Zealand Joint Registry data underestimates the rate of prosthetic joint infection. Acta Orthop 2016; 87(4): 346-50. doi: 10.3109/17453674.2016.1171639. DOI: https://doi.org/10.3109/17453674.2016.1171639
Gwynne-Jones D P, Sullivan T, Wilson R, Abbott J H. The relationship between preoperative Oxford hip and knee score and change in health-related quality of life after total hip and total knee arthroplasty: can it help inform rationing decisions? Arthroplast Today 2020; 6(3): 585-9. doi: 10.1016/j.artd.2020.04.009. DOI: https://doi.org/10.1016/j.artd.2020.04.009
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Copyright (c) 2025 Morgan C H Lingard, Christopher M A Frampton, Gary J Hooper
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