Comparison of different European and North American shoulder scoring systems

Alfahad, Nawaf (2018) Comparison of different European and North American shoulder scoring systems. PhD thesis, University of Nottingham.

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Background: Numerous shoulder scoring systems are in use world-wide to assess the outcomes from shoulder operations. Selecting the best outcome scoring instrument is challenging for the majority of musculoskeletal conditions. Outcome instruments can play an important role in the development of new procedures, techniques and protocols. The shoulder scoring systems that are currently used in North America are rarely applied alongside European shoulder scoring systems and vice versa. The lack of a universal shoulder scoring system impedes the evaluation process as it prevents valid comparison of outcomes from different research papers. The research aims were to develop a conversion equation for the six most commonly used outcome measures, to determine patients’ perceptions following shoulder arthroplasty surgery and to investigate differences between quantitative and qualitative outcomes in patients following shoulder arthroplasty surgery.

Methods: 93 participants with different shoulder pathologies were included in this study. The six commonest shoulder scoring systems, in the literature between 2013 and 2015, were used on each patient (Constant Score (CS), Oxford Shoulder Score (OSS), Simple Shoulder Test (SST), American Shoulder & Elbow Society Score (ASES) University of California Los Angeles Score (UCLA) and the Disabilities of the Shoulder and Hand Score (DASH)). The results were extracted from a database and compared using linear regression analyses to explore the level of correlation and to derive the correction factors to allow corrections to be made from one scoring system to another. In addition to the correlation and regression analysis, semi-structured qualitative interviews were conducted with 15 out 52 participants who had undergone shoulder arthroplasty to compare and contrast between derived thresholds of different shoulder scores and the patients’ experiences.

Results: The correlation coefficients varied between 0.9 (the best) for OSS score vs ASES score to – 0.73 (the worst) for CS score vs DASH score (significant at 0.01 level; 2-tailed). The linear regression analysis allows conversion of one score to another and the best 4 correlations are reproduced below.

For ASES vs. OSS the derived formula is: ASES = -4.68 + 1.8 x OSS

For UCLA vs. OSS the derived formula is: UCLA = 2.3634 + 0.5755 x OSS

For DASH vs. OSS the derived formula is: DASH = 84.2917 -1.5413 x OSS

For UCLA vs. CS the derived formula is: UCLA = 4.8918 + 0.3132 x CS

The validity of the 16 developed conversion equations was checked against two external datasets.

By categorizing the CS and other shoulder scores into excellent, very good, good, fair and poor categories, from the semi-structured interviews, there were no significant differences uncovered between very good and excellent categories. However, whilst there was much variability in the patients’ perceptions of their outcomes, there were clear indications in respondents’ answers that complimented the shoulder scoring outcomes measures.

Conclusion: This study has established a method of transforming particular shoulder scoring systems to the equivalent values in their counterparts. It is important to note that this is only applicable to grouped scores, not individual scores. This will allow a direct comparison between North American results and European results for shoulder surgery outcome studies, providing the limitations of this approach are appreciated. Despite the qualitative analysis of the semi-structured interviews showing a high degree of variance between individual respondents within the same group, categorised according to the CS and other shoulder outcome measures, generally patients’ perceptions of their shoulder function were reasonably consistent with the quantitative scores.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Wallace, Angus
Bayston, R.
Keywords: Shoulder scoring systems; Shoulder scores; Patient reported outcome measures
Subjects: W Medicine and related subjects (NLM Classification) > WE Muscoskeletal system
Faculties/Schools: UK Campuses > Faculty of Medicine and Health Sciences > School of Medicine
Item ID: 49319
Depositing User: Alfahad, Nawaf
Date Deposited: 27 Sep 2021 13:41
Last Modified: 18 Apr 2024 13:29

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