Pichonnaz C1,2, Ancey C1, Jaccard H2, Balmelli B2, Farron A2, Jolles BM2, Aminian K3, Gleeson N4
1School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland (HES-SO), Physiotherapy, Lausanne, Switzerland, 2University Hospital of Lausanne, Department of Musculoskeletal Medicine, Lausanne, Switzerland, 3Laboratory of Movement Analysis and Measurement, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 4Queen Margaret University, School of Health Sciences, Edinburgh, United Kingdom
Background: The validation of a very straightforward shoulder function score would be useful for routine evaluation in clinical practice. The Subjective Shoulder Value (SSV), an analog visual scale on which the patient rates the affected shoulder function from 0% (unusable) to 100% (fully healthy) in 5% increments, could be used for this purpose. Despite its regular use in clinical practice and research, most of its measurement properties are unknown to date.
Purpose: The aim of this study was to evaluate the measurement properties of the SSV in patients conservatively treated for current shoulder conditions.
Methods: Heighty-height patients [♀ 58%; right-handed 90%; dominant side affected 47%; 49.8 (18.3) years (SD); weight 74.0 (15.2) kg; height 169.4 (9.9) cm] and 20 healthy participants [♀ 50%; right-handed 90%; 28.2 (6.2) years; weight 74.7 (17.4) kg; height 175.0 (10.3) cm] were evaluated at baseline (1st medical consultation at the specialised shoulder unit) and six months later. Patients suffered either rotator cuff condition (n=20), instability (n=23), adhesive capsulitis (n= 22) or proximal humerus fracture (n=23). Shoulder function was evaluated using the Constant Score (CS), relative Constant Score (CSrel), Simple Shoulder Test (STT), QuickDASH, Western Ontario Shoulder Instability Index (WOSI), kinematic B-B Score, pain visual analog scale (pVAS), stiffness visual analog scale (sVAS) and EQ-5D quality of life questionnaire. The difference between assessment stages (Wilcoxon signed-rank test), the relationship amongst scales (Spearman correlations) and the effect sizes (Cohen´s d) were calculated.
Results: The mean (SD) SSV was 52.9% (20.9) at baseline and 70.4% (19.7) at 6 months (P 0.01) in the patient group. It was 98.7% (2.2) at baseline and 99.5% (1.5) at 6 months in the control group (P=0.14). The difference between groups was significant at both stages (P 0.01). At baseline the SSV was correlated with function scores (r=0.44 to 0.57), EQ5D (r=0.39), pVAS (r=-0.36) and sVAS (r=-0.46). At 6 months, it was correlated with function scores (r=0.52 to 0.71), EQ5D (r=0.54), pVAS (r=-0.56) and sVAS (r=-0.50). Cohen´s d was 0.86 for SSV and ranged from 0.58 to 0.97 for shoulder function scores. Specifically, for instability, Cohen´s d was 0.41 for SSV and 0.62 for WOSI.
Conclusion(s): The SSV was able to discriminate the amongst groups and between the measurements´ stages in the patients group. It was stable over time in the control group. The SSV was correlated with the shoulder function scores, and to a lesser extent, to pain, stiffness and quality of life. The correlations were higher at 6 months, showing that the patients probably learn to rate more precisely their shoulder function with experience. The responsiveness of the SSV compares to the other measurement approaches, with the exception of the WOSI. The SSV can thus be considered as a valid and responsive measurement tool. Research with larger samples is needed to evaluate with precision its measurement properties in various shoulder conditions. The day to day reliability should also be investigated.
Implications: The SSV has adequate measurement properties. It can be recommended for routine clinical evaluation and research, when a quick and unidimensional evaluation is needed.
Keywords: Shoulder, Patient Outcome Assessment, Validation studies
Funding acknowledgements: Swiss National Science Foundation DORE fund (SNF n° 135061)
Purpose: The aim of this study was to evaluate the measurement properties of the SSV in patients conservatively treated for current shoulder conditions.
Methods: Heighty-height patients [♀ 58%; right-handed 90%; dominant side affected 47%; 49.8 (18.3) years (SD); weight 74.0 (15.2) kg; height 169.4 (9.9) cm] and 20 healthy participants [♀ 50%; right-handed 90%; 28.2 (6.2) years; weight 74.7 (17.4) kg; height 175.0 (10.3) cm] were evaluated at baseline (1st medical consultation at the specialised shoulder unit) and six months later. Patients suffered either rotator cuff condition (n=20), instability (n=23), adhesive capsulitis (n= 22) or proximal humerus fracture (n=23). Shoulder function was evaluated using the Constant Score (CS), relative Constant Score (CSrel), Simple Shoulder Test (STT), QuickDASH, Western Ontario Shoulder Instability Index (WOSI), kinematic B-B Score, pain visual analog scale (pVAS), stiffness visual analog scale (sVAS) and EQ-5D quality of life questionnaire. The difference between assessment stages (Wilcoxon signed-rank test), the relationship amongst scales (Spearman correlations) and the effect sizes (Cohen´s d) were calculated.
Results: The mean (SD) SSV was 52.9% (20.9) at baseline and 70.4% (19.7) at 6 months (P 0.01) in the patient group. It was 98.7% (2.2) at baseline and 99.5% (1.5) at 6 months in the control group (P=0.14). The difference between groups was significant at both stages (P 0.01). At baseline the SSV was correlated with function scores (r=0.44 to 0.57), EQ5D (r=0.39), pVAS (r=-0.36) and sVAS (r=-0.46). At 6 months, it was correlated with function scores (r=0.52 to 0.71), EQ5D (r=0.54), pVAS (r=-0.56) and sVAS (r=-0.50). Cohen´s d was 0.86 for SSV and ranged from 0.58 to 0.97 for shoulder function scores. Specifically, for instability, Cohen´s d was 0.41 for SSV and 0.62 for WOSI.
Conclusion(s): The SSV was able to discriminate the amongst groups and between the measurements´ stages in the patients group. It was stable over time in the control group. The SSV was correlated with the shoulder function scores, and to a lesser extent, to pain, stiffness and quality of life. The correlations were higher at 6 months, showing that the patients probably learn to rate more precisely their shoulder function with experience. The responsiveness of the SSV compares to the other measurement approaches, with the exception of the WOSI. The SSV can thus be considered as a valid and responsive measurement tool. Research with larger samples is needed to evaluate with precision its measurement properties in various shoulder conditions. The day to day reliability should also be investigated.
Implications: The SSV has adequate measurement properties. It can be recommended for routine clinical evaluation and research, when a quick and unidimensional evaluation is needed.
Keywords: Shoulder, Patient Outcome Assessment, Validation studies
Funding acknowledgements: Swiss National Science Foundation DORE fund (SNF n° 135061)
Topic: Musculoskeletal: upper limb; Outcome measurement; Orthopaedics
Ethics approval required: Yes
Institution: Faculty of biology and medicine of the University of Lausanne
Ethics committee: Ethical Commission Faculty of biology and medicine, Lausanne
Ethics number: Protocol 205/10
All authors, affiliations and abstracts have been published as submitted.
