Body image in idiopathic scoliosis: a comparison study of psychometric properties between four patient-reported outcome instruments

Abstract

BackgroundFour patient-reported outcome (PRO) instruments are commonly used to assess body image in idiopathic scoliosis (IS): the Quality of Life Profile for Spinal Deformities (QLPSD), SRS-22 Self-Image scale, Spinal Appearance Questionnaire (SAQ), and Trunk Appearance Perception Scale (TAPS). The aim of this study is to compare the psychometric properties of these instruments in patients with IS and report the translational/cultural adaptation of the SAQ to Spanish.MethodsThe four instruments in a Spanish version were administered to 80 patients with IS aged 10 to 40 years old. The sample was stratified according to scoliosis magnitude (less and more than 45º). Analysis was also conducted for age groups. The psychometric properties studied included convergent and divergent construct validity, as well as internal consistency. Convergent validity was evaluated by correlation analysis between the self-image instruments and Cobb angle. Divergent validity was assessed with correlation analysis between PRO scores and SRS-22 dimensions scores such as Function, Pain and Mental Health.ResultsIn the overall sample, each of the PRO instruments demonstrated high internal consistency (QLPSD Body Image, α = 0.80; SRS-22 Self Image, α = 0.78; SAQ, α = 0.89; TAPS, α = 0.87), also both for younger and adult patients subgroups. Correlation with curve magnitude was significant for each of the four scales. However, the correlation was higher for the pictorial scales (SAQ Appearance r = 0.61, TAPS r = - 0.62) than for the textual scales (QLPSD-bi r = 0.36, SRS-22 Self-Image scale r = - 0.41). In the younger group, correlation between Cobb angle and textual scales (QLPSD-bi and SRS-22 Self-Image Scale) was not significant. Body Image scales showed significant correlations with SRS-22 Pain, Function and Mental Health dimensions.ConclusionsAll four instruments tested have good psychometric properties. Pictorial scales (SAQ Appearance and TAPS) correlated better with the radiological magnitude of the curve and this correlation is independent of age. Unexpectedly, all four scales demonstrated significant correlations with non-body image dimensions and the divergent hypothesis was not confirmed. Globally, pictorial scales showed slightly better construct validity to test body image perception than textual scales.

Do the SRS-22 self-image and mental health domain scores reflect the degree of asymmetry of the back in adolescent idiopathic scoliosis?

“…No studies are known to have used surface topography to directly compare which questionnaires correlate better with HRQOL in AIS. Several studies have, however, used Cobb angle to do this [ 40 , 41 ]. Matamalas et al compared three questionnaires; SRS-22, SAQ and TAPS in idiopathic scoliosis [ 41 ].…”

Does patient perception of shoulder balance correlate with clinical balance?

“…The Appearance domain is based on 10 drawings (items 1-10) with a score of 1 (least deformity) to 5 (greatest deformity) and a possible range from 10 to 50. The Expectations domain comprises four questions (items [11][12][13][14] and answers consisting of a five-point Likert scale, with a total sum ranging from 4 (lower expectations) to 20 (higher expectations) [9,10]. For the statistical analysis questions, 6 and 13 were used.…”

“…All patients completed a set of Patient-Reported Outcome Scores that included the validated Spanish version of SRS-22 [13], SAQ [10,11] and TAPS [14] questionnaires on the day of the visit. Questionnaires were administered using paper-based forms completed by the patients themselves without any assistance from the attending physician or the patients' parents prior to consultation.…”

“…The Spinal Appearance Questionnaire (SAQ) includes a question (item 6) which specifically asks the patient to rate their subjective perception of ShB. In addition, the instrument provides a scale (SAQ expectations) for determining the patient's expectations about treatment and, specifically, their expectations for ShB (item 13) [9][10][11].…”

Non-invasive interventions in idiopathic scoliosis: a systematic review

“…The IS can affect the social sphere, limiting job opportunities, social isolation and lower marriage rates (7), moreover interferes negatively on self image (8,9) and stress level (10). IS progression can result in back pain, reduced mobility and lung function (11), postural stability deficit (12 -14), muscle force imbalance (15,16), altered electromyographic activity (17), increased risk of lumbar and thoracic pain and degenerative diseases of the intervertebral disc (18,19).…”