Validity of a one-item drawing-based instrument to assess trunk deformity perception in kyphotic deformities.

Abstract

Body image and trunk appearance perception are two crucial attributes in determiningthequality of lifeofindividuals with spinal deformities.The Trunk Appearance Perception Scale (TAPS) is a drawing-based instrument used to evaluate this feature. TheTAPS does not include a sagittal view of the trunkso it is neverbeenusedto assess trunk deformity perception inhyperkyphoticpatients.Thisstudyaimsto analyze theeffect of introducing a newdrawing on the TAPS scalerepresentingthe trunk view in the sagittal plane. 170 non-surgical patients were included (mean age 16.9years and 77.4% women) distributed in three groups. CONTROL group (no deformity): 22 cases;KYPHOSIS group (sagittal deformity): 49 cases and SCOLIOSIS group (coronal deformity): 99 cases (mean Cobb 42.4º). Cross-sectional study.A new drawing (TAPS4) was designed to represent the deformity in the sagittal plane with five response options. Clinical (SRS-22 and TAPS 4-items) and radiological (kyphosis T4-T12) data were collected in all patients. The statistical analysis consisted in determining for each group theinternal consistencyof the 3-items TAPS vs 4-items TAPS, as well as the discriminant validity (correlation with kyphosis magnitude) and convergent validity (correlation with the SRS-22 image subscale).In addition, test-retest reliability of new item 4 was determined in a subgroup of 30 kyphotic patients.During control visit,thepatients received a complete physical examinationanda full-spine AP and lateralX-ray in standing position using a low-radiation technique and fulfilledinstruments TAPS 4 items and SRS-22r. The three groups were found to have statistically significant differencesinthe magnitude ofkyphosis, quality of life, body image perception,the 3-items TAPS,4-itemsTAPS and new item 4score. The addition of the item 4 to TAPS 3 itemsdid not cause a significant change in the internal consistency of the scales (Cronbach's alpha) (TAPS 3-items 0.8 vs. TAPS 4-items 0.8).Kyphosismagnitudewas not correlated with the 3-items TAPS and 4-items TAPSscores; however, in the KYPHOSIS group, a significant negative correlation was observed between kyphosis anditem 4(Rho = -0.4, p = 0.0001).A significant correlation was found in all groups between TAPS 3-items and TAPS 4-items and SRS-22 imagedomain; the correlation betweenitem4 and SRS-22bodyimagedomainwas 0.3 in the Scoliosis group and 0.7 in the Kyphosisgroup. The 4-items TAPS scale does not provide advantages in the assessment of trunk deformity over the 3-items scale. However, in patients with kyphosis, theitem 4 (Kypho-TAPS) alone isavalidand reliableinstrument to monitor the perception of thetrunkdeformity.