Improving the measurement of health-related quality of life in adolescent with idiopathic scoliosis: the SRS-7, a Rasch-developed short form of the SRS-22 questionnaire.

Scoliosis Research Society-22 (SRS-22) questionnaire was developed to evaluate health-related quality of life (HRQL) in adolescent idiopathic scoliosis (AIS) patients. Rasch analysis (RA) is a statistical procedure which turns questionnaire ordinal scores into interval measures. Measures from Rasch-compatible questionnaires can be used, similar to body temperature or blood pressure, to quantify disease severity progression and treatment efficacy. Purpose of the current work is to present Rasch analysis (RA) of the SRS-22 questionnaire and to develop an SRS-22 Rasch-approved short form. 300 SRS-22 were randomly collected from 2447 consecutive IS adolescents at their first evaluation (229 females; 13.9 ± 1.9 years; 26.9 ± 14.7 Cobb°) in a scoliosis outpatient clinic. RA showed both disordered thresholds and overall misfit of the SRS-22. Sixteen items were re-scored and two misfitting items (6 and 14) removed to obtain a Rasch-compatible questionnaire. Participants HRQL measured too high with the rearranged questionnaire, indicating a severe SRS-22 ceiling effect. RA also highlighted SRS-22 multidimensionality, with pain/function not merging with self-image/mental health items. Item 3 showed differential item functioning (DIF) for both curve and hump amplitude. A 7-item questionnaire (SRS-7) was prepared by selecting single items from the original SRS-22. SRS-7 showed fit to the model, unidimensionality and no DIF. Compared with the SRS-22, the short form scale shows better targeting of the participants' population. RA shows that SRS-22 has poor clinimetric properties; moreover, when used with AIS at first evaluation, SRS-22 is affected by a severe ceiling effect. SRS-7, an SRS-22 7-item short form questionnaire, provides an HRQL interval measure better tailored to these participants.

[1]  Everett V. Smith,et al.  International Conference on Objective Measurement: Applications of Rasch Analysis in Health Care , 2004, Medical care.

[2]  M. Tavernaro,et al.  Team care to cure adolescents with braces (avoiding low quality of life, pain and bad compliance): a case–control retrospective study. 2011 SOSORT Award winner , 2012, Scoliosis.

[3]  S. Lai,et al.  Radiographic and patient-based outcome analysis of different bone-grafting techniques in the surgical treatment of idiopathic scoliosis with a minimum 4-year follow-up: allograft versus autograft/allograft combination. , 2013, The spine journal : official journal of the North American Spine Society.

[4]  J. Thonnard,et al.  ACTIVLIM-Stroke: A Crosscultural Rasch-Built Scale of Activity Limitations in Patients With Stroke , 2012, Stroke.

[5]  Georg Rasch,et al.  Probabilistic Models for Some Intelligence and Attainment Tests , 1981, The SAGE Encyclopedia of Research Design.

[6]  D. Burton,et al.  Scoliosis Research Society-22 Patient Questionnaire: Responsiveness to Change Associated With Surgical Treatment , 2003, Spine.

[7]  Stefano Negrini,et al.  Why do we treat adolescent idiopathic scoliosis? What we want to obtain and to avoid for our patients. SOSORT 2005 Consensus paper , 2006, Scoliosis.

[8]  Alan Tennant,et al.  Application of Rasch analysis in the development and application of quality of life instruments. , 2004, Value in health : the journal of the International Society for Pharmacoeconomics and Outcomes Research.

[9]  D. Burton,et al.  The Reliability and Concurrent Validity of the Scoliosis Research Society-22 Patient Questionnaire for Idiopathic Scoliosis , 2003, Spine.

[10]  Carlyne Arnould,et al.  Développer et interpréter une échelle de mesure. Applications du modèle de Rasch , 2005 .

[11]  Luigi Tesio,et al.  Measuring behaviours and perceptions: Rasch analysis as a tool for rehabilitation research. , 2003, Journal of rehabilitation medicine.

[12]  S. Lai,et al.  The Reliability and Concurrent Validity of the Scoliosis Research Society-22r Patient Questionnaire Compared With the Child Health Questionnaire-CF87 Patient Questionnaire for Adolescent Spinal Deformity , 2007, Spine.

[13]  D. Burton,et al.  Discrimination validity of the scoliosis research society-22 patient questionnaire: relationship to idiopathic scoliosis curve pattern and curve size. , 2003, Spine.

[14]  I. Stokes,et al.  Terminology - glossary including acronyms and quotations in use for the conservative spinal deformities treatment: 8th SOSORT consensus paper , 2010, Scoliosis.

[15]  Alan Tennant,et al.  Modifying the Medical Research Council grading system through Rasch analyses , 2011, Brain : a journal of neurology.

[16]  S S Stevens,et al.  On the Theory of Scales of Measurement. , 1946, Science.

[17]  J. Sanders,et al.  Prevalence and Predictors of Pain in Surgical Treatment of Adolescent Idiopathic Scoliosis , 2011, Spine.

[18]  C. McHorney.  Ten Recommendations for Advancing Patient-Centered Outcomes Measurement for Older Persons , 2003, Annals of Internal Medicine.

[19]  Kathryn A. Lee,et al.  Development of a short version of the Lee Visual Analogue Fatigue Scale in a sample of women with HIV/AIDS: a Rasch analysis application , 2013, Quality of Life Research.

[20]  E. Fogarty,et al.  Scoliosis: a review , 2008, Pediatric Surgery International.

[21]  D. Burton,et al.  Adolescent idiopathic scoliosis: natural history and long term treatment effects , 2006, Scoliosis.

[22]  M Timothy Hresko,et al.  Clinical practice. Idiopathic scoliosis in adolescents. , 2013, The New England journal of medicine.

[23]  G. Neubauer,et al.  Analysis of internal construct validity of the SRS-24 questionnaire , 2012, European Spine Journal.

[24]  Stefano Negrini,et al.  2011 SOSORT guidelines: Orthopaedic and Rehabilitation treatment of idiopathic scoliosis during growth , 2012, Scoliosis.

[25]  B. Lonner,et al.  Discriminative validity of the Scoliosis Research Society 22 questionnaire among five curve-severity subgroups of adolescents with idiopathic scoliosis. , 2013, The spine journal : official journal of the North American Spine Society.

[26]  A. Tennant,et al.  Unified Balance Scale: an activity-based, bed to community, and aetiology-independent measure of balance calibrated with Rasch analysis. , 2011, Journal of rehabilitation medicine.

[27]  A. Tennant,et al.  Rasch analysis of the Modified Fatigue Impact Scale (MFIS) in multiple sclerosis , 2010, Journal of Neurology, Neurosurgery & Psychiatry.

[28]  L. Aulisa,et al.  Determination of quality of life in adolescents with idiopathic scoliosis subjected to conservative treatment , 2010, Scoliosis.

[29]  A. Tennant,et al.  An introduction to Rasch analysis for Psychiatric practice and research. , 2013, Journal of psychiatric research.

[30]  L. Portney,et al.  Foundations of Clinical Research: Applications to Practice , 2015 .

[31]  Harald Steen,et al.  Scoliosis detection, patient characteristics, referral patterns and treatment in the absence of a screening program in Norway , 2012, Scoliosis.

[32]  F. Altaf,et al.  Adolescent idiopathic scoliosis , 2013, BMJ : British Medical Journal.

[33]  B. Wright.  Reasonable mean-square fit values , 1994 .

[34]  David Andrich,et al.  Rasch Models For Measurement , 1988 .

[35]  L. Lenke,et al.  Proximal Junctional Kyphosis Results in Inferior SRS Pain Subscores in Adult Deformity Patients , 2013, Spine.

[36]  B V Reamy,et al.  Adolescent idiopathic scoliosis: review and current concepts. , 2001, American family physician.

[37]  Alan Tennant,et al.  The Rasch measurement model in rheumatology: what is it and why use it? When should it be applied, and what should one look for in a Rasch paper? , 2007, Arthritis and rheumatism.

[38]  A. Samdani,et al.  Effect of Spinal Deformity on Adolescent Quality of Life: Comparison of Operative Scheuermann Kyphosis, Adolescent Idiopathic Scoliosis, and Normal Controls , 2013, Spine.

[39]  M. Monticone,et al.  Reliability of the Scoliosis Research Society-22 Patient Questionnaire (Italian version) in mild adolescent vertebral deformities. , 2004, Europa medicophysica.

[40]  Konrad Pesudovs,et al.  Improving subjective scaling of pain using Rasch analysis. , 2005, The journal of pain : official journal of the American Pain Society.

[41]  James G. Wright,et al.  The characteristics of patient satisfaction measures. , 2000, Spine.

[42]  J. Thonnard,et al.  How many response levels do children distinguish on faces scales for pain assessment? , 2009, European journal of pain.

[43]  P. Sturm,et al.  Patient Satisfaction After Surgical Correction of Adolescent Idiopathic Scoliosis , 2011, Spine.

[44]  S. Weinstein,et al.  Idiopathic scoliosis: long-term follow-up and prognosis in untreated patients. , 1981, The Journal of bone and joint surgery. American volume.

[45]  Kai-Ming G. Fu,et al.  Clinical and radiographic parameters that distinguish between the best and worst outcomes of scoliosis surgery for adults , 2013, European Spine Journal.

[46]  T. Lowe,et al.  Results of the Scoliosis Research Society instrument for evaluation of surgical outcome in adolescent idiopathic scoliosis. A multicenter study of 244 patients. , 1999, Spine.

[47]  J. Linacre,et al.  Sample size and item calibration stability , 1994 .

[48]  Everett V. Smith.  Detecting and evaluating the impact of multidimensionality using item fit statistics and principal component analysis of residuals. , 2002, Journal of applied measurement.

[49]  P. Newton,et al.  Spinal Deformity Correction in Marfan Syndrome Versus Adolescent Idiopathic Scoliosis: Learning From the Differences , 2012, Spine.

[50]  J. Alonso,et al.  Classical test theory versus Rasch analysis for quality of life questionnaire reduction , 2003, Health and quality of life outcomes.