Validation of a Quality of Life Instrument in Spanish Patients With Rheumatic Diseases The Rosser Classification System Leticia Leon, PhD, MS,*† Luis Rodriguez-Rodriguez, MD, PhD,* Maria Dolores Aguilar, MD, PhD,‡ Juan Ángel Jover, MD, PhD,§‖ Cristina Vadillo, MD,§ Marta Redondo, PhD, MS,† and Lydia Abasolo, MD, PhD* Objective: The aim of this study was to assess the reliability and validity of the Spanish version of the Rosser classification system for disease states in patients with musculoskeletal disorders. Methods: Our study was based on a questionnaire validation design. Pa- tients were attended at an outpatient rheumatology clinic at Hospital Clínico San Carlos, Madrid, Spain. The Rosser classification system was completed by the physician from the research team (PMQ) and by the pa- tient (HMQ). Criterion standards: The EuroQol-5D for the HMQ and the physician global estimate (DOCGL) for the PMQ. Internal consistency re- liability was assessed using Cronbach α. Test-retest reliability and interob- server reliability were analyzed using the intraclass correlation coefficient. The criterion validity between HMQ and EuroQol-5D and between PMQ and DOCGL was assessed using the Spearman correlation coefficient. Results: The full analysis was based on 4 samples of patients (104 to 266 patients), most of whom were middle-aged women. For HMQ, Cronbach α was 0.70. Test-retest reproducibility was 0.7. With respect to criterion validity, significant correlations in the expected direction were ob- served. For PMQ, Cronbach α was 0.70, indicating excellent intraobserver and interobserver reliability. With respect to criterion validity, strong corre- lations were observed between the PMQ and the DOCGL. Conclusions: The Rosser classification system showed satisfactory reli- ability and suitable criterion validity for patients with musculoskeletal dis- orders. The instrument seems to be suitable for clinical decision making and research. Key Words: quality of life, rheumatic diseases, validation studies (J Clin Rheumatol 2018;00: 00–00) O ver the last 2 decades, major advances in health and medical care have generated a substantial increase in average life ex- pectancy, which has been accompanied by a parallel increase in the frequency of chronic diseases. 1,2 Chronic diseases are among the most relevant challenges for health systems in developing countries 3 because of their impact on quality of life (QOL) and health costs. 1 Consequently, clinical management is being restructured. A novel approach is needed, that is, one in which outpatient manage- ment is becoming more important than the hospital admission. Moreover, appropriate patient care requires specific strategies and interventions, as well as interaction between and integration of the various medical professionals involved. Management in routine outpatient care should be evaluated. 4,5 Assessment of QOL should accompany more traditional variables, such as mortality and morbidity, 1,2 when setting key objectives that will enable health professionals and stakeholders to meet the patient's expectations. 6 Quality of life is evaluated through patient-reported out- comes (PROs), 7 which are standardized questionnaires to obtain information directly from patients about how they function or feel in relation to their illness. A PRO can be disease-specific or ge- neric to any condition and can generate a profile of scores or a sin- gle index. Disease-specific PROs cover the severity, symptoms, and functional limitations specific to a particular disease state, condition, or diagnostic grouping (e.g., the Health Assessment Questionnaire). 8 Generic PROs are designed for use with any dis- ease group or population sample and can be applied to compare various types of disease. The problem is that most instruments (e.g., the Short-Form Health Questionnaire) are too complicated and lengthy for routine use in an ambulatory setting. 9 Explanation and performance are time consuming in daily clinical practice ow- ing to restrictions of caseload (number and complexity) and time available for consultations. Thus, such instruments are currently reserved for clinical and epidemiologic research. 10,11 Never- theless, 2 generic PROs that could prove potentially useful for evaluation of QOL in routine clinical practice are the EuroQol- 5D (EQ-5D) 12 and the Rosser classification system for disease states. 6,13 Their main advantages are that they are relatively simple to use, they represent the patient's preferences, they allow us to compare different clinical entities, and they enable calculation of quality-adjusted life-years. The Rosser classification system for disease states 6,13 covers preferences, independence, degree of disability, emotional distress, pain, and QOL, all from the patient's point of view. Data can be col- lected in 2 ways: through a self-administered questionnaire com- pleted by the patient (HMQ) 6 and through direct questions during From the *Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Hospital Clínico San Carlos; †Universidad Camilo José Cela; ‡Técnicas Avanzadas de Investigación en Servicios de Salud; §Rheumatology Unit, Hospital Clínico San Carlos; and ‖Medicine Department, Universidad Complutense, Madrid, Spain. This study was supported by project CP11/00189, which is integrated in the Plan Nacional de I + D + I, AES 2011, and cofunded by the Ministerio de Economía y Competitividad (Instituto de Salud Carlos III) and by the FondoEuropeo de Desarrollo Regional. This study was carried out in accordance with international ethical recommendations (Declaration of Helsinki and Oviedo Agreement). It was developed in accordance with the protocol and with our standard operating procedures, which ensure compliance with the standards of Good Clinical Practice. All patients included were asked to provide verbal informed consent. This study was approved by the Ethics and Clinical Trial Review Board of Hospital Clínico San Carlos. Author contributions: L.L., L.R.-R., L.A.: manuscript preparation, statistical methods; M.D.A., C.V.: data abstraction, quality assessment; M.R., J.Á.J.: manuscript preparation. Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal’s Web site (www.jclinrheum.com). Correspondence: Leticia Leon, PhD, MS, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Hospital Clínico San Carlos, Calle Martín Lagos, s/n, 28034 Madrid, Spain. E‐mail: lleon.hcsc@salud.madrid.org. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 1076-1608 DOI: 10.1097/RHU.0000000000000774 ORIGINAL ARTICLE JCR: Journal of Clinical Rheumatology • Volume 00, Number 00, Month 2018 www.jclinrheum.com 1 Copyright © 2018 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.