Validação do stroke specific quality of life (SS-QOL) para avaliação da participação de indivíduos acometidos pelo acidente vascular encefálico

Abstract

Background: Among the three components of the International Classification of Functioning, Disability and Health (ICF), the “participation” domain is considered the most complex to be evaluated with existing assessment tools. The use of quality of life questionnaires has been suggested for the assessment of participation among individuals following cerebrovascular accident (stroke), specifically the Stroke Specific Quality of Life (SS-QOL) scale. However, the majority of items on the SS-QOL scale evaluate other ICF categories. It is therefore necessary to perform an accurate evaluation of only the items on this questionnaire that address participation, with the validation and analysis of the psychometric properties of these specific items. Thus, the aim of the proposed study is to validate the SS-QOL scale for the evaluation of the participation component of the ICF. Methods: A preliminary analysis will be performed of the SS-QOL items that only address the ICF participation category. For such, the reliability and scoring patterns and answers of individuals will be analyzed and internal consistence will be determined using the intraclass correlation coefficient (CCI2,1) and their respective confidence intervals (CI) of 95% and the Rasch model, respectively. The analysis of reproducibility was analyzed by CCI2,1, standard error of measurement (SEM), minimal detectable change (MDC) and the test plot Bland-Altman. The cutoff point and the discriminatory power were estimated by Receiver-operating characteristic (ROC) curve with confidence interval (CI) of 95%. The analysis of construct validity was performed in the classic form: (1st) comparison of known groups; (2nd) convergent validity. An alpha risk ≤ 0.05 was considered for all analyses. Results: In the preliminary assessment identified that the 26 items that address participation, three showed erratic behavior. As to reproducibility, these items demonstrated excellent reliability (intra-examiner ICC2,1 = 0.96; inter-examiner ICC2,1 = 0.95). The standard error of measurement and minimum detectable change were adequate. The Bland-Altman plot demonstrated satisfactory agreement. The cutoff point ≥89 seems appropriate to discriminate individuals with and without restriction on participation. The 26 items of the SS-QOL evaluating the CIF participation component have adequate discriminatory power, with significant specificity (85.7%) to identify institutionalized individuals. It was observed that these items are able to differentiate individuals with and without restriction on participation. The assumptions a priori on the construct validity were achieved partly. The items have adequate validity of internal consistency. The ceiling and floor effects were considered adequate in the total score of the instrument, however, above acceptable standards in some areas. Conclusions: The 26 SS-QOL items that address the participation component of the ICF demonstrated a multidimensional construct, i.e. not only evaluate participation. However, they showed adequate reproducibility. The cutoff point ≥89 seems appropriate to discriminate individuals with and without restriction on participation. The ceiling and floor effects were considered adequate in the total score, however, above acceptable standards in some areas. In summary, it can be inferred that these items have adequate measurement properties, however, not only evaluate the construct participation.