Cultural adaptation and validation of instrument Modified Dyspnea Index

Author(s)

Cinthya Tamie Passos Miura

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
• Defense date: 2010-06-18

Examining board members

Maria Cecilia Bueno Jayme Gallani; Audrey Borghi e Silva; Neusa Maria Costa Alexandre

• Advisor: Maria Cecilia Bueno Jayme Gallani

Abstract

Dyspnea is an important symptom in cardiovascular diseases, which are important cause of morbidity and mortality worldwide. The subjectiveness of the symptom hampers its accurate quantification. Thus, questionnaires, as the Modified Dyspnea Index (MDI), have been developed in order to provide a more specific evaluation of the symptom. Objectives: The aim of this study were to cross-culturally adapt the instrument Modified Dyspnea Index for the Portuguese language of Brazil, to test its reliability and convergent validity by correlation of its scores with perceived exertion (Modified Borg Scale), respiratory muscle strength evaluation and assessment of health-related quality of life (Minnesota Living with Heart Failure). Methodology: The process of cultural adaptation followed rigorous methodology and included the steps of translation, back translation and evaluation of semantic, idiomatic, cultural and metabolic equivalence by a committee of experts. The Index of Content Validity was used to estimate the proportion of agreement among the judges. As the MDI is designed to be answered by health professionals based on an the evaluation of the patient, a User's Guide for administering the Brazilian-MDI in Portuguese was prepared, with purpose of standardizing its administration and rating. Reliability was assessed according to the criterion of inter-observer equivalence, evaluating the agreement between two health care providers (one nurse and one physiotherapist) regarding individual and total scores of patients with cardiovascular disease with dyspnea. Validity was tested according to the criterion of convergent validity, by the correlation between Brazilian-MDI and: Modified Borg Scale, health-related quality of life (Brazilian version of the Minnesota Living with Heart Failure - LHFQ) and maximal inspiratory (MIP) and maximal expiratory pressure (MEP). The instruments were interviewer- administered by a single researcher, due to the low educational level of the target population. Afterwards, the patients were submitted to the measurement of MIP and MEP. The agreement between the independent observers in 31 patients was evaluated with Kappa's coefficient; Spearman coefficients were used to test the correlations between Brazilian-MDI and the other measures (n=151). The significance level used was p <0.05. Results: Evaluation of the content validity resulted in the rewording of some sentences of the MDI. The coefficient of agreement between the independent observers was k = 0.960.The Brazilian-MDI was negatively and significant but weakly correlated to the Modified Borg Scale (r= -0.29; p=0.0003) and to the Brazilian-MDI and MIP and MEP measures (r= 0.26; p=0.0001 and r= 0.28; p=0.0006; respectively). However, the Brazilian-MDI was highly correlated to the scores of health-related quality of life, considering the LHFQ total score and the physical subscale, (r= -0.53, p=<0.0001; r= -0.59, p=<0.0001, respectively); and the emotional domain (r= -0.30; p=<0,0001). The adaptation of the MDI for use in a Brazilian population has been undertaken with rigor and the tests of its reliability and validity points to strong evidences of being a useful tool for use in research and clinical settings in evaluating dyspnea. (AU)

• FAPESP's process: 08/07649-4 - Cross Cultural Adaptation and Validation of the Modified Dyspnea Index
• Grantee: Cinthya Tamie Passos Miura
• Support Opportunities: Scholarships in Brazil - Master