RESUMO
OBJECTIVE: Breathlessness is a common and disabling symptom of pulmonary disease. Measuring its severity is recommended as such measurements can be helpful in both clinical and research settings. The oxygen-cost diagram (OCD) and the Medical Research Council (MRC) dyspnea scale were developed in English to measure severity of dyspnea. These scales were previously translated to Spanish and adapted for use in a Hispanic population. The objective of this study is to assess the psychometric properties of these scales. We propose the scales correlate well with measures of physiological impairment. METHODS: Subjects having pulmonary disease rated their perceptions of dyspnea using the scales, performed a spirometry test, and did a 6-min walk. Spearman correlation coefficients (p) were used to correlate dyspnea scores with spirometric parameters and distance walked (6MWD). RESULTS: Sixty-six patients having stable asthma (n = 36), chronic obstructive pulmonary disease (n = 19), or interstitial lung disease (n = 11) participated in the study. OCD scores showed a significant correlation with FEV1 (p = 0.41; p < 0.01), FEV1% (p = 0.36; p < 0.01), FVC (p = 0.44; p < 0.01), and FVC% (p = 0.37; p < 0.01) in the study population. The OCD scores were highly correlated with 6MWD (p = 0.59, p < 0.01). The MRC dyspnea scale showed significant inverse correlation with FEV1 (p = -0.34; p < 0.01) and 6MWD (p = -0.33; p < 0.05), but the correlations were weaker compared to the correlations with the OCD scale. CONCLUSION: The severity of breathlessness as measured by the adapted Spanish OCD showed a moderate to high correlation with spirometric parameters and 6MWD; therefore, the adapted OCD should prove to be useful in Puerto Rico.
Assuntos
Asma/diagnóstico , Dispneia/diagnóstico , Doenças Pulmonares Intersticiais/diagnóstico , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Asma/fisiopatologia , Estudos Transversais , Dispneia/etiologia , Feminino , Volume Expiratório Forçado , Humanos , Idioma , Doenças Pulmonares Intersticiais/fisiopatologia , Masculino , Pessoa de Meia-Idade , Oxigênio/metabolismo , Psicometria , Porto Rico , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Índice de Gravidade de Doença , Espirometria/métodos , Estatísticas não Paramétricas , Caminhada/fisiologia , Adulto JovemRESUMO
INTRODUCTION: Dyspnea is a common and disabling symptom for patients with chronic lung diseases. The Medical Research Council Dyspnea Scale (MRC) and the Oxygen Cost Diagram (OCD) are widely used instruments validated in English to measure breathlessness. OBJECTIVE: To translate and culturally adapt the MRC and the OCD for its use in Puerto Rico. METHOD: The scales were translated to Spanish and back translated. They were tested in patients attending a pulmonary clinic to assess its relevance and comprehension. Subjects answered the instruments, had a structured clinical interview and provided feedback. A multidisciplinary committee analyzed the source of misunderstanding using the input of the subjects, the clinical physicians, and the evaluators; made adjustments, and retested the instruments until inconsistencies were not observed. RESULTS: Placing emphasis on time spent walking instead of distance traveled improved the discrimination between grade two and three in the MRC. In the OCD, placing the activities to the right side eased the interpretation of the scale. Numerical symbols were eliminated to minimize discomfort in the severely impaired subjects reluctant to mark the line near zero. Reversing the order of both scales encouraged a thorough reading of the activities from minimal to high energy demanding eliciting a more fitting response compared to structured clinical interview especially in the severely ill patient. CONCLUSION: Using cross-cultural research methodologies to translate the MRC and OCD allowed the identification of differences in conceptualization when assessing the severity of dyspnea in Puerto Rico. Further testing is needed to confirm psychometric properties.