The Barthel index-dyspnea a tool for respiratory rehabilitation: reply to the letter by Chuang [Letter of clarification]

Abstract

Dear editor We read the remarkable letter by Chuang.1 We thank him for his valid suggestions on our paper. Interestingly, he focused on the two dimensions of the Barthel index-dyspnea (BI-d), which was exactly our goal. As rehabilitators, our goal is to provide patients with physical therapy depending on their health status and to improve their respiratory function. We need to verify and demonstrate the efficacy and the outcomes of respiratory rehabilitation, supported by physical therapy. For these reasons, we need an assessment device that measures respiratory improvement during daily motor activities that should be monitored. The modified Barthel index2 is a well-consolidated and widely used instrument to assess the performance of a person in a predetermined and fixed set of activities of daily living (ADLs). By proposing BI-d,3 we aimed to develop a scale to measure how dyspnea precludes or reduces the same ADLs, with the ultimate goal of globally assessing the effectiveness of rehabilitation. Hence, an assessment method that measures the impact of dyspnea on activities monitored by a rehabilitation program is of utmost importance for rehabilitators. Large part of Chuang’s letter is based on the Chronic Respiratory Questionnaire-dyspnea (CRQ-d). The CRQ-d is a health-related quality of life (health status) questionnaire, with a dyspnea “domain”.4 However, for our purposes, the CRQ-d is too individualized as each subject selects five activity items – “the most important” – out of 26 listed activities. Therefore, each subject may choose different items from other subjects in the same study group. Due to this significant methodology, CRQ was standardized recently into a version that contains a total of only five items with a dyspnea domain, all of which have to be responded.5 Conversely, the modified Barthel index2 includes a predetermined and fixed set of ADLs. This allows better comparison between subjects or group of subjects, before and after a treatment, a significant criterion in rehabilitation, and a specific field for which we mainly developed the scale. Moreover, CRQ-d is dyspnea centered, whereas BI-d is activity centered. This first paper on BI-d validation is auspicious. The metric qualities are good and the variability is acceptable, with 95% confidence intervals of correlation coefficient of BI-d versus 6-minute walking test being −0.609 and −0.352, respectively. As pointed out in our paper, additional studies in respiratory rehabilitation programs are required to further assess the applicability of the scale in a broadest context. Mild COPD patients are among those populations who are potential candidates of BI-d. Dr Chuang showed accurately that only 8.1% of our study population had mild COPD. This is obvious as COPD is largely underestimated, and patients usually consult a specialist only when they are diagnosed with GOLD 26 stage disease.7–9 Table 1 and Figure 1 show a few outcomes of four subjects based on the four GOLD stages. They also show that the less obstructed the patient, the lower the BI-d was. Conversely, the more obstructed the patient, the higher the BI-d was. After pulmonary rehabilitation, the BI-d improved in all patients. The best results were observed in GOLD 4 stage as they received a more intensive health care and rehabilitation program. On the other hand, the smallest limitation was assessed at the baseline, and the smallest differences in outcome were observed in subjects at GOLD 1 stage. Conclusion In conclusion, we consider it appropriate to uphold all items of both the modified Barthel index score (because they collect important information from a physical rehabilitation point of view) and of the Barthel dyspnea index (because they allow the estimate of the outcome of a specifically tailored respiratory rehabilitation program).