Translation, cross-cultural adaptation, and measurement properties of the Brazilian-Portuguese version of the idiopathic pulmonary fibrosis-specific version of the Saint George's Respiratory Questionnaire (SGRQ-I) for patients with interstitial lung disease.

ABSTRACT:

Background

The idiopathic pulmonary fibrosis-specific version of the St George's Respiratory Questionnaire (SGRQ-I) is a valid tool to assess health-related quality of life in patients with interstitial lung diseases (ILDs).

Objective

To translate and cross-culturally adapt the SGRQ-I to Brazilian-Portuguese, and to assess its measurement properties.

Methods

Phase one consisted of the translation and cross-cultural adaptation of the questionnaire. In phase two, intra- and inter-assessor reliability (intraclass correlation coefficient [ICC]), internal consistency (Cronbach's α), minimal detectable change (MDC), ceiling/floor effects, convergent validity (correlation with SF-36 questionnaire), and discriminative validity (according to clinical characteristics) were investigated.

Results

No significant adaptations were needed during the translation process of the SGRQ-I. In phase two, 30 patients with ILD were included (15 men; age 59 ± 10 years; Forced Vital Capacity 73 [61-80]%predicted). The total score on the SGRQ-I presented excellent intra-assessor (ICC: 0.93; 95%CI: 0.85, 0.97]) and inter-assessor (ICC: 0.88; 95%CI: 0.77, 0.94) agreement. Internal consistency was considered adequate for the domains impact, activity, and total score (0.79<α<0.88) but not for symptoms (α=0.43). MDC was 12.8 points and ceiling/floor effects were found in only 3% of patients. No discriminative validity was observed, but there was adequate convergent validity.

Conclusion

The results provide preliminary evidence of adequate measurement properties and validity of the Brazilian-Portuguese version of the SGRQ-I for patients with ILDs.

SUBMITTER: Aguiar WF 

PROVIDER: S-EPMC8721060 | biostudies-literature |

REPOSITORIES: biostudies-literature