Portuguese translation and validation of the Patient Generated Index (PGI) instrument for patients with Chronic Obstructive Pulmonary Disease: individualized quality of life assessment.

Objective To translate, adapt and validate the Patient Generated Index (PGI) for Brazilians with chronic obstructive pulmonary disease (COPD). Methods 50 volunteers with COPD, mostly men (74%), with 73.1 ± 8.9 years of age, FEV1 of 52.3 ± 14.5% of predicted and FEV1 / FVC of 56.2 ± 8.6% of predicted responded to PGI, to the Saint George Respiratory Questionnaire (SGRQ) and to perform Glittre Activities of Daily Living test (Glittre ADL). After 1-2 weeks, PGI was again applied for the analysis of relative and absolute reliability. Results The translation occurred without changes in the questionnaire. The score obtained in PGI had weak correlation with the SGRQ total score (r = -0.44, p <0.001) and with the impact domain (r = -0.40, p <0.05), presented a moderate correlation with the symptoms domain of the SGRQ (r = -0.55, p <0.001) and weak correlation with the activity domain (r = -0.31, p <0.05). A weak correlation was observed between PGI and Glittre ADL (r = -0.30; p <0.05). It was observed high reliability among the measures of PGI (ICCr = 0.94). Conclusion This study shows that the Brazilian version of PGI is a reliable and valid instrument to measure health-related quality of life (HRQL) in patients with COPD. It is a new and individualized form of evaluation of COPD patient-centered quality of life.