Responsiveness and minimal clinically important difference of SGRQ-I and K-BILD in idiopathic pulmonary fibrosis

Abstract

Background: Idiopathic pulmonary fibrosis (IPF) specific version of St. George's Respiratory Questionnaire (SGRQ-I) and King's Brief Interstitial Lung Disease questionnaire (K-BILD) are validated health-related quality of life (HRQL) instruments, but no or limited data exist on their responsiveness and minimal clinically important difference (MCID). The objectives of this study were to assess responsiveness of SGRQ-I and K-BILD and determine MCID separately for deterioration and improvement in a large, prospective cohort of patients with IPF in a real-world setting. Methods: Consecutive patients with IPF were recruited. SGRQ-I, K-BILD, SGRQ, Shortness of Breath Questionnaire, pulmonary function tests and 6-min walk test measurements were obtained at baseline and at six and 12 months; at six and 12 months, patients also completed Global Rating of Change Scales. Responsiveness was assessed using correlation coefficients and linear regression. Cox regression was used for mortality analyses. MCID was estimated using receiver operating characteristic curves with separate analyses for improvement and deterioration.Results: A total of 150 IPF patients were included and 124 completed the 12-month follow-up. Based on all HRQL anchors and most physiological anchors, responsiveness analyses supported the evidence pointing towards SGRQ-I and K-BILD as responsive instruments. Multivariate analyses showed an association between SGRQ-I and mortality (HR: 1.18, 95% CI: 1.02 to 1.36, p = 0.03) and a trend was found for K-BILD (HR: 0.82, 95% CI: 0.64 to 1.05, p = 0.12). MCID was estimated for all domains of SGRQ-I and K-BILD. MCID for improvement differed from deterioration for both SGRQ-I Total (3.9 and 4.9) and K-BILD Total (4.7 and 2.7).Conclusions: SGRQ-I and K-BILD were responsive to change concerning both HRQL and most physiological anchors. MCID was determined separately for improvement and deterioration, resulting in different estimates; especially a smaller estimate for deterioration compared to improvement in K-BILD. Trial registration: Clinicaltrials.gov, no. NCT02818712. Registered 30 June 2016.

Clusters of comorbidities in idiopathic pulmonary fibrosis

“…Exclusion criteria were intellectual or linguistic barriers preventing the completion of questionnaires. ILD-specific HRQL questionnaires have been validated in the same cohort [19][20][21].…”

Health-related quality of life of patients with idiopathic pulmonary fibrosis: a systematic review and meta-analysis

“…12 studies made use of the ILD-specific King A limited number of studies used disease-specific (IPF) instruments, although many of the studies were conducted after their development in 2010. Of these, five studies [52,[70][71][72][73] used the disease-specific format of the SGRQ, the SGRQ-I, and three used "A Tool to Assess Quality of life in IPF" (ATAQ-IPF) [44,48,74]. supplementary material S9.…”

Disease Behaviour During the Peri-Diagnostic Period in Patients with Suspected Interstitial Lung Disease: The STARLINER Study

“…No clear patterns of disease behaviour were observed for IPF versus non-IPF ILD for PROs. In patients with IPF, EQ-5D-5L health state VAS score and K-BILD total score tended to worsen over time, but these changes did not exceed previously reported ranges of the minimal clinically important difference (MCID) [ 29 , 30 ]. In patients with non-IPF ILD, the improvements from baseline in EQ-5D-5L health state VAS score and K-BILD total score were not greater than the previously reported range of MCIDs [ 29 , 30 ].…”

“…In patients with IPF, EQ-5D-5L health state VAS score and K-BILD total score tended to worsen over time, but these changes did not exceed previously reported ranges of the minimal clinically important difference (MCID) [ 29 , 30 ]. In patients with non-IPF ILD, the improvements from baseline in EQ-5D-5L health state VAS score and K-BILD total score were not greater than the previously reported range of MCIDs [ 29 , 30 ]. However, in patients with IPF, the deterioration from baseline in EQ-5D index score was within the reported MCID range of 0.005–0.054 [ 29 ] and the same applied for the improvement from baseline in EQ-5D index score in patients with non-IPF ILD [ 29 ].…”