TABLE 4.
First author [ref] Study type |
n | Treatment | IPF symptoms | Exacerbations | FEV1 | Other outcomes |
Medications | ||||||
Bradford [169] Retrospective observational |
262 | Chronic anti-reflux medications (>6 months non-p.r.n. use of any antacid, sucralfate, H2RA or PPI) versus non-users (<6 months of use or none) | N/A | N/A | Unchanged | Increased risk of hospitalisation and respiratory hospitalisation in chronic anti-reflux medication users; no effect on mortality |
Gribbin [170] Retrospective case–control |
920 | Anti-reflux medications (H2RA or PPI) | N/A | N/A | N/A | IPF diagnosis significantly associated with anti-reflux therapy (OR 2.20, 95% CI 1.88–2.58) |
Lee [171] Retrospective observational |
204 | Anti-reflux medications (H2RA or PPI) | N/A | N/A | N/A | Anti-reflux medications were an independent predictor of longer survival time; anti-reflux medications were associated with a lower radiological fibrosis score |
Lee [172] Retrospective observational |
242 | Anti-reflux medications (H2RA or PPI) | N/A | N/A | Unchanged | Patients taking anti-reflux medications at baseline had a smaller decrease in FVC at 30 weeks (−0.06 L, 95% CI −0.11 to −0.01) compared to those not taking anti-reflux medications (−0.12 L, 95% CI −0.17 to −0.08; difference 0.07 L, 95% CI 0–0.14; p=0.05). No change in all-cause mortality |
Kilduff [173] Prospective observational |
18 | Anti-reflux medications (H2RA or PPI) undergoing oesophageal pH–impedance | N/A | N/A | N/A | Significant decrease in the number of acid reflux events (p=0.02), but an increase in the number of non-acid reflux events (p=0.01); no change in cough frequency (p=0.70) |
Ghebremariam [174] Prospective observational |
215 | PPI therapy >12 months | N/A | N/A | N/A | Use of PPIs was associated with a significant reduction in the number of patients with lung transplantation or death (p=0.025) and a 1.4-year increase in longevity (median survival of 3.4 versus 2 years; p<0.001) |
Raghu [181] Prospective observational |
406 | Anti-reflux medications (H2RA or PPI) with and without nintedanib | N/A | N/A | N/A | Anti-reflux medication use at baseline did not influence the treatment effect of nintedanib on reducing decline in FVC in patients with IPF |
Lee [176] Retrospective observational |
786 | PPI any type (mean follow-up 2.6 years) | N/A | N/A | N/A | Patients administered PPI >4 months had a lower IPF-related mortality rate than patients on PPI <4 months; younger age, higher initial FVC and longer duration of PPI use, but not a diagnosis of GORD, were significantly associated with lower IPF-related mortality |
Kreuter [177] Pooled analysis |
291 | Anti-reflux medications (H2RA or PPI) For 52 weeks follow-up |
N/A | Overall and pulmonary infections higher in patients with advanced IPF treated with anti-reflux medications compared to those not treated | Unchanged | No difference in overall or IPF-related mortality between groups; no difference in hospitalisations between groups |
Kreuter [178] Post hoc RCT analysis |
623 | Anti-reflux medications (H2RA or PPI) with and without pirfenidone | N/A | Severe pulmonary infections higher in patients treated with anti-reflux medications compared to those not treated; no difference in all-cause hospitalisation rate | Unchanged | No significant differences in disease progression, all-cause mortality rate IPF-related mortality rate or mean change in percent FVC between groups; severe gastrointestinal adverse events were more frequent with anti-reflux medications |
Dutta [179] RCT |
45 | PPI (omeprazole) | N/A | Small excess of lower respiratory tract infection in omeprazole-treated group | Small reduction in FEV1 in omeprazole-treated group | Non-significant reduction in geometric mean cough frequency at the end of treatment, adjusted for baseline in the omeprazole group compared with placebo; omeprazole was well tolerated and adverse event profiles were similar in both groups; non-significant reduction in FVC associated with omeprazole |
Surgery | ||||||
Linden [180] Prospective observational |
19 | Nissen fundoplication (15-month follow-up) | N/A | N/A | Unchanged | Unchanged exercise capacity; stable oxygen requirements compared to IPF patients without fundoplication on transplant list |
Raghu [181] Retrospective observational |
27 | Nissen fundoplication | N/A | N/A | Unchanged | Improvement in mean DeMeester scores from 42 to 4 (p<0.01); trend toward stabilisation in observed FVC No 90-day deaths |
Raghu (WRAP-IPF trial) [34] RCT |
58 | Nissen fundoplication | N/A | Non-significant reduction in exacerbations & respiratory hospitalisations in surgery-treated group | N/A | Non-significant reduction in rate of change of FVC (p=0.28) and mortality over 48 weeks |
Abbreviations: IPF: interstitial pulmonary fibrosis; FEV1: forced expiratory volume in 1 s; H2RA: histamine-2 receptor antagonist; PPI: proton pump inhibitor; FVC: forced vital capacity; GORD: gastro-oesophageal reflux; RCT: randomised controlled trial.