We studied if Bronchiectasis (BR) and Rheumatoid arthritis (RA) when manifesting as an overlap syndrome (BROS) was associated with worse outcomes than other BR aetiologies applying the Bronchiectasis Severity Index (BSI).
We interrogated the Bronchiectasis Severity Index (BSI) databases of 1716 patients across 6 centres: Edinburgh, UK (608 patients), Dundee, UK (N=286), Leuven, Belgium (N=253), Monza, Italy (N=201), Galway Ireland (N=242) and Newcastle, UK (N=126). Patients were categorised as BROS (those with RA and Bronchiectasis without interstitial lung disease), idiopathic bronchiectasis, Bronchiectasis-COPD overlap syndrome (BCOS) and “other” BR aetiologies. Mortality rates, hospitalisation and exacerbation frequency were recorded.
We identified 147 patients with BROS (8.5% of cohort). There was a statistically significant relationship between BROS and mortality although this was not associated with higher rates of bronchiectasis exacerbations or bronchiectasis-related hospitalisations. The mortality rate over a mean of 48 months was 9.3% for idiopathic BR, 8.6% in patients with “other” causes of BR, 18% for RA and 28.5% for BCOS. Mortality was statistically higher in BROS and BCOS compared with all other aetiologies. The BSI scores were statistically but not clinically significantly higher in those with BROS when compared to idiopathic BR (BSI mean 7.7 vs. 7.1 respectively, p <0.05). BCOS had significantly higher BSI scores (mean 10.4), Pseudomonas aeruginosa colonization rates (24%) and prior hospitalisation rates (58%).
Both BROS and BCOS groups have an excess of mortality -the mechanisms for this may be complex but these data highlight that these subgroups require additional study to understand this excess mortality.