Trends in diagnostic investigations
| Year | Surgical lung biopsy | Bronchoalveolar lavage |
| Unknown | 21.6 | 11.8 |
| 2013 | 16.1 | 11.9 |
| 2014 | 10.5 | 4.0 |
| 2015 | 11.2 | 2.2 |
| 2016 | 8.1 | 4.5 |
| 2017 | 5.1 | 3.9 |
| 2018 | 2.8 | 3.8 |
| 2019 (to 31 October 2019) | 1.2# | 1.3# |
Data are presented as % patients. #: comparing the proportion of patients undergoing surgical lung biopsy (p=0.42) and undergoing bronchoalveolar lavage (p=0.43) by year; statistical analysis performed using one-way ANOVA with Kruskal–Wallis. Cases where the year of presentation was unknown were excluded.