An audit of patients with a diagnosis of idiopathic pulmonary fibrosis (IPF) in Canterbury, New Zealand

AIM: In tight of new therapies and guidelines for the management of idiopathic pulmonary fibrosis (IPF), and in the absence of local epidemiological data, we sought to ascertain a current estimate of the prevalence of IPF in Canterbury and to audit local practices. METHODS: We performed a retrospective observational study of patients with IPF in Canterbury, New Zealand and the wider region. Patients were identified through a systematic search of hospital records and included if they were alive on 1 January 2017, had a histological or radiological diagnosis of usual interstitial pneumonia and clinical correlation consistent with a diagnosis of IPF. Clinical data was extracted from the clinical record. Follow up was complete until April 2018. RESULTS: Sixty-eight patients were included, median follow up 33 (14-49) months. Fifteen (22.1%) patients died during follow up, median survival 19 (6.5-54) months. Estimated prevalence of IPF was 6.53/100,000 persons. Six (8.8%) patients were discussed at the Interstitial lung disease multi-disciplinary meeting. Resting Sp02 and end-of-life discussions were documented in 44 (64.7%) and 19 (27.9%) patients respectively, while oxygen therapy was prescribed to 15 (22.7%). 20/36 (55.5%) patients eligible for pirfenidone were treated. Those treated were more likely to have undergone a six-minute walk test (5/20 vs 3/48, p<0.05) or have been hospitalised in the last 12 months (12/20 vs 3/48, p<0.05). 7/20 patients remained on treatment at the end of follow-up (eight discontinued, five deceased). CONCLUSION: In this study the estimated prevalence of IPF in the Canterbury region is 6.53/100,000 persons. Furthermore, we have identified limitations in local practice relevant for service development.