Barriers to timely diagnosis of interstitial lung disease in the real world: the INTENSITY survey

Background: The diagnosis of idiopathic pulmonary fibrosis (IPF) and other interstitial lung diseases (ILD) presents significant clinical challenges. To gain insights regarding the diagnostic experience of patients with ILD and to identify potential barriers to a timely and accurate diagnosis, we developed an online questionnaire and conducted a national survey of adults with a self-reported diagnosis of ILD. Methods: A pre-specified total of 600 subjects were recruited to participate in a 40-question online survey. E-mail invitations containing a link to the survey were sent to 16427 registered members of the Pulmonary Fibrosis Foundation. Additionally, an open invitation was posted on an online forum for patients and caregivers (www.inspire.com). The recruitment and screening period was closed once the pre-defined target number of respondents was reached. Eligible participants were adult U.S. residents with a diagnosis of IPF or a non-IPF ILD. Results: A total of 600 eligible respondents met the eligibility criteria and completed the survey. Of these, 55% reported >= 1 misdiagnosis and 38% reported >= 2 misdiagnoses prior to the current diagnosis. The most common misdiagnoses were asthma (13.5%), pneumonia (13.0%), and bronchitis (12.3%). The median time from symptom onset to current diagnosis was 7 months (range, 0-252 months), with 43% of respondents reporting a delay of >= 1 year and 19% reporting a delay of >= 3 years. Sixty-one percent of respondents underwent at least one invasive diagnostic procedure. Conclusions: While a minority of patients with ILD will experience an appropriate and expedient diagnosis, the more typical diagnostic experience for individuals with ILD is characterized by considerable delays, frequent misdiagnosis, exposure to costly and invasive diagnostic procedures, and substantial use of healthcare resources. These findings suggest a need for physician education, development of clinical practice recommendations, and improved diagnostic tools aimed at improving diagnostic accuracy in patients with ILD.