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

Abstract

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 16 427 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.

Keywords: Diagnosis; Idiopathic pulmonary fibrosis; Interstitial lung disease.

Fig. 1

Survey response summary. ^*Includes 503 respondents from the Pulmonary Fibrosis Foundation membership and 97 respondents from the open invitation posted on the Inspire.com patient forum

Fig. 2

Reported frequency of misdiagnosis (a) and time from initial misdiagnosis to final diagnosis (b)

Fig. 3

Most commonly reported misdiagnoses (reported by > 3% of respondents). ILD = interstitial lung disease

Fig. 4

Time from initial onset of symptoms to final diagnosis

Fig. 5

Diagnostic investigations.  Data are presented as percentage of respondents, with the mean frequency per respondent in parentheses. The mean frequency is based on the number of respondents reporting the corresponding diagnostic investigation

Fig. 6

Quality of life assessments. Data are presented as the percentage of respondents for each response category