Lag Between Recognition of IPF Symptoms, Diagnosis Found in UK Study

People who have a history of a cough, accompanied by worsening shortness of breath and weight loss, should be assessed for idiopathic pulmonary fibrosis (IPF), a recent study suggests.

This conclusion was based on an analysis of past patient records in the U.K., which sought to understand the pattern of signs and symptoms leading up to an IPF diagnosis. The results indicate a lag between when the symptoms are first recognized in patients and when they are ultimately diagnosed with the respiratory system disease.

The study, “Historical database cohort study addressing the clinical patterns prior to idiopathic pulmonary fibrosis (IPF) diagnosis in UK primary care,” was published in the journal BMJ Open.

IPF is the most common of the idiopathic interstitial pneumonias that affect the walls of the alveoli, or tiny air sacs in the lungs, where oxygen and carbon dioxide are exchanged. Because it is a rare disease, many physicians lack firsthand experience with IPF. In addition, its diagnosis is complicated by the non-specific features present in the disease’s early stages.

To better understand how to identify individuals at risk of developing IPF, researchers from the U.K. and Singapore examined medical records from the Optimum Patient Care Research Database. This clinical research database contains records of approximately 7 million patients from more than 700 primary care centers across the U.K.

From these records, the researchers identified 462 patients who were at least 30 years old, and had seen a general practitioner at least one year before their IPF diagnosis, as well as consulting with a chest specialist prior to diagnosis.

A majority (58.9%) of the patients were male and had an average age of 75 at the time of their diagnosis. Among them, 63.7% had a history of smoking and 9.8% were current smokers. A total of 88 patients had a common lung function test, called a  spirometry, recorded during the 90 days prior to their IPF diagnosis; 160 had the test within a year before they were diagnosed.

Cough and shortness of breath — known as dyspnea — were the most commonly recorded symptoms over one year leading up to an IPF diagnosis. Slightly more than three-quarters (77.9%) of the patients had consulted a respiratory specialist within one year prior to then seeing a chest specialist.

With seven years’ worth of individual records to look back on, the researchers noted that consultations for coughing and dyspnea increased over the four to five years before the patients’ diagnoses. There was a markedly rapid rise in consultations for these symptoms during the one year prior to diagnosis.

The records further showed a strong association between cough and dyspnea, and weight loss, loss of appetite, and fatigue or malaise. Weight loss commonly followed the complaints of cough and dyspnea. Nearly half of the group (47.5%) recorded weight losses of more than 5 kilograms (11 pounds).

The likelihood of an individual receiving an IPF diagnosis showed a lag between the recognition of their symptoms and the final diagnosis. Half (50%) of patients were diagnosed within five years from their first recorded cough, and within three years from their first recorded dyspnea. However, it took 13 years from the first cough, and 10 years from the first dyspnea for 90% of the patients to receive their diagnoses.

According to the researchers, general practitioners should suspect IPF in patients who have a history of increasingly frequent consultations for cough and dyspnea, particularly when the symptoms are accompanied by weight loss. These individuals should be assessed for a possible IPF diagnosis, the investigators said.