Women Receive Treatment Later Than Do Men for Interstitial Lung Disease
Presenter: Deborah Assayag, MD
Men are more likely than women to receive earlier treatment for interstitial lung disease (ILD), and this gender difference affects survival outcomes.
Gender appears to be important in the diagnosis and prognosis of patients with ILD. Sex-based differences in patient management have been established in some chronic diseases, such as cardiovascular diseases, but previous studies have not adequately examined these considerations in fibrotic ILD.
A new study set out to determine whether patient sex affects treatment initiation among patients with ILD and idiopathic pulmonary fibrosis (IPF) enrolled in a large prospective cohort. The cohort was comprised of 2,292 patients, including 1,198 females (52%) and 1,093 males (48%). Male patients were more likely to be older (66 years vs 60 years), to have ever smoked (71% vs 52%), and to have IPF (42% vs 15%).
The patients in this observational study were taken from a prospective multicenter registry, the Canadian Registry for Pulmonary Fibrosis (CARE-PF). They were enrolled if they had fibrotic ILD, including IPF, connective-tissue-disease-related ILD, hypersensitivity pneumonitis, or unclassifiable ILD. Sex was identified as “male” or “female” on a baseline clinical data form. Date of diagnosis was defined as date of first computed tomography scan showing ILD or date of surgical lung biopsy for ILD.
Time to treatment initiation was defined as time between dates of diagnosis and first instance of ILD-related medication. Medications included anti-fibrotics and immunomodulating medications. Kaplan-Meier curves and Cox proportional hazards models were used to determine the association of patient sex with time-to-treatment initiation, stratified by ILD diagnosis (IPF vs non-IPF ILD), and adjusted for predetermined covariates (age, baseline lung function, smoking).
Results show no gender-based differences in the total proportion of treated patients over the study duration; “however, male patients had significantly shorter time-to-treatment initiation compared with female patients across all diagnoses and for IPF,” said Deborah Assayag, MD, assistant professor at McGill University, Montreal, Canada.
After adjusting for age and lung function, male gender remained significantly associated with earlier time-to-treatment initiation. This difference was significant for all patients (HR 1.24), and in those with IPF (HR 1.90).
“When we looked at survival in treated vs untreated patients, we found that untreated female patients had significantly worse prognosis and lower survival than female patients who were treated,” said Assayag. Possible explanations for this discrepancy include female patients are thought to have a better prognosis overall and are treated later; female patients are less likely to be referred to ILD clinics to start treatment earlier; and uncontrolled bias or confounders, she said.
In conclusion, Assayag said: “In a large Canadian cohort of patients, males are more likely to receive earlier treatment for ILD and IPF than females after adjusting for age, smoking status, and lung function.” The results need to be validated in other prospective longitudinal cohorts and more work is needed to understand the reasons behind this difference, she added.
Link to abstract: Sex Based Differences in the Treatment of Interstitial Lung Diseases in Canada
Deborah Assayag, MD
Financial relationships with relevant companies within the past 24 months:
Boehringer Ingelheim Canada: research grants, speaker fees, consulting fees.
Hoffmann-LaRoche Canada: speaker fees, consulting fees.