Gender and racial equity in clinical research for idiopathic pulmonary fibrosis: a systematic review and meta-analysis

Health disparities and associated social determinants of health in interstitial lung disease: a narrative review

BACKGROUND

Health disparities are prevalent across respiratory diseases. Social determinants of health are closely associated with health disparities and account for between 30% and 55% of all health outcomes. In people with interstitial lung disease (ILD), disparities have the potential to significantly impact access to care and health outcomes along many stages of the disease journey.

AIM

This review aimed to provide an overview of health disparities in ILD, focusing on the determinants of health and access to care from diagnosis to end of life and to report on some approaches being proposed to address these disparities.

METHODS

A narrative review of the literature was undertaken using three electronic databases (Ovid Embase, Medline and CINAHL) from inception to May 2024. Disparities and social determinants were mapped to the domains of the Dahlgren-Whitehead model of social determinants of health.

RESULTS

A total of 31 studies were eligible for inclusion. Common disparities identified included differences in antifibrotic utilisation, representation in clinical trials, access to ILD care and lung transplantation waiting lists. Associated social determinants included race/ethnicity, gender, geography and socioeconomic status. Paradoxically, telehealth technology and utilisation have the potential to improve access to diagnostic and treatment options for marginalised communities but may exacerbate disparities for those with lower digital literacy and access.

CONCLUSION

Reducing health disparities in ILD will require an awareness and understanding of the root cause of the disparities at both the individual and societal level in order to develop effective interventions that improve access to care for all living with ILD.

Integrating the assessment of quality of life in care and research in pulmonary fibrosis

PURPOSE OF REVIEW

Pulmonary fibrosis (PF) negatively influences health-related quality of life (HRQOL). Patients living with PF have voiced the desire for a focus on symptoms and HRQOL in both disease monitoring and treatment decisions.

RECENT FINDINGS

Currently available disease modifying treatments do little to impact HRQOL. Newer studies evaluating pharmacologic and nonpharmacologic therapies targeting symptoms and HRQOL in PF have been conducted with some promising results. There is increasing recognition of the importance of incorporating HRQOL as a higher tier endpoint in clinical trials. Disease-specific measure of HRQOL have been developed for those living with PF, and there is ongoing work to better understand the validity and reliability characteristics of these tools. In addition to research, there is recognition of the potential benefits of measuring HRQOL and symptoms in clinical practice in facilitate integrating patient perspective into care and allow for more personalized treatment approaches.

SUMMARY

There is increased momentum to discover treatments that impact HRQOL in PF. More work is desperately needed to identify better treatment targets, and to incorporate HRQOL and symptoms as higher tier endpoints in clinical trials. Further work is also needed to address the practicalities of integrating HRQOL measurement into clinical care.

Missing out on effective care in idiopathic pulmonary fibrosis: Racial inequality in access to anti-fibrotic therapy

See related article

Telehealth Services: Improving Equity in Pulmonary Health Outcomes

Expansion of telehealth services has the potential to attenuate health inequities in pulmonary medicine, by improving access to care and health outcomes in patients with lung disease. These telehealth services include remote patient monitoring, synchronous telemedicine, and remote pulmonary rehabilitation. Currently, patients who are White, well-educated, wealthy, and from urban areas are the most likely to benefit from telehealth services. Without clear policy decisions and planning to overcome the "Digital Divide," telehealth services will only exacerbate existing disparities within the pulmonary disease. We describe the benefits and limitations of these new technologies and their impact on improving equity in pulmonary medicine.

Sex- and Race-Based Differences in the Treatment of Interstitial Lung Diseases in North America and Australasia

BACKGROUND

Biological sex, gender, and race are important considerations in patients with interstitial lung diseases (ILDs).

RESEARCH QUESTION

Does a patient's sex assigned at birth, and race, influence ILD treatment initiation?

STUDY DESIGN AND METHODS

Patients with ILD from three longitudinal prospective registries were compared in this observational study. ILD-related medications included antifibrotics and immunomodulating medications. Race was dichotomized as "White" vs "non-White." Time to treatment initiation was determined from the date of the initial ILD registry visit to the date of first medication initiation. Proportions of treated patients were compared between groups by χ2 test. Cox proportional analysis was used to determine how sex and race were associated with time to treatment initiation stratified by ILD diagnosis.

RESULTS

A total of 4,572 patients were included across all cohorts. The proportion of men who received treatment was higher than for women in the Canadian cohort (47% vs 40%; P < .001), and the proportion of White patients who received treatment was also higher compared with non-White patients (46% vs 36%; P < .001). In contrast, the proportion of treated men in the Chicago cohort was lower compared with women (56% vs 64%; P = .005), and that of White patients was lower compared with non-White patients (56% vs 69%; P < .001). No sex- or race-based differences in proportions of patients treated were found in the Australasian cohort. White race was significantly associated with earlier treatment initiation compared with non-White race across diagnoses in the Canadian cohort, whereas the opposite association was found in the Australasian cohort.

INTERPRETATION

Sex- and race-based differences exist in the initiation of ILD treatment, with variability across different cohorts in different countries. Reasons for these differences need to be further explored in future studies.

Evaluation of Pulmonary Fibrosis Outcomes by Race and Ethnicity in US Adults

Importance

Pulmonary fibrosis (PF) is characterized by progressive scarring of lung tissue and poor survival. Racial and ethnic minority populations face the greatest risk of morbidity and mortality from disparities impacting respiratory health, but the pattern of age at clinically relevant outcomes across diverse racial and ethnic populations with PF is unknown.

Objective

To compare the age at PF-related outcomes and the heterogeneity in survival patterns among Hispanic, non-Hispanic Black, and non-Hispanic White participants.

Design, Setting, and Participants

This cohort study included adult patients with a PF diagnosis and used data from prospective clinical registries: the Pulmonary Fibrosis Foundation Registry (PFFR) for the primary cohort and registries from 4 geographically distinct tertiary hospitals in the US for the external multicenter validation (EMV) cohort. Patients were followed between January 2003 and April 2021.

Exposures

Race and ethnicity comparisons between Black, Hispanic, and White participants with PF.

Main Outcomes and Measures

Age and sex distribution of participants were measured at the time of study enrollment. All-cause mortality and age at PF diagnosis, hospitalization, lung transplant, and death were assessed in participants over 14 389 person-years. Differences between racial and ethnic groups were compared using Wilcoxon rank sum tests, Bartlett 1-way analysis of variance, and χ2 tests, and crude mortality rates and rate ratios were assessed across racial and ethnic categories using Cox proportional hazards regression models.

Results

In total, 4792 participants with PF were assessed (mean [SD] age, 66.1 [11.2] years; 2779 [58.0%] male; 488 [10.2%] Black, 319 [6.7%] Hispanic, and 3985 [83.2%] White); 1904 were in the PFFR and 2888 in the EMV cohort. Black patients with PF were consistently younger than White patients (mean [SD] age at baseline, 57.9 [12.0] vs 68.6 [9.6] years; P < .001). Hispanic and White patients were predominantly male (Hispanic: PFFR, 73 of 124 [58.9%] and EMV, 109 of 195 [55.9%]; and White: PFFR, 1090 of 1675 [65.1%] and EMV, 1373 of 2310 [59.4%]), while Black patients were less likely to be male (PFFR, 32 of 105 [30.5%] and EMV, 102 of 383 [26.6%]). Compared with White patients, Black patients had a lower crude mortality rate ratio (0.57 [95% CI, 0.31-0.97), but for Hispanic patients, the mortality rate ratio was similar to that of White patients (0.89; 95% CI, 0.57-1.35). Mean (SD) hospitalization events per person were highest among Black patients compared with Hispanic and White patients (Black: 3.6 [5.0]; Hispanic, 1.8 [1.4]; and White, 1.7 [1.3]; P < .001). Black patients were consistently younger than Hispanic and White patients at first hospitalization (mean [SD] age: Black, 59.4 [11.7] years; Hispanic, 67.5 [9.8] years; and White, 70.0 [9.3] years; P < .001), lung transplant (Black, 58.6 [8.6] years; Hispanic, 60.5 [6.1] years; and White, 66.9 [6.7] years; P < .001), and death (Black, 68.7 [8.4] years; Hispanic, 72.9 [7.6] years; and White, 73.5 [8.7] years; P < .001). These findings remained consistent in the replication cohort and in sensitivity analyses within prespecified deciles of age groups.

Conclusions and Relevance

In this cohort study of participants with PF, racial and ethnic disparities, especially among Black patients, were found in PF-related outcomes, including earlier onset of death. Further research is essential to identify and mitigate the underlying responsible factors.

The Association between Exposures and Disease Characteristics in Familial Pulmonary Fibrosis

Rationale: Heterogeneous characteristics are observed in familial pulmonary fibrosis (FPF), suggesting that nongenetic factors contribute to disease manifestations. Objectives: To determine the relationship between environmental exposures and disease characteristics of FPF, including the morphological characteristics on chest computed tomography (CT) scan, and timing of FPF symptom onset, lung transplantation, or death. Methods: Subjects with FPF with an exposure questionnaire and chest CT were selected from a prospective cohort at Vanderbilt. Disease characteristics were defined by lung parenchymal findings on chest CT associated with fibrotic hypersensitivity pneumonitis (fHP) or usual interstitial pneumonia (UIP) and by time from birth to symptom onset or a composite of lung transplantation or death. After assessing the potential for confounding by sex or smoking, adjusted logistic or Cox proportional hazards regression models identified exposures associated with fHP or UIP CT findings. Findings were validated in a cohort of patients with sporadic pulmonary fibrosis enrolled in the LTRC (Lung Tissue Research Consortium) study. Results: Among 159 subjects with FPF, 98 (61.6%) were males and 96 (60.4%) were ever-smokers. Males were less likely to have CT features of fHP, including mosaic attenuation (FPF: adjusted [for sex and smoking] odds ratio [aOR], 0.27; 95% confidence interval [CI], 0.09-0.76; P = 0.01; LTRC: aOR, 0.35; 95% CI, 0.21-0.61; P = 0.0002). Organic exposures, however, were not consistently associated with fHP features in either cohort. Smoking was a risk factor for honeycombing in both cohorts (FPF: aOR, 2.19; 95% CI, 1.12-4.28; P = 0.02; LTRC: aOR, 1.69; 95% CI, 1.22-2.33; P = 0.002). Rock dust exposure may also be associated with honeycombing, although the association was not statistically-significant when accounting for sex and smoking (FPF: aOR, 2.27; 95% CI, 0.997-5.15; P = 0.051; LTRC: aOR, 1.51; 95% CI, 0.97-2.33; P = 0.07). In the FPF cohort, ever-smokers experienced a shorter transplant-free survival (adjusted hazard ratio, 1.64; 95% CI, 1.07-2.52; P = 0.02), whereas sex was not associated with differential survival (male adjusted hazard ratio, 0.75; 95% CI, 0.50-1.14; P = 0.18). Conclusions: In FPF, smoking contributes to shortened transplant-free survival and development of honeycombing, a finding that is also likely applicable to sporadic pulmonary fibrosis. Females are more likely to manifest CT features of fHP (mosaic attenuation), a finding that was incompletely explained by sex differences in exposures. These findings may have implications for pulmonary fibrosis classification and management.