Results Summary
What was the research about?
Pulmonary fibrosis (PF) is a health problem that causes scarring in the lungs. Patients with PF have a hard time breathing, feel tired, and may have poor quality of life. Fifty percent of people with PF die within three years of diagnosis.
Many doctors prescribe treatment with oxygen for patients with PF. The equipment for oxygen treatment can be hard to handle and can make it hard for people to leave the house. Little research has been done on whether oxygen treatment helps patients with PF.
The research team wanted to learn how patients and caregivers felt about oxygen treatment, including its benefits and downsides. The team wanted to find out if oxygen treatment improves
- Breathing
- Coughing
- Quality of life
- Tiredness
- Physical activity
What were the results?
Patients with PF took surveys before and after oxygen treatment. From the surveys, the research team found that
- After one month of oxygen treatment, patients felt less tired than before. But there were no changes in breathing, quality of life, coughing, or physical activity.
- Nine to 12 months after oxygen treatment, patients had a harder time breathing and coughed more than they did 1 month after treatment. Patients said that coughing affected their quality of life and their health was worse than it had been one month after treatment.
The team also talked with 5 patients with PF who were on oxygen treatment and 20 caregivers of patients with PF who had been using oxygen for at least eight months. The research team found that
- Before treatment, all patients thought oxygen would help them feel better. After treatment, four patients said it improved symptoms. But patients felt frustrated with the oxygen equipment. They also felt judged by other people in public.
- Caregivers thought oxygen treatment helped patients feel better. But caregivers also said that they had to do more physical work at home. They also felt that the burden of oxygen treatment strained their relationships with patients.
Who was in the study?
The study included 43 patients with PF who received oxygen treatment. Ninety-three percent of patients were white.
What did the research team do?
The research team surveyed the patients by email three times: one week before starting oxygen treatment, one month after starting treatment, and 9 to 12 months after starting treatment. The team asked patients to wear a GPS and an activity monitor for seven days around the time the surveys were taken. The surveys asked patients about ease of breathing, quality of life, tiredness, and coughing. The team compared results from the surveys and monitors across the three timepoints.
The research team also interviewed 5 of the patients with PF and the 20 caregivers by phone. The team asked about the benefits and downsides of oxygen treatment. The team interviewed patients one week before starting oxygen treatment, one month after starting treatment, and 9 to 12 months after starting treatment. The team interviewed caregivers after patients had been on oxygen treatment for at least eight months.
What were the limits of the study?
The study had few patients. Results might be different if more patients took part in the study. Also, the research team didn’t know if patients used oxygen correctly or took other medicines. These actions could affect how well oxygen treatment helped patients.
Future research could compare patients with PF who receive oxygen treatment with those who don’t.
How can people use the results?
Patients with PF and their doctors can use the results of this study to talk about the potential benefits and downsides of oxygen treatment.
Professional Abstract
Objective
To evaluate the effect of supplemental oxygen on breathing and physical activity in patients with pulmonary fibrosis (PF) by comparing dyspnea, quality of life, and patient and caregiver perceptions of oxygen use before and after treatment
Study Design
Design Element | Description |
---|---|
Design | Longitudinal mixed-methods study |
Population |
|
Interventions/ Comparators |
Supplemental oxygen use |
Outcomes |
Primary: dyspnea Secondary: physical activity, mobility, general quality of life, fatigue, cough-specific quality of life, and patients’ and caregivers’ perceptions of supplemental oxygen use |
Timeframe | 9-12-month follow-up for primary outcome |
In this longitudinal mixed-methods study, researchers compared outcomes in patients with PF before and after they received supplemental oxygen. Researchers had previously enrolled 300 patients with PF from across the United States in a database of potential patients for studies. For this study, the team enrolled 43 database patients who were about to begin supplemental oxygen treatment. Of the 43 patients, 93% were white, and 56% had a diagnosis of idiopathic PF.
The research team collected surveys and activity monitor data one week before patients started using oxygen and then 1 month and 9–12 months after starting oxygen. Researchers compared mean values for the three timepoints using paired t-tests. To assess outcomes over time, researchers performed slope analysis using linear mixed models using the timepoint at which the surveys were collected, forced vital capacity, age, and gender as predictors. The slope analysis used all available data rather than excluding data from patients who failed to complete one or more surveys.
Researchers also interviewed 5 patients with PF and 20 informal caregivers by phone to understand their perceptions of and experiences with supplemental oxygen. The research team conducted three interviews with the five patients when they collected survey data. The team interviewed caregivers once after patients had used supplemental oxygen for at least eight months. Researchers used grounded theory and a team analytic approach to identify themes from the interviews.
Results
- Comparisons of outcomes before oxygen use and one month after starting oxygen. Supplemental oxygen did not appear to improve dyspnea, quality of life, cough-specific quality of life, or physical activity, but it significantly improved fatigue (p=0.03).
- Comparisons of outcomes 1 month after and 9–12 months after starting oxygen. Over time, patients with PF had worse dyspnea (p=0.05), cough-specific quality of life (p=0.02), and quality of life, assessed in terms of general-health (p=0.01) and vitality (p=0.04).
- Benefits and hardships for patients with PF. During interviews, patients with PF said that they expected supplemental oxygen would improve their symptoms. Four of the five interviewed patients said they experienced the expected benefits. The hardships of oxygen use included having to carry cumbersome equipment and dealing with the social stigma of using oxygen in public.
- Benefits and hardships for informal caregivers. Caregivers felt that oxygen helped patients be more active and feel less fatigued. However, caregivers also felt that helping with the treatment increased the amount of physical work the caregivers did at home. Caregivers said that oxygen use also strained their relationships with patients.
Limitations
The study had a small number of patients and no control group. Thus, results should be considered exploratory. Most patients received care from centers of excellence; results may not be generalizable to other healthcare settings. Researchers could not confirm whether patients used oxygen as prescribed, the prescribed oxygen achieved target blood oxygen saturation levels, or patients had drug-related side effects from other medications. These actions could affect PF symptoms and patient quality of life.
Conclusions and Relevance
These results do not support or discourage the use of supplemental oxygen in patients with PF. Supplemental oxygen may improve patients’ fatigue in the short term. Physicians can discuss the benefits and hardships of supplemental oxygen use with patients and caregivers.
Future Research Needs
Future research could compare outcomes in patients with PF who use supplemental oxygen with outcomes in patients who do not.
Final Research Report
View this project's final research report.
More to Explore...
Study Protocol
View this project's study protocol.
Journal Citations
Related Journal Citations
Peer-Review Summary
Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also confirms that the research has followed PCORI’s Methodology Standards. During peer review, experts who were not members of the research team read a draft report of the research. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. Reviewers do not have conflicts of interest with the study.
The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve how the research team analyzed its results or reported its conclusions. Learn more about PCORI’s peer-review process here.
In response to peer review, the PI made changes including
- Updating the abstract to better match the results presented in the text, including the result that the primary outcome analysis did not show statistically significant differences between the compared interventions
- Adding to both the abstract and the full report a discussion of the lack of a control group and why it is a study limitation
- Stating clearly that the slope analyses were secondary analyses and that no sensitivity analyses had been performed
- Modifying some potentially objectionable language in the Background section