Minimum site visits were: baseline, diagnosis, and EOS for each participant. From inclusion into the study, participants were followed for up to12 months. The EOS was defined as: If no diagnosis was made 12 months after inclusion, the participant left the study; Participants diagnosed with non-ILD left the study on the date of diagnosis; Participants diagnosed with IPF or non-IPF ILD were followed up to the start of drug treatment (within 6 months) or up to 6 months if no drug treatment was prescribed. Therefore, the total length of the study was variable for each participant. Measurements were taken daily by home spirometry. The semi-annual mean FVC decline was calculated by use of the estimated semi-annual FVC decline of each individual participant. The individual FVC decline was estimated by applying a linear regression model to all acceptable FVC measurements flagged as 'Good blow' collected by the individual participant during the entire peri-diagnostic period (up to 18 months).

Participants diagnosed with IPF. Only participants for whom data were collected are included in the analysis.

Minimum site visits were: baseline, diagnosis, and EOS for each participant. From inclusion into the study, participants were followed for up to12 months. The EOS was defined as: If no diagnosis was made 12 months after inclusion, the participant left the study; Participants diagnosed with non-ILD left the study on the date of diagnosis; Participants diagnosed with IPF or non-IPF ILD were followed up to the start of drug treatment (within 6 months) or up to 6 months if no drug treatment was prescribed. Therefore, the total length of the study was variable for each participant. Measurements were taken daily by home spirometry. The semi-annual mean FVC decline was calculated by use of the estimated semi-annual FVC decline of each individual participant. The individual FVC decline was estimated by applying a linear regression model to all acceptable FVC measurements flagged as 'Good blow' collected by the individual participant during the entire peri-diagnostic period (up to 18 months).

Participants diagnosed with non-IPF ILD. Only participants for whom data were collected are included in the analysis.

The peri-diagnostic period covered the pre-diagnostic period (from inclusion into the study (enrollment visit), participants were followed for a maximum of 12 months in the pre-diagnostic assessment period) and the post-diagnostic period (from diagnosis to the start of drug treatment within 6 months or a maximum of 6 months if no drug treatment was prescribed).

Participants diagnosed with IPF and non-IPF ILD. Only participants for whom data were collected are included in the analysis.

The peri-diagnostic period covered the pre-diagnostic period (from inclusion into the study (enrollment visit), participants were followed for a maximum of 12 months in the pre-diagnostic assessment period) and the post-diagnostic period (from diagnosis to the start of drug treatment within 6 months or a maximum of 6 months if no drug treatment was prescribed).

Participants diagnosed with IPF and non-IPF ILD. Only participants for whom data were collected are included in the analysis.

The 6MWT measures the distance a patient is able to walk quickly on a flat, hard surface in a period of 6 minutes. The peri-diagnostic period covered the pre-diagnostic period (from inclusion into the study (enrollment visit), participants were followed for a maximum of 12 months in the pre-diagnostic assessment period) and the post-diagnostic period (from diagnosis to the start of drug treatment within 6 months or a maximum of 6 months if no drug treatment was prescribed).

Participants diagnosed with IPF and non-IPF ILD. Only participants for whom data were collected are included in the analysis.

Patients were asked to wear an accelerometer during the course of the study which provided information on their physical activity at home, with daily measurements used to investigate the development of physical function capacity. The peri-diagnostic period covered the pre-diagnostic period (from inclusion into the study (enrollment visit), participants were followed for a maximum of 12 months in the pre-diagnostic assessment period) and the post-diagnostic period (from diagnosis to the start of drug treatment within 6 months or a maximum of 6 months if no drug treatment was prescribed).

Participants diagnosed with IPF and non-IPF ILD. Only participants for whom data were collected are included in the analysis.

Data collection was impacted by technical problems that could not be solved, thus invalid data collected was not analyzed.

The K-BILD questionnaire was specifically developed to analyze the health status of participants with ILD. The questionnaire consists of 15 items (assessed by the patients on a scale ranging from 1 to 7, where 1 and 7 represent worst and best health status). Items are compiled into 3 domains: breathlessness and activities (range: 0-21), psychological (range: 0-34) , and chest symptoms (range: 0-8). To score the K-BILD, the Likert response scale weightings for individual items are combined and scores are transformed to a range of 0-100 by using logit values (higher scores indicate better health status). The peri-diagnostic period covered the pre-diagnostic period (from enrollment visit participants were followed for up to 12 months) and the post-diagnostic period (from diagnosis to the start of drug treatment within 6 months or a maximum of 6 months if no drug treatment was prescribed).

All enrolled participants completed the questionnaire. Only participants for whom data were collected are included in the analysis.

The mMRC dyspnea scale was used to grade the effects of breathlessness on daily activities over time. The following grading categories are used for this scale: Grade 0 - I only get breathless with strenuous exercise; Grade 1 - I get short of breath when hurrying on the level or walking up a slight hill; Grade 2 - I walk slower than people of the same age on the level because of breathlessness or have to stop for breath when walking on my own pace; Grade 3 - I stop for breath after walking about 100 yards or after a few minutes on level ground; Grade 4 - I am too breathless to leave the house. The peri-diagnostic period covered the pre-diagnostic period (from inclusion into the study (enrollment visit), participants were followed for a maximum of 12 months in the pre-diagnostic assessment period) and the post-diagnostic period (from diagnosis to the start of drug treatment within 6 months or a maximum of 6 months if no drug treatment was prescribed).

All enrolled participants. Only participants for whom data were collected are included in the analysis. Data of post-diagnosis period for non-ILD participants and participants without diagnosis were not collected.

The EQ-5D-5L questionnaire is a self-reported health status questionnaire that assesses mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each item is rated by the participant on a five-point scale indicating the followings: Level 1 - no problem; Level 2 - slight problems; Level 3 - moderate problems; Level 4 - severe problems; Level 5 - extreme problems. The peri-diagnostic period covered the pre-diagnostic period (from inclusion into the study (enrollment visit), participants were followed for a maximum of 12 months in the pre-diagnostic assessment period) and the post-diagnostic period (from diagnosis to the start of drug treatment within 6 months or a maximum of 6 months if no drug treatment was prescribed).

All enrolled participants. Data of post-diagnosis period for non-ILD participants and participants without diagnosis were not collected as participants already discontinued from the study.

The EQ-VAS questionnaire is a self-reported questionnaire that measures health state. The VAS is a 100 mm scale from worst (0 mm) to best (100 mm) health the participant can imagine. The peri-diagnostic period covered the pre-diagnostic period (from inclusion into the study (enrollment visit), participants were followed for a maximum of 12 months in the pre-diagnostic assessment period) and the post-diagnostic period (from diagnosis to the start of drug treatment within 6 months or a maximum of 6 months if no drug treatment was prescribed).

All enrolled participants. Only participants for whom data were collected are included in the analysis. Data of post-diagnosis period for non-ILD participants and participants without diagnosis were not collected.

The EQ-5D-5L questionnaire is a self-reported health status questionnaire that assesses mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. A unique health state is defined for each participant by combining the levels from each of the 5 dimensions. Each state is referred to in terms of a 5 digit code, e.g. state 11111 indicates no problems on any of the 5 dimensions, while state 12345 indicates no problems with mobility, slight problems with washing or dressing, moderate problems with usual activities, severe pain or discomfort and extreme anxiety or depression. From these 5 answers an index value is derived between 0 and 1, with a higher value corresponding with a better Quality of Life.

All enrolled participants. Only participants for whom data were collected are included in the analysis. Data of post-diagnosis period for non-ILD participants and participants without diagnosis were not collected.

The FAS is a fatigue questionnaire consisting of 10 items; five questions reflect physical fatigue and five questions analyze mental fatigue. A five-point scale (one for "never" to five for "always") is used for participant responses. The scale score is calculated by summing all items. Therefore, the FAS scores can range from 10 to 50. The peri-diagnostic period covered the pre-diagnostic period (from inclusion into the study (enrollment visit), participants were followed for a maximum of 12 months in the pre-diagnostic assessment period) and the post-diagnostic period (from diagnosis to the start of drug treatment within 6 months or a maximum of 6 months if no drug treatment was prescribed).

All enrolled participants. Only participants for whom data were collected are included in the analysis. Data of post-diagnosis period for non-ILD participants and participants without diagnosis were not collected.

The VAS are 100 mm scales on which participants indicate the severity of their cough, the urge to cough and their fatigue. In the VAS, participants had to record their health state on a scale ranging from 0 (best imaginable health state) to 100 (worst imaginable health state). A mean of this health state was recorded for participant analyzed in this outcome measure. The peri-diagnostic period covered the pre-diagnostic period (from inclusion into the study (enrollment visit), participants were followed for a maximum of 12 months in the pre-diagnostic assessment period) and the post-diagnostic period (from diagnosis to the start of drug treatment within 6 months or a maximum of 6 months if no drug treatment was prescribed).

All enrolled participants. Only participants for whom data were collected are included in the analysis. Data of post-diagnosis period for non-ILD participants and participants without diagnosis were not collected.

The correlation of FVC (mL) between home and site spirometry was analyzed by taking into account the individually estimated linear regression models of each participant for home-based FVC measurements and site FVC measurements. This analysis was performed for participants diagnosed with IPF or non-IPF ILD in the peri-diagnosis period. The peri-diagnostic period covered the pre-diagnostic period (from inclusion into the study (enrollment visit), participants were followed for a maximum of 12 months in the pre-diagnostic assessment period) and the post-diagnostic period (from diagnosis to the start of drug treatment within 6 months or a maximum of 6 months if no drug treatment was prescribed).

Only IPF and non-IPF ILD participants with non-zero declines are included in the analysis.

The measure represents the correlation of distance walked (meter) assessed by physical function capacity at home and the 6MWT at the site in the peri-diagnosis period. The peri-diagnostic period covered the pre-diagnostic period (from inclusion into the study (enrollment visit), participants were followed for a maximum of 12 months in the pre-diagnostic assessment period) and the post-diagnostic period (from diagnosis to the start of drug treatment within 6 months or a maximum of 6 months if no drug treatment was prescribed).

Only IPF and non-IPF ILD participants with non-zero declines are included in the analysis.

The number of participants requiring the hospitalization were counted during pre- and post-diagnosis period.

All enrolled participants.

The number of participants requiring the hospitalization were counted during pre- and post-diagnosis period. Investigator-reported acute exacerbations, deaths, and events related to study assessments were only collected in the clinical database. As the study had no protocol mandated IMP or treatment requirements, any untoward occurrences such as AEs and SAEs were not collected.

All enrolled participants.

Acute exacerbation was defined as per Collard et al. 2016. Investigator-reported acute exacerbations, deaths, and events related to study assessments were only collected in the clinical database. As the study had no protocol mandated IMP or treatment requirements, any untoward occurrences such as AEs and SAEs were not collected.

All enrolled participants. Data of post-diagnosis period for non-ILD participants and participants without diagnosis were not collected.

The number of participants, who died due to any cause, were counted during pre- and post-diagnosis period.

All enrolled participants.

The number of participants, who died due to respiratory-related diseases, were counted during pre- and post-diagnosis period.

All enrolled participants.

The number of participants with events related to the study assessments were counted during pre- and post-diagnosis period. Investigator-reported acute exacerbations, deaths, and events related to study assessments were only collected in the clinical database. As the study had no protocol mandated IMP or treatment requirements, any untoward occurrences such as AEs and SAEs were not collected.

All enrolled participants.