A Study to Assess the Efficacy of Gefapixant (MK-7264/AF-219), in Participants With Chronic Cough (MK-7264-006) (EPICC)

Daytime Objective Cough Frequency (per hour) is the total number of cough events during the monitoring period (in general, 24-hr interval) the participant is awake divided by the total duration (in hours) for the monitoring period the participants is awake. 24-hour sound recordings were collected using a digital recording device. Change from baseline in awake cough frequency = (post-treatment awake cough frequency - baseline awake cough frequency). A negative result indicates a decrease in cough frequency, while a positive result indicates an increase in cough frequency.

Cough Severity VAS: scored from 0 to 100 using a 10 mm visual analogue scale with 0 at 0mm and 100 at 100mm with 0 representing no cough and 100 the most severe cough. Change from baseline in daytime cough severity = (post-treatment daytime cough severity - baseline daytime cough severity). A negative result indicates a decrease in cough severity, while a positive result indicates an increase in cough severity.

Nighttime Objective Cough Frequency = Total number of cough events during the monitoring period the participant is asleep divided by the total duration (in hours) for the monitoring period the participant is asleep. 24 hour sound recording were collected with a digital recording device. Change from baseline in nighttime cough frequency = (post-treatment nighttime cough frequency - baseline nighttime cough frequency). A negative result indicates a decrease in cough frequency, while a positive result indicates an increase in cough frequency.

Cough Severity VAS: scored from 0 to 100 using a 10 mm visual analogue scale with 0 at 0mm and 100 at 100mm with 0 representing no cough and 100 the most severe cough. Change from baseline in nighttime cough severity = (post-treatment nighttime cough severity - baseline nighttime cough severity). A negative result indicates a decrease in cough severity, while a positive result indicates an increase in cough severity.

Total (0-24 hours) Objective Cough Frequency = Total number of cough events during the monitoring period divided by the total duration (in hours, i.e., 24 hours mostly) for the monitoring period. 24-hour sound recordings were collected using a digital recording device. A negative result indicates a decrease in cough frequency, while a positive result indicates an increase in cough frequency.

At the end of each study period, participants were asked to complete the global rating of change scale questionnaire. The participants were asked to record whether their cough frequency was "worse", "about the same", or "better". If better or worse, the participants were then asked "by how much" with a 7-category rating scale. Therefore, a 15-point ordered scale was used (1=minimum, a very great deal better to 15=maximum, a very great deal worse with a score of 8=indicating no change).

At the end of each study period, participants were asked to complete the global rating of change scale questionnaire. The participants were asked to record whether their cough severity was "worse", "about the same", or "better". If better or worse, the participants were then asked "by how much" with a 7-category rating scale. Therefore, a 15-point ordered scale was used (1=minimum, a very great deal better to 15=maximum, a very great deal worse with a score of 8=indicating no change).

The CQLQ Questionnaire included 28 items that described negative aspects of quality of life specific to chronic cough. Subscales include: Physical complaints, Psychosocial issues, Functional abilities, Emotional wellbeing, Extreme physical complaints, and Personal safety fears. Participants indicated their degree of agreement with each statement on a 4 point scale (1 = strongly disagree; 2 = disagree; 3 = agree; 4 = strongly agree). CQLQ scores (28 for least impact, 112 for highest impact) used a mixed effect model with terms for treatment sequence, participant within sequence, treatment, and period. Change from baseline in CQLQ scores = (posttreatment CQLQ scores - baseline CQLQ scores). A negative result indicates a decrease in CQLQ scores (lowest cough impact on health-related quality of life), while a positive result indicates an increase in CQLQ scores (highest cough impact on health-related quality of life).

UtCQ is determined through the use of a 100mm visual analogue scale (VAS) (ranging between 0 for "no urge to cough" and 100 for "severe urge to cough"). Change from baseline in UtCQ scores = (post-treatment UtCQ scores - baseline UtCQ scores). A negative result indicates a decrease in UtCQ scores (lowest impact), while a positive result indicates an increase in UtCQ scores (highest impact).

Daytime Objective Cough Frequency (per hour) is the total number of cough events during the monitoring period (in general, 24-hr interval) the participant is awake divided by the total duration (in hours) for the monitoring period the participants is awake. 24-hour sound recordings were collected using a digital recording device.

Cough Severity VAS is scored from 0 to 100 using a 10 mm visual analogue scale with 0 at 0mm and 100 at 100mm with 0 representing no cough and 100 the most severe cough.

Nighttime Objective Cough Frequency is the total number of cough events during the monitoring period the participant is asleep divided by the total duration (in hours) for the monitoring period the participant is asleep. 24 hour sound recording were collected with a digital recording device.

Nighttime cough severity was scored from 0 to 100 using a 10 mm visual analogue scale with 0 at 0mm and 100 at 100mm with 0 representing no cough and 100 the most severe cough.

Total (0-24 hours) Objective Cough Frequency = Total number of cough events during the monitoring period divided by the total duration (in hours, i.e., 24 hours mostly) for the monitoring period. 24-hour sound recordings were collected using a digital recording device.

The CQLQ Questionnaire included 28 items that described negative aspects of quality of life specific to chronic cough. Subscales include: Physical complaints, Psychosocial issues, Functional abilities, Emotional wellbeing, Extreme physical complaints, and Personal safety fears. Participants indicated their degree of agreement with each statement on a 4 point scale (1 = strongly disagree; 2 = disagree; 3 = agree; 4 = strongly agree). CQLQ scores (28 for least impact, 112 for highest impact) used a mixed effect model with terms for treatment sequence, participant within sequence, treatment, and period. Change from baseline in CQLQ scores = (posttreatment CQLQ scores - baseline CQLQ scores). A negative result indicates a decrease in CQLQ scores (lowest cough impact on health-related quality of life), while a positive result indicates an increase in CQLQ scores (highest cough impact on health-related quality of life).

UtCQ is determined through the use of a 100mm visual analogue scale (VAS) (ranging between 0 for "no urge to cough" and 100 for "severe urge to cough").