Restarting Triple Therapy With Robust Monitoring for Adverse Events (RETRIAL)

Inclusion Criteria: RETRIAL-Mental Health: * PWCF age 6 years and up (if age is \< 12 years old, the PWCF's caregiver will complete daily diaries and surveys; see "Caregiver Participant Inclusion Criteria" below) * Eligible for VTD and intending to take it * Experienced new or worsening mental health symptoms after initiating ETI, which led to one of the following changes in treatment to currently taking: 1. No modulators 2. A modulator other than ETI 3. A flipped dose of ETI 4. A reduced dose of ETI * Willing to delay first VTD dose for short period of time to complete the Baseline assessments * Has access to a smart device (phone, tablet, etc.) capable of receiving messages with survey links * Is English-speaking. RETRIAL-LIVER: * A person with CF age 6 years and up * Eligible for VTD and intending to take it * Experienced drug-induced liver injury (as defined by local care team) after initiating ETI, which led to one of the following changes in treatment to currently taking: 1. no modulators; or 2. a modulator other than ETI; or 3. a reduced or altered dose of ETI; * Willing to delay first VTD dose for short period of time to complete the Baseline assessments * Has access to a smart device (phone, tablet, etc.) capable of receiving messages with survey links * Is English-speaking. Exclusion Criteria: RETRIAL-Mental Health: * Cannot access VTD * Currently, or prior history of, taking VTD * Unable or unwilling to follow protocol * If \<12 years old, having another \<12-year-old person in the same household consented into the study * Is actively listed on any transplant list, or within 3 months post-transplant surgery * Is currently pregnant (test not required) * Anticipated change in CF Care Centers in the next 6 months * Any situation that, in the opinion of the Investigator, would compromise the safety of the patient or the quality of the data. RETRIAL-LIVER: * Cannot access VTD * Currently, or prior history of, taking VTD * Unable or unwilling to follow protocol * If \<12 years old, having another \<12-year-old person in the same household consented into the study * Any severe, decompensated liver disease (e.g. Child-Pugh, Class C) * Is actively listed on any transplant list, or within 3 months post-transplant surgery (any organ), or history of liver transplant * Is currently pregnant (test not required) * Anticipated change in CF Care Centers in the next 6 months * Any situation that, in the opinion of the Investigator, would compromise the safety of the patient or the quality of the data. Caregiver Participant: Inclusion Criteria: * Is a primary, daily caregiver of a person with CF under the age of 12 enrolled in the study * Has access to smart device (phone, tablet, etc.) capable of receiving messages with survey links * Is able to read and complete surveys and Daily Diary in English. Exclusion Criteria: \- Any situation that, in the opinion of the Investigator, would compromise the safety of the patient or the quality of the data.