Table 1 Examples of open-ended questioning from the patient semi-structured interview guide

General

• Tell me about what it is like to have [GBA-PD^a].

• Tell me about a bad day with [GBA-PD].

• Now tell me about a really good day for you?

• How does your [GBA-PD] change from day to day?

• Has your [GBA-PD] changed from one year ago to now? Please describe.

• [If time since diagnosis is more than 1.5 years] Has your [GBA-PD] changed at all since you were first diagnosed? Please describe.

• Does your [GBA-PD] change during the day?

Symptoms

• Tell me about any symptoms you experience that are caused by your [GBA-PD].

• Which three of the symptoms that you described are the most bothersome for you? Why?

• Which of the symptoms are the least bothersome for you? Why?

• Are there any symptoms that you used to have but you don’t have any more?

• Are there any symptoms that you are concerned about experiencing in the future?

• Which three of those symptoms would you consider it most important for a treatment to improve? Why?

Impacts

• Tell me about how [GBA-PD] affects your daily life.

• Are there any activities that you are now completely unable to do because of your [GBA-PD]?

• Which impacts have the greatest effect on your life? Why?

• Which impacts have less of an effect on your life? Why?