Table 1 Acupuncture treatment details based on the STRICTA 2010 checklist[29]

1. Acupuncture rationale

1a) Style of acupuncture

- Manual acupuncture based on traditional meridian theory.

1b) Reasoning for treatment provided, based on historical context, literature sources, and/or consensus methods, with references where appropriate

- Partially-individualized manual acupuncture treatments based on the traditional meridian theory, clinical experience, and consensus by the experts in acupuncture and FD.

1c) Extent to which treatment was varied

- Partially-individualized acupuncture treatment, i.e., fixed points plus optional points according to symptoms.

2. Details of needling

2a) Number of needle insertions per subject per session (mean and range where relevant)

- From 9 to 19.

2b) Names (or location if no standard name) of points used (uni/bilateral)

- Nine fixed points: LI4, ST36, LR3, and SP4 (bilateral) and CV12 (unilateral).

- Optional points according to individual symptoms: GB21, SI14, PC6, EX-HN5, and ST34 (bilateral).

2c) Depth of insertion, based on a specified unit of measurement, or on a particular tissue level

- From 5 to 30 mm.

2d) Response sought (e.g., de qi or muscle twitch response)

- ‘De qi’ sensation.

2e) Needle stimulation (e.g., manual, electrical)

- Manual stimulation: needle rotation with thumb and index fingers at 3 Hz.

2f) Needle retention time

- Fifteen minutes.

2g) Needle type (diameter, length, and manufacturer or material)

- A sterilized stainless steel needle (0.25?×?40 mm, Dongbang Acupuncture Inc., Bundang, Sungnam, Korea).

3. Treatment regimen

3a) Number of treatment sessions

- Eight treatment sessions in both acupuncture and waitlist groups.

3b) Frequency and duration of treatment sessions

- Twice weekly for 4 weeks, 15 minutes for each session.

4. Other components of treatment

4a) Details of other interventions administered to the acupuncture group (e.g., moxibustion, cupping, herbs, exercises, lifestyle advice)

- No other interventions during the study period allowed.

4b) Setting and context of treatment, including instructions to practitioners, and information and explanations to patients

- University hospitals.

- Participants will be informed about acupuncture treatment in the study as follows: “In this study, acupoint for FD will be used based on traditional Korean medicine textbook and FD-related reports.”

5. Practitioner background

5) Description of participating acupuncturists (qualification or professional affiliation, years in acupuncture practice, other relevant experience)

- Korean Medicine Doctors who have a license and at least 3 years of experience in gastrointestinal disorders. They went through 10 hours of training and simulation to ensure that they are able to provide identical acupuncture treatment in accordance with a pre-defined protocol.

6. Control or comparator interventions

6a) Rationale for the control or comparator in the context of the research question, with sources that justify this choice

- A waitlist group will be adopted as a first step before we move on to a sham controlled trial.

6b) Precise description of the control or comparator. If sham acupuncture or any other type of acupuncture-like control is used, provide details as for items 1 to 3 above.

- Participants in the waitlist will not receive acupuncture treatment after randomization for 4 weeks, during which period, there will be six telephone visits. After this waiting period, they then will receive twice weekly acupuncture sessions for 4 weeks in the same manner as in the acupuncture group.