Table 1.

Trial characteristics based on WHO trial registration dataset

Data category	Trial information
Primary registry and trial identifying number	ClinicalTrials.gov (NCT03357029)
Date of registration in primary registry	29 November 2017
Secondary identifying numbers	North Denmark Region Committee on Health Research Ethics: protocol number N-20170023
Source(s) of monetary or material support	The study is conducted as a sponsor–investigator initiated study with financial support from Independent Research Fund Denmark (DFF: 7016-00073).
Primary sponsor	JBF
Secondary sponsor	NA
Contact for public queries	JBF
Contact for scientific queries	JBF
Public title	Neuromodulation in patients with painful chronic pancreatitis (CP)
Scientific title	Study protocol for a randomised double-blinded, sham-controlled, prospective, cross-over clinical trial of vagal neuromodulation for pain treatment in patients with CP
Country of recruitment	Denmark
Healthy conditions(s) or problems studied	CP
Interventions	2-week transcutaneous vagal nerve stimulation (t-VNS) on the cervical vagal area (self-administering vagal nerve stimulation bilaterally to the cervical vagal area, the times per day).
Key inclusion and exclusion criteria	Inclusion criteria: age≥18 years; patients with a diagnosis of CP diagnosed using the Mayo Clinic diagnostic criteria; the participants must be able to read and understand Danish; the patients must suffer from chronic abdominal pain characteristic for CP, meet the criteria for chronic pain (pain≥3 days per week in at least 3 months) and must consider their pain as insufficiently treated with their usual analgesic treatment; personally, signed and dated informed consent document and the power of attorney document; patients willing and able to comply with the scheduled visits, treatment plan, laboratory tests and other trial procedures. Exclusion criteria: patients with any clinically significant abnormalities that in the opinion of the investigator may increase the risk associated with trial participation or may interfere with the interpretation of the trial results; alcohol dependence; illegal drug dependencies; participating in another study where investigational drug is used; patients must not suffer from painful conditions other than CP that make them unable to distinguish the pain associated with CP from the chronic pain of other origin; cardiovascular diseases; low blood pressure<100/60, not able to understand or follow the instructions; any condition with elevated intracranial pressure; female patients who are pregnant; contraindications for MRI; previous surgery on vagal nerve; known neuropathy.
Study type	Interventional allocation: randomised Masking: double blind Assignment: crossover Primary purpose: treatment
Date of first enrolment	January 2018
Target sample size	21
Recruitment status	Recruiting
Primary outcome(s)	Change in NRS scores in pain diary
Key secondary outcomes (s)	Assessment of the effect of t-VNS on (A) resting state brain function assessed by MRI, and (B) brain metabolites assessed by MR spectroscopy.

DFF, Danmarks Frie Forskningsfond (Independent Research Fund Denmark); MR, magnetic resonance; NRS, Numeric Rating Scale.