This single-centre, randomized, counterbalanced, within-subjects clinical trial compared four techniques for reducing pain and improving comfort during ventrogluteal intramuscular cyanocobalamin injection in adults. Participants presenting to a family health centre for prescribed vitamin B12 injection each received four injections, one with each technique: standard injection, internal rotation of the extremity, local cold application, and ShotBlocker. Technique order was assigned using a 4 x 4 Latin-square randomization. Pain and comfort were measured immediately after each injection using 0-10 participant-reported scales.
Who can participate
Age range
18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Adults aged 18 years or older.
* Presented to the family health centre for a prescribed course of cyanocobalamin intramuscular injection.
* Able to read, understand, and respond to study instruments in Turkish.
* Provided written informed consent.
Exclusion Criteria:
* Contraindication to ventrogluteal intramuscular injection.
* Local skin lesion, inflammation, edema, scarring, or sensory disturbance over either ventrogluteal site.
* Body mass index less than 18.5 or greater than 35 kg/m2.
* Concurrent regular analgesic or anti-inflammatory use.
* Chronic pain condition.
* Clinically diagnosed psychiatric disorder under active treatment.
* Pregnancy or lactation.
* Known cold intolerance, cold urticaria, or Raynaud phenomenon.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.