NCT04895683.

Study name	Can Behavioural‐science Informed Text Messages Improve COVID‐19 Vaccination Uptake in North West London? A RCT
Starting date	May 11, 2021
Contact information	Sarah Huf, 07496632732, s.huf@imperial.ac.uk
Methods	Study design: randomised controlled trial Type of publication: trial registration Setting: Central London Country: UK Language: English
Intervention	Active comparator: current practice; text message invitation Experimental: Behavioural Science informed SMS content Experimental: Pre‐alert and behavioural science‐informed SMS content
Population	Population: residents registered with a GP practice in the Central London (Westminster) Clinical Commissioning Group (CCG) Inclusion criteria: age 18‐49; Not previously invited for COVID‐19 vaccination Exclusion criteria: patients who have notified their GP that they wish to decline the COVID‐19 vaccination; Patients' whose medical records report a severe allergy to medicines (as per the JCVI guidance).
Outcomes	Primary outcome COVID‐19 vaccination uptake at 3 weeks [ Time frame: 3 weeks from invitation text message] Secondary outcomes COVID‐19 vaccination uptake at 8 weeks [Time frame: 8 weeks from invitation text message] COVID‐19 vaccination uptake by demographics [Time frame: 3 and 8 weeks]
Estimated completion date and number of participants	11 May 2022 with 120,000 participants
Notes	Funding: Imperial College Healthcare NHS Trust COI: NR