Cancer loyalty card study-2 (CLOCS-2): protocol for an observational case-control study focusing on the patient interval in cancer diagnosis.
Sima Toopchiani, Saphsa Codling, Yuscah Pondeca...
https://pubmed.ncbi.nlm.nih.gov/42128509Actively Recruiting
Age: 18Years +
All Genders
Healthy Volunteers
ID06447064
Cancer Loyalty Card Study 2: a Retrospective Observational Case-Control Study
Led by Imperial College London · Updated on 2026-03-25
2900
Participants Needed
1
Research Sites
8 weeks
Total Duration
On this page
Sponsors
I
Imperial College London
Lead Sponsor
U
University of Birmingham
Collaborating Sponsor
AI-Summary
What this Trial Is About
Cancer is a leading cause of death worldwide, responsible for about 9.6 million deaths each year. Early diagnosis is crucial to improve outcomes, as it allows treatments like surgery and radiotherapy to be more effective before the cancer spreads. This study focuses on ten types of cancer—colon, oesophageal, stomach, liver, bladder, uterine, vulval, ovarian, endometrial, and pancreatic—which often show vague symptoms that may delay diagnosis and treatment. The study examines whether purchase data from high street retailers Tesco and Boots can reveal changes in buying habits related to symptoms before a cancer diagnosis. It will compare 1,450 recently diagnosed cancer patients with 1,450 control participants without these cancers. Participants must be 18 or older and hold loyalty cards from these retailers. Six years of past purchase data will be collected and analyzed alongside questionnaire responses about health and lifestyle. Participants will complete an online questionnaire and provide informed consent, including agreeing to share their loyalty card data. The study will collect pseudonymised purchase data, focusing on items like pain relief medications. Researchers will assess purchase behaviors over three years to develop risk profiles and predictive models. The study runs through April 2027, with participant data securely managed and optional re-contact for future studies.
CONDITIONS
Brief Title
Cancer Loyalty Card Study 2 (CLOCS-2)
Who Can Participate
Age: 18Years +
All Genders
Healthy Volunteers
Eligibility Criteria
You may qualify if you...
- Individuals aged over 18 years
- Residing in the United Kingdom at the time of giving informed consent
- Registered with an NHS GP Practice
- Diagnosed with one of the specified cancer types in the last 24 months (cases) or no cancer diagnosis in the last 6 years except non-melanoma skin cancer (controls)
- Primary registered cardholder of a Tesco Clubcard or Boots Advantage Card loyalty card and consent to share loyalty card data
- Provide written informed consent
- Willing and able to comply with all study activities
- If not the primary cardholder but from the same household, the primary cardholder must also enroll
You will not qualify if you...
- Individuals under 18 years of age
- Non-UK residents at the time of consent
- Individuals without an eligible loyalty card or with no household member holding one
- Participants not primary registered cardholders where the primary cardholder is unwilling to join or does not make purchases for them
- Cases diagnosed with eligible cancer types more than 24 months ago (except non-melanoma skin cancer)
- Cases with ineligible cancer diagnoses in the last 6 years (except non-melanoma skin cancer)
- Controls with any cancer diagnosis in the last 6 years (except non-melanoma skin cancer)
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
1
2
3
Your Study Journey
Screening
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (online)
Diagnostic Evaluation
Duration - Up to 1 week
Participants complete an online questionnaire about their health, clinical history, and lifestyle choices. ID verification may be required if retailer data cannot be matched.
1 online questionnaire completion
Long-term Monitoring
Duration - Up to 6 years retrospective
Participants' past six years of purchase history from Tesco and Boots loyalty cards are analyzed in a pseudonymised and secure manner to study purchase behaviours related to cancer diagnosis.
No visits; data collected from retailer records
Trial Site Locations
Total: 1 location
1
Imperial College Healthcare NHS Trust
London, United Kingdom
Actively Recruiting
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Research Team
Y
Yuscah Pondeca
D
Dr James Flanagan
How is the study designed?
Study Type
OBSERVATIONAL
Masking
N/A
Allocation
N/A
Model
N/A
Primary Purpose
N/A
Number of Arms
2
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