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Cancer Loyalty Card Study

Cancer Loyalty Card Study: a Retrospective Observational Case-Control Study

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT03994653
Acronym
CLOCS
Enrollment
963
Registered
2019-06-21
Start date
2019-11-04
Completion date
2022-07-28
Last updated
2025-01-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Ovarian Neoplasms

Keywords

Ovarian cancer, Cancer of the ovary, Observational study, Case-control study, Cancer Loyalty Card Study, CLOCS

Brief summary

Approximately 7,400 new cases of ovarian cancer are diagnosed each year in the United Kingdom (UK), and with over 4,000 women dying from the disease each year it is a particularly lethal form of cancer. The symptoms for ovarian cancer are not well known and vague, and most women are diagnosed at a late stage when the cancer has already spread around the abdominal cavity with poor prognosis. Novel methods are needed to improve earlier detection and thereby improve survival from this disease. The Cancer Loyalty Card Study (CLOCS) proposes to use loyalty card data from two participating high street retailers to investigate purchase behaviour as an opportunity for cancer symptom surveillance. The investigators aim to conduct a case-control study of ovarian cancer patients matched with women without ovarian cancer and to explore public preferences for how to communicate potential outcomes of the commercial and health data linkages back to individuals. Eligible participants will be women in the UK who own at least one loyalty card with the participating high street retailers. Of these women, those who have been diagnosed with ovarian cancer are eligible to participate in the study as cases, while women who have not been diagnosed with ovarian cancer are eligible to participate as controls. Upon choosing to participate, all participants will be asked to complete a short questionnaire about well-established ovarian cancer risk factors and common symptoms either in the clinic (cases) or online/from a packet in the mail(controls). This information will be used in risk assessment for ovarian cancer of participants, which will be used at the analysis stage.

Detailed description

Purpose and Design The Cancer Loyalty Card Study (CLOCS) is addressing whether or not data already collected by high street retailers can detect significant changes in purchase behaviours of ovarian cancer patients prior to their diagnosis. The investigators aim to conduct a case-control study of ovarian cancer patients matched with women who do not have ovarian cancer. The study aims to recruit at least 500 recently diagnosed ovarian cancer patients and at least 500 healthy women as controls and collate up to 7 years of prior purchase data. This is a database only study. Recruitment Loyalty card holders will be invited to join the study by email and post from the high street retailers and can choose to sign up via the CLOCS website or via post by returning the consent form to the study team through the mail. There will also be a press release about the study inviting loyalty card holders to visit the CLOCS website for more information and join the study. Women, 18 years or older, who have a loyalty card at the participating high street retailers are eligible to join. Women with ovarian cancer and who own at least one of the participating high street retailer's loyalty cards will be recruited in a clinic by a member of their healthcare team where the study is open. Any woman considering joining the study can contact the research team using the contact details on the information sheet. Consent Ovarian cancer patients will be given the information sheet and consent form in the clinic by a member of their healthcare team. They can take as much time as they need to read through the information sheet. If they choose to participate, they can complete the consent form whenever is convenient for them and return it to the CLOCS team in the free post envelope provided to them in the clinic. Women without ovarian cancer will be presented with the information sheet and consent form in an email or letter in the mail from their high street retailer if they hold a loyalty card with them and return them to the CLOCS team in a free post envelope. They can also find the information sheet and consent form on the CLOCS website and consent online. Methods Consenting participants will complete a brief questionnaire about ovarian cancer risk factors, which will also be returned to the CLOCS team through the mail or on the website (healthy volunteers only). Participants with ovarian cancer will also have a clinical form for a member of their clinical team to complete in the clinic. This will be sent to the CLOCS team along with their consent and risk factor questionnaire in the free post envelope. Two ovarian cancer patients have reviewed all questionnaires and CLOCS documents and expressed their approval. Women without ovarian cancer from the general UK population have also reviewed the risk factor questionnaire and expressed their approval saying the questionnaire is 'easy to understand' and 'straightforward'. If participants consent to be re-contacted by the CLOCS team for future studies or for loyalty card detail clarification,they will provide either a contact email or phone number. There is no further action needed from participants once they complete their consent form and questionnaire (and clarify loyalty card details if necessary)

Interventions

For cases, the study recruiter at the Trust will present this in the clinic. Controls will complete this online or at home when volunteering to participate. The participant questionnaire will be completed by the participant.

For cases, the study recruiter at the trust will complete this form together with the participant. Controls will not complete this form.

Sponsors

Cancer Research UK
CollaboratorOTHER
Imperial College Healthcare NHS Trust
CollaboratorOTHER
Sandwell & West Birmingham Hospitals NHS Trust
CollaboratorOTHER
University College London Hospitals
CollaboratorOTHER
County Durham and Darlington NHS Foundation Trust
CollaboratorOTHER_GOV
Walsall Healthcare NHS Trust
CollaboratorOTHER
Surrey and Sussex Healthcare NHS Trust
CollaboratorOTHER
Airedale NHS Foundation Trust
CollaboratorOTHER
Abertawe Bro Morgannwg University Health Board
CollaboratorOTHER
Gateshead Health NHS Foundation Trust
CollaboratorOTHER
Norfolk and Norwich University Hospitals NHS Foundation Trust
CollaboratorOTHER
The Leeds Teaching Hospitals NHS Trust
CollaboratorOTHER
NHS Lothian
CollaboratorOTHER_GOV
East Lancashire Hospitals NHS Trust
CollaboratorOTHER
University Hospitals Bristol and Weston NHS Foundation Trust
CollaboratorOTHER
Royal Surrey County Hospital NHS Foundation Trust
CollaboratorOTHER
Royal Marsden NHS Foundation Trust
CollaboratorOTHER
Velindre NHS Trust
CollaboratorOTHER_GOV
Cardiff and Vale University Health Board
CollaboratorOTHER_GOV
South Tees Hospitals NHS Foundation Trust
CollaboratorOTHER
West Hertfordshire Hospitals NHS Trust
CollaboratorOTHER
The Christie NHS Foundation Trust
CollaboratorOTHER
Manchester University NHS Foundation Trust
CollaboratorOTHER_GOV
NHS Greater Glasgow and Clyde
CollaboratorOTHER
Imperial College London
Lead SponsorOTHER

Study design

Observational model
CASE_CONTROL
Time perspective
RETROSPECTIVE

Eligibility

Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* Women, at least 18 years old, recently diagnosed with ovarian cancer (preferably recruited just after diagnosis and during treatment period,but are still eligible if diagnosed up to 2 years prior, at the latest) who hold at least one participating high street retailer loyalty card are eligible to join the CLOCS as cases. Women, at least 18 years old, who have not been diagnosed with ovarian cancer and hold at least one participating high street retailer loyalty card are eligible to join the CLOCS as controls.

Exclusion criteria

* Women under the age of 18 years and, since this is a study about ovarian cancer,men will not be eligible to join this study. Women who do not own loyalty cards with the participating high street retailers are not eligible to join this study.

Design outcomes

Primary

MeasureTime frameDescription
Purchase Behaviours (Purchase of Items)24 monthsThe primary outcome of the CLOCS will be to define the time by which the cases and controls are statistically significantly (p=0.05) different in their purchase behaviours leading up to ovarian cancer diagnosis. A higher purchase amount of relevant items (pain and indigestion medications) in cases compared to controls associated with cancer.

Secondary

MeasureTime frameDescription
Alert About Cancer Symptoms Assessed by Purchase Behaviour3 yearsThe secondary outcome of the CLOCS will be defining a purchase threshold as an alert about cancer symptoms in individuals

Countries

United Kingdom

Participant flow

Pre-assignment details

The target enrolment for this study was 1000. However, the study enrolled 963 participants (306 cases and 657 controls). 609 participants remained after confirming first part of eligibility (182 cases and 427 controls). 273 participants remained after confirming second part of eligibility (153 cases and 120 controls)

Participants by arm

ArmCount
Cases
Participants diagnosed with ovarian cancer Risk Factor Questionnaire: For cases, the study recruiter at the Trust will present this in the clinic. Controls will complete this online or at home when volunteering to participate. The participant questionnaire will be completed by the participant. Clinical Questionnaire: For cases, the study recruiter at the trust will complete this form together with the participant. Controls will not complete this form.
182
Controls
Participants without ovarian cancer Risk Factor Questionnaire: For cases, the study recruiter at the Trust will present this in the clinic. Controls will complete this online or at home when volunteering to participate. The participant questionnaire will be completed by the participant.
427
Total609

Baseline characteristics

CharacteristicCasesControlsTotal
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
84 Participants59 Participants143 Participants
Age, Categorical
Between 18 and 65 years
98 Participants368 Participants466 Participants
Age, Continuous64.7 years
STANDARD_DEVIATION 10.9
51.6 years
STANDARD_DEVIATION 13.7
55.5 years
STANDARD_DEVIATION 14.2
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants0 Participants0 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
181 Participants411 Participants592 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
1 Participants16 Participants17 Participants
Region of Enrollment
United Kingdom
182 participants427 participants609 participants
Sex: Female, Male
Female
182 Participants427 Participants609 Participants
Sex: Female, Male
Male
0 Participants0 Participants0 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 00 / 0
other
Total, other adverse events
0 / 00 / 0
serious
Total, serious adverse events
0 / 00 / 0

Outcome results

Primary

Purchase Behaviours (Purchase of Items)

The primary outcome of the CLOCS will be to define the time by which the cases and controls are statistically significantly (p=0.05) different in their purchase behaviours leading up to ovarian cancer diagnosis. A higher purchase amount of relevant items (pain and indigestion medications) in cases compared to controls associated with cancer.

Time frame: 24 months

Population: All participants for whom loyalty card data was received (cases and controls)

ArmMeasureGroupValue (MEAN)Dispersion
CasesPurchase Behaviours (Purchase of Items)6 months (0-6)3.2 number of items purchasedStandard Deviation 8.4
CasesPurchase Behaviours (Purchase of Items)12 months (0-12)5.9 number of items purchasedStandard Deviation 13.6
CasesPurchase Behaviours (Purchase of Items)24 months (0-24)11.4 number of items purchasedStandard Deviation 25
ControlsPurchase Behaviours (Purchase of Items)6 months (0-6)2.0 number of items purchasedStandard Deviation 3
ControlsPurchase Behaviours (Purchase of Items)12 months (0-12)4.3 number of items purchasedStandard Deviation 6.3
ControlsPurchase Behaviours (Purchase of Items)24 months (0-24)8.5 number of items purchasedStandard Deviation 11.4
Comparison: Fishers exact test, conducted at each month prior to diagnosis comparing total purchases of relevant products (pain and indigestion medication) compared with all purchases in both cases and controls.~Power calculation: we used a power calculation assuming the Fisher Exact Test to calculate the minimum group size to detect a difference in purchase proportions that we hypothesised with 80% statistical power.p-value: <0.00195% CI: [2.07, 4.12]Fisher Exact
Secondary

Alert About Cancer Symptoms Assessed by Purchase Behaviour

The secondary outcome of the CLOCS will be defining a purchase threshold as an alert about cancer symptoms in individuals

Time frame: 3 years

Source: ClinicalTrials.gov · Data processed: Feb 17, 2026