Cancer Loyalty Card Study (CLOCS)

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

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.

Study Overview

• Status: Completed
• Conditions: Ovarian Neoplasms
• Intervention / Treatment: Other: Risk Factor Questionnaire; Other: Clinical Questionnaire

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)

• Study Type: Observational
• Enrollment (Actual): 963

Contacts and Locations

Study Locations

• United Kingdom
  • London, United Kingdom
    • Imperial College Healthcare NHS Trust

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

All participants will be females in the UK who are at least 18 years old and who own at least one of the participating high street retailer loyalty cards. Participants who have been diagnosed with ovarian cancer are considered cases. Participants who do not have ovarian cancer are considered controls.

Description

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.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Cases; Participants diagnosed with ovarian cancer	Other: 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.; Other Names: Participant Questionnaire; Other: Clinical Questionnaire; For cases, the study recruiter at the trust will complete this form together with the participant. Controls will not complete this form.
Controls; Participants without ovarian cancer	Other: 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.; Other Names: Participant Questionnaire

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	3 years

Collaborators and Investigators

• Sponsor: Imperial College London
• Collaborators: Royal Marsden NHS Foundation Trust; University College London Hospitals; The Leeds Teaching Hospitals NHS Trust; Norfolk and Norwich University Hospitals NHS Foundation Trust; Cancer Research UK; NHS Lothian; Manchester University NHS Foundation Trust; Abertawe Bro Morgannwg University Health Board; Cardiff and Vale University Health Board; University Hospitals Bristol and Weston NHS Foundation Trust; The Christie NHS Foundation Trust; Imperial College Healthcare NHS Trust; East Lancashire Hospitals NHS Trust; NHS Greater Glasgow and Clyde; Velindre NHS Trust; South Tees Hospitals NHS Foundation Trust; Sandwell & West Birmingham Hospitals NHS Trust; County Durham and Darlington NHS Foundation Trust; Royal Surrey County Hospital NHS Foundation Trust; Airedale NHS Foundation Trust; Gateshead Health NHS Foundation Trust; West Hertfordshire Hospitals NHS Trust; Surrey and Sussex Healthcare NHS Trust; Walsall Healthcare NHS Trust
• Investigators: Principal Investigator: James Flanagan, PhD, Imperial College London

Publications and helpful links

General Publications

• Flanagan JM, Skrobanski H, Shi X, Hirst Y. Self-Care Behaviors of Ovarian Cancer Patients Before Their Diagnosis: Proof-of-Concept Study. JMIR Cancer. 2019 Jan 17;5(1):e10447. doi: 10.2196/10447.
• Brewer HR, Hirst Y, Sundar S, Chadeau-Hyam M, Flanagan JM. Cancer Loyalty Card Study (CLOCS): protocol for an observational case-control study focusing on the patient interval in ovarian cancer diagnosis. BMJ Open. 2020 Sep 8;10(9):e037459. doi: 10.1136/bmjopen-2020-037459.
• Brewer HR, Chadeau-Hyam M, Johnson E, Sundar S, Flanagan J, Hirst Y. Cancer Loyalty Card Study (CLOCS): feasibility outcomes for an observational case-control study focusing on the patient interval in ovarian cancer. BMJ Open. 2023 Jun 14;13(6):e066022. doi: 10.1136/bmjopen-2022-066022.

Study record dates

Study Major Dates

• Study Start (Actual): November 4, 2019
• Primary Completion (Actual): January 31, 2022
• Study Completion (Actual): July 28, 2022

Study Registration Dates

• First Submitted: June 19, 2019
• First Submitted That Met QC Criteria: June 20, 2019
• First Posted (Actual): June 21, 2019

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: January 17, 2025
• Last Verified: January 1, 2025

More Information

Terms related to this study

• Keywords: Ovarian cancer; Observational study; Case-control study; Cancer of the ovary; Cancer Loyalty Card Study; CLOCS
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Endocrine System Diseases; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Genital Diseases, Female; Endocrine Gland Neoplasms; Ovarian Diseases; Adnexal Diseases; Genital Neoplasms, Female; Gonadal Disorders; Ovarian Neoplasms
• Other Study ID Numbers: 19IC5156

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Only aggregated and anonymised survey data will be shared with other researchers after publication. No sensitive individual level data will be shared.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No