Loyalty-Card Purchase Data

Uses

Preparation

Comparisons

Where it comes from

Highlighted claims

• CLOCS-2 requests up to six years of backdated loyalty-card purchase data when available. — Cancer loyalty card study-2 (CLOCS-2): protocol for an observational case-control study focusing on the patient interval in cancer diagnosis
• For cases, purchase data are backdated from cancer diagnosis; for controls, they are backdated from study consent. — Cancer loyalty card study-2 (CLOCS-2): protocol for an observational case-control study focusing on the patient interval in cancer diagnosis
• Purchase data include purchase-level records, dates, store location by postcode, and retailer-supplied product categories. — Cancer loyalty card study-2 (CLOCS-2): protocol for an observational case-control study focusing on the patient interval in cancer diagnosis
• Prescription pharmacy data are excluded because prescriptions are not part of loyalty-card purchase histories. — Cancer loyalty card study-2 (CLOCS-2): protocol for an observational case-control study focusing on the patient interval in cancer diagnosis
• The study captures over-the-counter medicine purchases and food purchases as possible indicators of symptom management or dietary change. — Cancer loyalty card study-2 (CLOCS-2): protocol for an observational case-control study focusing on the patient interval in cancer diagnosis
• Tesco data access uses OpenID Connect authentication to reduce manual identity verification and participant burden. — Cancer loyalty card study-2 (CLOCS-2): protocol for an observational case-control study focusing on the patient interval in cancer diagnosis