Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2023 Jan 26;9:e41762. doi: 10.2196/41762

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

©Hannah R Brewer, Yasemin Hirst, Marc Chadeau-Hyam, Eric Johnson, Sudha Sundar, James M Flanagan. Originally published in JMIR Public Health and Surveillance (https://publichealth.jmir.org), 26.01.2023.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in JMIR Public Health and Surveillance, is properly cited. The complete bibliographic information, a link to the original publication on https://publichealth.jmir.org, as well as this copyright and license information must be included.

PMC Copyright notice

Combined pain and indigestion medications in the Cancer Loyalty Card Study (CLOCS). Cases (n=153) were matched with controls with respect to age and store card use (HSR1 only, HSR2 only, or HSR1+HSR2) at a 2:1 ratio with replacement (n=306 controls in matched analysis, 77 unique individuals). Participants with a previous diagnosis of cancer were excluded. Where possible, the same 24 months of purchases from controls were aligned to each matched case leading to their diagnosis (–24 months to –1 month on the X-axis); otherwise, the last 24 months of purchases were used for controls. (A) Average cumulative purchases of combined pain and indigestion medications in cases (red) and controls (black). (B) Purchases summed on a sliding 3-month window for cases and controls comparing all purchases to purchase of both pain and indigestion medication bought together. The Fisher exact test was used to calculate the odds ratios and significance of enrichment at each month prior to diagnosis. Dx: diagnosis; HSR: high street retailer.