Last week, Walmart made headlines with a claim that new weight loss drugs might be making people buy less food. Walmart US CEO John Furner told Bloomberg<\/em><\/a> that people taking Wegovy, Ozempic, and similar drugs showed a \u201cslight change\u201d in their purchasing habits: \u201cjust less units, slightly less calories.\u201d How does Walmart know this? Because, Bloomberg<\/em> indicates, it can compare people\u2019s prescription history against their food shopping patterns. It\u2019s the kind of data mining that\u2019s likely possible for any big retail-and-pharmacy operation \u2014 and one that raises questions about how private health records should be.<\/p>\n<\/div>\n We don\u2019t know the details of Walmart\u2019s research. The company didn\u2019t respond to a request for more information from The Verge<\/em>, and Bloomberg <\/em>offers a brief two-sentence recap:<\/p>\n<\/div>\n The Bentonville, Arkansas-based retailer is studying changes in sales patterns using anonymized data on shopper populations. It can look at the purchasing changes among people taking the drug and can also compare those habits to similar people who aren\u2019t taking the shots.<\/p>\n<\/blockquote>\n<\/div>\n Walmart is strategically well-positioned to do this. It operates both a pharmacy program and a network of around 5,200 stores<\/a> across the US, including about 3,500 one-stop-shopping supercenters, so it\u2019s got a lot of people filling prescriptions the same place they buy food. Many shoppers likely wouldn\u2019t be surprised to learn that Walmart is tracking general retail purchases to forecast future customer demand, and Bloomberg <\/em>suggests Walmart and others could use this data to prepare for a future where people buy less food.<\/p>\n<\/div>\n But someone\u2019s prescriptions are more legally and ethically sensitive than their average grocery run. Pharmacy records can bluntly reveal health conditions many people would rather keep private \u2014 not just whether they\u2019re trying to lose weight, but whether they\u2019ve obtained abortion pills or are dealing with stigmatized mental health conditions. And while the US leaves huge gaps<\/a> in consumer privacy protections, pharmacy records are protected by the Health Insurance Portability and Accountability Act (HIPAA), which limits how they can be disclosed without patient consent. That raises a question Bloomberg<\/em> doesn\u2019t mention: should companies like Walmart be able to funnel them into other parts of their business operations? And if so, what should the limits be?<\/p>\n<\/div>\n \u201cThe buying and selling of prescription data is a complex issue balancing patient privacy, commercial interests, and regulatory oversight,\u201d says Tara Sklar, faculty director of the Health Law & Policy Program at the University of Arizona\u2019s law school.\u00a0At a federal level, Sklar says, HIPAA restricts how companies can release health data that\u2019s tied to an individual. <\/p>\n<\/div>\n The catch here, however, is \u201cindividual.\u201d Companies \u2014 including major chains like CVS<\/a> and Rite Aid<\/a> \u2014 have faced fines for doing things like throwing out pill bottles with visible patient names and prescriptions. But per Bloomberg<\/em>, Walmart promises its data is anonymized, or stripped of identifying details that could be tied back to specific patients.<\/p>\n<\/div>\n Unfortunately, the idea that huge, complex datasets can be meaningfully \u201canonymous\u201d is largely a polite fiction<\/a>. (Absent more detail from Walmart, it\u2019s also not clear what kind of patient consent might have been given for the Ozempic research.) \u201cEven anonymized prescription details can reveal a lot about individuals,\u201d says Sklar. \u201cDetails like medication, dosage, timing, prescriber, pharmacy, etc. can be very unique to an individual, which makes it easier to re-identify someone.\u201d The more widely this information is released, the greater the odds that it could be used in ways it\u2019s not intended, and that people could see private details of their lives exposed.<\/p>\n<\/div>\n Walmart is far from the only company that\u2019s in a position to do this kind of analysis. Amazon, for instance, launched its own pharmacy service<\/a> in late 2020 as part of a larger push into health care<\/a> and has moved steadily<\/a> into grocery sales. Its access to medical data has raised concerns among privacy advocates<\/a>. Privacy isn\u2019t the only issue on the table either: a recent antitrust lawsuit accuses Amazon of leveraging<\/a> its data trove to cement a retail monopoly. We don\u2019t know if Amazon is using health records for the kind of research Walmart described \u2014 the company didn\u2019t respond to questions from The Verge<\/em> about the matter. But pharmacy records could add yet another powerful source of data to its operation.<\/p>\n<\/div>\n \u201cPatients do not expect pharmacies to share or sell records of their medication, anonymized or not.\u201d<\/p>\n<\/div>\n<\/div>\n Sklar notes that HIPAA isn\u2019t the only rule in play around medical records. The Federal Trade Commission also publishes a set of guidelines dubbed the Fair Information Practice Principles (FIPPs) that emphasize making sure a company\u2019s use of health data is consistent with patients\u2019 expectations. And recently, the FTC has cracked down on some allegedly flagrant breaches of trust \u2014 like the case of GoodRx, which allegedly let Google, Facebook, and other web companies target ads<\/a> using personal health information. GoodRx agreed to an unusually harsh ban on sharing health details with third parties as part of a settlement. \u201cPatients do not expect pharmacies to share or sell records of their medication, anonymized or not,\u201d says Sklar.<\/p>\n<\/div>\n But in an economy filled with highly consolidated companies that prize unfettered access to data, it\u2019s unclear when customers can expect that their pharmacy records will be used for purposes besides their own health care \u2014 and what options they have if they don\u2019t want that data spread around.<\/p>\n<\/div>\n And on top of all that, this research doesn\u2019t really tell us if Ozempic is making people buy less food. GLP-1 drugs like Ozempic and Wegovy, which are formally approved for diabetes but widely used for weight loss<\/a>, do appear to have skyrocketed in popularity. But Walmart\u2019s Furner told Bloomberg <\/em>it\u2019s \u201ctoo early to draw any definitive conclusions\u201d on their impact for the company \u2014 and when publicly available details on the research are so skimpy, that goes doubly true for anyone outside it.<\/p>\n<\/div>\n<\/div>\n\n