According to a report in Mobile Health News last month, Apple has a problem with patient-entered glucose readings in its Health app. Devices in the U.S. and some other countries measure blood glucose levels in “milligrams per deciliter” (mg/dL). In some other countries, the standard unit is “millimoles per liter” (mmol/L). The Health app is not able to accept manual entry of data in those units, so the company is going to release an update to the program so that it will not let users manually enter data unless it’s in mg/dL. The Apple HealthKit does support both units of measure, so presumably in the future Apple will be able to release a version of the Health app that accepts either one.
This problem simply highlights just how difficult it is to create data systems that are robust enough to handle the wide variety of information that is generated by consumer and clinical devices. This includes handling different units of measure and tracking them accurately. Add on the layers of data security and protecting patient privacy (such as required by HIPAA) and the task becomes positively daunting. If your running app miscalculates the distance you covered in this morning’s run by a multiple of 10, it’s just annoying. If a health app gets the units wrong on a measure used by healthcare professionals for diagnosis and treatment, the results can be catastrophic.
This misstep by Apple is not likely to improve its reputation among healthcare professionals for handling patient data. Apple’s response to the problem is available here.