ISO 15197:2013 and Regulatory Standards

ISO 15197:2013 and Regulatory Standards

ISO 15197:2013 is the international standard for blood glucose monitoring systems that people with diabetes use to test their own capillary blood, which in practice means a home meter and its test strips [1]. As of October 2026 it is still the edition in force, and its successor is only at the committee-draft stage [1]. In the US, the FDA doesn't clear meters against it. The agency set its own accuracy recommendations in two guidances issued on September 29, 2020, and each one explains why the ISO criteria fall short of what the FDA wants [2] [3].

What ISO 15197:2013 requires

ISO published the 2013 text on May 14, 2013, as the second edition, replacing ISO 15197:2003 [1]. The heart of it is two accuracy criteria checked in a laboratory study, set out in clause 6.3 [4]:

• Criterion A: at least 95% of results fall within ±15 mg/dL of the comparison method below 100 mg/dL, and within ±15% at or above 100 mg/dL [4].
• Criterion B: at least 99% of results land in zones A and B of the consensus error grid [4].

The comparison method is a laboratory measurement of the same blood, using the manufacturer's reference procedure [5]. The consensus error grid comes from a 2000 study that asked 100 diabetes experts to sort meter errors into five risk categories [6]. Zones A and B are the grid's clinically acceptable zones [5].

Two other requirements matter to anyone buying strips. A manufacturer has to show the accuracy criteria hold across three different reagent lots, meaning three separate production batches of strips [5]. A second study, under clause 8, checks accuracy when intended users run the tests themselves [4].

What changed from the 2003 edition

The first edition allowed results within ±15 mg/dL below 75 mg/dL and within ±20% at or above 75 mg/dL [7]. The 2013 revision narrowed the percentage band to ±15% and moved the switch point up to 100 mg/dL [4] [7]. In Europe, the 2013 edition is published as EN ISO 15197:2015 [5].

Some studies reported against both editions at once. A 2015 evaluation of Bayer's Contour Plus system found that all of its laboratory results met both sets of criteria, and that 99.1% of fingerstick results from 220 people with diabetes new to the meter met the 2013 criteria [7]. Did the tighter limits push manufacturers to build better strips? The studies we read measure compliance, not cause, so we can't say the standard by itself drove that.

Passing on paper and passing in independent tests

Here's what surprised us. In a study published in 2020, researchers bought 18 CE-marked meters and their strips, all described as current-generation, from pharmacies in eight European countries and tested one lot of each [5]. Only 14 met criterion A [5]. The most accurate kept 95% of its results within ±7.7 mg/dL or ±7.7%, while the least accurate needed ±19.7 [5]. That was one lot per system rather than the standard's three, but more than one in five systems still missed the limit [5].

How the FDA's September 2020 guidances differ

The FDA reviews meters and strips through 510(k) premarket submissions, the route our article on 510(k) regulatory pathways for test strips walks through [2]. Its two final guidances, both dated September 29, 2020, cover over-the-counter systems for self-testing and prescription systems that health care professionals use at the point of care. Each replaced a version from October 2016 [2] [3].

Both documents acknowledge that many manufacturers design their studies around ISO 15197 [2] [3]. For home use, the FDA says the ISO criteria "are not sufficient to adequately protect lay-users," partly because the standard doesn't adequately address performance at low glucose levels or across strip lots [2]. For professional settings it goes further and does not recommend the ISO criteria at all [3].

Home (over-the-counter) meters

• 95% of results within ±15% of the comparator method and 99% within ±20%, across the meter's entire claimed measuring range [2].
• The study is done by lay users testing themselves, with strips from at least 10 vials covering at least 3 lots, after typical shipping and handling [2].
• The meter should measure accurately from at least 50 to 400 mg/dL, unless the manufacturer justifies a different range [2].
• Release checks on each outgoing strip lot "typically should be tighter" than the study criteria [2].

The low end is where the gap shows. Take a laboratory value of 60 mg/dL: ISO's ±15 mg/dL allows a reading anywhere from 45 to 75, which works out to ±25%, while the FDA's ±15% narrows that to 51 to 69 [2] [4]. The second criterion differs too. ISO uses the error grid; the FDA uses a fixed ±20% band [2] [4].

Prescription point-of-care meters

The professional-use guidance asks for 95% of values within ±12% above 75 mg/dL (±12 mg/dL below 75), and 98% within ±15% above 75 mg/dL (±15 mg/dL below 75) [3]. Unlike the home-use guidance, it keeps a fixed mg/dL allowance at low glucose, as ISO does [3] [4].

What "recommendation" means here

Both guidances are nonbinding. The FDA writes that a meter may still be found substantially equivalent when it misses the criteria, if other features of the meter or its setting of use compensate, and the manufacturer is expected to give a clinical justification for the results that fall outside [2] [3]. The home-use guidance also asks makers of third-party strips, sold by a company other than the meter's maker, to explain how they'll handle design changes to the meter. Its reason: strips and meters work as integral systems [2].

Where the third edition stands

As of October 2026, ISO's open-data records list the 2013 edition as being replaced by ISO/CD 15197, a third edition that is still a committee draft with no publication date [1]. We couldn't find a public text of the draft, so we can't tell whether its accuracy limits will change.

Until a third edition is published, the 2013 criteria remain the international benchmark that accuracy studies test against, under that name or as EN ISO 15197:2015 [1] [5]. A new ISO edition wouldn't by itself change the FDA's recommendations, because the 2020 guidances set their own criteria [2] [3].

Reading an accuracy claim as a strip user

A box that says a system meets ISO 15197:2013 is pointing to accuracy studies run against the criteria above [4]. US clearance is a separate FDA review built on the 2020 guidance [2]. Both rest on studies of at least three strip lots [2] [5]. For the lots that follow, the FDA asks that release checks ensure every lot shipped performs as labeled in the hands of the intended user [2]. Our article on post-market surveillance and lot-to-lot variability covers what happens after strips reach the shelf. If you're weighing whether a meter is accurate enough for the decisions you make with it, that's a conversation to have with your care team.