Period-tracking apps like Flo and Clue are releasing assessments that help determine users' risk of hormonal disorders—but experts say the assessments are often inaccurate and might cause unnecessary worry, Natasha Singer reports for the New York Times.

Cheat sheets: Evidence-based medicine 101

The 'shift' toward digital health assessments

Today, more consumers are using health apps to track or monitor their health and daily activities. But, Singer reports, these apps are increasingly shifting from tools that "simply quantif[y] consumers' health data to medicalizing it." But according to a study published in the journal Nature Digital Medicine, most health assessments performed through apps lack high-level clinical evidence on their outcomes.

Menstrual-tracking apps Flo and Clue are two of the latest health apps to fall under scrutiny. Both apps offer a feature that purports to assess a woman's risk of polycystic ovary syndrome (PCOS), a hormone imbalance disorder that can affect a woman's fertility.

In September of this year, more than 636,000 women completed a Flo health assessment that evaluated their risk for PCOS. Of those women, the app recommended that 240,000 of them, or about 38%, see their doctors about the disorder. According to Singer, Clue declined to share similar data on its assessments usage.

Singer reports that neither Flo nor Clue has conducted clinical studies to determine the accuracy of the assessments. As a result, the women the apps label as possible PCOS patients may not be at risk for the condition at all, leading to unnecessary worry and doctor's visits.

"You could be making a lot of people concerned they have a problem that they don't know will have absolutely no clinical consequences for them," said Jennifer Doust, a professor of clinical epidemiology at Bond University in Australia.

'Err on the side of caution'

Officials for both Clue and Flo insist that the assessments should not be considered definitive diagnoses, and instead are meant to raise awareness about PCOS and encourage women to visit their provider.

When the Flo assessment detects that a user could be at risk, it tells the individual that their symptoms "could be a manifestation of PCOS" while Clue tells users that the disorder could be a "possible cause" of their symptoms.

Daniel Thomas, head of data science for Clue, said, "We err on the side of caution." He added, "Even if we think it's more likely that they don't have PCOS than having PCOS, but it's one of these gray zone cases, we would also still ask them to see the doctor."

But while some women have found the assessments to be helpful, others, like Sasha O'Marra, a copywriter in Toronto, find the popularity of the assessments troublesome and "irresponsible," Singer writes. When O'Marra completed Flo's assessment in July, the app said her acne and irregular menstrual cycle could indicate she has PCOS, but O'Marra said her menstrual cycle probably changed because she had just switched birth control methods.

"It's very concerning to me. Telling people they might have something like PCOS without understanding the context behind their symptoms is a slippery slope," she said (Singer, New York Times, 10/27).