contributed articles

THERE IS DEMONSTRABLE appeal in consumer-wearable devices like activity trackers, having now been used by approximately 10% of American adults to track measures of their fitness or well-being. 4 Because activity trackers are most commonly used for motivating a change in behavior toward modest personal fitness goals or healthy activity levels over time, 8 it is easy to forget they are also used to inform more critical decision making and serious investigations of self, including tracking ongoing health conditions and disease progression; 24 tracking mood, with potential implications for mental-health treatment; 4 and self-diagnosing problems involving health or other concerns. 22

These popular uses expose the potential variability
of “uncertainty tolerance” among multiple users. 12

Those undertaking a serious investigation of self require
a certain level of precision and data
accuracy, as well as details regard-
ing correlations between variables,
whereas salient information for those
with a casual interest in their fitness
may simply want to know whether they
have met some target or are generally
improving over time. Technological ad-
vances, both recent and on the horizon
for health wearables, are predicted by
some experts to enable breakthroughs
in disease prevention, prediction, and
management, areas for which uncer-
tainty tolerance differs significantly
from that of the wearable consumer. 10
In addition to existing health wear-
ables that claim to measure blood
pressure, breathing rate, and mood or
emotions and stress through galvanic
skin response, wearables may soon
be able to measure or infer health in-
dicators like blood glucose, calories
consumed, hydration, and heart strain
(for details, see https://www.wareable.
com/fitness-trackers).

Here, we explore the implications of, and difficulties in designing for, uncertainties regarding health wearables. We begin with the relatively minimal negative impact of uncertainty in current consumer uses of these gadgets as a way to demonstrate the known-but-as-yet-unresolved challenges in communicating health data to users. We next argue that seemingly innocuous uncertainties emerging in the present use of wearables need attending to, as they are likely to pro-

Uncertainty in
Current and
Future Health
Wearables
DOI: 10.1145/3199201

Expect inherent uncertainties in health-wearables data to complicate future decision making concerning user health.

BY BRAN KNOWLES, ALISON SMITH-RENNER,
FOROUGH POURSABZI-SANGDEH, DI LU, AND HALIMAT ALABI

key insights

˽ Unlike popular use scenarios involving today’s consumers, more ambitious future use of health wearable data can be expected to involve even less tolerance for data uncertainty.

˽ Here, we explore the effect of uncertainty on several forward-looking scenarios in which health-wearable data is used to guide critical health decision making.

˽ Areas in need of further research include how to provide users access to confirmatory evidence of reliability, preserve provenance of uncertainties, and tailor communication about uncertainties to users.