Global shipments for health wearable devices will reach 97.6 million units in 2021, up from 2.5 million in 2016, according to a report from Tractica. The report also predicted that health wearable revenues will reach $17.8 billion yearly at that time.

“The market for healthcare wearables is very much in its infancy, though there is a considerable amount of activity across the healthcare value chain,” Tractica Research Director Aditya Kaul said in a statement.  “Wearables are being seen as an extension of the digital transformation of healthcare, helping pharmaceutical companies to expand clinical trials, enabling insurance companies to engage with customers by incentivizing healthier living, helping healthcare providers to improve the delivery of healthcare, and empowering patients by providing them access to their own health data.”

While Tractica expects a large number of shipments to come from well-known healthcare wearable devices, like fitness trackers and smartwatches, the category will also see shipments from newer wearables, including connected wearable patches, pain management devices, and posture monitors.

Last month, Tractica reported that in general wearable device shipments will increase from 85 million units in 2015 to 559.6 million units by 2021, representing a compound annual growth rate (CAGR) of 36.9 percent.

Tractica said at the time that it adjusted its prediction upwards from previous years in part because fitness trackers had stronger than expected growth and the market wasn't as cannibalized by the smartwatch market as originally expected.