On profitability, gross margin in the fourth quarter was 70.9% (up 90 basis points year over year), while full-year gross margin was 70.6% (up 170 basis points). Wilson said the improvement reflected operational efficiencies in manufacturing, automation, and workflow optimization, along with scale benefits, partially offset by product mix.Wilson noted that “new store” growth—accounts open less than 12 months—represented approximately 68% of year-over-year volume growth. U.S. home enrollment for Zio Services ...