a nonsignificant trendp = 0.054
Fitting a spline model suggested that the first linear spline exhibited a significant increasing trend in usage (RR: 1.06 per quarter; p = 0.012), followed by a significant decline from Q4–2020 to Q1–2022 (RR: 0.89 per quarter; p < 0.001), before a nonsignificant trend until Q4–2023 (RR: 1.04; p = 0.054; Fig.