a decreasing trendp < 0.001
The baseline rate indicated that 26.23% (95% CI: 19.94–34.49%, p < 0.001) of eligible youth received at least one HPV vaccine dose in the first quarter with a decreasing trend over time to 18.7% (95% CI: 15.42–21.84) or 0.81 times per quarter (95% CI: 0.72–0.88, p < 0.001), and assuming no effects from any other factors ( Figure 9 a,b).