a decreasing trendp < 0.01
There were more boy cases than girl cases every year, and the prevalence rate ratios ranged from 1.26 to 1.39 ( p < 0.05 in all years), with a decreasing trend over time ( p < 0.01).
There were more boy cases than girl cases every year, and the prevalence rate ratios ranged from 1.26 to 1.39 ( p < 0.05 in all years), with a decreasing trend over time ( p < 0.01).