a significant trendp = 0.034
As demonstrated by linear regression model in Table 4 we observed a significant trend that survivors with CCI ≥ 1 ( β = 5.2, p = 0.034), tumor sits at nasopharynx ( β =-9.1, p = 0.034), or treated by 2DRT ( β =-12.2, p < 0.01) had a higher probability to report a high level of xerostomia.