a decreasing trendP-value ≤ 0.05
an increasing trendP-value ≤ 0.05
A constant trend is considered when AAPC is not significant (P-value > 0.05), an increasing trend when AAPC is significant (P-value ≤ 0.05) and positive, and a decreasing trend when AAPC is significant (P-value ≤ 0.05) and negative.