highly significantP<0.001
Wilcoxon rank-sum tests comparing SSPGI and SDPGI distributions among the short sleep and combined long/intermediate sleep categories, and LSPGI and SDPGI distributions among the long sleep and combined short/intermediate sleep categories, revealed highly significant differences (P<0.001), confirming that SSPGI, LSPGI, and SDPGI effectively distinguish between the respective sleep duration categories.