Table 2. ROC analysis of aging inflection point age among different age groups in Jiangxi Province, China, 2020–2022.

Age group	Dimension	AUC (95% CI)	Sensitivity	Specificity	Youden index	Inflection point age	P-value
Abbreviation: ROC=receiver operator characteristic; AUC=area under curve; CI=confidence interval.
Middle-aged	Total	0.694 (0.658, 0.729)	0.599	0.713	0.3124	53.16	0.0001
	Physiological	0.709 (0.673, 0.743)	0.604	0.724	0.3276	53.18	0.0001
	Psychological	0.547 (0.508, 0.585)	0.789	0.311	0.1000	48.00	0.0344
	Social	0.661 (0.573, 0.648)	0.548	0.654	0.2019	53.09	0.0001
Young elderly	Total	0.658 (0.625, 0.691)	0.645	0.602	0.2473	66.33	0.0001
	Physiological	0.703 (0.670, 0.734)	0.608	0.703	0.3111	67.73	0.0001
	Psychological	0.539 (0.504, 0.574)	0.279	0.809	0.0878	70.25	0.0547
	Social	0.566 (0.531, 0.600)	0.311	0.821	0.1322	70.00	0.0011
Elderly	Total	0.697 (0.633, 0.755)	0.483	0.836	0.3190	81.20	0.0001
	Physiological	0.745 (0.684, 0.800)	0.776	0.621	0.3966	78.87	0.0001
	Psychological	0.610 (0.544, 0.674)	0.440	0.793	0.2328	81.20	0.0029
	Social	0.594 (0.528, 0.658)	0.672	0.509	0.1810	78.44	0.0118