Table 9.

Threshold effect analysis of perceived stress and social connection on work engagement using piece-wise linear regression

	Crude			Adjusted
	β	95%CI	P	β	95%CI	P
Perceived stress
K < 27	-0.809	(-1.211, -0.408)	< 0.001	-0.787	(-1.178, -0.396)	< 0.001
K ≥ 27	-0.361	(-0.446, -0.275)	< 0.001	-0.318	(-0.403, -0.232)	< 0.001
Social connection
K < 101	0.126	(0.083, 0.169)	< 0.001	0.074	(0.023, 0.124)	0.004
K ≥ 101	1.017	(0.665, 1.370)	< 0.001	0.482	(0.337, 0.627)	< 0.001

Note: Crude: no adjustment; Adjusted: adjusted for age, family support; K: the optimal threshold point in the non-linear relationship

Abbreviations: CI, confidence interval