Table 4.

Average lifetime night shift frequency and risk of NAFLD

Variables	Average lifetime night shift frequency			Ptrend	Mediation effect (%) (95% CI)
	None	< 8/month	≥ 8/month
Case/Sample	333/57003	81/9778	88/8278
Incidence rate (/100,000 person years)	48.29	68.72	87.94
Model 1	1.00	1.41 (1.10–1.79)	1.77 (1.39–2.24)	< 0.001
Model 2	1.00	1.32 (1.03–1.68)	1.53 (1.20–1.95)	< 0.001
Model 3	1.00	1.27 (1.01–1.61)	1.45 (1.15–1.83)	< 0.001
Mediation model	1.00	1.18 (0.94–1.5)	1.29 (1.02–1.63)	0.018	29.6 (14.0–52.1) P < 0.001

Model 1 was adjusted for age, sex, and ethnicity (white or others)

Model 2 was model 1 plus further adjustment for Townsend deprivation index, education level (university/college degree or others), household income (less than £18,000, £18,000 to £30,999, £31,000 to £51,999, £52,000 to £100,000, greater than £100,000, or do not know/prefer not to answer), self-reported smoking status (never, former or current smoker), self-reported frequency of alcohol intake (daily/almost daily, 1–4 times a week, 1–3 times a month, or special occasions only/never), and physical activity level (< 600, 600–3000, > 3000 MET minutes per week, or missing)

Model 3 was model 2 plus further adjustment for diabetes, hypertension, and PRS for NAFLD

The mediation model was adjusted for BMI separately in addition to model 3, and the mediation effect was calculated