Table 7 Mediation by an index of overall psychological well-being in the longitudinal associations between obesity and the incidence of NCDs in HRS.

Outcomes	Mediation by an index of overall psychological well-being measures
	Obesity vs. normal weight			Obesity class II & III vs. normal weight
	n	Estimate	95% CI	n	Estimate	95% CI
Hypertension	1659	0.001	−0.010, 0.012	1115	−0.077	−0.244, 0.090
Heart disease	4742	0.003	−0.018, 0.023	2834	0.002	−0.019, 0.023
Stroke	NA			3611	0.065	−0.048, 0.179
Diabetes	4687	−0.001	−0.002, 0.001	2911	0.004	−0.004, 0.012
Arthritis	2135	−0.039	−0.093, 0.015	1309	−0.021	−0.079, 0.047

All the mediation analyses were adjusted for age, sex, ethnicity, marital status, employment status, the number of years in education, and wealth index. Index of overall psychological well-being was developed by re-standardising the average standardised scores of 10 psychological well-being related measures (depressive symptoms, life satisfaction, loneliness, positive affect, negative affect, purpose in life, anxiety, hopelessness, pessimism, and personal constraint). As only a binary or continuous independent variable is allowed, causal mediation analysis excluded participants with overweight for the comparison between obesity vs. normal weight, and participants with overweight and Class I obesity for the comparison between Class II & III obesity vs. normal weight, resulting in a smaller analytical sample size compared to previous regression analyses that allowed an ordinal independent variable to be fitted.
n analytical sample size (excluding participants with the outcome before and at baseline and missing observations), Estimate the overall proportion due to mediation or the proportion mediated, CI confidence interval, NA not applicable (e.g., no significant risk differences in developing stroke between participants with obesity vs. normal weight at p < 0.05—see Table 4).
*p < 0.05; **p < 0.01; ***p < 0.001.

Search