Table 3.

Linear mixed regressions by survey

Variable	HbA1c	Cholesterol	CVD risk${}_{\mathit{log}}$
NHANES
Intercept	4.882 [4.837; 4.927]	4.962 [4.920; 5.005]	− 0.673 [− 0.709; − 0.637]
Degree (ref. other qualification)	− 0.246 [− 0.291; − 0.201]	− 0.069 [− 0.112; − 0.027]	− 0.167 [− 0.196; − 0.138]
No qualification	0.210 [0.176; 0.245]	0.107 [0.075; 0.140]	0.101 [0.079; 0.124]
Year	0.018 [0.015; 0.020]	− 0.021 [− 0.023; − 0.019]	− 0.019 [− 0.021; − 0.017]
Degree x Year	0.003 [0.001; 0.006]	0.003 [0.001; 0.006]	0.002 [0.000; 0.003]
No qualification x Year	− 0.001 [− 0.003; 0.001]	− 0.007 [− 0.009; − 0.006]	− 0.002 [− 0.003; − 0.001]
n	138012	136204	127492
m	148	148	148
HSE
Intercept	3.824 [3.652; 3.995]	5.073 [5.039; 5.107]	− 0.326 [− 0.351; − 0.301]
Degree (ref. other qualification)	− 0.006 [− 0.045; 0.033]	− 0.011 [− 0.052; 0.029]	− 0.068 [− 0.103; − 0.033]
No qualification	0.054 [0.026; 0.082]	0.281 [0.253; 0.310]	0.285 [0.260; 0.309]
Year	0.047 [0.045; 0.049]	− 0.029 [− 0.031; − 0.028]	− 0.012 [− 0.013; − 0.010]
Degree x Year	− 0.004 [− 0.006; − 0.002]	0.000 [− 0.002; 0.002]	− 0.001 [− 0.003; 0.001]
No qualification x Year	0.005 [0.003; 0.006]	− 0.021 [− 0.023; − 0.019]	− 0.008 [− 0.010; − 0.007]
n	66071	88809	39469
m	31	32	31
SHS
Intercept	4.257 [4.132; 4.381]	4.666 [4.539; 4.792]	− 0.207 [− 0.343; − 0.072]
Degree (ref. other qualification)	0.210 [0.010; 0.411]	0.018 [− 0.121; 0.158]	0.171 [− 0.054; 0.397]
No qualification	0.244 [0.060; 0.429]	0.110 [− 0.021; 0.241]	0.283 [0.077; 0.489]
Year	0.059 [0.051; 0.066]	0.002 [− 0.005; 0.010]	− 0.005 [− 0.013; 0.003]
Degree x Year	− 0.017 [− 0.029; − 0.004]	− 0.000 [− 0.011; 0.011]	− 0.014 [− 0.028; 0.001]
No qualification x Year	− 0.007 [− 0.020; 0.005]	− 0.006 [− 0.017; 0.005]	− 0.009 [− 0.023; 0.005]
n	7168	10781	3723
m	21	21	21

Coefficients $\beta$ and 99% confidence intervals. m and n: number of random-effect strata levels and sample size, respectively. HbA1c glycated haemoglobin, CVD cardiovascular disease, Log logarithm