. 2020 Dec 15;15(12):e0243972. doi: 10.1371/journal.pone.0243972

Table 3. Results of linear multilevel models with NEADL score as the dependent variable and individual-level random intercepts.

	Unadjusted models				Adjusted models
	Model 1: unadjusted, no interaction		Model 2: unadjusted, with interaction		Model 3: adjusted, no interaction		Model 4: adjusted, with interaction
VARIABLES	Coefficients (95% CI)	p-value	Coefficients (95% CI)	p-value	Coefficients (95% CI)	p-value	Coefficients (95% CI)	p-value
Time point (reference: baseline)
6-months	-1.017	0.063	-0.991	0.068	-0.966	0.078	-0.961	0.078
	(-2.087 to 0.053)		(-2.053 to 0.071)		(-2.040 to 0.107)		(-2.028 to 0.107)
12-months	-1.163	0.053	-1.289^**	0.032	-1.282^*	0.033	-1.392^*	0.020
	(-2.343 to 0.017)		(-2.466 to -0.112)		(-2.461 to -0.103)		(-2.568 to -0.215)
EFI: reference (reference: fit)
EFI: mild frailty	-3.653^**	0.010	-3.313^*	0.019	-1.464	0.223	-1.153	0.340
	(-6.423 to -0.883)		(-6.088 to -0.538)		(-3.818 to 0.891)		(-3.519 to 1.213)
EFI: moderate frailty	-10.507^**	<0.001	-10.407^**	<0.001	-6.104^**	<0.001	-5.836^**	<0.001
	(-13.441 to -7.572)		(-13.354 to -7.461)		(-8.606 to -3.601)		(-8.365 to -3.308)
EFI: severe frailty	-17.290^**	<0.001	-18.058^**	<0.001	-10.138^**	<0.001	-11.053^**	<0.001
	(-20.946 to -13.634)		(-21.924 to -14.192)		(-13.525 to -6.751)		(-14.610 to -7.496)
Depressed (based on GDS-15)	-6.710^**	<0.001	4.213	0.434	-6.411^**	<0.001	3.958	0.505
Depressed (based on GDS-15)	(-8.684 to -4.735)		(-6.343 to 14.769)		(-8.274 to -4.549)		(-7.677 to 15.592)
Interaction: Frailty X Depression
Interaction: mild frailty X depressed			-14.189^**	0.014			-12.526^**	0.045
Interaction: mild frailty X depressed			(-25.526 to -2.851)				(-24.790 to -0.262)
Interaction: moderate frailty X depressed			-11.143^*	0.045			-11.200	0.065
Interaction: moderate frailty X depressed			(-22.042 to -0.244)				(-23.115 to 0.714)
Interaction: severe frailty X depressed			-8.469	0.144			-7.281	0.244
Interaction: severe frailty X depressed			(-19.829 to 2.892)				(-19.536 to 4.974)
Age (in years)					-0.703^**	<0.001	-0.713^**	<0.001
					(-0.899 to -0.507)		(-0.909 to -0.517)
Female					-0.634	0.517	-0.772	0.430
					(-2.550 to 1.283)		(-2.688 to 1.145)
Ethnicity: white					15.274^**	<0.001	15.315^**	<0.001
					(12.189 to 18.359)		(12.233 to 18.396)
Education (reference: no formal qualification)
GCSE or AS/A levels					3.795^**	0.002	3.705^**	0.003
					(1.351 to 6.240)		(1.255 to 6.156)
Higher National Certificate or diploma					4.251^**	0.003	4.205^**	0.003
					(1.453 to 7.048)		(1.409 to 7.001)
University degree					3.120	0.062	2.876	0.086
University degree					(-0.156 to 6.395)		(-0.405 to 6.156)
Living situation (reference: living alone)
With family					-7.143^*	<0.001	-7.132^**	<0.001
					(-10.108 to -4.178)		(-10.095 to -4.168)
With partner/spouse					-2.284^*	0.036	-2.460^*	0.024
					(-4.415 to -0.154)		(-4.591 to -0.330)
Comorbidity (Katz comorbidity index)					-0.930^**	<0.001	-0.936^**	<0.001
Comorbidity (Katz comorbidity index)					(-1.428 to -0.433)		(-1.432 to -0.439)
Constant	58.426^***	<0.001	58.388^***	<0.001	43.033^***	<0.001	43.083^***	<0.001
	(56.020 to 60.831)		(55.987 to 60.789)		(39.018 to 47.048)		(39.072 to 47.095)
Random effects parameters
Patient-level (SD)	11.690		11.693		8.099		8.097
	(10.820–12.631)		(10.824–12.631)		(7.360 to 8.912)		(7.360–8.909)
Residual	6.040		5.990		6.140		6.099
	(5.637–6.472)		(5.591–6.418)		(5.719 to 6.592)		(5.680–6.548)

AS/A Level: advanced subsidiary/advanced level; CI: confidence interval; EFI: electronic frailty index; GCSE: general certificate of education; GDS: geriatric depression scale; SD; standard deviation

*** p<0.001

** p < .001

* p<0.05