Cognitive impairment in eating disorder patients of short and long-term duration: a case–control study

Figures & data

Table 1 Sociodemographic features in clinical and control groups

Socio-demographic variables	Long-term ED	Short-term ED	Senior control	Junior control	Significant differences
	(n=41)	(n=41)	(n=33)	(n=33)	Student t test
					c1/c2
Age^a M (SD)	30.80 (6.22)	20.51 (4.82)	31.03 (3.41)	21.00 (2.44)	−0.20/-0.56
Years of education^a M (SD)	14.31 (3.01)	12.56 (2.59)	14.48 (3.15)	12.60 (2.14)	0.82/-0.08
					Among groups
Level of studies	N (%)	N (%)	N (%)	N (%)	X2
Primary or secondary^b	1 (29)	26 (63)	9 (26)	15 (46)	10.65*^d
Secondary non-university^b	12 (29)	8 (20)	10 (29)	13 (40)	1.37
University^b	14 (34)	6 (15)	12 (35)	5 (14)	6.35
Post graduate^c	3 (8)	1 (2)	2 (6)	0 (0)	1.00

Notes: ^aStudent t test; ^bChi squared test; ^cFisher’s Exact test; ^dST-ED>LT-ED and SC; *p<0.05.

Abbreviations: ED, eating disorder; ST-ED, short-term eating disorder; LT-ED, long-term eating disorder; SC, senior control; JC, junior control; c1, comparison LT-ED vs SC; c2, comparison ST-ED vs JC.

Table 2 Clinical features and diagnoses in clinical sample

Clinical variables	Long-term ED	Short-term ED	Statistics
	(n=41)	(n=41)
			Student t test
Body mass index (BMI)^a M (SD)	20.18 (1.60)	20.44 (1.82)	-0.68
Years of ED onset^a M (SD)	14.80 (4.80)	1.21 (0.33)	18.07***
Eating Disorders	N (%)	N (%)	X2
Anorexia Nervosa Restrictive^b	13 (32%)	13 (32%)	0.00
Anorexia Nervosa Purging^b	10 (24%)	10 (24%)	0.00
Bulimia Nervosa Purging^b	10 (24%)	9 (22%)	0.05
Bulimia Nervosa Non-Purging^c	3 (7%)	0 (0%)	- -
Binge Eating Disorder^c	1 (2%)	1 (2%)	0.00
Eating Disorder Not Otherwise	4 (10%)	8 (20%)	1.33
Specified^c
Axis I
None^b	19 (46%)	25 (61%)	0.82
Affective disorder^c	7 (17%)	4 (10%)	0.82
Anxiety disorder^b	5 (12%)	8 (19%)	0.69
Substance abuse^c	9 (22%)	4 (10%)	1.92
Affective + anxiety disorder^c	1 (2%)	0 (0%)	- -
Any Axis I disorder^b	22 (54%)	16 (39%)	0.94
Axis II
None^b	17 (42%)	36 (88%)	6.81**
Cluster A^c	0 (0%)	0 (0%)	- -
Cluster B^b	14 (34%)	5 (12%)	4.26*
Cluster C^c	9 (22%)	0 (0%)	- -
Not Otherwise Specified^c	1 (2%)	0 (0%)	- -
Any Axis II disorder^b	24 (54%)	5 (39%)	12.45***
Substance abuse
No Use^b	31 (76%)	35 (85%)	0.24
Alcohol^c	5 (12%)	0 (0%)	- -
Cannabis^c	0 (0%)	5 (12%)	- -
Cocaine^c	1 (2%)	0 (0%)	- -
Alcohol + Cannabis^c	0 (0%)	1 (2%)	- -
Alcohol + Cocaine^c	2 (5%)	0 (0%)	- -
Alcohol + Opiates^c	1 (2%)	0 (0%)	- -
More than 2 substances^c	1 (2%)	0 (0%)	- -
Any substance abuse disorder^b	10 (24%)	6 (15%)	1.03

Notes: ^aStudent t test; ^bChi squared test; ^cFisher’s Exact test. *p<.05; **p<.010; ***p<.001; – no statistics does apply.

Abbreviation: ED, eating disorder.

Table 3 Means and standard deviations in each neuropsychological variable by group

Neuropsychological variables	Long-term ED M (SD)	Short-term ED M (SD)	Senior control M (SD)	Junior control M (SD)	Statistics between groups ANCOVA	Post-hoc Scheffé p-value c1 ¦c2 ¦c3	Effect size Cohen’s d c1 ¦c2 ¦c3
Matrix Rotation^a	n=33	n=34	n=33	n=33
Test Time	0.16 (0.92)	0.05 (0.99)	-0.41 (0.95)	0.20 (1.06)	F=2.32; df=3; p=.076	NS¦ NS ¦ NS	- - ¦ - - ¦ - -
Test Number	-0.44 (1.18)	-0.03 (1.07)	0.30 (0.69)	0.17 (0.86)	F=4.69; df=3; p=.004	NS¦ .023 ¦ NS	- - ¦ -.77 ¦ - -
Stroop^a	n=32	n=33	n=1	n=31
Name Cost	0.46 (0.95)	0.03 (0.95)	-0.25 (0.89)	-0.26 (1.07)	F=4.61; df=3; p=.004	NS¦ .038 ¦NS	- - ¦ .77 ¦ - -
Color Cost	-0.57 (1.53)	0.21 (0.78)	0.15 (0.50)	0.18 (0.71)	F=3.22; df=3; p=.025	.028¦ NS ¦ NS	-.64¦ - - ¦ - -
Trail Making Test^a	n=33	n=33	n=32	n=32
Part A	0.29 (0.81)	0.15 (1.64)	-0,24 (0.43)	-0-22 (0.54)	F=2.40; df=3; p=.070	NS¦ NS ¦NS	- -¦ - - ¦ - -
Part B	0.44 (1.30)	-0.35 (0.84)	-0.34 (0.41)	-0.07 (1.09)	F=3.63; df=3; p=.015	NS¦ .017 ¦NS	- -¦ .81 ¦ - -
Part B-A	0.26 (0.98)	-0.15 (1.34)	-0.19 (0.29)	0.77 (1.05)	F=1.37; df=3; p=.256	NS¦ NS ¦ NS	- -¦ - - ¦ - -
Tower of London (ToL)^a	n=31	n=32	n=32	n=32
Total	0.46 (1.18)	-0.04 (0.75)	-0.37 (0.94)	-0.04 (0.94)	F=4.59; df=3; p=.004	NS ¦.010 ¦ NS	- -¦ .78 ¦ - -
Posner Test^a	n=33	n=35	n=30	n=29
By validity condition
Invalid Mean	0.47 (1.57)	-0.27 (0.28)	0.01 (1.05)	-0.21 (0.26)	F=3.80; df=3; p=.012	.023¦ NS ¦ NS	.65 ¦ - - ¦ - -
Neutral Mean	0.18 (1.25)	-0.18 (0.15)	0.13 (1.54)	-0.11 (0.32)	F=1.05; df=3; p=.374	NS¦ NS ¦ NS	- - ¦ - - ¦ - -
Valid Mean	0.28 (1.14)	0.07 (1.45)	-0.12 (0.44)	-0.27 (0.31)	F=2.30; df=3; p=.081	NS¦ NS ¦ NS	- - ¦ - - ¦ - -

Table

					Student t test	Cohen’s d c1
Rey Figure^b	n=33	n=24
Copy Total	-0.20 (1.27)	0.28 (0.22)	- -	- -	t=-2.13; df=34; p=.040	-.53
Copy Time	-0.08 (0.95)	0.10 (1.07)	- -	- -	t=-0.65; df=54; p=.520	- -
Memory Total	-0.32 (1.04)	0.45 (0.75)	- -	- -	t=-3.08; df=55; p=.002	-.85
Memory Time	-0.21 (0.97)	0.28 (0.97)	- -	- -	t=-1.85; df=53; p=.071	- -
Delayed Recall Total	-0.29 (1.02)	0.41 (0.82)	- -	- -	t=-2.74; df=54; p=.008	-.76
Delayed Recall Time	-0.10 (1.09)	0.14 (0.86)	- -	- -	t=-0.86; df=51; p=.394	- -
Wechsler^b	n=31	n=33
Vocabulary Test	0.07 (1.19)	-0.07 (0.79)	- -	- -	t=0.57; df=51; p=.571	- -
Hayling^b	n=30	n=32
Part A	0.34 (1.07)	-0.32 (0.82)	- -	- -	t=2.71; df=60; p=.010	.69
Part B	0.42 (1.23)	-0.41 (0.42)	- -	- -	t=3.46; df=35; p=.001	.90

Notes: Raw scores were transformed to z-scores; ^aANCOVA with age and level of studies as covariates, with a subsequent ANOVA with Scheffé’s post-hoc; ^bStudent t test; *p<.05; **p<.010; ***p<.001.

Abbreviations: NS, not significant; ED, eating disorder; Comparisons: c1, long-term ED vs short-term ED; c2, long-term ED vs senior control; c3, short-term ED vs junior control.

Table 4 Absolute frequencies of persons and relative percentages with cognitive impairment by group

Neuropsychological variables	Long-term ED		Short-term ED		Senior control		Junior control		Contrast of frequencies on WCI in all groups	WCI proportions comparison between groups (z-scores)			Effect size
	n	%WCI	n	%WCI	n	%WCI	n	%WCI	X2 df=3
Matrix Rotation^a
Test Number	13	39.3	3	8.8	2	6.1	1	3.0	14.52***	2.93**	3.23**	1.01	.36 ¦.40 ¦ - -
Stroop^a
Name Cost	9	28.1	5	15.2	2	6.5	2	6.5	7.33	1.27	2.26*	0.00	- - ¦ .28 ¦ - -
Color cost	11	34.4	2	6.1	2	6.5	2	6.5	14.29***	2.85**	2.74**	-0.06	.35 ¦.34 ¦ - -
Trail Making Test^b
Part A	12	36.4	5	15.2	5	15.6	6	18.8	4.85	1.97*	1.90	-0.38	.24 ¦ - - ¦ - -
Part B	16	48.5	7	21.2	5	15.6	5	15.6	10.03*	2.32*	2.83**	0.58	.28 ¦ .35 ¦ - -
Tower of London (ToL)^a
Total	9	29.0	2	6.3	4	12.5	2	6.3	7.71	2.38*	1.62	0.00	.30 ¦ - - ¦ - -
Posner^a
Invalid	4	12.1	2	5.7	2	6.7	2	6.9	1.20	0.93	0.73	-0.19	- - ¦ - - ¦ - -
Neutral	6	18.2	1	2.9	2	6.7	2	6.9	5.36	2.07*	1.37	-0.76	.25 ¦ - - ¦ - -
Valid	7	21.2	6	17.1	2	6.7	2	6.9	4.88	0.43	1.65	1.23	- - ¦ - - ¦ - -

Rey Figure^a							X2 df=1	c1 (z-scores) c1
Copy	0	0.0	0	0.0	- -	- -	- -	- -	- -
Memory Total	12	36.4	1	4.2	- -	- -	9.30**	2.86**	.38
Delayed Recall Total	10	30.3	2	8.3	- -	- -	5.33*	2.01*	.26
Wechsler^a
Vocabulary Test	0	0.0	0	0.0	-	-	-	-	-
Hayling^b
Part A	18	60.0	14	43.8	-	-	0.27	1.28	-
Part B	27	90.0	23	71.9	-	-	0.75	1.80	-

Notes: ^aFisher’s Exact test; ^bChi-squared test; *p<.05; **p<.010; ***p<.001; Φ=Effect size for contingency table analysis.

Abbreviations: WCI, with cognitive impairment; c1, long-TermED vs short-term ED; c2, long-term ED vs senior control; c3, short-term ED vs junior control.