Validation of the short assessment of health literacy (SAHL-D) and short-form development: Rasch analysis

Table 3 DIF for educational groups (N = 1217)

Item	Educational group^a	DIF contrast^b	Prob (Welch t)^c
Apnea	1 vs 3	−1.01	.0003
Psoriasis	1 vs 3	−.70	.0005
Adrenalin	1 vs 3	−.67	.8777
Malaise	1 vs 3	−.63	.0005
Delirium	1 vs 3	−.53	.0128
Chlamydia	1 vs 3	−.50	.0059
Psoriasis	2 vs 3	−.72	.0001
Chlamydia	2 vs 3	−.60	.0002
Delirium	1 vs 2	−.70	.0007
Apnea	1 vs 2	−.62	.0260
Palliation	3 vs 2	−.74	.0000
Prenatal	3 vs 2	−.76	.0000
Euphoria	2 vs 1	−.75	.0014
Pancreas	2 vs 1	−.59	.0015
Euphoria	3 vs 1	−1.17	.0000
Pancreas	3 vs 1	−.91	.0000
Prenatal	3 vs 1	−.96	.0000
Palliation	3 vs 1	−.53	.0044

^aNote. Education group 1 = low; 2 = middle; 3 = high
^bNote. The DIFcontrast measure illustrates the difference between the item measures or the difference of the item between two groups. A difference of at least 0.50 logits is required for DIF to be noticeable. A negative DIF contrast means that the item was easier for the group on the left, whereas a positive DIF contrast means that the item was more difficult for the group on the left
^cNote. The Prob illustrates the probability of observing this amount of contrast by chance. Only items that are statistically significant at the p < 0.05 level are displayed