Table 2

Response characteristics, item calibrations, and item-fit statistics of items in the Isfahan Adult Food Security Scale

Item*

Affirmative responses (%)**

Item calibration***

SE****

Item infit

Item outfit


AD1 Worried food would run out

48.7

3.45

0.078

0.76

1.85

AD2 Food ran out; did not have money for more

53.1

2.86

0.085

0.95

1.47

AD3 Could not afford to eat nutritious meal

50.9

3.17

0.081

0.97

4.20

AD4 Cut size of meal or skipped meal

26.7

5.90

0.077

1.03

1.80

AD5 Ate less than thought he/she should

21.3

6.58

0.084

0.90

1.62

AD6 Hungry but did not eat

13.2

7.93

0.101

0.76

0.81

AD7 Lost weight

10.3

8.60

0.113

1.09

2.03

AD8 Did not eat for whole day

7.2

9.51

0.134

1.05

1.14

Mean

6.00

Standard deviation

2.44

Discrimination parameter

1.00

Number of cases*****

2,003

1,241

1,241

1,241

1,241


*The full wording of each question specified the time reference (previous 12 months) and specified that the condition occurred because of a lack of money for food.

**Percent affirmative responses(%) of all households

***Item calibration indicates the severity of the item. The calibrations for the adult scale were estimated on a logistic scale (that is, with discrimination equal to 1). The zero point of the adult scale (which is arbitrary) was set such that the mean of item scores was 6.0, a value which ensures that all item scores and all household scores are greater than zero.

****Standard error of estimation of item calibration

*****The scaling analysis sample omits households that affirmed no items or that affirmed all items, since those responses do not provide information about the severity of the items relative to one another.

Rafiei et al. Nutrition Journal 2009 8:28   doi:10.1186/1475-2891-8-28

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