Item (frequency) Food secure (397) Food insecure (134) 3 Balanced meal (162) 2 Food last (109) 5 Skip meals (93) 7 Eat less (75) 8 How often (70) 10 Hungry (31) 202 (51) 37 (28) 48 (30) 30 (28) 24 (26) 16 (21) 16 (23) 9 (29) BMC Public Health 2004, 4 http://www.biomedcentral.com/1471-2458/4/22 Table 6: Associations of food security items with consumption of vegetables and salads. Figures are frequencies (row percent) except where indicated. Eats vegetables ≥5–6 days per week (row %) Odds ratio (95% CI)a P value - 0.43 (0.24 to 0.77) 0.42 (025 to 0.70) 0.44 (0.23 to 0.84) 0.42 (0.22 to 0.82) 0.32 (0.14 to 0.73) 0.36 (0.16 to 0.82) 0.51 (0.17 to 1.49) 0.004 0.001 0.012 0.010 0.007 0.014 0.218 a relative odds of consuming vegetables ≥ 5–6 days per week if affirmative, adjusted for age, gender, ethnic group and clustering by household Table 7: Frequency of consumption of ten food items for each food security item. Figures are frequencies (percent of row total). Whether eaten ≥5–6 times per week Whether eaten at least weekly Item (frequency) Fruit Green vegetables and salads Rice Bread and bread rolls Legumes (peas, beans and lentils) Ground Fish provisions (including shellfish) Sweets, chocolate etc Sweet biscuits or cake Burgers, fried chicken or pizzas Food secure (397) 218 (55) 202 (51) Food insecure (134) 53 (40) 37 (28) 3 Balanced meal (162) 70 (43) 48 (30) 2 Food last (109) 44 (40) 30 (28) 5 Skip meals (93) 39 (42) 24 (26) 7 Eat less (75) 25 (33) 16 (21) 8 How often (70) 27 (39) 16 (23) 10 Hungry (31) 13 (42) 9 (29) 254 (64) 272 (69) 87 (65) 84 (63) 101 (63) 103 (64) 67 (61) 65 (60) 62 (67) 60 (65) 50 (67) 41 (55) 47 (67) 48 (69) 23 (74) 18 (58) 173 (44) 67 (50) 84 (52) 50 (46) 47 (51) 38 (51) 34 (49) 10 (32) 253 (64) 103 (77) 117 (72) 82 (75) 72 (77) 54 (72) 57 (81) 20 (65) 255 (64) 70 (52) 96 (59) 62 (57) 49 (53) 46 (61) 38 (54) 18 (58) 116 (29) 31 (23) 47 (29) 28 (26) 21 (23) 21 (28) 14 (20) 12 (39) 161 (41) 47 (35) 61 (38) 34 (31) 33 (35) 23 (31) 27 (39) 7 (23) 106 (27) 40 (30) 39 (24) 24 (22) 32 (34) 22 (29) 29 (41) 6 (19) items. The estimate for the lowest prevalence item was very imprecise. Food insecurity was associated with reduced consumption of green vegetables and salads even after additional adjustment for income (as a categorical variable) and education (as categorised previously [7]) giving an adjusted odds ratio of 0.52, 95% confidence interval 0.28 to 0.96, P = 0.038. There was no evidence for an interaction with ethnicity in either set of analyses. Table 7 shows descriptive data for the other nine food items reported previously [7] for each of the food security items separately. The previously reported associations were consistent for across food security items for con- sumption of fruit and green vegetables and salads. The remaining food items were not associated with food secu- rity status [7] and this finding was consistent for each food security item separately. Discussion The present study evaluated the food insecurity item responses and provides evidence for their reliability and validity in this setting [16]. The six items of the short form household food security scale gave consistent responses. Cronbach's alpha was similar to the values of 0.84 and 0.86 reported by Kendall et al [16], for a slightly different group of items, and 0.86 reported by Hamilton et al [21] for the US food security measure. Streiner and Norman [3] suggest that values for alpha should exceed 0.70, while values in excess of 0.90 might suggest that some items are redundant. The reliability of the measure was also sup- ported by the high level of agreement for item responses of individuals in the same households. The item response theory models provided evidence for the validity of the instrument in this context. Estimated item thresholds were generally consistent with the relative severity of food insecurity represented by each item in US data. The main departure from this pattern related to the 'balanced meal' item which was consistently the item with lowest severity in these data. The associations between item responses and household income and consumption of green vegeta- bles and salads were consistent, and, at least for income, graded according to the severity of food insecurity represented by the item. These results provide evidence of criterion-related validity [16] similar to the results Page 6 of 9 (page number not for citation purposes)