Stepwise tailoring and test-retest of reproducibility of an ethnic-specific FFQ to estimate nutrient intakes for South Asians in New Zealand.

Objective: To develop and test-retest the reproducibility of an ethnic-specific FFQ to estimate nutrient intakes for South Asians (SA) in New Zealand (NZ).

Design: Using culturally appropriate methods, the NZFFQ, a validated dietary assessment tool for NZ adults, was modified to include SA food items by analysing foods consumed by SA participants of the Adult Nutrition Survey, in-person audit of ethnic food stores and a web scan of ethnic food store websites in NZ. This was further refined via three focus group discussions, and the resulting New Zealand South Asian Food Frequency Questionnaire (NZSAFFQ) was tested for reproducibility.

Setting: Auckland and Dunedin, NZ.

Participants: Twenty-nine and 110 males and females aged 25-59 years of SA ethnicity participated in the focus group discussions and the test-retest, respectively.

Results: The development phase resulted in a SA-specific FFQ comprising of 11 food groups and 180 food items. Test-retest of the NZSAFFQ showed good reproducibility between the two FFQ administrations, 6 months apart. Most reproducibility coefficients were within or higher than the acceptable range of 0·5-0·7. The lowest intraclass correlation coefficients (ICC) were observed for β-carotene (0·47), vitamin B12 (0·50), fructose (0·55), vitamin C (0·57) and selenium (0·58), and the highest ICC were observed for alcohol (0·81), iodine (0·79) and folate (0·77). The ICC for fat ranged from 0·70 for saturated fats to 0·77 for polyunsaturated fats. The ICC for protein and energy were 0·68 and 0·72, respectively.

Conclusions: The developed FFQ showed good reproducibility to estimate nutrient intakes and warrants the need for validation of the instrument.