As a summary of our results, the inclusion of a Q-F measure performed as expected. It did improve DSM criteria by including respondents at the lower end of the dependence continuum. When a Q-F measure was included, it did not change the overall performance of the diagnostic criteria. But our analyses also found cross-country variation in the difficulty of endorsing a heavy drinking criterion such as and 5+ drinks weekly/monthly for men/women, one of the best Q-F candidate measures for these samples. Although differential item functioning was also observed among several other DSM-IV criteria, the heavy drinking measures appeared to exhibit some of the largest cross-cultural variation in the difficulty parameter seen among all DSM-IV criteria. While the four countries examined here are clearly not representative of all drinking cultures and although the ER samples are likely different from their respective general populations, findings here suggest that caution should be used in including culturally sensitive measures such as heavy drinking in the proposed DSM-V, and that additional research in this area is necessary.
