Due to demographic bias in the sample, in particular, a greater proportion of women, and those with higher levels of education it is possible that there will be response bias in the data. The high proportion of women in the sample may be due to greater interest and participation in studies of this nature, but may also be indicative of higher levels of females in the target population, in particular in the main industry sectors represented in the data, i.e. recreational and equestrian. There are no official statistics on gender breakdown across horse industry sub-populations in Australia, but data indicate that the equestrian sector in the United States may comprise 80% women [33] , so the gender bias may reflect a gender bias in the main industry sub-populations in our data. Research data often report higher levels of psychological distress in women in the general population, and therefore, the gender demographic bias in our study might have led to an elevation in the levels of psychological distress reported in this study. However, the absence of a significant gender effect in this study, and the close matching of relative levels of psychological distress in men and women with data from the Australian general population, suggests that EI, as an adversity, was exerting similar impacts on males and females. It is not possible to explain why there was an absence of a gender difference in the data. One possible explanation is that the timing of the study; around the height of the EI epidemic, and the high levels of psycho-logical distress generally, reflected peak, acute levels in which gender differences were minimised and insignificant.