some evidence that financial incentives have no impact on chlamydia screening.The main limitation to the study is that in spite of most respondents saying they would be willing to return postal samples for chlamydia testing, it is likely that actual response rates would be much less in practice. This is reflected in the results of studies by Macleod et al. 3 and Bloomfield et al. 4 who found that uptake of postal chlamydia screening was only around 20-30%. In addition, coverage was lower in areas that were more deprived, and had higher proportions of residents from ethic minority groups. 3 The other weaknesses of the study are the small size and that findings may not be generalizable to non-GU medicine populations. Respondents were also given a specified list of possible 'encouragers' and 'barriers' to testing that they ticked; although they were able to suggest other answers, this could have been a possible source of bias. However, a website where anyone could order postal chlamydia test kits and check their results online has been shown to be effective in expanding testing among young people. 5 Morris and colleagues demonstrated that chlamydia screening in non-clinical settings may be a cost-effective way of identifying infection in those who do not regularly access health care. Our results from an ethnically diverse inner city population suggest that a public health campaign involving postal chlamydia testing could also contribute to the control of chlamydia infection in some ethnically diverse, possibly hard-to-reach populations.i Note that the changing denominator reflects either:(1) The number of respondents who answered the question; or (2) The proportion of respondents who selected a given option for questions where they were asked to select the options that applied to them.