Goodall et al. BMC Public Health 2012, 12:747 http://www.biomedcentral.com/1471-2458/12/747 behavior change interventions with MSM can reduce the frequency of UAI with partners of unknown HIV status [27] but there is a lack of evidence on less intensive sin- gle session interventions or interventions designed to re- duce condom errors in MSM. It is possible that the lower frequency of condom problems in MSM might re- duce the impact of condom skills training – although interventions to reduce problems may increase overall levels of use. Such interventions could focus on a num- ber of condom skills, for example, appropriate sized con- doms, skills relating to appropriate use or skills relating to condom communication and negotiation. Strengths of our study included use of both clinical and community samples, the high proportion of HIV positive men included in the sample and the matching of self-report risk behavior to clinical records. Limita- tions of the study include convenience sampling of populations at selected venues. This could limit the transferability of study findings to MSM populations in other settings and locations. Epidemiological studies show that MSM recruited from community settings have higher rates of undiagnosed HIV infection than those recruited from STI clinics [14] and men in differ- ent community samples report widely differing rates of UAI [28,29]. The effect of convenience sampling was mitigated by recruiting from both STI clinics and com- munity venues. All ‘gay identified’ commercial venues in Edinburgh were included. All MSM attending STI clinics and all men attending each community venue during the sampling period; which included different weekdays and different sample times over the 4-month study period; were asked to participate in an attempt to obtain a representative sample. Response rates were high for both clinic and community samples although it is acknowledged that high response rates do not ne- cessarily mean a representative samples. As the study was designed to inform the development of prevention interventions which are likely to be delivered through the same clinics and commercial venues and to the same population, this methodology also carries some advantages. A further limitation is the reliance of this study on subjective reporting of condom use, condom problems, sexual behavior and STI diagnoses. This may have resulted in misclassification of both exposure and outcome. MSM participating in the study may have under-reported high-risk sexual behavior in an attempt to satisfy perceived social norms, but the reported levels of UAI suggest that this occurred to no greater extent than in other published studies and surveys. The use of self-completed anonymous questionnaires may have reduced under-reporting by maintaining anonym- ity, although further improvements may have been seen through the use of computer–assisted survey technol- ogy. Any under-reporting of high-risk sexual behavior Page 7 of 8 is likely to have been evenly distributed throughout the samples, resulting in non-differential bias. This would have lead to an under-estimation of any association be- tween risk behavior and STI diagnosis and is unlikely therefore to change any of our conclusions. It was also not possible to estimate the incidence of STIs using our cross-sectional methodology or to establish any temporal relationship. Another limitation is the moder- ate internal consistency within the condom problem score. The condom problem score included a large number (23) of relatively varied and potentially unre- lated issues, which may happen in isolation or in differ- ent circumstances. This limits its value as a global measure and suggests that a refinement of the score, informed by other recent publications [8-10] might be possible. Despite these limitations, the study findings did allow hypotheses to be formed around factors that may be associated with STI diagnosis and the types of intervention that may be successful, highlighting pos- sible areas for further study. There is good evidence that condom problems were more important than demographic characteristics, including HIV status, in explaining the variance of STI acquisition among the clinic sample of MSM. While causality cannot be in- ferred from this study, the study adds to the evidence base in providing a link between scores of condom problems and biological endpoints. Moreover it directs research attention to focus upon the feasibility and de- velopment of condom skills interventions in this popu- lation. A refinement of the condom problem scale devised in this study, or modifications of the scale could potentially be used as a measure of the effective- ness of behavioral interventions and might also allow larger scale observational studies with the power to confirm or refute associations between reported con- dom problems and incident STI. Single items or sub- sets of items from the scale also have potential for use as a tool for the clinical targeting of behavioral inter- ventions in MSM. Moreover, targeting those who ex- perience condom problems may improve the overall frequency and consistency of condom use, regardless of whether condom problems themselves are causal in the acquisition of STI in MSM. Conclusions This exploratory study highlighted the potential import- ance of targeted condom use skills interventions amongst MSM. The study also emphasised the need for further research to examine the utility of condom prob- lem measures in targeting behavioral interventions to improve sexual health amongst MSM and to explore the link between condom problems and the desired bio- logical endpoint, a reduction in STI acquisition.