For the first time in the UK, this study found significant associations linking measures of condom problems to STI risk amongst MSM. Although condom errors and other problems have been increasingly recognised as a likely factor in reducing condom effectiveness  and the correlates of condom problems in men have been explored [7, 17], biological end point evidence of an association with STI acquisition is scarce in all groups and absent in MSM. An association between condom problems and incident chlamydial and gonococcal infections was shown in a small subsample (21 infections in 130 individuals) of the large Project Respect intervention trial . In a study of 1973 consistent condom users, condom errors were reported much less frequently by MSM than men who have sex with women and an association between condom problems and prevalent STI was seen in heterosexual but not homosexual subjects . We found strong univariate associations between condom proficiency and problem scores and measures of STI acquisition, although only condom problem score remained independently associated after correction for UAI partners. It is entirely conceivable that men who report lower condom proficiency and more condom problems are less likely to use condoms and this requires further exploration. Critically, our study found independent effects of condom problems in relation to self-reported STI acquisition and not laboratory confirmed STIs among the clinic sample. This too is suggestive of a link between condom problems and other risk behaviors rather than a direct link with STI transmission. However, it is important to note that the sample size for men who were found to have a laboratory confirmed STI was small (n = 38); it is therefore possible that sample size may have meant inadequate power to detect any association between condom problems and laboratory confirmed STIs that did exist.
Number of UAI partners was strongly associated with self-reported STI diagnosis over the previous 12 months as well as with prevalent STI. This is unsurprising and is consistent with other behavioral community based surveys of self-reported STIs in MSM  and with clinic based surveys of HIV positive MSM . With evidence of ongoing high-risk behavior in some MSM there is clearly a continuing need for interventions to promote condom use to successfully reduce STI acquisition.
Men at high risk of HIV in Scotland are in contact with prevention services  and interventions are likely to be acceptable . A UK study to determine whether condom thickness affects condom breakage found that user characteristics, including lack of confidence in condom use, rather than condom characteristics were associated with condom breakage among MSM . Although clinic based behavioral interventions have been proven to reduce the risk of STIs in a large randomized controlled trial  it is recognised that these interventions are resource intensive and recent work has focused on reducing the duration and frequency of interventions. Recent studies have shown a reduction in repeat STIs following a single session of condom skills training delivered to young heterosexual African American men by a lay health adviser . A small pilot study of home based condom skills training showed some improvement in measures of condom self-efficacy and reduction in condom errors in 30 young heterosexual men . The condom self-efficacy and error scores used in that study had high internal consistency but have not been shown to be indicators of STI risk. There is good evidence that intensive multi-session clinic based brief behavior change interventions with MSM can reduce the frequency of UAI with partners of unknown HIV status  but there is a lack of evidence on less intensive single session interventions or interventions designed to reduce condom errors in MSM. It is possible that the lower frequency of condom problems in MSM might reduce the impact of condom skills training – although interventions to reduce problems may increase overall levels of use. Such interventions could focus on a number of condom skills, for example, appropriate sized condoms, 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. Limitations 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  and men in different community samples report widely differing rates of UAI [28, 29]. The effect of convenience sampling was mitigated by recruiting from both STI clinics and community 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 necessarily 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 anonymity, although further improvements may have been seen through the use of computer–assisted survey technology. Any under-reporting of high-risk sexual behavior 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 between 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 moderate internal consistency within the condom problem score. The condom problem score included a large number (23) of relatively varied and potentially unrelated issues, which may happen in isolation or in different 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 possible 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 inferred 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 development of condom skills interventions in this population. 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 effectiveness of behavioral interventions and might also allow larger scale observational studies with the power to confirm or refute associations between reported condom problems and incident STI. Single items or subsets of items from the scale also have potential for use as a tool for the clinical targeting of behavioral interventions in MSM. Moreover, targeting those who experience 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.