You wouldn't think it would be that difficult to use a male condom. Basically, you get a fresh condom, open it carefully, put it on the right way up, and set to. However, according to the research, the number of people who make mistakes when using condoms is astronomical. In their review of 50 articles from 14 countries, the scientists found that common errors included - not using condoms throughout the sexual experience, failing to leave room at the tip or squeeze out the air, applying the condom inside out, choosing the wrong lubricants, and failing to hold on to the condom during withdrawal.
Depending on the study, up to half of all participants reported either putting the condom on too late (after penetration had begun) or taking it off too early (and still continuing to have sex.) In other research, up to one third of participants flipped the condom over after applying it - a big no-no, since it may already be contaminated with pre-ejaculatory fluid - or unrolled it completely before putting it on. Failing to leave room at the tip and/or remove the air from the tip were also quite common.
The primary take home message of the study was that we have to do a better job teaching people about the proper way to use a condom- including how and when to apply them and what lubricants are safe to use. This is particularly true since the vast majority of breakage and slippage seems to happen within a relatively small group of users - a potent suggestion that user error may be the most important factor in condom failure.