There has been a long history of challenges regarding aspects of condom use. Numerous studies have attempted to understand factors that account of variation in use, be these related to user characteristics (knowledge, attitudes, gender, etc), actual and/or perceived partner characteristics (gender, perceived risk category, assertiveness skills, etc), immediate contextual factors (relationship status, location, condom availability, the impact of desire, alcohol, etc), distal factors (pricing, perceptions of quality, the impact of sex education programmes, etc), and other factors. Very many articles have been published in a very wide range of journals and more popular media.

The vast majority of such articles have used just one or two simple questions to assess condom use as the outcome variable. Some studies explore intended use, while others ask about actual use. Questionnaire items normally cover one or more of the following—use at first intercourse, use at most recent intercourse, use at first intercourse with most recent partner, etc—using a binary response option. Others ask about regularity of usage over some time period, generally using a Likert type scale ranging from ‘never’ to ‘always’ with varying numbers of points (normally three or five) in between these extremes.

There are, of course, immense challenges regarding the accuracy of the data collected. Although the selection of ‘always’ and ‘never’ provide unambiguous anchor points, there is likely to be fairly wide variation in the ways in which terms like …