This cross-sectional study is based on data from the 2004 DHS. The survey was approved by the Ethics Committee of the ORC Macro at Calverton in the USA and by the National Ethics Committee in the Ministry of Health in Cameroon. All study participants gave informed consent before participation and all information was collected confidentially.

Methods used in the Cameroon DHS have been published elsewhere 25 . Briefly, the survey used a two-stage cluster sampling technique. The country was stratified into 12 domains (10 provinces and 2 major cities). Each domain is made up of enumeration areas (EAs) established by a general population and housing census in 2003. The sampling frame was a list of all EAs (clusters). Within each domain, a two-stage sample was selected. The first stage involved selecting 466 clusters (primary sampling units) with a probability proportional to the size, the size being the number of households in the cluster. The second stage involved the systematic sampling of households from the selected clusters. All men aged 15 to 59 years in the selected households were interviewed.

Data were collected by visiting households and conducting face-to-face interviews to obtain information on demographic characteristics, wealth, and sexual behaviour; among other data. For the current study we extracted information on the 4409 sexually active men who participated in the survey.

We extracted data on sexual behaviour, wealth, age, place of residence, marital status, and religion.

We used five characteristics to define sexual behaviour: (a) age at first sexual activity (17 years or less versus more than 17 years), (b) condom use during the last sex with a non-spousal non-cohabiting partner (no versus yes), (c) number of sex partners in the last 12 months (2 or more versus 1 or none), (d) number of lifetime sex partners (more than 5 versus 5 or less), (e) ever paid for sex (yes or no). The cut-off points for age at coital debut and number of lifetime sex partners are based on the median values of Cameroonian men. In this study, unsafe sexual behaviour refers to behaviours that put people at risk of sexual transmission of HIV such as early onset of sexual activity, unprotected sex, multiple concurrent sex partners, multiple lifetime sex partners, and commercial sex.

Two variables were measured as proxy measures of wealth, that is, the wealth index and level of education attained. A score was attributed to each household amenity and the total score constituted the wealth index score 26 . We divided this score into three equal classes of wealth based percentiles, that is, less than 33.33th percentile (low, i.e. poorest), 33.33 to 66.66th percentile (medium, i.e. moderately rich), and more than 66.66th percentile (high, i.e. richest). The level of education attained was defined as never been to school, primary, and secondary or higher education.

Other variables were defined as follows: age was stratified into three 15 year age bands (15–29 years, 30–44 years, and 45–59 years), place of residence was defined as rural or urban, religion (was stratified into Christians, Muslims, and others), and marital status (was defined as never married, currently married, and divorced or widowed).

All cases in the DHS data are given weights to adjust for differences in probability of selection of subjects and to adjust for the non-response in order to produce the proper representation of the whole country 25 . The weight is determined such that it is inversely proportional to the response rate as well as the probability of selection. Therefore, the use of weights corrects for the differential response rates and the unequal probability used to select subjects in the sample. Data were collected and analysed using SPSS version 13.0 for Windows. We used individual weights data analysis in this study. Values for categories of the socio-demographic variables are expressed as absolute numbers (proportions). Unadjusted logistic regression analyses were carried out to investigate the bivariate relationship between each socio-demographic variable and sexual behaviour. Multiple logistic regression analyses were then carried out to find out which of the characteristics were independently associated with sexual behaviour. In the logistic regression models, the dependent variables were sexual behaviours (age at sexual debut, condom use in last casual sex, purchase of sexual services, number of sex partners in the previous 12 months, and number of lifetime sex partners) and the independent variables were wealth index, educational level, age, marital status, religion, and place of residence. The significance tests were two-tailed and statistical significance was defined at the alpha level of 0.05.

A total of 4409 sexually active men participated in the study. Their mean age was 32.4 (standard deviation [SD] 11.4) years and the mean age at first sex was 18.0 (SD 4.1) years. The socio-demographic characteristics of the study population are shown in Table 1. Most of the study population was quite young, with the age group 15–29 years making up 48.3%. A majority of the men were married (60.5%) and the rest had never married (28.7%) or were divorced or widowed (10.9%). More than half (52.1%) had at least secondary education and 56% have had more than five lifetime sex partners.

Bivariate associations between socio-demographic characteristics of the study population, including wealth, and sexual behaviour are shown in Table 2. Compared to poor men, the wealthiest men were more likely to start sexual activity at 17 years or less (OR 1.84, 95% CI 1.59 to 2.13) and less likely to have used a condom in the last sex with a non-spousal non-cohabiting partner (OR 0.16, 95% CI 0.13 to 0.19). In addition, the richest third of the study population were more likely to have had at least two concurrent sex partners in the last 12 months (OR 1.40, 95% CI 1.22 to 1.62) and more than five lifetime partners (OR 1.66, 95% CI 1.45 to 1.90). Wealth was not significantly associated with transactional sex. Compared with those who had never been to school, men who had secondary or higher education were more likely to have started sex at 17 years or less (OR 4.88, 95% CI 3.91 to 6.06) and less likely to have used a condom in the last sex with a non-spousal non-cohabiting partner (OR 0.8, 95% CI 0.06 to 0.12). In addition, the more educated men were more likely to have had at least two concurrent sex partners in the last 12 months (OR 1.32, 95% CI 1.08 to 1.60) and more than five lifetime sex partners (OR 2.02, 95% CI 1.68 to 2.43). The association between educational level attained and purchase of sexual services was not consistent.

Compared to men aged 15–29 years, those 45–59 years old were less likely to have had their sexual debut at less than 18 years (OR 0.20, 95% CI 0.17 to 0.25) and more likely to have used a condom in the last sex with a non-spousal non-cohabiting partner (OR 9.28, 95% CI 7.04 to 12.24). However, the oldest men (45–59 years) were more likely to have had at least two concurrent sex partners in the last 12 months (OR 1.32, 95% CI 1.11 to 1.56) and more than five lifetime partners (OR 4.43, 95% CI 3.88 to 5.06). Concerning transactional sex, the 45–59 year old men were less likely to have ever paid for sex (OR 0.17, 95% CI 0.06 to 0.47) but this was not a consistent trend with advancing age (P for trend = 0.154). Compared to men from the rural area, men from urban areas started sexual activity earlier (OR 1.37, 95% CI 1.22 to 1.54), were less likely to use a condom in sex with a non-spousal non-cohabiting partner (OR 0.31, 95% CI 0.26 to 0.36), and more likely to have had at least two concurrent sex partners in the last 12 months (OR 1.18, 95% CI 1.05 to 1.33) and more than five lifetime partners (OR 1.27, 95% CI 1.14 to 1.42). There was no difference in purchase of sexual services. Compared to Christians, Muslims (OR 0.46, 95% CI 0.39 to 0.54) were less likely to have had coital debut at an early age (P for trend = 0.036), more likely to use a condom in sex with a non-spousal non-cohabiting partner (OR 1.96, 95% CI 1.60 to 2.40), and less likely to have either concurrent (OR 0.69, 95% CI 0.59 to 0.82) or multiple lifetime (OR 0.47, 95% CI 0.40 to 0.54) sex partners. However, Muslims were more likely than Christians to pay for sex (OR 1.96, 95% CI 1.13 to 3.38). Men practising other religions were less likely to start sexual activity early (OR 0.73, 95% CI 0.61 to 0.88), more likely to use a condom in sex with a non-spousal non-cohabiting partner (OR 1.48, 95% CI 1.19 to 1.84) and less likely to have more than five lifetime partners (OR 0.81, 95% CI 0.69 to 0.96) compared to Christians. There was no difference between the two religious groups with regards to having concurrent sex partners in the previous 12 months and paying for sex. Compared to men who have never married, the married men were less likely to have paid for sex (OR 0.58, 95% CI 0.38 to 0.87) and more likely to have used a condom in the last sex with a non-spousal non-cohabiting partner (OR 7.07, 95% CI 6.04 to 8.32), had at least two concurrent sex partners in the last 12 months (OR 2.11, 95% CI 1.86 to 2.41), and more than five lifetime partners (OR 5.15, 95% CI 4.53 to 5.84). The pattern of risk behaviour was similar for divorced or widowed men compared to their counterparts who have never married.

Table 3 shows the adjusted odds ratios from the multiple logistic regression modelling. After controlling for marital status, place of residence, religion, and age, wealth and education remained significantly associated with unsafe sexual behaviours. Compared to poor men, the wealthiest men were less likely to use a condom in the last sex with a non-spousal non-cohabiting partner (OR 0.43, 95% CI 0.32 to 0.56) and more likely to have had at least two concurrent (OR 1.38, 95% CI 1.12 to 1.19) and more than five lifetime (OR 1.97, 95% CI 1.60 to 2.43) sex partners. There was no significant association between being wealthy and either age of coital debut or paying for sex. Compared to men who had never been to school, those with secondary or higher education were more likely to have started sex early (OR 2.73, 95% CI 2.10 to 3.56), less likely to have used a condom in the last sex with a non-spousal non-cohabiting partner (OR 0.24, 95% CI 0.16 to 0.38), and more likely to have had more than five lifetime partners (OR 2.59, 95% CI 2.02 to 3.31). In addition, there was a significant trend towards multiple concurrent sexual partnerships with increasing level of education (P for trend = 0.002).

Other independent predictors of sexual behaviour were age, place of residence, religion, and marital status. Compared to young men (15–29 years), men in the oldest age group (45–59 years) were less likely to have had coital debut at younger than 18 years (OR 0.30, 95% CI 0.24 to 0.36), more likely to have used a condom in the last sex with a non-spousal non-cohabiting partner (OR 3.90, 95% CI 2.86 to 5.30) and less likely to have paid for sex (OR 0.20, 95% CI 0.07 to 0.61), but more likely to have had more than five lifetime sex partners (OR 4.06, 95% CI 3.29 to 5.02). Concerning place of residence, men living in urban areas were less likely to have used a condom in the last sex with a non-spousal non-cohabiting partner (OR 0.65, 95% CI 0.53 to 0.80) and more likely to have paid for sex (OR 2.10, 95% CI 1.24 to 3.56). For religion, Muslims were less likely to have started sex early (OR 0.68, 95% CI 0.56 to 0.82), had multiple concurrent sex partners in the last 12 months (OR 0.74, 95% CI 0.61 to 0.89), or multiple lifetime sex partners (OR 0.51, 95% CI 0.42 to 0.61), but more likely to have paid for sex (OR 2.12, 95% CI 1.22 to 4.03). Compared to never married men, married men were less likely to have had first sex at less than 18 years (OR 0.68, 95% CI 0.58 to 0.81) and more likely to have used condoms in the last sex with a non-spousal non-cohabiting partner (OR 3.49, 95% CI 2.86 to 4.25), but more likely to have had at least two concurrent sex partners in the last 12 months (OR 2.26, 95% CI 1.91 to 2.67).