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The distribution of sex acts and condom use within partnerships in a rural sub-Saharan African population.

Smith J, Nyamukapa C, Gregson S, Lewis J, Magutshwa S, Schumacher C, Mushati P, Hallett T, Garnett G - PLoS ONE (2014)

Bottom Line: Both men and women reported fewer unprotected sex acts with non-regular compared to regular partners (men: 0.26 fewer every two weeks (95% confidence interval 0.18-0.34); women: 0.16 (0.07-0.23)).These variables were also associated with more consistent condom use.This will enable a better understanding of the spread of HIV and other STDs in this rural sub-Saharan population.

View Article: PubMed Central - PubMed

Affiliation: Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom.

ABSTRACT

Introduction: In an HIV/AIDS epidemic driven primarily by heterosexual transmission, it is important to have an understanding of the human sexual behaviour patterns that influence transmission. We analysed the distribution and predictors of within-partnership sexual behaviour and condom use in rural Zimbabwe and generated parameters for use in future modelling analyses.

Methods: A population-based cohort was recruited from a household census in 12 communities. A baseline survey was carried out in 1998-2000 with follow-up surveys after 3 and 5 years. Statistical distributions were fitted to reported within-partnership numbers of total, unprotected and protected sex acts in the past two weeks. Multilevel linear and logistic regression models were constructed to assess predictors of the frequency of unprotected sex and consistent condom use.

Results: A normal distribution of ln(sex acts+1) provided the best fit for total and unprotected sex acts for men and women. A negative binomial distribution applied to the untransformed data provided the best fit for protected sex acts. Condom use within partnerships was predominantly bimodal with at least 88% reporting zero or 100% use. Both men and women reported fewer unprotected sex acts with non-regular compared to regular partners (men: 0.26 fewer every two weeks (95% confidence interval 0.18-0.34); women: 0.16 (0.07-0.23)). Never and previously married individuals reported fewer unprotected sex acts than currently married individuals (never married men: 0.64 (0.60-0.67); previously married men: 0.59 (0.50-0.67); never married women: 0.51 (0.45-0.57); previously married women: 0.42 (0.37-0.47)). These variables were also associated with more consistent condom use.

Discussion: We generated parameters that will be useful for defining transmission models of HIV and other STIs, which rely on a valid representation of the underlying sexual network that determines spread of an infection. This will enable a better understanding of the spread of HIV and other STDs in this rural sub-Saharan population.

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Related in: MedlinePlus

Partnership characteristics.A and B. Boxplots showing the total number of sex acts in the past two weeks by age for (A) men and (B) women. The heavy solid line marks the median and the box edges show the lower and upper quartiles. Whiskers show the minimum and maximum results which are no more than 1.5 multiplied by the interquartile range (IQR) from the box and outliers are not shown. C and D. Scatterplots showing the relationship between respondent age and age difference with partner reported by (C) men and (D) women. Solid lines mark the linear regression of respondent-partner age difference on respondent; these are in the form y = mx+c, where x is the respondent age and y is the respondent-partner age difference. For men (C), m = 0.30 (95% confidence interval [CI95] −0.31 to −0.29) and c = 3.4 (2.9–3.9). For women (D), m = −0.013 (−0.033–0.0065) and c = 7.0 (6.3–7.6).
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pone-0088378-g003: Partnership characteristics.A and B. Boxplots showing the total number of sex acts in the past two weeks by age for (A) men and (B) women. The heavy solid line marks the median and the box edges show the lower and upper quartiles. Whiskers show the minimum and maximum results which are no more than 1.5 multiplied by the interquartile range (IQR) from the box and outliers are not shown. C and D. Scatterplots showing the relationship between respondent age and age difference with partner reported by (C) men and (D) women. Solid lines mark the linear regression of respondent-partner age difference on respondent; these are in the form y = mx+c, where x is the respondent age and y is the respondent-partner age difference. For men (C), m = 0.30 (95% confidence interval [CI95] −0.31 to −0.29) and c = 3.4 (2.9–3.9). For women (D), m = −0.013 (−0.033–0.0065) and c = 7.0 (6.3–7.6).

Mentions: The number of sex acts within a partnership varies by age (Figures 3A and B). For men, the median number of sex acts in the past two weeks decreases from 2 at age 15–16 to 1 at age 17–19 years then increases to a plateau of 3 from 20 years which continues until age 49 years. For women, teenagers aged 15–16 years report a median of 3 sex acts per fortnight within a partnership, increasing to a peak of 4 for 17–24 year-olds. This then declines with increasing age. The denominator in this analysis is sexually active individuals reporting sexual activity within a partnership in the past month, so it is important to note that this does not represent a peak of sexual activity for all 17–24 year-old women.


The distribution of sex acts and condom use within partnerships in a rural sub-Saharan African population.

Smith J, Nyamukapa C, Gregson S, Lewis J, Magutshwa S, Schumacher C, Mushati P, Hallett T, Garnett G - PLoS ONE (2014)

Partnership characteristics.A and B. Boxplots showing the total number of sex acts in the past two weeks by age for (A) men and (B) women. The heavy solid line marks the median and the box edges show the lower and upper quartiles. Whiskers show the minimum and maximum results which are no more than 1.5 multiplied by the interquartile range (IQR) from the box and outliers are not shown. C and D. Scatterplots showing the relationship between respondent age and age difference with partner reported by (C) men and (D) women. Solid lines mark the linear regression of respondent-partner age difference on respondent; these are in the form y = mx+c, where x is the respondent age and y is the respondent-partner age difference. For men (C), m = 0.30 (95% confidence interval [CI95] −0.31 to −0.29) and c = 3.4 (2.9–3.9). For women (D), m = −0.013 (−0.033–0.0065) and c = 7.0 (6.3–7.6).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3928170&req=5

pone-0088378-g003: Partnership characteristics.A and B. Boxplots showing the total number of sex acts in the past two weeks by age for (A) men and (B) women. The heavy solid line marks the median and the box edges show the lower and upper quartiles. Whiskers show the minimum and maximum results which are no more than 1.5 multiplied by the interquartile range (IQR) from the box and outliers are not shown. C and D. Scatterplots showing the relationship between respondent age and age difference with partner reported by (C) men and (D) women. Solid lines mark the linear regression of respondent-partner age difference on respondent; these are in the form y = mx+c, where x is the respondent age and y is the respondent-partner age difference. For men (C), m = 0.30 (95% confidence interval [CI95] −0.31 to −0.29) and c = 3.4 (2.9–3.9). For women (D), m = −0.013 (−0.033–0.0065) and c = 7.0 (6.3–7.6).
Mentions: The number of sex acts within a partnership varies by age (Figures 3A and B). For men, the median number of sex acts in the past two weeks decreases from 2 at age 15–16 to 1 at age 17–19 years then increases to a plateau of 3 from 20 years which continues until age 49 years. For women, teenagers aged 15–16 years report a median of 3 sex acts per fortnight within a partnership, increasing to a peak of 4 for 17–24 year-olds. This then declines with increasing age. The denominator in this analysis is sexually active individuals reporting sexual activity within a partnership in the past month, so it is important to note that this does not represent a peak of sexual activity for all 17–24 year-old women.

Bottom Line: Both men and women reported fewer unprotected sex acts with non-regular compared to regular partners (men: 0.26 fewer every two weeks (95% confidence interval 0.18-0.34); women: 0.16 (0.07-0.23)).These variables were also associated with more consistent condom use.This will enable a better understanding of the spread of HIV and other STDs in this rural sub-Saharan population.

View Article: PubMed Central - PubMed

Affiliation: Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom.

ABSTRACT

Introduction: In an HIV/AIDS epidemic driven primarily by heterosexual transmission, it is important to have an understanding of the human sexual behaviour patterns that influence transmission. We analysed the distribution and predictors of within-partnership sexual behaviour and condom use in rural Zimbabwe and generated parameters for use in future modelling analyses.

Methods: A population-based cohort was recruited from a household census in 12 communities. A baseline survey was carried out in 1998-2000 with follow-up surveys after 3 and 5 years. Statistical distributions were fitted to reported within-partnership numbers of total, unprotected and protected sex acts in the past two weeks. Multilevel linear and logistic regression models were constructed to assess predictors of the frequency of unprotected sex and consistent condom use.

Results: A normal distribution of ln(sex acts+1) provided the best fit for total and unprotected sex acts for men and women. A negative binomial distribution applied to the untransformed data provided the best fit for protected sex acts. Condom use within partnerships was predominantly bimodal with at least 88% reporting zero or 100% use. Both men and women reported fewer unprotected sex acts with non-regular compared to regular partners (men: 0.26 fewer every two weeks (95% confidence interval 0.18-0.34); women: 0.16 (0.07-0.23)). Never and previously married individuals reported fewer unprotected sex acts than currently married individuals (never married men: 0.64 (0.60-0.67); previously married men: 0.59 (0.50-0.67); never married women: 0.51 (0.45-0.57); previously married women: 0.42 (0.37-0.47)). These variables were also associated with more consistent condom use.

Discussion: We generated parameters that will be useful for defining transmission models of HIV and other STIs, which rely on a valid representation of the underlying sexual network that determines spread of an infection. This will enable a better understanding of the spread of HIV and other STDs in this rural sub-Saharan population.

Show MeSH
Related in: MedlinePlus