Ecological determinants of risky sexual behaviours among adolescents and young adults in Cape Town, South Africa: a cumulative risk factor approach
Date
2018
Authors
Muchiri, Evans Mwiti
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
South Africa is experiencing a youth bulge, and many demographers share the view that the
country would experience a demographic dividend, by having a larger working population
relative to the dependent population. A ‘demographic dividend’ is characterised by an
accelerated economic growth that occurs when there is a growing proportion of productive
people in the workforce compared to the dependent population. For a demographic dividend
to occur, change in age structure takes place, and a significant decline in fertility is observed.
Decrease in fertility and improving health can lead to a shift in age structure of a population,
decreasing the ratio of dependent population. In the case of South Africa, with a total
population estimated at 55 million in 2015, people aged between 15 and 35 years constituted
36% of the population, according to Statistics South Africa (StatsSA, 2015). However, low
life expectancy occasioned by HIV and AIDS, and lost schooling time due to teenage
pregnancies impacting on future productivity and earnings, makes it not obvious for South
Africa to experience a demographic dividend. Besides, increasing mortality from AIDS
related illnesses, and the impact of unwanted pregnancy on fertility, may have a strong
bearing on outcomes relevant to demography and population studies.
Despite South African youth constituting less than 1% of the global youth (15-24 years)
population, the country accounts for up to 15% of HIV youth population globally living with
HIV according to the UNAIDS (UNAIDS, 2016). Increased mortality among adolescents and
young adults living with HIV due to AIDS related illnesses reduces life expectancy that has
important implications on demographic aspects of the population. Despite AIDS-related
deaths among adults (15+ years) having been declining since the rollout of antiretroviral
treatment (ART) in 2004, recent statistics from UNAIDS indicate that AIDS-related deaths
among adolescents may actually be increasing due to low uptake of ART treatment
(UNAIDS, 2014).
While HIV is one of the unintended consequences of unprotected sex, unwanted pregnancy is
another indicator of unprotected sexual activity. More than 30% of teenage girls in South
Africa report experiencing pregnancy whose majority are unplanned (Jewkes, Morrell, &
Christofides, 2009). In absolute numbers, more than 99,000 school attending teenagers fell
pregnant in 2013, a rise since 2011 when 66,000 school attending teenage pregnancies were
reported(StatsSA, 2013a). Maternal mortality and health implications related to childbearing
is higher among teenage mothers compared to general population, because their reproductive
systems have not fully developed, and struggle to deliver naturally. In South Africa, an
estimated 36% of all maternal deaths occurred to teenage mothers even though they only
accounted for 8% of all new births. Childbirth at a young age leads to health complications
that may result in mortality and increases the risk of developing obstetric fistulae. Acquiring
HIV infections and unintended underage pregnancy have significant contribution to
morbidity, mortality and fertility, aspects that are relevant for demography and population
studies field.
Globally, shift towards late marriage in many countries has led to an increase in premarital
sexual activity (Blum, 2007). It has been reported that adolescents and young adults become
sexually active in their teen years and rarely takes precaution to practice safe sex. Research
has established a clear association between risky sexual behaviours of unprotected sex, early
age at sex debut, and multiple and concurrent partnerships to increased risk of HIV infection
and unwanted pregnancy (Ghebremichael, Larsen, & Paintsil, 2009; Pettifor, O'Brien,
Macphail, Miller, & Rees, 2009; Pettifor, van der Straten, Dunbar, Shiboski, & Padian,
2004). Risky sexual behaviours are defined by the increased risk of a negative outcome of
contracting or transmitting disease or the occurrence of unwanted pregnancy. Research
studies in South Africa have reported high levels of unsafe sexual practices among
adolescents and young adults (Pettifor et al., 2009).
Previous studies have reported on correlates of risky sexual behaviours among adolescents
and young adults, however, these studies mainly analysed individual level attributes using
cross-sectional datasets (McHunu, Peltzer, Tutshana, & Seutlwadi, 2012; Onoya, Zuma,
Zungu, Shisana, & Mehlomakhulu, 2015; Shisana et al., 2014; Zuma, Mzolo, & Makonko,
2011). Besides, studies of risky sexual behaviours among adolescents and young adults have
mainly investigated the effect of risk factors studied in isolation. This study aims to add to
existing literature by seeking to understand whether risk factors occurring at the individual,
household, and community levels may have a cumulative effect.
Furthermore, analyses of risky sexual behaviours have mainly used cross-sectional datasets
because of the complex nature of collecting longitudinal dataset for sexual behaviours. Cross
sectional analyses may inform on associations but are limited to making causal inferences
and lack information on trends over time. Therefore, this study incorporated all factors at the
individual, household, and community levels to investigate for significant determinants of
risky sexual behaviours. Further, this study used a longitudinal approach to investigate on
trends and determinants of risky sexual behaviours among adolescents and young adults, and
assessed whether significant risk factors for risky sexual behaviours may have a cumulative
effect is a timely contribution to literature. The cumulative risk model adopted in this
research assumes that the effect of ecological risk factors act in a cumulative way; arguing
that increasing risk factors present in the ecology of adolescents and young adults may
correlate to an increasing likelihood of reporting outcomes of risk sexual behaviours.
Research on the cumulative risk model has only been reported in the United States of
America and England which represent contexts of developed countries and has not been
assessed before in Sub-Saharan Africa (Small & Luster, 1994). Therefore, results from
testing the model in high HIV settings may add contribution to existing literature and may
inform research in South Africa and sub-Saharan Africa. Understanding why adolescents and
young adults in urban Cape Area, South Africa engage in risky sexual behaviours, and
whether significant risk factors act cumulatively, would contribute immensely to the study of
demography and population studies for both South Africa and the African continent. Findings
from this thesis would inform on the design and implementation of effective interventions
that may reduce the occurrence of risky sexual behaviours.
Data Sources and Methods
Data from the Cape Area Panel Study (CAPS) that enrolled 4,752 adolescents aged between
14 and 22 years in urban Cape Town, South Africa, were used to investigate trends and
ecological determinants of risky sexual behaviours. The CAPS data were collected in waves
of surveys with the baseline survey conducted in 2002 while the last recorded survey was in
2009. The CAPS sampling plan was to produce a household sample that was representative
of households in urban Cape Town A young adult respondent was identified from a selected
household and interviewed, and was similarly followed-up in subsequent survey waves, for
updated responses. The surveys focused on a wide range of issues affecting the adolescents
and young adults participating in the various waves of the surveys. These included school,
work, household living arrangements, sexual behaviours and reproductive health. Further, the
young adult sample was designed to produce a representative sample of the population aged
14 to 22 years in urban Cape Town. The Wave 1 survey was conducted in 2002, and
subsequent surveys for Wave 2a/2b conducted in 2003/2004, Wave 3 in 2005, Wave 4 in
2006, and Wave 5 in 2009. A longitudinal analysis dataset was defined for outcomes of early
age at sex debut, multiple sexual partnerships, and inconsistency in condom use. Baseline
characteristics were defined from the baseline survey and were used to inform on factors that
were significantly different for the binary outcomes during the follow-up period until survey
Wave 5. Dependent variables were created as binary responses experienced during the
follow-up, for early sexual debut, reporting multiple sexual partnerships, and consistency in
the use of condoms where all analyses were conducted stratified by gender. An adapted
ecological systems framework was used to organise risk factors according to levels of the
ecology including factors at individual, household, and community levels.
Descriptive statistics were performed for baseline characteristics of the sample using
frequencies and proportions. Bivariate analyses for the binary outcomes of risky sexual
behaviours were performed, with differences between outcome groups assessed using Chi
square tests. The level of significance for all statistical tests, and univariate and multivariate
models was set at p<0.05. A univariate and multivariate discriminant function analyses
(DFA) was applied to identify risk factors that were significantly different between the binary
outcome groups. The DFA expresses a dependent variable as a linear combination of
independent variables that best explains differences between outcome groups. The DFA
technique was used to predict a categorical dependent variable from continuous or binary
responses and assumes the normality of the explanatory variables.
The study further applied a cumulative risk analysis where significant ecological risk factors
identified in the multivariate models were hypothesised to have a cumulative effect on risky
sexual behaviours. Risk indices were created for factors that were significant in multivariate
analyses to represent presence or absence of risk. The generated indices were summed to
represent a cumulative risk and a correlation between the cumulative risk and the outcomes of
risky sexual behaviours were investigated. Simple linear regression analyses were conducted
to study the relationship between cumulative risk index and proportion of adolescents and
young adults reporting the risky sexual behaviour outcome.
Results
A total of 4,752 respondents were interviewed, with 45.0% of the respondents being males,
with a sample mean age of 18 (SD 2.5) years and a range of between 14 years and 22 years at
baseline. The majority of respondents were unmarried with 98.9% reporting to have never
been married during while only 28.3% reported working in the last year. At Wave 1 (2002),
only 46% of respondents were sexually experienced compared to 94.3% at the end of Wave 5
(2009) survey showing a steady increase over the period. The mean age at sexual debut at
Wave 1 was reported to be 16.2 (SD 1.8) years and increased to 19.4 (2.8) years at Wave 5
progressively increasing during the period. At Wave 1 71.5% used protection against disease
or pregnancy, compared to 65.1% at Wave 5 showing a decline in condom use during the
period. Number of reported sexual partners in the last 12 months was steady at a median of 1
for both Wave 1 and Wave 5.
Determinants for early age at sexual debut included years of education and age of first sex
partner for both males and females at the individual level. While at the household level, only
spending time with a mother was significant for females. Most community level factors were
significant for both males and females including proportion unemployed, proportion
individual Africans, and proportion below poverty line. Furthermore, additional determinants
of risky sexual behaviours never reported before were identified, with more emphasis on the
importance role of community level socio-economic status including mean years of education
and employment status of household heads. Significant differences in sexual behaviours were
observed at individual level characteristics of schooling status, planning to marry in the short
term, living with a single or both parents, and community levels of education and
employment. The study found that ecological risk factors had a cumulative effect, meaning
that as more risk factors became present, there was a corresponding increase in reports of
risky sexual behaviours for the three outcomes investigated.
Conclusions
This study finds that the prevalence of risky sexual behaviour among young adults in urban
Cape Town to be high, even though observed levels were not particularly different from
levels observed in developed countries. However, in the context of a high HIV incidence of
South Africa, these are important issues that need to be addressed. The important role that
community socio-economic status plays was evident with a many of community factors
returning significant for risky sexual behaviour studied. Findings from this study demonstrate
that risk factors for sexual behaviour appear at all levels of the ecology that include
characteristics at the individual, household and community levels. Further it was
demonstrated that as factors becomes more prevalent in the context of the adolescents and
young adults respondents, they reported increasingly engaging in risky sexual behaviours
indicating that ecological risk factors had a cumulatively.
Interventions for risky sexual behaviour should be designed to include factors at all levels of
the ecology as their effect tends to be cumulative. Socio-economic incentives that provide
cash handouts to adolescents and young adults should be encouraged that intervenes to keep
adolescents away from risky sexual activity. These programmes have worked in KwaZulu
Natal province, South Africa and have potential to work in urban Cape Town. Cash
incentives have been effective in preventing pregnancy and marriage among adolescent girls
in Kenya and India (Handa et al., 2015). Monthly stipends on school-attending condition
would not only provide adolescents and young adults with schooling opportunities but also
provide required economic incentives to stay away from transactional sex.
These findings are important for public health and population studies in South Africa because
understanding risky sexual behaviours may inform on the design of effective programmes for
mitigating the negative health outcomes associated. Since findings indicate that as ecological
risk factors accumulate, risky sexual behaviours increase, this is important for policy and
programme design. Programmes for reducing early sex initiation, unprotected sexual activity,
and multiple partnerships among adolescents and young adults impact on fertility, mortality,
and informs whether the country would achieve a demographic dividend. The flexibility of
the ecological systems model was demonstrated in these analyses where it was adapted into
the unique and specific settings of sub-Saharan Africa and in the case of Cape Town, an
urban settings with differing socio-economic status communities. Therefore, the ecological
systems framework was a powerful and a practical tool to study sexual behaviours in South
Africa. Research on the effectiveness of programmes that compensate for the cumulative risk
that is occasioned in communities with low socio-economic status is urgently required.
Description
A thesis submitted to the Faculty of Humanities and Social Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy (PhD.) in Demography and Population Studies,Johannesburg, 2018
Keywords
Citation
Muchiri, Evans Mwiti (2018) Ecological determinants of risky sexual behaviours among adolescents and young adults in Cape Town, South Africa: a cumulative risk factor approach, University of the Witwatersrand, Johannesburg, https://hdl.handle.net/10539/27096