Abstract:
Background: Injecting drug use (IDU) is a key driver of the HIV epidemic particularly when individuals experience
psychosocial conditions and risky sexual behavior in a syndemic manner. This study sets out to assess evidence of a
syndemic pattern of psychosocial conditions (IDU, depression, intimate partner violence (IPV)) on one the hand and
risky sexual behavior on the other while accounting for the socio-economic disadvantage among women who
inject drugs (WWID) in low-income urban settings in Kenya.
Methods: Using a cross-sectional study design, this study recruited 306 WWIDs from two sites in Nairobi between
January 2017 and July 2017. Multiple methodologies including descriptive analyses of co-occurrences of
psychosocial conditions at the individual level, standard logistic regression analyses to examine relationships and
interactions within and between psychosocial conditions and risky sexual behavior, and classification trees
algorithm for predictive modeling via machine learning were employed.
Results: The prevalence of the psychosocial conditions was as follows: IDU, 88%; depression, 77.1%; and IPV, 84%.
The prevalence of risky sexual behavior was 69.3%. IDU and depression were related to each other (P < 0.05) and
each of them with risky sexual behavior (P < 0.05). The highest 2-way and 3-way co-occurrence of conditions were
reported in IDU and depression (72%) and in IDU, depression, and risky sexual behavior (62%), respectively,
indicating clustering of the conditions at the individual level. Further, each additional psychosocial condition
(IDU and depression) was associated with sixfold odds (P = 0.000) of having risky sexual behavior suggesting a
dose-response relationship. Logistic regression analyses incorporating multiplicative interactive effects returned
three significant variables (P < 0.05): IDU*depression interaction effect, “Age when delivered the first child,” and
“Income.” Classification tree modeling represented a 5-level interaction analysis with IDU and depression predicted
to have the highest influence on risky sexual behavior.
Conclusion: Findings provide possible evidence of a syndemic pattern involving IDU, depression, and risky sexual
behavior suggesting the need for an integrated approach to the implementation of harm reduction interventions
among WWID in low-income urban settings in Kenya. This work highlights the need for further studies to
authenticate the findings and to characterize pathways in the syndemic development in WWID.