Imperial College London

ProfessorSimonGregson

Faculty of MedicineSchool of Public Health

Professor in Demography and Behavioural Science
 
 
 
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Contact

 

+44 (0)20 7594 3279s.gregson

 
 
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Location

 

LG27Praed StreetSt Mary's Campus

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Summary

 

Publications

Publication Type
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244 results found

Skovdal M, Sorensen O, Muchemwa D, Nyamwanza R, Maswera R, Svendsen M, Nyamukapa C, Thomas R, Gregson Set al., 2023, “It will not be easy to accept”: Parents conflicting attitudes towards pre-exposure prophylaxis for HIV prevention amongst adolescent girls and young women in Zimbabwe, Research in Social and Administrative Pharmacy, Vol: 19, Pages: 266-271, ISSN: 1551-7411

Background:Pre-exposure prophylaxis, or PrEP, is a pill that has been hailed as a ‘game changer’ for HIV prevention, based on the belief it provides adolescent girls and young women (AGYW) with a level of user-control. However, engagement with PrEP is often dependent on societal factors, such as social attitudes towards gender, sexuality, and PrEP. As parents' communication on sexual and reproductive health issues with AGYW are central to HIV prevention, it is critical to explore how parents talk and think about PrEP.Objective:To examine parental attitudes towards PrEP for HIV prevention amongst adolescent girls and young women in eastern Zimbabwe.Method:A qualitative interview study with 14 parents from two districts in Manicaland, eastern Zimbabwe. Interviews were transcribed, translated, and subjected to thematic network analysis. The concept of ‘attitudes’ steered the analytical work.Results:Parents' attitudes towards PrEP are conflictual, multi-layered, and contingent on the context in which they reflect and talk about PrEP. While parents aspired to be supportive of innovative HIV prevention methods and wanted to see girl-children protected from HIV, they struggled to reconcile this positive and accepting attitude towards PrEP with traditional ‘good girl’ notions, which stigmatize pre-marital sex. Although a few parents articulated an acceptance of PrEP use amongst their daughters, for many this was simply not possible. Many parents thus co-produce public gender orders that prevent adolescent girls and young women from engaging with PrEP.Conclusions:While parents’ conflicting attitudes towards PrEP may provide spaces and opportunities for change, harmful gender norms and negative attitudes towards PrEP must be addressed at a community and cultural level. Only then can parents and their children have productive conversations about sexual health.

Journal article

Davis K, Moorhouse L, Maswera R, Mandizvidza P, Dadirai T, Museka T, Nyamukapa C, Smit M, Gregson Set al., 2023, Associations between HIV status and self-reported hypertension in a high HIV prevalence sub-Saharan African population: a cross-sectional study, BMJ Open, Vol: 13, ISSN: 2044-6055

Objectives: This study examined whether HIV status and antiretroviral therapy (ART)-exposure were associated with self-reported hypertension in Zimbabwe. Design: Study data were taken from a cross-sectional, general population survey, which included HIV testing (July 2018 – December 2019). Setting: The data were collected in Manicaland Province, Zimbabwe.Participants: 9,780 people aged 15 years and above were included. Outcome measure: Self-reported hypertension was the outcome measure. This was defined as reporting a previous diagnosis of hypertension by a doctor or nurse. After weighting of survey responses by age and sex using household census data, chi-squared tests and logistic regression were used to explore whether HIV status and ART-exposure were associated with self-reported hypertension.Results: The weighted prevalence of self-reported hypertension was 13.6% (95% Confidence Interval: 12.9%-14.2%) and the weighted prevalence of HIV was 11.1% (10.4%-11.7%). In univariable analyses, there was no evidence of a difference in the weighted prevalence of self-reported hypertension between people living with HIV (PLHIV) and HIV-negative people (14.1%, 11.9%-16.3% vs 13.3%, 12.6%-14.0%; p=0.503) or between ART-exposed and ART-naive PLHIV (14.8%, 12.0%-17.7% vs 12.8%, 9.1%-16.4%, p=0.388). Adjusting for socio-demographic variables in logistic regression did not alter this finding (odds ratios: HIV status: 0.88, 0.70-1.10, p=0.261; ART-exposure: 0.83, 0.53-1.30, p=0.411). Conclusions: Approximately one in seven PLHIV self-reported having hypertension, highlighting an important burden of disease. However, no associations were found between HIV status or ART-exposure and self-reported hypertension, suggesting that it will be valuable to focus on managing other risk factors for hypertension in this population. These findings should be fully accounted for as Zimbabwe re-orients its health system towards non-communicable disease control and management.

Journal article

Skovdal M, Jensen FJB, Maswera R, Beckmann N, Nyamukapa C, Gregson Set al., 2023, Temporal discrepancies in "rapid" HIV testing: explaining misdiagnoses at the point-of-care in Zimbabwe, BMC INFECTIOUS DISEASES, Vol: 23

Journal article

Beckmann N, Skovdal M, Maswera R, Nyamukapa C, Gregson Set al., 2022, Rituals of care: Strategies adopted by HIV testers to avoid misdiagnosis in rapid HIV testing in Zimbabwe, Global Public Health, Vol: 17, Pages: 4169-4182, ISSN: 1744-1692

A growing number of studies highlight high levels of misdiagnosis in the scale-up of HIV rapid testing programmes, which often remain invisible to individual testers. Drawing on interviews with HIV testers and observations in four health facilities in Zimbabwe, we show that testers navigated the translation of the standardised, dis-embodied norms of laboratory-based testing into the body work of point-of-care testing through ritualisation of laboratory-practices in their daily clinical work. Yet, this was interrupted through the challenging work conditions the testers face. They ritualised careful procedures, forcing themselves to focus even if queues were long, and making quality assurance procedures part of their daily routine. They actively tried to reduce their workloads and double-checked and discussed unexpected results, especially when a test result did not match their evaluation of clients’ circumstances or clinical status. This helped not only to increase confidence in the authenticity of their diagnosis, but also to share responsibility for potential errors. Existing approaches to tackle the problem of misdiagnosis through quality assurance (QA) procedures mainly focus on adjusting individual testers’ performance and ensuring that basic testing resources were present, thus falling short of creating a work environment that is conducive to high quality testing.

Journal article

Rao A, Moorhouse L, Maswera R, Dadirai T, Mandizvidza P, Nyamukapa C, Nayagam S, Gregson Set al., 2022, Status of the HIV epidemic in Manicaland, east Zimbabwe prior to the outbreak of the COVID-19 pandemic, PLoS One, Vol: 17, Pages: 1-19, ISSN: 1932-6203

BackgroundManicaland province in eastern Zimbabwe has a high incidence of HIV. Completion of the seventh round of the Manicaland Survey in 2018–2019 provided the opportunity to assess the state of the epidemic prior to the start of the COVID-19 pandemic. The study aims were to: a) estimate HIV seroprevalence and assess whether prevalence has declined since the last round of the survey (2012–2013), b) describe and analyse the socio-demographic and behavioural risk factors for HIV infection and c) describe the HIV treatment cascade.MethodsParticipants were administered individual questionnaires collecting data on socio-demographic characteristics, sexual relationships, HIV prevention methods and treatment access, and were tested for HIV. Descriptive analyses were followed by univariate and multivariate analyses of risk factors for HIV seropositvity using logistic regression modelling based on the proximate-determinants framework.ResultsHIV prevalence was 11.3% [95% CI; 10.6–12.0] and was higher in females than males up to 45–49 years. Since 2012–2013 HIV prevalence has significantly declined in 30–44 year-olds in males, and 20–44 year-olds in females. The HIV epidemic has aged since 2012–2013, with an increase in the mean age of HIV positive persons from 38 to 41 years. Socio-demographic determinants of HIV prevalence were church denomination in males, site-type, wealth-status, employment sector and alcohol use in females, and age and marital status in both sexes. Behavioural determinants associated with increased odds of HIV were a higher number of regular sexual partners (lifetime), non-regular sexual partners (lifetime) and condom use in both sexes, and early sexual debut and concomitant STIs in females; medical circumcision was protective in males. HIV status awareness among participants testing positive in our study was low at 66.2%. ART coverage amongst all participants testing positive for HIV in our study was 65.

Journal article

Skovdal M, Clausen CL, Magoge-Mandizvidza P, Dzamatira F, Maswera R, Nyamwanza RP, Nyamukapa C, Thomas R, Gregson Set al., 2022, How gender norms and 'good girl' notions prevent adolescent girls and young women from engaging with PrEP: qualitative insights from Zimbabwe, BMC Womens Health, Vol: 22, ISSN: 1472-6874

Background:Pre-exposure prophylaxis, or PrEP, has been hailed for its promise to provide women with user-control. However, gender-specific challenges undermining PrEP use are beginning to emerge. We explore the role of gender norms in shaping adolescent girls and young women’s (AGYW) engagement with PrEP.Methods:We draw on qualitative data from 12 individual interviews and three focus group discussions with AGYW from eastern Zimbabwe. Interviews were transcribed and thematically coded in NVivo 12. Emerging themes were further investigated using Connell’s notion of ‘emphasised femininity’.Results:Participants alluded to the patriarchal society they are part of, with ‘good girl’ notions subjecting them to direct and indirect social control. These controls manifest themselves through the anticipation of intersecting sexuality- and PrEP-related stigmas, discouraging AGYW from engaging with PrEP. AGYW recounted the need for permission to engage with PrEP, forcing them to consider engaging with PrEP in secrecy. In addition, limited privacy at home, and fear of disclosure of their health clinic visits, further heightened their fear of engaging with PrEP. PrEP is not simply a user-controlled HIV prevention method, but deeply entrenched within public gender orders.Conclusion:AGYW face significant limitations in their autonomy to initiate and engage with PrEP. Those considering PrEP face the dilemma of Scylla and Charybdis: The social risks of stigmatisation or risks of HIV acquisition. Efforts to make PrEP available must form part of a combination of social and structural interventions that challenge harmful gender norms.

Journal article

Davis K, Pickles M, Gregson S, Hargreaves J, Ayles H, Bock P, Pliakas T, Thomas R, Ohrnberger J, Bwalya J, Bell-Mandla N, Shanaube K, Probert W, Hoddinott G, Bond V, Hayes R, Fidler S, Hauck Ket al., 2022, The effect of universal testing and treatment for HIV on health-related quality of life - data from the HPTN 071 (PopART) cluster randomised trial in Zambia and South Africa, AIDS 2022, Publisher: International AIDS Society, ISSN: 1758-2652

Conference paper

Gregson S, Dadirai T, Maswera R, Moorhouse L, Museka T, Mandizvidza P, Dzamatira F, Tsenesa B, Nyamukapa C, Skovdel Met al., 2022, Survey measurements of community norms on adolescent girls and young women's (AGYW) sexual behaviour and use of condoms for HIV prevention in Manicaland, East Zimbabwe, 24th International AIDS Conference, Publisher: International AIDS Society, Pages: 88-88, ISSN: 1758-2652

Background: Qualitative data suggest pre-marital sex stigma presents a major obstacle to AGYW's use of HIV prevention methods. Lack of social acceptability therefore is included as a barrier to motivation to use condoms in HIV prevention cascades. Representative survey data on community norms are rare but necessary to test the validity of this assumption and measure their contributions to gaps in prevention cascades. Methods: General-population survey participants in Manicaland (ages≥15,N = 9803) were asked if they agreed/disagreed with statements on social norms. AGYW were asked whether community views are an obstacle to their using condoms. Proportions agreeing/disagreeing with these statements were calculated, variations in community members’ views were investigated in multivariable logistic-regression models, and the association between AGYW's perceiving negative community norms and condom use was measured.Results: 93.5%(95%CI,93%-94%) of respondents agreed that ‘Many young women have sex before marriage these days’. 57%(56%-59%) of men and 70%(69%-71%) of women disagreed that ‘If I have a teenage daughter and she has sex before marriage, I would be ok with this’; and 41%(40%-43%) of men and 57%(56%-59%) of women disagreed that ‘If I have a teenage daughter, I would tell her about condoms’. Fathers but not mothers were more likely to disagree with their daughters having sex before marriage (Figure). Similar proportions of parents and other community members were against telling daughters about condoms. 68%(61%-75%) of sexually-active unmarried AGYW said negative community views were unimportant in decisions to use condoms. Condom use didn't differ between those who agreed/disagreed that negative community views are important (46.9% vs. 50.0%; AOR = 0.88, 95%CI, 0.48–1.62; N = 202).Conclusions: Community resistance to condom promotion based on pre-marital sex stigma may be weakening as a barrier to AGYW's motivat

Conference paper

Shamsuddin S, Davis K, Moorhouse L, Mandizvida P, Maswera R, Dadirai T, Nyamukapa C, Gregson Set al., 2022, Association between psychological distress and later reports of hypertension amongst adults in East Zimbabwe, 31st European Meeting on Hypertension and Cardiovascular Protection (ESH 2022), Publisher: Lippincott, Williams & Wilkins, Pages: e213-e213, ISSN: 0263-6352

Conference paper

Skovdal M, Magoge-Mandizvidza P, Dzamatira F, Maswera R, Nyamukapa C, Thomas R, Mugurungi O, Gregson Set al., 2022, Improving access to pre-exposure prophylaxis for adolescent girls and young women: recommendations from healthcare providers in eastern Zimbabwe, BMC Infectious Diseases, Vol: 22, Pages: 1-10, ISSN: 1471-2334

BackgroundIn sub-Saharan Africa, adolescent girls and young women (AGYW) are at high risk of acquiring HIV. A growing number of sub-Saharan African countries are beginning to avail pre-exposure prophylaxis, or PrEP, but with limited success. Unpacking strategies to overcome barriers to the uptake of PrEP is critical to prevent HIV amongst AGYW. This article explores health professionals’ views and recommendations on what is required to increase uptake of PrEP.MethodsThe study draws on interview data from 12 providers of HIV prevention services in eastern Zimbabwe. The healthcare providers were purposefully recruited from a mix of rural and urban health facilities offering PrEP. The interviews were transcribed and imported into NVivo 12 for thematic coding and network analysis.ResultsOur analysis revealed six broad strategies and 15 concrete recommendations which detail the range of elements healthcare providers consider central for facilitating engagement with PrEP. The healthcare providers called for: (1) PrEP marketing campaigns; (2) youth-friendly services or corners; (3) improved PrEP delivery mechanisms; (4) improvements in PrEP treatment; (5) greater engagement with key stakeholders, including with young people themselves; and (6) elimination of costs associated with PrEP use. These recommendations exemplify an awareness amongst healthcare providers that PrEP access is contingent on a range of factors both inside and outside of the clinical setting.ConclusionsHealthcare providers are at the frontline of the HIV epidemic response. Their community-embeddedness, coupled with their interactions and encounters with AGYW, make them well positioned to articulate context-specific measures for improving access to PrEP. Importantly, the breadth of their recommendations suggests recognition of PrEP use as a complex social practice that requires integration of a combination of interventions, spanning biomedical, structural, and behavioural domains.

Journal article

Moorhouse L, Schaefer R, Eaton JW, Dadirai T, Maswera R, Museka T, Mandizvidza P, Dzamatira F, Tsenesa B, Hallett TB, Nyamukapa C, Gregson Set al., 2022, Male partners' influence on adolescent girls and young women's use of combination HIV prevention: insights from analysis of HIV-prevention cascade data collected in a general-population survey in Manicaland, Zimbabwe, AIDS 2022

Conference paper

Hall E, Davis K, Ohrnberger J, Pickles M, Gregson S, Thomas R, James H, Pliakas T, Justin B, Dunbar R, Shanaube K, Graeme H, Virginia B, Bock P, Ayles H, Stangl A, Donnell D, Hayes R, Fidler S, Hauck Ket al., 2022, Associations between HIV stigma and health-related quality of life among people living with HIV in Zambia and South Africa: Cross-sectional analysis of data from the HPTN071 (PopART) study, AIDS 2022

Conference paper

Skovdal M, Beckmann N, Maswera R, Nyamukapa C, Gregson Set al., 2022, The (in)visibility of misdiagnosis in point-of-care HIV testing in Zimbabwe, Medical Anthropology: cross-cultural studies in health and illness, Vol: 41, Pages: 404-417, ISSN: 0145-9740

There is a global trend to introduce point-of-care diagnostic tests, enabling healthcare workers at any level to test, provide results, and initiate immediate treatment if necessary. This article explores how healthcare workers conducting rapid HIV tests – in contexts of limited external quality assurance mechanisms – ascertain the accuracy of their test results. Drawing on interview data and participant observations from health facilities in Zimbabwe, we open the black box of misdiagnosis (in)visibility and reveal a range of proxies and markers that HIV testers draw on to develop certainty, or question, the reliability of their diagnostic classifications.

Journal article

Goodwin T, Gregson S, Maswera R, Moorhouse L, Nyamukapa Cet al., 2021, Understanding the determinants and consequences of HIV status disclosure in Manicaland, Zimbabwe: cross-sectional and prospective analyses, AIDS Care: psychological and socio-medical aspects of AIDS-HIV, Vol: 33, Pages: 1577-1594, ISSN: 0954-0121

Few longitudinal studies have measured trends and effects of disclosure over ART scale-up in general-population samples. We investigated levels, determinants and outcomes of disclosure to relatives and partners in a large general-population cohort in Zimbabwe. Trends in disclosure levels from 2003-2013 were analysed, and multivariable logistic regression was used to identify determinants. Longitudinal analyses were conducted testing associations between disclosure and prevention/treatment-related outcomes. Disclosure to anyone increased from 79% to 100% in men and from 63% to 98% in women from 2003-2008; but declined to 89% in both sexes in 2012-2013. More women than men disclosed to relatives (67.8% versus 44.4%; p<0.001) but fewer women disclosed to partners (85.3% versus 95.0%; p<0.001). In 2012-13, younger age, secondary/higher education, being single, and experience of stigma were associated with disclosure to relatives in both sexes. Partner characteristics and HIV-group attendance were associated with disclosure to partners for women. Reactions to disclosure were generally supportive but less so for females than males disclosing to partners (92.0% versus 97.4%). Partner disclosure was associated with greater social support and treatment adherence in females. To conclude, this study shows disclosure is vital to HIV prevention and treatment, and programmes to facilitate disclosure should be re-invigorated.

Journal article

Chang A, Maswera R, Moorhouse L, Nyamukapa C, Skovdal M, Gregson Set al., 2021, The determinants and impacts of age-disparate relationships on women in Zimbabwe: A life course perspective, Social Science and Medicine – Population Health, Vol: 16, Pages: 1-9, ISSN: 2352-8273

Age-disparate relationships (ADR) with older men have been studied mostly in the context of HIV and found to be associated with increased HIV prevalence among young women in sub-Saharan Africa. Less is known about the impact of ADR on the broader life course of women. The objectives of this study are to identify the factors associated with being in ADR and estimate the association between ADR and a set of life outcomes in Manicaland, Zimbabwe. We used data from a general population open-cohort survey from 1998 to 2013 in Manicaland. We applied binary logistic regression models to estimate the odds ratios for association between socio-demographic determinants and ADR and multinomial logistic regression models to estimate the association between ADR and women's life outcomes. We found that women with less education, younger age at first sex and first marriage were more likely to be in ADR, and women in ADR have male partners with less education and less skilled employment. In terms of life and relationship outcomes, women in ADR had mostly negative life outcomes compared to women not in ADR. Future policies and research on ADR in women should reflect these complexities and study a wider range of life outcomes, beyond the commonly studied narrower topics such as HIV.

Journal article

Stapley J, Davis K, Dadirai T, Moorhouse L, Eaton J, Maswera R, Nyamukapa C, Gregson Set al., 2021, Impact of community-level ART coverage on HIV-related stigmatising attitude within a general population cohort in Manicaland, east Zimbabwe; a longitudinal study, 12th Annual International Conference on Stigma

Conference paper

Tlhajoane M, Dzamatira F, Kadzura N, Nyamukapa C, Eaton JW, Gregson Set al., 2021, Incidence and predictors of attrition among patients receiving ART in eastern Zimbabwe before, and after the introduction of universal ‘treat-all’ policies: A competing risk analysis, PLOS Global Public Health, Vol: 1, Pages: 1-15

As HIV treatment is expanded, attention is focused on minimizing attrition from care. We evaluated the impact of treat-all policies on the incidence and determinants of attrition amongst clients receiving ART in eastern Zimbabwe. Data were retrospectively collected from the medical records of adult patients (aged≥18 years) enrolled into care from July 2015 to June 2016—pre-treat-all era, and July 2016 to June 2017—treat-all era, selected from 12 purposively sampled health facilities. Attrition was defined as an absence from care >90 days following ART initiation. Survival-time methods were used to derive incidence rates (IRs), and competing risk regression used in bivariate and multivariable modelling. In total, 829 patients had newly initiated ART and were included in the analysis (pre-treat-all 30.6%; treat-all 69.4%). Incidence of attrition (per 1000 person-days) increased between the two time periods (pre-treat-all IR = 1.18 (95%CI: 0.90–1.56) versus treat-all period IR = 1.62 (95%CI: 1.37–1.91)). In crude analysis, patients at increased risk of attrition were those enrolled into care during the treat-all period, <34 years of age, WHO stage I at enrolment, and had initiated ART on the same day as HIV diagnosis. After accounting for mediating clinical characteristics, the difference in attrition between the pre-treat-all, and treat-all periods ceased to be statistically significant. In a full multivariable model, attrition was significantly higher amongst same-day ART initiates (aSHR = 1.47, 95%CI:1.05–2.06). Implementation of treat-all policies was associated with an increased incidence of ART attrition, driven largely by ART initiation on the same day as HIV diagnosis which increased significantly in the treat all period. Differentiated adherence counselling for patients at increased risk of attrition, and improved access to clinical monitoring may improve retention in care.

Journal article

Davis K, Perez-Guzman P, Hoyer A, Brinks R, Gregg E, Althoff KN, Justice AC, Reiss P, Gregson S, Smit Met al., 2021, Correction to: Association between HIV infection and hypertension: a global systematic review and meta-analysis of cross-sectional studies., BMC Medicine, Vol: 19, Pages: 228-228, ISSN: 1741-7015

Journal article

Davis K, Muzariri K, Mangenah C, Dadirai T, Mandizvidza P, Maswera R, Nyamukapa C, Hauck K, Gregson S, Pickles Met al., 2021, Modelling the interaction between depression and HIV incidence in Manicaland, East Zimbabwe, Fast Track Cities 2021

Conference paper

Risher K, Cori A, Reniers G, Marston M, Calvert C, Crampin A, Dadirai T, Dube A, Gregson S, Herbst K, Lutalo T, Moorhouse L, Mtenga B, Nabukalu D, Newton R, Price AJ, Tlhajoane M, Todd J, Tomlin K, Urassa M, Vandormael A, Fraser C, Slaymaker E, Eaton Jet al., 2021, Age patterns of HIV incidence in eastern and southern Africa: a collaborative analysis of observational general population cohort studies, The Lancet HIV, Vol: 8, Pages: e429-e439, ISSN: 2405-4704

Background: As the HIV epidemic in sub-Saharan Africa matures, evidence about the age distribution of new HIV infections and how this has changed over the epidemic is needed to guide HIV prevention. We assessed trends in age-specific HIV incidence in six population-based cohort studies in eastern and southern Africa, reporting changes in average age at infection, age distribution of new infections, and birth cohort cumulative incidence. Methods: We used a Bayesian model to reconstruct age-specific HIV incidence from repeated observations of individuals’ HIV serostatus and survival collected among population HIV cohorts in rural Malawi, South Africa, Tanzania, Uganda, and Zimbabwe. The HIV incidence rate by age, time and sex was modelled using smooth splines functions. Incidence trends were estimated separately by sex and study. Estimated incidence and prevalence results for 2000-2017, standardised to study population distribution, were used to estimate average age at infection and proportion of new infections by age. Findings: Age-specific incidence declined at all ages, though the timing and pattern of decline varied by study. The average age at infection was higher in men (cohort means: 27·8-34·6 years) than women (cohort means: 24·8-29·6 years). Between 2000 and 2017, the average age at infection increased slightly: cohort means 0·5-2·8 years among men and -0·2-2·5 years among women. Across studies, between 38-63%(cohort means)of women’s infections were among 15-24-year-olds and between 30-63% of men’s infections were in 20-29-year-olds. Lifetime risk of HIV declined for successive birth cohorts. Interpretation: HIV incidence declined in all age groups and shifted slightly, but not dramatically, to older ages. Disproportionate new HIV infections occur among 15-24-year-old 4women and20-29-year-oldmen, supporting focused prevention in these groups. But 40-60% of infections were outside these

Journal article

Wolock T, Flaxman S, Risher K, Dadirai T, Gregson S, Eaton Jet al., 2021, Evaluating distributional regression strategies for modelling self-reported sexual age-mixing, eLife, Vol: 10, Pages: 1-38, ISSN: 2050-084X

The age dynamics of sexual partnership formation determine patterns of sexually transmitted disease transmission and have long been a focus of researchers studying human immunodeficiency virus. Data on self-reported sexual partner age distributions are available from a variety of sources. We sought to explore statistical models that accurately predict the distribution of sexual partner ages over age and sex. We identified which probability distributions and outcome specifications best captured variation in partner age and quantified the benefits of modelling these data using distributional regression. We found that distributional regression with a sinh-arcsinh distribution replicated observed partner age distributions most accurately across three geographically diverse data sets. This framework can be extended with well-known hierarchical modelling tools and can help improve estimates of sexual age-mixing dynamics.

Journal article

Davis K, Perez Guzman P, Hoyer A, Brinks R, Gregg E, Althoff KN, Justice AC, Reiss P, Gregson S, Smit Met al., 2021, Association between HIV infection and hypertension: a global systematic review and meta-analysis of cross-sectional studies, BMC Medicine, Vol: 19, ISSN: 1741-7015

Background:Improved access to effective antiretroviral therapy has meant that people living with HIV (PLHIV) are surviving to older ages. However, PLHIV may be ageing differently to HIV-negative individuals, with dissimilar burdens of non-communicable diseases, such as hypertension. While some observational studies have reported a higher risk of prevalent hypertension among PLHIV compared to HIV-negative individuals, others have found a reduced burden. To clarify the relationship between HIV and hypertension, we identified observational studies and pooled their results to assess whether there is a difference in hypertension risk by HIV status.Methods:We performed a global systematic review and meta-analysis of published cross-sectional studies that examined hypertension risk by HIV status among adults aged > 15 (PROSPERO: CRD42019151359). We searched MEDLINE, EMBASE, Global Health and Cochrane CENTRAL to August 23, 2020, and checked reference lists of included articles. Our main outcome was the risk ratio for prevalent hypertension in PLHIV compared to HIV-negative individuals. Summary estimates were pooled with a random effects model and meta-regression explored whether any difference was associated with study-level factors.Results:Of 21,527 identified studies, 59 were eligible (11,101,581 participants). Crude global hypertension risk was lower among PLHIV than HIV-negative individuals (risk ratio 0.90, 95% CI 0.85–0.96), although heterogeneity between studies was high (I2 = 97%, p < 0.0001). The relationship varied by continent, with risk higher among PLHIV in North America (1.12, 1.02–1.23) and lower among PLHIV in Africa (0.75, 0.68–0.83) and Asia (0.77, 0.63–0.95). Meta-regression revealed strong evidence of a difference in risk ratios when comparing North American and European studies to African ones (North America 1.45, 1.21–1.74; Europe 1.20, 1.03–1.40).Conclusions:Our findings suggest that the r

Journal article

Gregson S, Moorhouse L, Dadirai T, Sheppard H, Mayini J, Beckmann N, Skovdal M, Dzangare J, Moyo B, Maswera R, Pinsky B, Mharakurwa S, Francis I, Mugurungi O, Nyamukapa Cet al., 2021, Comprehensive investigation of sources of misclassification errors in routine HIV testing in Zimbabwe, Journal of the International AIDS Society, Vol: 24, ISSN: 1758-2652

IntroductionMisclassification errors have been reported in rapid diagnostic HIV tests (RDTs) in sub‐Saharan African countries. These errors can lead to missed opportunities for prevention‐of‐mother‐to‐child‐transmission (PMTCT), early infant diagnosis and adult HIV‐prevention, unnecessary lifelong antiretroviral treatment (ART) and wasted resources. Few national estimates or systematic quantifications of sources of errors have been produced. We conducted a comprehensive assessment of possible sources of misclassification errors in routine HIV testing in Zimbabwe.MethodsRDT‐based HIV test results were extracted from routine PMTCT programme records at 62 sites during national antenatal HIV surveillance in 2017. Positive‐ (PPA) and negative‐percent agreement (NPA) for HIV RDT results and the false‐HIV‐positivity rate for people with previous HIV‐positive results (“known‐positives”) were calculated using results from external quality assurance testing done for HIV surveillance purposes. Data on indicators of quality management systems, RDT kit performance under local climatic conditions and user/clerical errors were collected using HIV surveillance forms, data‐loggers and a Smartphone camera application (7 sites). Proportions of cases with errors were compared for tests done in the presence/absence of potential sources of errors.ResultsNPA was 99.9% for both pregnant women (N = 17224) and male partners (N = 2173). PPA was 90.0% (N = 1187) and 93.4% (N = 136) for women and men respectively. 3.5% (N = 1921) of known‐positive individuals on ART were HIV negative. Humidity and temperature exceeding manufacturers’ recommendations, particularly in storerooms (88.6% and 97.3% respectively), and premature readings of RDT output (56.0%) were common. False‐HIV‐negative cases, including interpretation errors, occurred despite staff training and good algorithm compliance, and were not reduced by existing external or internal quality assurance procedures. PPA was l

Journal article

Gregson S, Nyamukapa C, 2021, Did sexual behaviour differences between HIV infection and treatment groups offset the biological preventative effects of ART roll-out in Zimbabwe?, Population Studies: a journal of demography, Vol: 75, Pages: 457-476, ISSN: 0032-4728

HIV incidence declines have been slower than expected during the roll-out of antiretroviral treatment (ART) services in subSaharan African populations suffering generalised epidemics. Using data from a general population, open-cohort, HIV serosurvey (2004-2013), we found evidence for initial reductions in sexual activity and multiple sexual partnerships followed byincreases in the period of ART scale-up, in high HIV-prevalence areas in Manicaland, east Zimbabwe. Recent populationlevel increases in condom use were also recorded but reflected largely high use by the rapidly growing proportion of HIVinfected individuals on treatment. Sexual risk behaviour increased in susceptible uninfected individuals and in untreated – andtherefore more infectious – HIV-infected men, which may have slowed the decline in HIV incidence in this population.Intensified primary HIV prevention programmes, together with strengthened risk screening, referral and support servicesfollowing HIV testing, could help to maximise the impact of ‘test-and-treat’ programmes in reducing new infections.

Journal article

Skovdal M, Maswera R, Kadzura N, Nyamukapa C, Rhead R, Wringe A, Gregson Set al., 2020, Parental obligations, care and HIV treatment: How care for others motivates self-care in Zimbabwe, Journal of Health Psychology, Vol: 25, Pages: 2178-2187, ISSN: 1359-1053

This article examines how parental obligations of care intersect with HIV treatment-seeking behaviours and retention. It draws on qualitative data from eastern Zimbabwe, produced from 65 interviews. Drawing on theories of practice and care ethics, our analysis revealed that norms of parental obligation and care acted as key motivators for ongoing engagement with HIV services and treatment. Parents' attentiveness to the future needs of their children ( caring about), and sense of obligation ( taking care of) and improved ability to care ( caregiving) following treatment initiation, emerged as central to understanding their drive for self-care and engagement with HIV services.

Journal article

Schafer R, Thomas R, Robertson L, Eaton J, Mushati P, Nyamukapa C, Hauck K, Gregson Set al., 2020, Spillover HIV prevention effects of a cash transfer trial in East Zimbabwe: evidence from a cluster-randomised trial and general-population survey, BMC Public Health, Vol: 20, ISSN: 1471-2458

BackgroundBenefits of cash transfers (CTs) for HIV prevention have been demonstrated largely in purposively designed trials, commonly focusing on young women. It is less clear if CT interventions not designed for HIV prevention can have HIV-specific effects, including adverse effects. The cluster-randomised Manicaland Cash Transfer Trial (2010–11) evaluated effects of CTs on children’s (2–17 years) development in eastern Zimbabwe. We evaluated whether this CT intervention with no HIV-specific objectives had unintended HIV prevention spillover effects (externalities).MethodsData on 2909 individuals (15–54 years) living in trial households were taken from a general-population survey, conducted simultaneously in the same communities as the Manicaland Trial. Average treatment effects (ATEs) of CTs on sexual behaviour (any recent sex, condom use, multiple partners) and secondary outcomes (mental distress, school enrolment, and alcohol/cigarette/drug consumption) were estimated using mixed-effects logistic regressions (random effects for study site and intervention cluster), by sex and age group (15–29; 30–54 years). Outcomes were also evaluated with a larger synthetic comparison group created through propensity score matching.ResultsCTs did not affect sexual debut but reduced having any recent sex (past 30 days) among young males (ATE: − 11.7 percentage points [PP] [95% confidence interval: -26.0PP, 2.61PP]) and females (− 5.68PP [− 15.7PP, 4.34PP]), with similar but less uncertain estimates when compared against the synthetic comparison group (males: -9.68PP [− 13.1PP, − 6.30PP]; females: -8.77PP [− 16.3PP, − 1.23PP]). There were no effects among older individuals. Young (but not older) males receiving CTs reported increased multiple partnerships (8.49PP [− 5.40PP, 22.4PP]; synthetic comparison: 10.3PP (1

Journal article

Davis K, Guzman PP, Gregson S, Smit Met al., 2020, Comparing the prevalence of hypertension by HIV status in sub-Saharan African adults: a systematic review and meta-analyses of cross-sectional studies, HIV Glasgow, Publisher: JOHN WILEY & SONS LTD, Pages: 70-70

Background: Some evidence from high-income countries (HICs) suggests that PLHIV experience a higher hypertension prevalence thanHIV-negative individuals. It is unclear whether this is the case in subSaharan Africa (SSA), where large-scale integration of hypertensionservices into HIV programmes is being considered. We examined thehypothesis that living with HIV is associated with higher hypertensionprevalence among adults in SSA.Materials and methods: A systematic review of MEDLINE, EMBASE,Global Health, Cochrane Database of Systematic Reviews, CochraneCentral Register of Controlled Trials and African Journals Online wasperformed, following PRISMA guidelines, to identify cross-sectionalstudies assessing hypertension prevalence in PLHIV and HIV-negativeindividuals >15 years, in SSA. Only studies defining hypertension as“study-ascertained blood pressure ≥140/90 mmHg”, or as “studyascertained blood pressure ≥140/90 mmHg and/or history of antihypertensive medication usage”, were included. Risk of bias assessmentsaddressed adequacy of sample sizes, participant selection and HIV andhypertension status measurement. Random effects models were usedto pool odds ratios (ORs) for prevalent hypertension.Results: We identified 1431 unique studies, of which 12 wereselected for quantitative analysis, providing data on 107 425 participants (49.4% to 69.6% female). The 12 studies collected data between2003 and 2015, in South Africa, Tanzania and Uganda. Risk of biaswas low to moderate, with participant selection a key source of bias.Hypertension prevalence ranged from 5.3% to 51.7% among PLHIVand 8.2% to 65.4% in HIV-negative individuals. Overall, hypertensionprevalence was 41% lower among PLHIV than HIV-negative individuals when using the ≥140/90 mmHg definition (n = 5, OR 0.59, 95%CI 0.55 to 0.64) and 34% lower when using the definition thatincluded medication (n = 7, OR 0.66, 95% CI 0.47 to 0.99).Conclusions: Robust studies comparing hypertension

Conference paper

Davis K, Moorhouse L, Maswera R, Nyamukapa C, Smit M, Gregson Set al., 2020, Examining associations between HIV status and high blood pressure (hypertension) in a high HIV prevalence population in Manicaland, east Zimbabwe: a cross-sectional study of adults, HIV Glasgow, Publisher: JOHN WILEY & SONS LTD, Pages: 69-69

Background: Evidence from high‐income countries indicates that PLHIV experience a higher hypertension prevalence than HIV‐negative individuals. However, it is unclear whether this applies in sub‐Saharan Africa, where behaviour and healthcare access differ. It is also unclear whether reported differences in hypertension prevalence result from socio‐demographic differences between PLHIV and HIV‐negative individuals or from HIV infection and treatment. We analysed data from Manicaland, Zimbabwe, to test the hypothesis that PLHIV had a higher hypertension prevalence than HIV‐negative individuals and assess whether controlling for socio‐demographic factors affected this relationship.Materials and methods: A cross‐sectional study, including interviews and HIV testing, was performed at two urban sites, a town and a roadside trading area (07/2018 to 03/2019). All young women (15 to 24 years) and men (15 to 29 years), and a random sample of 2/3 of older adults were eligible. Individuals were considered hypertensive if they reported ever being diagnosed with hypertension by a doctor/nurse. Logistic regression was used to estimate odds ratios (ORs) for prevalent hypertension, controlling for socio‐demographic confounders. Weights were used in all analyses to compensate for unequal selection probabilities.Results: Among 3404 participants (2169 men; 1235 women), the weighted HIV prevalence was 10.8% (95% CI 9.7 to 11.9%). There were more women among PLHIV (PLHIV: 62.5%, 57.2 to 67.8%; HIV‐negative: 53.2%, 52.2% to 54.2%) and PLHIV were older (>45 years: PLHIV: 40%, 31.8% to 48.2%; HIV‐negative: 25.3%, 23.9% to 26.6%). Hypertension prevalence was higher among PLHIV (20.6%, 16.3% to 25.0%) than HIV‐negative individuals (16.4%, 15.1% to 17.6%; OR 1.33, 1.01 to 1.76, p = 0.048). However, hypertension prevalence was higher in older individuals and women, so after adjusting for age and gender the difference in hypertension between PLHIV and HIV‐negative individuals was non‐signific

Conference paper

Skovdal M, Pickles MR, Hallett TB, Nyamukapa C, Gregson Set al., 2020, Complexities to consider when communicating risk of COVID-19, Public Health, Vol: 186, Pages: 283-285, ISSN: 0033-3506

Journal article

Skovdal M, Beckmann N, Maswera R, Nyamukapa C, Gregson Set al., 2020, Uncertainties, work conditions and testing biases: Potential pathways to misdiagnosis in point-of-care rapid HIV testing in Zimbabwe, PLoS One, Vol: 15, Pages: 1-17, ISSN: 1932-6203

Disconcerting levels of misdiagnosis are common in point-of-care rapid HIV testing programmes in sub-Saharan Africa. To investigate potential pathways to misdiagnosis, we interviewed 28 HIV testers in Zimbabwe and conducted weeklong observations at four testing facilities. Approaching adherence to national HIV testing algorithms as a social and scripted practice, dependent on the integration of certain competences, materials and meanings, our thematic analysis revealed three underlying causes of misdiagnosis: One, a lack of confidence in using certain test-kits, coupled with changes in testing algorithms and inadequate training, fed uncertainties with some testing practices. Two, difficult work conditions, including high workloads and resource-depleted facilities, compounded these uncertainties, and meant testers got distracted or resorted to testing short-cuts. Three, power struggles between HIV testers, and specific client-tester encounters created social interactions that challenged the testing process. We conclude that these contexts contribute to deviances from official and recommended testing procedures, as well as testing and interpretation biases, which may explain cases of misdiagnoses. We caution against user-error explanations to misdiagnosis in the absence of a broader recognition of how broader structural determinants affect HIV testing practices.

Journal article

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