Browsing by Author "Claassens, Mareli"
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- ItemCharacteristics of clients who access mobile compared to clinic HIV counselling and testing services : a matched study from Cape Town, South Africa(BioMed Central, 2014-12) Meehan, Sue-Ann; Naidoo, Pren; Claassens, Mareli; Lombard, Carl; Beyers, NuldaBackground: Studies within sub-Saharan African countries have shown that mobile services increase uptake of HIV counselling and testing (HCT) services when compared to clinics and are able to access different populations, but these have included provider-initiated HCT in clinics. This study aimed to compare the characteristics of clients who self-initiated HCT at either a mobile or a clinic service in terms of demographic and socio-economic variables, also comparing reasons for accessing a particular health service provider. Methods: This study took place in eight areas around Cape Town. A matched design was used with one mobile HCT service matched with one or more clinics (offering routine HCT services) within each of the eight areas. Adult clients who self-referred for an HIV test within a specified time period at either a mobile or clinic service were invited to participate in the study. Data were collected between February and April 2011 using a questionnaire. Summary statistics were calculated for each service type within a matched pair and differences of outcomes from pairs were used to calculate effect sizes and 95% confidence intervals. Results: 1063 participants enrolled in the study with 511 from mobile and 552 from clinic HCT services. The proportion of males accessing mobile HCT significantly exceeded that of clinic HCT (p < 0.001). The mean age of participants attending mobile HCT was higher than clinic participants (p = 0.023). No significant difference was found for socio-economic variables between participants, with the exception of access to own piped water (p = 0.029). Participants who accessed mobile HCT were significantly more likely to report that they were just passing, deemed an “opportunistic” visit (p = 0.014). Participants who accessed clinics were significantly more likely to report the service being close to home or work (p = 0.035). Conclusions: An HCT strategy incorporating a mobile HCT service, has a definite role to play in reaching those population groups who do not typically access HCT services at a clinic, especially males and those who take advantage of the opportunity to test. Mobile HCT services can complement clinic services.
- ItemDevelopment and validation of a prediction model for active tuberculosis case finding among HIV-negative/unknown populations(Nature Research (part of Springer Nature), 2019) Shih, Yun-Ju; Ayles, Helen; Lonnroth, Knut; Claassens, Mareli; Lin, Hsien-HoENGLISH ABSTRACT: A prediction model of prevalent pulmonary tuberculosis (TB) in HIV negative/unknown individuals was developed to assist systematic screening. Data from a large TB screening trial were used. A multivariable logistic regression model was developed in the South African (SA) training dataset, using TB symptoms and risk factors as predictors. The model was converted into a scoring system for risk stratification and was evaluated in separate SA and Zambian validation datasets. The number of TB cases were 355, 176, and 107 in the SA training, SA validation, and Zambian validation datasets respectively. The area under curve (AUC) of the scoring system was 0·68 (95% CI 0·64-0·72) in the SA validation set, compared to prolonged cough (0·58, 95% CI 0·54-0·62) and any TB symptoms (0·6, 95% CI 0·56–0·64). In the Zambian dataset the AUC of the scoring system was 0·66 (95% CI 0·60–0·72). In the cost-effectiveness analysis, the scoring system dominated the conventional strategies. The cost per TB case detected ranged from 429 to 1,848 USD in the SA validation set and from 171 to 10,518 USD in the Zambian dataset. The scoring system may help targeted TB case finding under budget constraints.
- ItemInterpretation of serial interferon-gamma test results to measure new tuberculosis infection among household contacts in Zambia and South Africa(BioMed Central, 2020-10-15) Sloot, Rosa; Shanaube, Kwame; Claassens, Mareli; Telisinghe, Lily; Schaap, Ab; Godfrey-Faussett, Peter; Ayles, Helen; Floyd, SianBackground: A more stringent QuantiFERON-TB Gold In-Tube (QFT) conversion (from negative to positive) definition has been proposed to allow more definite detection of recent tuberculosis (TB) infection. We explored alternative conversion definitions to assist the interpretation of serial QFT results and estimate incidence of TB infection in a large cohort study. Methods: We used QFT serial results from TB household contacts aged ≥15 years, collected at baseline and during two follow-up visits (2006–2011) as part of a cohort study in 24 communities in Zambia and South Africa (SA). Conversion rates using the manufacturers’ definition (interferon-gamma (IFN-g) < 0.35 to ≥0.35, ‘def1’) were compared with stricter definitions (IFN-g < 0.2 to ≥0.7 IU/ml, ‘def2’; IFN-g < 0.2 to ≥1.05 IU/ml, ‘def3’; IFN-g < 0.2 to ≥1.4 IU/ml, ‘def4’). Poisson regression was used for analysis. Results: One thousand three hundred sixty-five individuals in Zambia and 822 in SA had QFT results available. Among HIV-negative individuals, the QFT conversion rate was 27.4 per 100 person-years (CI:22.9–32.6) using def1, 19.0 using def2 (CI:15.2–23.7), 14.7 using def3 (CI:11.5–18.8), and 12.0 using def4 (CI:9.2–15.7). Relative differences across def1-def4 were similar in Zambia and SA. Using def1, conversion was less likely if HIV positive not on antiretroviral treatment compared to HIV negative (aRR = 0.7, 95%CI = 0.4–0.9), in analysis including both countries. The same direction of associations were found using def 2–4. Conclusion: High conversion rates were found even with the strictest definition, indicating high incidence of TB infection among household contacts of TB patients in these communities. The trade-off between sensitivity and specificity using different thresholds of QFT conversion remains unknown due to the absence of a reference standard. However, we identified boundaries within which an appropriate definition might fall, and our strictest definition plausibly has high specificity.
- ItemIt’s complicated : why do tuberculosis patients not initiate or stay adherent to treatment? a qualitative study from South Africa(BioMed Central, 2016-11-25) Skinner, Donald; Claassens, MareliBackground: Individuals who test positive for active tuberculosis (TB) but do not initiate treatment present a challenge to TB programmes because they contribute to ongoing transmission within communities. To better understand why individuals do not initiate treatment, or are adherent after initiating treatment, South African respondents were approached to obtain insights as to which factors enabled and inhibited the treatment process. Methods: This qualitative work was nested in a larger study investigating initial loss to follow-up (LTFU) amongst new smear positive TB patients across five provinces of South Africa. In-depth interviews were done with 41 adherent and initial LTFU respondents. Results: Key issues contributing to initial LTFU appeared to be a poor knowledge, or low awareness of TB treatment; stigma around TB including its connection to HIV; immediate problems in the respondents’ lives particularly poverty, lack of access to transport and the need to continue working; and problems in the healthcare facilities including under resourced facilities, poor functioning health systems and negative staff attitudes. In contrast the reasons given for being adherent related to the level of illness, support received at home and healthcare facilities, a belief in the health system and positive experiences in the health service including positive attitudes from staff. Conclusions: Key changes need to be made to the healthcare system to enable patients to initiate treatment and remain adherent, but the six month regimen of daily observed treatment presents real practical and personal challenges to patients. Alternative strategies to DOTS at facility level should be investigated to bring services closer to communities to encourage patients to access care, initiate and adhere to treatment.
- ItemPatient diagnostic rate as indicator of tuberculosis case detection, South Africa(Centers for Disease Control and Prevention, 2016) Claassens, Mareli; Van Schalkwyk, Cari; Dunbar, Rory; Ayles, Helen; Beyers, NuldaENGLISH SUMMARY : To address the uncertainty of the indirectly measured tuberculosis case detection rate, we used survey data stratified by HIV status to calculate the patient diagnostic rate, a directly measurable indicator, in 8 communities in South Africa. Rates were lower among HIV-negative than HIV-positive persons. Tuberculosis programs should focus on HIV-negative persons.
- ItemPatient predictors of health-seeking behaviour for persons coughing for more than two weeks in high-burden tuberculosis communities : the case of the Western Cape, South Africa(BMC (part of Springer Nature), 2019) Christian, Carmen; Burger, Cobus; Claassens, Mareli; Bond, Virginia; Burger, RonelleBackground: This study aimed to analyse the patient predictors of health-seeking behaviour for persons coughing for more than 2 weeks to better understand this vulnerable and important population. Methods: The study analysed data from a cohort study (SOCS - Secondary Outcome Cohort Study) embedded in a community randomised trial ZAMSTAR (Zambia and South Africa TB and AIDS Reduction Study) in eight high-burden TB communities in the Western Cape, South Africa. These datasets are unique as they contain TB-related data as well as data on health, health-seeking behaviour, lifestyle choices, employment, socio-economic status, education and stigma. We use uni- and multivariate logistic regressions to estimate the odds ratios of consulting for a cough (of more than 2 weeks duration) for a range of relevant patient predictors. Results: Three hundred and forty persons consulted someone about their cough and this represents 37% of the 922 participants who reported coughing for more than 2 weeks. In the multivariate analysis, respondents of black ethnic origin (OR 1.99, 95% CI 1.28–3.12, P < 0.01), those with higher levels of education (OR 1.05 per year of education, 95% CI 1.00–1.10, P = 0.05), and older respondents (OR 1.02 per year, 95% CI 1.01–1.04, P < 0.01) had a higher likelihood of consulting for their chronic cough. Individuals who smoked (OR 0.63, 95% CI 0.45–0.88, P < 0.01) and those with higher levels of socio-economic status (OR 0.81, 95% CI 0.71–0.92, P < 0.01) were less likely to consult. We find no evidence of stigma playing a role in health-seeking decisions, but caution that this may be due to the difficulty of accurately and reliably capturing stigma due to, amongst other factors, social desirability bias. Conclusions: The low levels of consultation for a cough of more than 2 weeks suggest that there are opportunities to improve case-finding. These findings on health-seeking behaviour can assist policymakers in designing TB screening and active case-finding interventions that are targeted to the characteristics of those with a chronic cough who do not seek care.