The Indirect Estimation of Migration: A Critical Review
In: International migration review: IMR, Band 21, Heft 4, S. 1395-1445
ISSN: 1747-7379, 0197-9183
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In: International migration review: IMR, Band 21, Heft 4, S. 1395-1445
ISSN: 1747-7379, 0197-9183
In: International migration review: IMR, Band 21, Heft 4, S. 1395-1444
ISSN: 0197-9183
In: Population and development review, Band 20, Heft 4, S. 912
ISSN: 1728-4457
In: http://www.biomedcentral.com/1471-2458/15/195
Abstract Background The Tanzanian Government started scaling up its antiretroviral treatment (ART) program from referral, regional and district hospitals to primary health care facilities in October 2004. In 2010, most ART clinics were decentralized to primary health facilities. ART coverage, i.e. people living with HIV (PLHIV) on combination treatment as a proportion of those in need of treatment, provides the basis for evaluating the efficiency of ART programs at national and district level. We aimed to evaluate adult ART and pre-ART care coverage by age and sex at CD4 < 200, < 350 and all PLHIV in the Rufiji district of Tanzania from 2006 to 2010. Methods The numbers of people on ART and pre-ART care were obtained from routinely aggregated, patient-level, cohort data from care and treatment centers in the district. We used ALPHA model to predict the number in need of pre-ART care and ART by age and sex at CD4 < 200 and < 350. Results Adult ART coverage among PLHIV increased from 2.9% in 2006 to 17.6% in 2010. In 2010, coverage was 20% for women and 14.8% for men. ART coverage was 30.2% and 38.7% in 2010 with reference to CD4 criteria of 350 and 200 respectively. In 2010, ART coverage was 0 and 3.4% among young people aged 15–19 and 20–24 respectively. ART coverage among females aged 35–39 and 40–44 was 30.6 and 35% respectively in 2010. Adult pre-ART care coverage for PLHIV of CD4 < 350 increased from 5% in 2006 to 37.7% in 2010. The age-sex coverage patterns for pre-ART care were similar to ART coverage for both CD4 of 200 and 350 over the study period. Conclusions ART coverage in the Rufiji district is unevenly distributed and far from the universal coverage target of 80%, in particular among young men. The findings in 2010 are close to the most recent estimates of ART coverage in 2013. To strive for universal coverage, both the recruitment of new eligible individuals to pre-ART and ART and the successful retention of those already on ART in the program need to be prioritized.
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In: Studies in family planning: a publication of the Population Council, Band 46, Heft 4, S. 405-422
ISSN: 1728-4465
In Tanzania, unmet need for contraception is high, particularly in the postpartum period. Contraceptive counseling during routine antenatal HIV testing could reach 97 percent of pregnant women with much‐needed information, but requires an understanding of postpartum contraceptive use and its relationship to antenatal intentions. We conducted a baseline survey of reproductive behavior among 5,284 antenatal clients in Northern Tanzania, followed by an intervention offering contraceptive counseling to half the respondents. A follow‐up survey at 6–15 months postpartum examined patterns and determinants of postpartum contraceptive use, assessed their correspondence with antenatal intentions, and evaluated the impact of the intervention. Despite high loss to follow‐up, our findings indicate that condoms and hormonal methods had particular and distinct roles in the postpartum period, based on understandings of postpartum fertility. Antenatal intentions were poor predictors of postpartum reproductive behavior. Antenatal counseling had an effect on postpartum contraceptive intentions, but not on use. Different antenatal/contraceptive service integration models should be tested to determine how and when antenatal counseling can be most effective.
BACKGROUND: The Tanzanian Government started scaling up its antiretroviral treatment (ART) program from referral, regional and district hospitals to primary health care facilities in October 2004. In 2010, most ART clinics were decentralized to primary health facilities. ART coverage, i.e. people living with HIV (PLHIV) on combination treatment as a proportion of those in need of treatment, provides the basis for evaluating the efficiency of ART programs at national and district level. We aimed to evaluate adult ART and pre-ART care coverage by age and sex at CD4 < 200, < 350 and all PLHIV in the Rufiji district of Tanzania from 2006 to 2010. METHODS: The numbers of people on ART and pre-ART care were obtained from routinely aggregated, patient-level, cohort data from care and treatment centers in the district. We used ALPHA model to predict the number in need of pre-ART care and ART by age and sex at CD4 < 200 and < 350. RESULTS: Adult ART coverage among PLHIV increased from 2.9% in 2006 to 17.6% in 2010. In 2010, coverage was 20% for women and 14.8% for men. ART coverage was 30.2% and 38.7% in 2010 with reference to CD4 criteria of 350 and 200 respectively. In 2010, ART coverage was 0 and 3.4% among young people aged 15-19 and 20-24 respectively. ART coverage among females aged 35-39 and 40-44 was 30.6 and 35% respectively in 2010. Adult pre-ART care coverage for PLHIV of CD4 < 350 increased from 5% in 2006 to 37.7% in 2010. The age-sex coverage patterns for pre-ART care were similar to ART coverage for both CD4 of 200 and 350 over the study period. CONCLUSIONS: ART coverage in the Rufiji district is unevenly distributed and far from the universal coverage target of 80%, in particular among young men. The findings in 2010 are close to the most recent estimates of ART coverage in 2013. To strive for universal coverage, both the recruitment of new eligible individuals to pre-ART and ART and the successful retention of those already on ART in the program need to be prioritized.
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In: Journal of the International AIDS Society, Band 12, Heft 1, S. 31-31
ISSN: 1758-2652
BackgroundIndividuals diagnosed with HIV in developing countries are not always successfully linked to onward treatment services, resulting in missed opportunities for timely initiation of antiretroviral therapy, or prophylaxis for opportunistic infections. In collaboration with local stakeholders, we designed and assessed a referral system to link persons diagnosed at a voluntary counselling and testing (VCT) clinic in a rural district in northern Tanzania with a government‐run HIV treatment clinic in a nearby city.MethodsTwo‐part referral forms, with unique matching numbers on each side were implemented to facilitate access to the HIV clinic, and were subsequently reconciled to monitor the proportion of diagnosed clients who registered for these services, stratified by sex and referral period. Delays between referral and registration at the HIV clinic were calculated, and lists of non‐attendees were generated to facilitate tracing among those who had given prior consent for follow up.Transportation allowances and a "community escort" from a local home‐based care organization were introduced for patients attending the HIV clinic, with supportive counselling services provided by the VCT counsellors and home‐based care volunteers. Focus group discussions and in‐depth interviews were conducted with health care workers and patients to assess the acceptability of the referral procedures.ResultsReferral uptake at the HIV clinic averaged 72% among men and 66% among women during the first three years of the national antiretroviral therapy (ART) programme, and gradually increased following the introduction of the transportation allowances and community escorts, but declined following a national VCT campaign. Most patients reported that the referral system facilitated their arrival at the HIV clinic, but expressed a desire for HIV treatment services to be in closer proximity to their homes. The referral forms proved to be an efficient and accepted method for assessing the effectiveness of the VCT clinic as an entry point for ART.ConclusionThe referral system reduced delays in seeking care, and enabled the monitoring of access to HIV treatment among diagnosed persons. Similar systems to monitor referral uptake and linkages between HIV services could be readily implemented in other settings.
BACKGROUND: Individuals diagnosed with HIV in developing countries are not always successfully linked to onward treatment services, resulting in missed opportunities for timely initiation of antiretroviral therapy, or prophylaxis for opportunistic infections. In collaboration with local stakeholders, we designed and assessed a referral system to link persons diagnosed at a voluntary counselling and testing (VCT) clinic in a rural district in northern Tanzania with a government-run HIV treatment clinic in a nearby city. METHODS: Two-part referral forms, with unique matching numbers on each side were implemented to facilitate access to the HIV clinic, and were subsequently reconciled to monitor the proportion of diagnosed clients who registered for these services, stratified by sex and referral period. Delays between referral and registration at the HIV clinic were calculated, and lists of non-attendees were generated to facilitate tracing among those who had given prior consent for follow up.Transportation allowances and a "community escort" from a local home-based care organization were introduced for patients attending the HIV clinic, with supportive counselling services provided by the VCT counsellors and home-based care volunteers. Focus group discussions and in-depth interviews were conducted with health care workers and patients to assess the acceptability of the referral procedures. RESULTS: Referral uptake at the HIV clinic averaged 72% among men and 66% among women during the first three years of the national antiretroviral therapy (ART) programme, and gradually increased following the introduction of the transportation allowances and community escorts, but declined following a national VCT campaign. Most patients reported that the referral system facilitated their arrival at the HIV clinic, but expressed a desire for HIV treatment services to be in closer proximity to their homes. The referral forms proved to be an efficient and accepted method for assessing the effectiveness of the VCT clinic as an entry point for ART. CONCLUSION: The referral system reduced delays in seeking care, and enabled the monitoring of access to HIV treatment among diagnosed persons. Similar systems to monitor referral uptake and linkages between HIV services could be readily implemented in other settings.
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OBJECTIVES: Rates of first-line treatment failure and switches to second-line therapy are key indicators for national HIV programmes. We assessed immunological treatment failure defined by WHO criteria in the Tanzanian national HIV programme. METHODS: We included adults initiating first-line therapy in 2004-2011 with a pre-treatment CD4 count, and ≥6-months of follow-up. We assessed subhazard ratios (SHR) for immunological treatment failure, and subsequent switch to second-line therapy, using competing risks methods to account for deaths. RESULTS: Of 121 308 adults, 7% experienced immunological treatment failure, and 2% died without observed immunological treatment failure, over a median 1.7 years. The 6-year cumulative probability of immunological treatment failure was 19.0% (95% CI 18.5, 19.7) and of death, 5.1% (4.8, 5.4). Immunological treatment failure predictors included earlier year of treatment initiation (P < 0.001), initiation in lower level facilities (SHR = 2.23 [2.03, 2.45] for dispensaries vs. hospitals), being male (1.27 [1.19, 1.33]) and initiation at low or high CD4 counts (for example, 1.78 [1.65, 1.92] and 5.33 [4.65, 6.10] for <50 and ≥500 vs. 200-349 cells/mm(3) , respectively). Of 7382 participants in the time-to-switch analysis, 6% switched and 5% died before switching. Four years after immunological treatment failure, the cumulative probability of switching was 7.3% (6.6, 8.0) and of death, 6.8% (6.0, 7.6). Those who immunologically failed in dispensaries, health centres and government facilities were least likely to switch. CONCLUSIONS: Immunological treatment failure rates and unmet need for second-line therapy are high in Tanzania; virological monitoring, at least for persons with immunological treatment failure, is required to minimise unnecessary switches to second-line therapy. Lower level government health facilities need more support to reduce treatment failure rates and improve second-line therapy uptake to sustain the benefits of increased coverage.
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In: IASSIST quarterly: IQ, Band 40, Heft 2, S. 18
ISSN: 2331-4141
Open-access for existing LMIC demographic surveillance data using DDI
In: Journal of biosocial science: JBS, Band 35, Heft 2, S. 189-199
ISSN: 1469-7599
Recent studies in sub-Saharan Africa have shown that fertility is reduced among HIV-infected women compared with uninfected women. The size and pattern of this fertility reduction has important implications for antenatal clinic-based surveillance of the epidemic and also for estimates and projections of the demographic impact of the epidemic. This paper examines the association between HIV and fertility in Kisesa, a rural area in Tanzania, where HIV prevalence among adults is about 6% and gradually increasing. The analysis is based on data obtained through a demographic surveillance system in Kisesa during 1994–98 and two large sero-surveys of all residents in 1994–95 and 1996–97. The HIV-associated fertility reduction among women was investigated by estimating fertility rates by HIV status and prevalence rates by fertility status. A substantial reduction (29%) was observed in fertility among HIV-infected women compared with HIV-uninfected women. The fertility reduction was most pronounced during the terminal stages of infection, but no clear association with duration of infection was observed. Use of modern contraception was higher among HIV-infected women. However, both among contracepting and noncontracepting women, a substantial reduction in fertility was seen among HIV-infected women.
In: Bulletin of the World Health Organization: the international journal of public health = Bulletin de l'Organisation Mondiale de la Santé, Band 93, Heft 11, S. 768-774
ISSN: 1564-0604
BACKGROUND: HIV counselling and testing (HCT) services can play an important role in HIV prevention by encouraging safe sexual behaviours and linking HIV-infected clients to antiretroviral therapy (ART). However, regular repeat testing by high-risk HIV-negative individuals is important for timely initiation of ART as part of the 'treatment as prevention' approach. AIM: To investigate HCT use during a round of HIV serological surveillance in northwest Tanzania in 2010, and to explore rates of repeat testing between 2003 and 2010. METHODS: HCT services were provided during the fourth, fifth and sixth rounds of serological surveillance in 2003-2004 (Sero-4), 2006-2007 (Sero-5) and 2010 (Sero-6). HCT services have also been available at a government-run health centre and at other clinics in the study area since 2005. Questionnaires administered during sero-surveys collected information on socio-demographic characteristics, sexual behaviour and reported previous use of HCT services. RESULTS: The proportion of participants using HCT increased from 9.4% at Sero-4 to 16.6% at Sero-5 and 25.5% at Sero-6. Among participants attending all three sero-survey rounds (n = 2,010), the proportions using HCT twice or more were low, with 11.1% using the HCT service offered at sero-surveys twice or more, and 25.3% having tested twice or more if reported use of HCT outside of sero-surveys was taken into account. In multivariable analyses, individuals testing HIV-positive were less likely to repeat test than individuals testing HIV-negative (aOR 0.17, 95% CI 0.006-0.52). DISCUSSION/CONCLUSIONS: Although HCT service use increased over time, it was disappointing that the proportions ever testing and ever repeat-testing were not even larger, considering the increasing availability of HCT and ART in the study area. There was some evidence that HIV-negative people with higher risk sexual behaviours were most likely to repeat test, which was encouraging in terms of the potential to pick-up those at greatest risk of HIV-infection.
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In: International journal of population data science: (IJPDS), Band 3, Heft 4
ISSN: 2399-4908
IntroductionStudies based on high-quality linked data in developed countries show that residual linkage errors impact the bias and precision of subsequent analyses. Since 2015, we conducted point-of-contact interactive record linkage (PIRL) between serological survey data and manually digitised medical records with low data quality from three clinics in rural Tanzania.
Objectives and ApproachWe sought to determine the impact of the substantial linkage errors made by automated probabilistic linkage (a commonly used, less accurate, but much cheaper alternative to PIRL) on the bias and precision of inferences drawn from Cox regression analyses, comparing time from a positive HIV diagnostic test to registration at a local HIV care and treatment clinic (CTC) by testing modality (sero-survey vs. clinic). Using PIRL links as the gold standard, we quantified false/missed matches, compared characteristics between linked and unlinked data, and evaluated regression estimates at low, medium, and high (25th, 50th, and 75th percentile) match score thresholds.
ResultsBetween 2015-2017, 297 and 147 individuals with gold standard links received HIV+ test results in sero-surveys and clinics, respectively. Automated probabilistic linkage correctly identified 276 individuals (positive predictive value [PPV]=62%) at the low threshold and 43 individuals (PPV=96%) at the high threshold. At the lowest threshold, false matches were more likely to be clinic testers and less likely to register at CTC. These differences attenuated with increased threshold. Testing modality was significantly associated with time to CTC registration in the gold standard data (adjusted hazard ratio [HR] 6.42, 95%CI 4.45-9.28). Increasing false matches progressively weakened the association (low threshold: HR 4.99, 95%CI 3.45-7.21). Increases in missed matches were strongly correlated with a reduction in the precision of coefficient estimates (R-squared=0.94; p=0.0001).
Conclusion/ImplicationsWhile the significance of inferences did not change, a clear direction of bias was identified. High rates of false matches in this setting reduced the magnitude of the association; missed matches reduced precision. Adjusting for these biases could provide more robust results using data with considerable linkage errors.