Steven E. Gregorich

Efficacy of voluntary HIV-1 counselling and testing in individuals and couples in Kenya, Tanzania, and Trinidad: A randomised trial

The authors aim was to determine the efficacy of HIV-1 voluntary counseling and testing (VCT) in reducing unprotected intercourse among individuals and sex-partner couples in Nairobi (Kenya) Dar es Salaam (Tanzania) and Port of Spain (Trinidad). Individual or couple participants were randomly assigned HIV-1 VCT or basic health information. At first follow-up (mean 7.3 months after baseline) health-information participants were offered VCT and all VCT participants were offered retesting. Sexually transmitted infections were diagnosed and treated at first follow-up. The second follow-up (mean 13.9 months after baseline) involved only behavioral assessment and all participants were again offered VCT. 3120 individuals and 586 couples were enrolled. The proportion of individuals reporting unprotected intercourse with non-primary partners declined significantly more for those receiving VCT than those receiving health information (men 35% reduction with VCT vs. 13% reduction with health information; women 39% reduction with VCT vs. 17% reduction with health information) and these results were maintained at the second follow-up. Individual HIV-1-infected men were more likely than uninfected men to reduce unprotected intercourse with primary and non-primary partners whereas HIV-1-infected women were more likely than uninfected women to reduce unprotected intercourse with primary partners. Couples assigned VCT reduced unprotected intercourse with their enrolment partners significantly more than couples assigned health information but no differences were found in unprotected intercourse with non-enrolment partners. Couples in which one or both members were diagnosed with HIV-1 were more likely to reduce unprotected intercourse with each other than couples in which both members were uninfected. These changes were replicated by those in the health-information group diagnosed with HIV-1 at first follow-up. (authors)BACKGROUND Our aim was to determine the efficacy of HIV-1 voluntary counselling and testing (VCT) in reducing unprotected intercourse among individuals and sex-partner couples in Nairobi (Kenya), Dar es Salaam (Tanzania), and Port of Spain (Trinidad). METHODS Individual or couple participants were randomly assigned HIV-1 VCT or basic health information. At first follow-up (mean 7.3 months after baseline) health-information participants were offered VCT and all VCT participants were offered retesting. Sexually transmitted infections were diagnosed and treated at first follow-up. The second follow-up (mean 13.9 months after baseline) involved only behavioural assessment, and all participants were again offered VCT. FINDINGS 3120 individuals and 586 couples were enrolled. The proportion of individuals reporting unprotected intercourse with non-primary partners declined significantly more for those receiving VCT than those receiving health information (men, 35% reduction with VCT vs 13% reduction with health information; women, 39% reduction with VCT vs 17% reduction with health information), and these results were maintained at the second follow-up. Individual HIV-1-infected men were more likely than uninfected men to reduce unprotected intercourse with primary and non-primary partners, whereas HIV-1-infected women were more likely than uninfected women to reduce unprotected intercourse with primary partners. Couples assigned VCT reduced unprotected intercourse with their enrolment partners significantly more than couples assigned health information, but no differences were found in unprotected intercourse with non-enrolment partners. Couples in which one or both members were diagnosed with HIV-1 were more likely to reduce unprotected intercourse with each other than couples in which both members were uninfected. These changes were replicated by those in the health-information group diagnosed with HIV-1 at first follow-up. INTERPRETATION These data support the efficacy of HIV-1 VCT in promoting behaviour change.

Do Self-Report Instruments Allow Meaningful Comparisons Across Diverse Population Groups? Testing Measurement Invariance Using the Confirmatory Factor Analysis Framework

Comparative public health research makes wide use of self-report instruments. For example, research identifying and explaining health disparities across demographic strata may seek to understand the health effects of patient attitudes or private behaviors. Such personal attributes are difficult or impossible to observe directly and are often best measured by self-reports. Defensible use of self-reports in quantitative comparative research requires not only that the measured constructs have the same meaning across groups, but also that group comparisons of sample estimates (eg, means and variances) reflect true group differences and are not contaminated by group-specific attributes that are unrelated to the construct of interest. Evidence for these desirable properties of measurement instruments can be established within the confirmatory factor analysis (CFA) framework; a nested hierarchy of hypotheses is tested that addresses the cross-group invariance of the instruments psychometric properties. By name, these hypotheses include configural, metric (or pattern), strong (or scalar), and strict factorial invariance. The CFA model and each of these hypotheses are described in nontechnical language. A worked example and technical appendices are included.

Cost-effectiveness of voluntary HIV-1 counselling and testing in reducing sexual transmission of HIV-1 in Kenya and Tanzania.

BACKGROUND Access to HIV-1 voluntary counselling and testing (VCT) is severely limited in less-developed countries. We undertook a multisite trial of HIV-1 VCT to assess its impact, cost, and cost-effectiveness in less-developed country settings. METHODS The cost-effectiveness of HIV-1 VCT was estimated for a hypothetical cohort of 10000 people seeking VCT in urban east Africa. Outcomes were modelled based on results from a randomised controlled trial of HIV-1 VCT in Tanzania and Kenya. Our main outcome measures included programme cost, number of HIV-1 infections averted, cost per HIV-1 infection averted, and cost per disability-adjusted life-year (DALY) saved. We also modelled the impact of targeting VCT by HIV-1 prevalence of the client population, and the proportion of clients who receive VCT as a couple compared with as individuals. Sensitivity analysis was done on all model parameters. FINDINGS HIV-1 VCT was estimated to avert 1104 HIV-1 infections in Kenya and 895 in Tanzania during the subsequent year. The cost per HIV-1 infection averted was US

Positive and negative life events after counselling and testing : the Voluntary HIV-1 Counselling and Testing Efficacy Study

249 and

Socioeconomic status, health behavior, and leukocyte telomere length in the National Health and Nutrition Examination Survey, 1999–2002

346, respectively, and the cost per DALY saved was

The influence of social and sexual networks in the spread of HIV and syphilis among men who have sex with men in Shanghai, China.

12.77 and

Condom use in unmarried Latino men: A test of cultural constructs.

17.78. The intervention was most cost-effective for HIV-1-infected people and those who received VCT as a couple. The cost-effectiveness of VCT was robust, with a range for the average cost per DALY saved of

Draw the Line/Respect the Line: A Randomized Trial of a Middle School Intervention to Reduce Sexual Risk Behaviors

5.16-27.36 in Kenya, and

Beyond race or ethnicity and socioeconomic status : Predictors of prenatal testing for down syndrome

6.58-45.03 in Tanzania. Analysis of targeting showed that increasing the proportion of couples to 70% reduces the cost per DALY saved to

The structure of cockpit management attitudes.

10.71 in Kenya and