Cost for sickle cell disease screening using isoelectric focusing with dried blood spot samples and estimation of price thresholds for a point-of-care test in Uganda.

BACKGROUND: Early identification through newborn screening is the first step in active management of sickle cell disease (SCD). Uganda currently screens newborns and infants under 2 years for SCD in high HIV-burden districts using isoelectric focusing with dried blood spot samples. Our analysis sought to estimate the costs per child screened for SCD using this method in Uganda and then to use those data to estimate the price threshold for screening with a point-of-care (POC) test. METHODS: We estimated the financial and economic costs per child screened for SCD using data from health facilities and the Central Public Health Laboratory. These costs included sample collection, transportation, and laboratory processing. Price thresholds for a POC test were estimated using two scenarios. RESULTS: The price threshold of an SCD POC test used for diagnosis would be $3.77 when taking into account only financial costs and $5.14 when taking into account economic costs. Thresholds for a POC test used for screening would be $3.07-$3.51 and $4.38-$5.09, respectively, depending on test specificity. CONCLUSION: The price threshold of a POC test for SCD will depend on the assumptions on how it will be used - either as a screening or diagnostic test. If used for screening, test specificity will have significant impact. Results from this type of costing study can allow developers to incorporate quantitatively estimated price thresholds for innovative products into target product profiles early in the product development cycle.

What are the constraints and opportunities for HIVST scale-up in Africa? Evidence from Kenya, Malawi and South Africa.

INTRODUCTION: HIV self-testing (HIVST) has the potential to increase uptake of HIV testing among untested populations in sub-Saharan Africa and is on the brink of scale-up. However, it is unclear to what extent HIVST would be supported by stakeholders, what policy frameworks are in place and how variations between contexts might influence country-preparedness for scale-up. This qualitative study assessed the perceptions of HIVST among stakeholders in three sub-Saharan countries. METHODS: Fifty-four key informant interviews were conducted in Kenya (n=16), Malawi (n=26) and South Africa (n=12) with government policy makers, academics, activists, donors, procurement specialists, laboratory practitioners and health providers. A thematic analysis was conducted in each country and a common coding framework allowed for inter-country analysis to identify common and divergent themes across contexts. RESULTS: Respondents welcomed the idea of an accurate, easy-to-use, rapid HIV self-test which could increase testing across all populations. High-risk groups, such as men, Men who have sex with men (MSM), couples and young people in particular, could be targeted through a range of health facility and community-based distribution points. HIVST is already endorsed in Kenya, and political support for scale-up exists in South Africa and Malawi. However, several caveats remain. Further research, policy and ensuing guidelines should consider how to regulate, market and distribute HIVST, ensure quality assurance of tests and human rights, and critically, link testing to appropriate support and treatment services. Low literacy levels in some target groups would also need context-specific consideration before scale up. World Health Organization (WHO) policy and regulatory frameworks are needed to guide the process in those areas which are new or specific to self-testing. CONCLUSIONS: Stakeholders in three HIV endemic sub-Saharan countries felt that HIVST will be an important complement to existing community and facility-based testing approaches if accompanied by the same essential components of any HIV testing service, including access to accurate information and linkages to care. While there is an increasingly positive global policy environment regarding HIVST, several implementation and social challenges limit scale-up. There is a need for further research to provide contextual and operational evidence that addresses concerns and contributes to normative WHO guidance.

What should the ideal HIV self-test look like? A usability study of test prototypes in unsupervised HIV self-testing in Kenya, Malawi, and South Africa.

HIV self-testing (HIVST) is increasingly being sought and offered globally, yet there is limited information about the test features that will be required for an HIV self-test to be easy to use, acceptable to users, and feasible for manufacturers to produce. We conducted formative usability research with participants who were naïve to HIVST using five prototypes in Kenya, Malawi, and South Africa. The tests selected ranged from early-stage prototypes to commercially ready products and had a diverse set of features. A total of 150 lay users were video-recorded conducting unsupervised self-testing and interviewed to understand their opinions of the test. Participants did not receive a test result, but interpreted standardized result panels. This study demonstrated that users will refer to the instructions included with the test, but these can be confusing or difficult to follow. Errors were common, with less than 25% of participants conducting all steps correctly and 47.3% of participants performing multiple errors, particularly in sample collection and transfer. Participants also had difficulty interpreting results. To overcome these issues, the ideal HIV self-test requires pictorial instructions that are easy to understand, simple sample collection with integrated test components, fewer steps, and results that are easy to interpret.

Human papillomavirus testing and cervical cytology in primary screening for cervical cancer among women in rural China: comparison of sensitivity, specificity, and frequency of referral.

The causal relationship between persistent high-risk human papillomavirus infection and cervical cancer is widely accepted. HR-HPV DNA testing, alone or in combination with Pap smear testing, may have a role in primary screening. The screening results (VIA, VILI, Pap, and HR-HPV DNA) of 9,057 women in rural China were analyzed to determine the screening performance for the detection of CIN3+. All screening strategies had comparable AUCs (0.9). Cotesting strategies had the overall highest sensitivity for CIN3+ (99.4%), followed by HR-HPV DNA testing alone (96.3%), Pap alone (80.2%), and reflex testing (75.4%). Reflex testing had the highest specificity (96.7%), followed by Pap alone (93.3%), HR-HPV DNA testing alone (85.5%), and both cotesting strategies (LSIL: 84.8%, HSIL: 84.8%). Of the single-test strategies, HR-HPV DNA testing had a higher sensitivity (96.3% vs. 80.2%) compared with Pap testing. The specificity of the Pap test was higher (93.3% vs. 85.5%) and it had a lower percent referred for colposcopy (7.8% vs. 15.8%) than HR-HPV DNA testing. HR-HPV DNA testing with a 10.0 cutoff point (relative light units/cutoff ratio) had a sensitivity (85.2%) and specificity (90.6%) estimate comparable to Pap testing. A single-test primary screening strategy with adequate performance would permit less frequent screening and be most appropriate. Of the primary screening strategies investigated in this setting in China, the performance of HR-HPV DNA testing with an increased cutoff-point might best meet these criteria.

A new HPV-DNA test for cervical-cancer screening in developing regions: a cross-sectional study of clinical accuracy in rural China.

BACKGROUND: A new test (careHPV; QIAGEN, Gaithersburg, MD, USA) has been developed to detect 14 high-risk types of carcinogenic human papillomavirus (HPV) in about 2.5 h, to screen women in developing regions for cervical intraepithelial neoplasia (CIN). We did a cross-sectional study to assess the clinical accuracy of careHPV as a rapid screening test in two county hospitals in rural China. METHODS: From May 10 to June 15, 2007, the careHPV test was done locally by use of self-obtained vaginal and provider-obtained cervical specimens from a screening population-based set of 2530 women aged 30 to 54 years in Shanxi province, China. All women were assessed by visual inspection with acetic acid (VIA), Digene High-Risk HPV HC2 DNA Test (HC2), liquid-based cytology, and colposcopy with directed biopsy and endocervical curettage as necessary. In 2388 women with complete data, 441 women with negative colposcopy, but unsatisfactory or abnormal cytology or who were positive on HC2 or the new careHPV test, were recalled for a second colposcopy, four-quadrant cervical biopsies, and endocervical curettage. An absence of independence between the tests was not adjusted for and the Bonferroni correction was used for multiple comparisons. FINDINGS: Complete data were available for 2388 (94.4%) women. 70 women had CIN2+ (moderate or severe CIN or cancer), of whom 23 had CIN3+. By use of CIN2+ as the reference standard and area-under-the-curve analysis with a two-sided alpha error level of 0.0083, the sensitivities and specificities of the careHPV test for a cut-off ratio cut-point of 0.5 relative light units, were 90.0% (95% CI 83.0-97.0) and 84.2% (82.7-85.7), respectively, on cervical specimens, and 81.4% (72.3-90.5) and 82.4% (80.8-83.9), respectively, on vaginal specimens (areas under the curve not significantly different, p=0.0596), compared with 41.4% (29.9-53.0) and 94.5% (93.6-95.4) for VIA (areas under the curve significantly different, p=0.0001 and p=0.0031, for cervical and vaginal-specimen comparisons for the careHPV test, respectively). The sensitivity and specificity of HC2 for cervical specimens were 97.1% (93.2-100) and 85.6% (84.2-87.1), respectively (areas under the curve not significantly different from the careHPV test on cervical specimens, p=0.0163). INTERPRETATION: The careHPV test is promising as a primary screening method for cervical-cancer prevention in low-resource regions.

"Heat in their intestine": colorectal cancer prevention beliefs among older Chinese Americans.

OBJECTIVE: Data regarding disease prevention behaviors among Asian-American populations are limited. This study explored the beliefs of older Chinese Americans toward colorectal cancer screening modalities, including fecal occult blood testing (FOBT). DESIGN AND PARTICIPANTS: We conducted 30 semistructured, open-ended, qualitative interviews in Mandarin and Cantonese, focusing on colorectal cancer prevention and health-seeking behavior. Participants were Chinese patients 50-79 years of age recruited from a community clinic in Seattle, Washington. RESULTS: When asked about colorectal cancer prevention, interviewees discussed such concepts as maintenance of positive energy (qi) and spirit (jing shen) and moderation of exercise and diet. Until prompted, participants did not discuss FOBT. Interviewees believed that colorectal cancer was caused by diets high in foods with "heat" (huo qi) or by intestinal toxins from frequent constipation. Participants presumed that FOBT is unnecessary in the absence of symptoms. CONCLUSIONS: Patients in our study expressed beliefs about health promotion and causes of colorectal cancer that differed from Western biomedical concepts. Failure to recognize these different beliefs may create inadvertent confusion among elderly Chinese-American patients. Health promotion programs to increase colorectal cancer screening must incorporate these concepts to improve cultural relevance among Chinese-American patients.