Modelling the healthcare costs of an opportunistic chlamydia screening programme.

OBJECTIVES: To estimate the average cost per screening offer, cost per testing episode and cost per chlamydia positive episode for an opportunistic chlamydia screening programme (including partner management), and to explore the uncertainty of parameter assumptions, based on the costs to the healthcare system. METHODS: A decision tree was constructed and parameterised using empirical data from a chlamydia screening pilot study and other sources. The model was run using baseline data from the pilot, and univariate and multivariate sensitivity analyses were conducted. RESULTS: The total estimated cost for offering screening over 12 months to 33,215 females aged 16-24 was 493,412 pounds . The average cost (with partner management) was 14.88 pounds per screening offer (90% credibility interval (CI) 10.34 to 18.56), 21.83 pounds per testing episode (90% CI 18.16 to 24.20), and 38.36 pounds per positive episode (90% CI 33.97 to 42.25). The proportion of individuals accepting screening, the clinician (general practitioner/nurse) time and their relative involvement in discussing screening, the test cost, the time to notify patients of their results, and the receptionist time recruiting patients had the greatest impact on the outcomes in both the univariate and multivariate sensitivity analyses. CONCLUSIONS: Results from this costing study may be used to inform resource allocation for current and future chlamydia screening programme implementation

Learning about sex: Results from Natsal 2000.

11-13 September 2002

Diversity in the organization of elastin bundles and intramembranous muscles in bat wings

Unlike birds and insects, bats fly with wings composed of thin skin that envelops the bones of the forelimb and spans the area between the limbs, digits, and sometimes the tail. This skin is complex and unusual; it is thinner than typical mammalian skin and contains organized bundles of elastin and embedded skeletal muscles. These elements are likely responsible for controlling the shape of the wing during flight and contributing to the aerodynamic capabilities of bats. We examined the arrangement of two macroscopic architectural elements in bat wings, elastin bundles and wing membrane muscles, to assess the diversity in bat wing skin morphology. We characterized the plagiopatagium and dactylopatagium of 130 species from 17 families of bats using cross‐polarized light imaging. This method revealed structures with distinctive relative birefringence, heterogeneity of birefringence, variation in size, and degree of branching. We used previously published anatomical studies and tissue histology to identify birefringent structures, and we analyzed their architecture across taxa. Elastin bundles, muscles, neurovasculature, and collagenous fibers are present in all species. Elastin bundles are oriented in a predominantly spanwise or proximodistal direction, and there are five characteristic muscle arrays that occur within the plagiopatagium, far more muscle than typically recognized. These results inform recent functional studies of wing membrane architecture, support the functional hypothesis that elastin bundles aid wing folding and unfolding, and further suggest that all bats may use these architectural elements for flight. All species also possess numerous muscles within the wing membrane, but the architecture of muscle arrays within the plagiopatagium varies among families. To facilitate present and future discussion of these muscle arrays, we refine wing membrane muscle nomenclature in a manner that reflects this morphological diversity. The architecture of the constituents of the skin of the wing likely plays a key role in shaping wings during flight

HIV testing and high risk sexual behaviour among London's migrant African communities: a participatory research study.

OBJECTIVES: To describe the demographic and behavioural factors associated with HIV testing among migrant Africans in London. METHODS: A cross sectional survey of migrants from five sub-Saharan African communities (Congo, Kenya, Uganda, Zambia, Zimbabwe) resident in London was carried out. The study formed part of a larger community based participatory research initiative with migrant African communities in London-the MAYISHA project. Trained, ethnically matched interviewers recruited study participants in a variety of community venues. A brief self completion questionnaire collected data on demographic characteristics, utilisation of sexual health services, HIV testing history, sexual behaviour, and attitudes. RESULTS: Valid questionnaires were obtained from 748 participants (396 men and 352 women), median ages 31 and 27 years, respectively. Median length of UK residence was 6 years. 34% of men and 30% of women reported ever having had an HIV test. HIV testing was significantly associated with age and previous STI diagnosis among women; and additionally, nationality, education, employment, and self perceived risk of acquiring HIV among men. After controlling for significant demographic variables, previous diagnosis of an STI (adjusted odds ratio and 95% confidence interval for men: 2.96, 1.63 to 5.38, and women 2.03, 1.06 to 3.88) and perceived risk of acquiring HIV for men (adjusted OR 2.28, 95%CI 1.34 to 3.90) remained independently associated. CONCLUSION: Among these high HIV prevalence migrant communities, these data suggest that HIV testing remains largely associated with an individual's STI history or self perceived risk. This strategy may be inappropriate given the potential for onward and vertical transmission. Antenatal HIV testing combined with proactive targeted HIV testing promotion should be prioritised

Sexual behaviour in Britain: partnerships, practices, and HIV risk behaviours.

BACKGROUND: Sexual behaviour is a major determinant of sexual and reproductive health. We did a National Survey of Sexual Attitudes and Lifestyles (Natsal 2000) in 1999-2001 to provide population estimates of behaviour patterns and to compare them with estimates from 1990-91 (Natsal 1990). METHODS: We did a probability sample survey of men and women aged 16-44 years who were resident in Britain, using computer-assisted interviews. Results were compared with data from respondents in Natsal 1990. FINDINGS: We interviewed 11161 respondents (4762 men, 6399 women). Patterns of heterosexual and homosexual partnership varied substantially by age, residence in Greater London, and marital status. In the past 5 years, mean numbers of heterosexual partners were 3.8 (SD 8.2) for men, and 2.4 (SD 4.6) for women; 2.6% (95% CI 2.2-3.1) of both men and women reported homosexual partnerships; and 4.3% (95% CI 3.7-5.0) of men reported paying for sex. In the past year, mean number of new partners varied from 2.04 (SD 8.4) for single men aged 25-34 years to 0.05 (SD 0.3) for married women aged 35-44 years. Prevalence of many reported behaviours had risen compared with data from Natsal 1990. Benefits of greater condom use were offset by increases in reported partners. Changes between surveys were generally greater for women than men and for respondents outside London. INTERPRETATION: Our study provides updated estimates of sexual behaviour patterns. The increased reporting of risky sexual behaviours is consistent with changing cohabitation patterns and rising incidence of sexually transmitted infections. Observed differences between Natsal 1990 and Natsal 2000 are likely to result from a combination of true change and greater willingness to report sensitive behaviours in Natsal 2000 due to improved survey methodology and more tolerant social attitudes

Putting the public (back) into public health: leadership, evidence and action.

There is a strong evidence-based rationale for community capacity building and community empowerment as part of a strategic response to reduce health inequalities. Within the current UK policy context, there are calls for increased public engagement in prevention and local decision-making in order to give people greater control over the conditions that determine health. With reference to the challenges and opportunities within the English public health system, this essay seeks to open debate about what is required to mainstream community-centred approaches and ensure that the public is central to public health. The essay sets out the case for a reorientation of public health practice in order to build impactful action with communities at scale leading to a reduction in the health gap. National frameworks that support local practice are described. Four areas of challenge that could potentially drive an implementation gap are discussed: (i) achieving integration and scale, (ii) effective community mobilization, (iii) evidencing impact and (iv) achieving a shift in power. The essay concludes with a call to action for developing a contemporary public health practice that is rooted in communities and offers local leadership to strengthen local assets, increase community control and reduce health inequalities

Young men’s views towards the barriers and facilitators of internet-based Chlamydia trachomatis screening: a qualitative study

Background: There is a growing number of Internet-based approaches that offer young people screening for sexually transmitted infections. Objective: This paper explores young men’s views towards the barriers and facilitators of implementing an Internet-based screening approach. The study sought to consider ways in which the proposed intervention would reach and engage men across ages and socioeconomic backgrounds. Methods: This qualitative study included 15 focus groups with 60 heterosexual young men (aged 16-24 years) across central Scotland, drawn across age and socioeconomic backgrounds. Focus groups began by obtaining postcode data to allocate participants to a high/low deprivation category. Focus group discussions involved exploration of men’s knowledge of chlamydia, use of technology, and views toward Internet-based screening. Men were shown sample screening invitation letters, test kits, and existing screening websites to facilitate discussions. Transcripts from audio recordings were analyzed with "Framework Analysis". Results: Men’s Internet and technology use was heterogeneous in terms of individual practices, with greater use among older men (aged 20-24 years) than teenagers and some deprivation-related differences in use. We detail three themes related to barriers to successful implementation: acceptability, confidentiality and privacy concerns, and language, style, and content. These themes identify ways Internet-based screening approaches may fail to engage some men, such as by raising anxiety and failing to convey confidentiality. Men wanted screening websites to frame screening as a serious issue, rather than using humorous images and text. Participants were encouraged to reach a consensus within their groups on their broad design and style preferences for a screening website; this led to a set of common preferences that they believed were likely to engage men across age and deprivation groups and lead to greater screening uptake. Conclusions: The Internet provides opportunities for re-evaluating how we deliver sexual health promotion and engage young men in screening. Interventions using such technology should focus on uptake by age and socioeconomic background. Young people should be engaged as coproducers of intervention materials and websites to ensure messages and content are framed appropriately within a fast-changing environment. Doing so may go some way to addressing the overall lower levels of testing and screening among men compared with women

Quantification of tumour vasculature and hypoxia by immunohistochemical staining and HbO2 saturation measurements

Despite the possibility that tumour hypoxia may limit radiotherapeutic response, the underlying mechanisms remain poorly understood. A new methodology has been developed in which information from several sophisticated techniques is combined and analysed at a microregional level. First, tumour oxygen availability is spatially defined by measuring intravascular blood oxygen saturations (HbO2) cryospectrophotometrically in frozen tumour blocks. Second, hypoxic development is quantified in adjacent sections using immunohistochemical detection of a fluorescently conjugated monoclonal antibody (ELK3-51) to a nitroheterocyclic hypoxia marker (EF5), thereby providing information relating to both the oxygen consumption rates and the effective oxygen diffusion distances. Third, a combination of fluorescent (Hoechst 33342 or DiOC7(3)) and immunohistological (PECAM-1/CD31) stains is used to define the anatomical vascular densities and the fraction of blood vessels containing flow. Using a computer-interfaced microscope stage, image analysis software and a 3-CCD colour video camera, multiple images are digitized, combined to form a photo-montage and revisited after each of the three staining protocols. By applying image registration techniques, the spatial distribution of HbO2 saturations is matched to corresponding hypoxic marker intensities in adjacent sections. This permits vascular configuration to be related to oxygen availability and allows the hypoxic marker intensities to be quantitated in situ. © 1999 Cancer Research Campaig