Duration: December 1998 - February 2001 Commissioned by the sixteen London Health Authority Commissioners, the Link Evaluation included work by both Sigma Research, and the Thomas Coram Research Unit at the Institute of Education, University of London. The LINK Evaluation aimed to identify whether and why HIV prevention interventions are successful for Gay men in London. Objectives of the study included: Identification and agreement of health promotion aims with all commissioners and prevention agencies within the partnership. Collation of data and information from related studies of Gay men’s HIV health promotion needs and comparable programme evaluations. Annual health promotion ‘Activity Map' which described all HIV health promotion interventions planned for London for each year. Annual ‘Needs Map' report concerning the needs of Gay men in London. Examination of the collective impact of the activities of collaborating agencies on the population of Gay men in London. Four examinations of the performance and impact of individual interventions or groups of interventions sharing methodological characteristics. The LINK Evaluation was a rolling programme of utilisation-focussed outcome evaluation and needs assessment of HIV health promotion intended to reduce the incidence of HIV through sex between men resident in London. A range of research methods were employed including: self-completion questionnaires, face-to-face interviews and workshops. Sample sizes varied according to the specific programme activity: 1500 men were recruited to a rolling cohort to examine their changing HIV health promotion needs, a further 200 were recruited for more in-depth needs and experiences mapping and over 100 agencies were recruited to examine the health promotion activity being delivered in London. Findings were useful in answering questions such as: i) What needs required addressing - the Needs Map was used to prioritise health promotion aims and population groups, and to guide intervention selection and the development of services within a broad programme planning approach. ii) Which interventions best address identified need - findings regarding the performance and impact of specific interventions were used in order to maximise cost-efficiency. iii) Where interventions were being implemented, and where they were not - the Activity Maps were used to gauge intended impact, identify gaps in provision and to facilitate collaborative planning. iv) Whether the programme of HIV health promotion was working - the programme evaluation findings were used to identify the overall impact of a strategic and collaborative London-wide programme and to inform future developments. v) Why the programme of HIV health promotion was working - the in-depth data from those exposed to interventions was used to identify the key features of a strategic programme which contribute to change. Two reports are available: London counts: HIV prevention needs and interventions among gay and bisexual men in 16 London Health Authorities and HIV health promotion activity map for Greater London 1999-2000.