title: Evaluation design for large-scale HIV prevention programmes: the case of Avahan, the India AIDS initiative.
abstract: BACKGROUND
  Closing the HIV prevention gap to prevent HIV infections requires rapid, worldwide rollout of large-scale national programmes. Evaluating such programmes is challenging and complex, requiring clarity of evaluation purpose and evidential approaches substantively different to those employed for pilots and small programmes.
  
  
  OBJECTIVE
  This paper describes the evaluation design for the implementation phase of Avahan, the India AIDS initiative, a large HIV prevention programme funded by the Bill and Melinda Gates Foundation. Avahan, which began in December 2003, has a 10-year charter to impact the Indian epidemic and its response by implementing an HIV prevention programme targeting core and bridge groups in 83 districts of six Indian states, transferring the programme to the Government of India, and disseminating programme learning.
  
  
  METHODS
  The foundation commissioned an external process to design Avahan's evaluation framework. An independent advisory group oversees and guides course corrections in the execution of this framework.
  
  
  RESULTS
  Avahan's evaluation framework comprises: trend and synthetic analysis of data from core, bridge and household biobehavioural surveys in a subset of intervention districts, denominator estimates and programme monitoring from all intervention districts, and government's antenatal surveillance (two sites per district in all districts); bespoke transmission dynamics modelling to estimate infections averted (subset of districts); cost effectiveness studies (subset of districts). In addition, there are other knowledge-building and quality-monitoring activities.
  
  
  CONCLUSIONS
  Rather than a small set of monofocal outcome measures, scaled programmes require nuanced evaluations that approximate programmatic scale by collecting data with different levels of geographical scope, synthesize multiple data and methods to arrive at a composite picture, and can cope with continuous environmental and programme evolution.
authors.affiliation: Bill and Melinda Gates Foundation, New Delhi, India. padma.chandrasekaran@india.gatesfoundation.org
authors.forename: Padma
authors.initials: P
authors.lastname: Chandrasekaran
authors.forename: Gina
authors.initials: G
authors.lastname: Dallabetta
authors.forename: Virginia
authors.initials: V
authors.lastname: Loo
authors.forename: Stephen
authors.initials: S
authors.lastname: Mills
authors.forename: Tobi
authors.initials: T
authors.lastname: Saidel
authors.forename: Rajatashuvra
authors.initials: R
authors.lastname: Adhikary
authors.forename: Michel
authors.initials: M
authors.lastname: Alary
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Lowndes
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Boily
authors.forename: James
authors.initials: J
authors.lastname: Moore
mesh_terms: D004196:Disease Outbreaks / Q000517:prevention & control; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission; D006293:Health Promotion / Q000458:organization & administration; D006801:Humans; D007194:India / Q000453:epidemiology; D015397:Program Evaluation / Q000379:methods*