the review should make clear whether relevant gender issues as defined by major data users are covered by existing data collection programmes and made available to users based on this review the strategy of gender mainstreaming can involve collecting new types of data expanding data collection in some areas to fill existing knowledge gaps and better disseminating data already collected hedman perucci and sundstrom united nations the strategy of gender mainstreaming should be based on strong collaboration between users and producers of data strong internal coordination within the national statistical office and the national statistical system and data sharing agreements between the national statistical office and other agencies of the national statistical system or other producers of data