RT Journal Article SR Electronic T1 Comparing the effectiveness of a crowdsourced video and a social marketing video in promoting condom use among Chinese men who have sex with men: a study protocol JF BMJ Open JO BMJ Open FD British Medical Journal Publishing Group SP e010755 DO 10.1136/bmjopen-2015-010755 VO 6 IS 10 A1 Chuncheng Liu A1 Jessica Mao A1 Terrence Wong A1 Weiming Tang A1 Lai Sze Tso A1 Songyuan Tang A1 Ye Zhang A1 Wei Zhang A1 Yilu Qin A1 Zihuang Chen A1 Wei Ma A1 Dianming Kang A1 Haochu Li A1 Meizhen Liao A1 Katie Mollan A1 Michael Hudgens A1 Barry Bayus A1 Shujie Huang A1 Bin Yang A1 Chongyi Wei A1 Joseph D Tucker YR 2016 UL http://bmjopen.bmj.com/content/6/10/e010755.abstract AB Introduction Crowdsourcing has been used to spur innovation and increase community engagement in public health programmes. Crowdsourcing is the process of giving individual tasks to a large group, often involving open contests and enabled through multisectoral partnerships. Here we describe one crowdsourced video intervention in which a video promoting condom use is produced through an open contest. The aim of this study is to determine whether a crowdsourced intervention is as effective as a social marketing intervention in promoting condom use among high-risk men who have sex with men (MSM) and transgender male-to-female (TG) in China.Method We evaluate videos developed by crowdsourcing and social marketing. The crowdsourcing contest involved an open call for videos. Entries were judged on capacity to promote condom use, to be shareable or ‘go viral’ and to give value to the individual. 1170 participants will be recruited for the randomised controlled trial. Participants need to be MSM age 16 and over who have had condomless anal sex in the last 3 months. Recruitment will be through an online banner ad on a popular MSM web page and other social media platforms. After completing an initial survey, participants will be randomly assigned to view either the social marketing video or the crowdsourcing video. Follow-up surveys will be completed at 3 weeks and 3 months after initial intervention to evaluate condomless sex and related secondary outcomes. Secondary outcomes include condom social norms, condom negotiation, condom self-efficacy, HIV/syphilis testing, frequency of sex acts and incremental cost.Ethics and dissemination Approval was obtained from the ethical review boards of the Guangdong Provincial Center for Skin Diseases and STI Control, UNC and UCSF. The results of this trial will be made available through publication in peer-reviewed journals.Trial registration number NCT02516930.