© 2017 The Author(s). Background: HIV testing for marginalized populations is critical to controlling the HIV epidemic. However, the HIV testing rate among men who have sex with men (MSM) in China remains low. Crowdsourcing, the process of shifting individual tasks to a group, has been increasingly adopted in public health programs and may be a useful tool for spurring innovation in HIV testing campaigns. We designed a multi-site study to develop a crowdsourced HIV test promotion campaign and evaluate its effectiveness against conventional campaigns among MSM in China. Methods: This study will use an adaptation of the stepped wedge, randomized controlled trial design. A total of eight major metropolitan cities in China will be randomized to sequentially initiate interventions at 3-month intervals. The intervention uses crowdsourcing at multiple steps to sustain crowd contribution. Approximately 1280 MSM, who are 16 years of age or over, live in the intervention city, have not been tested for HIV in the past 3 mmonths, and are not living with HIV, will be recruited. Recruitment will take place through banner advertisements on a large gay dating app along with other social media platforms. Participants will complete one follow-up survey every 3 months for 12 months to evaluate their HIV testing uptake in the past 3 months and secondary outcomes including syphilis testing, sex without condoms, community engagement, testing stigma, and other related outcomes. Discussion: MSM HIV testing rates remain poor in China. Innovative methods to promote HIV testing are urgently needed. With a large-scale, stepped wedge, randomized controlled trial our study can improve understanding of crowdsourcing's long-term effectiveness in public health campaigns, expand HIV testing coverage among a key population, and inform intervention design in related public health fields. Trial Registration: ClinicalTrials.gov, NCT02796963. Registered on 23 May 2016.

Objective To describe the cause and nature of injuries, and care-seeking behaviour following injury, among community-dwelling older adults. Methods We used 10years of the nationally representative Integrated Health Interview Series data, providing information on individual characteristics, cause and nature of injuries, and care-seeking behaviour for 3074 adults 65years of age and older. Univariate and bivariate analyses were used to evaluate overall patterns and test for group-level differences. Results Approximately 40% of injuries were characterised as hip fracture, head injury and/or other fracture, with the remaining 60% consisting of other, milder types of injuries like bruises, strains and sprains. Fifty-eight per cent of injuries required a visit to the emergency room or transportation via an emergency vehicle, and 19% required hospitalisation. Injuries sustained in a fall were more likely to be serious than those due to other reasons. Older women, those ages 80+, those living with others with no spouse or partner present and those with activities of daily living/instrumental activities of daily living disabilities were more vulnerable to serious injuries and serious injury consequences relative to other older adults. Conclusions Our results suggest that injuries, especially falls, are a pressing public health concern for the growing population of older adults. Injury prevention outreach should take extra measures to reach certain subgroups of older adults that have been identified as especially vulnerable. Because so many injuries are due to reasons other than falling and/or do not result in hospitalisation, more interventions should be designed for general injury prevention and outpatient settings.

BACKGROUND N-Nitroso compounds are thought to play a significant role in the development of gastric cancer. Epidemiological data, however, are sparse in examining the associations between biomarkers of exposure to N-nitroso compounds and the risk of gastric cancer. METHODS A nested case-control study within a prospective cohort of 18,244 middle-aged and older men in Shanghai, China, was conducted to examine the association between urinary level of N-nitroso compounds and risk of gastric cancer. Information on demographics, usual dietary intake, and use of alcohol and tobacco was collected through in-person interviews at enrollment. Urinary levels of nitrate, nitrite, N-nitroso-2-methylthiazolidine-4-carboxylic acid (NMTCA), N-nitrosoproline (NPRO), N-nitrososarcosine (NSAR), N-nitrosothiazolidine-4-carboxylic acid (NTCA), as well as serum H. pylori antibodies were quantified in 191 gastric cancer cases and 569 individually matched controls. Logistic regression method was used to assess the association between urinary levels of N-nitroso compounds and risk of gastric cancer. RESULTS Compared with controls, gastric cancer patients had overall comparable levels of urinary nitrate, nitrite, and N-nitroso compounds. Among individuals seronegative for antibodies to H. pylori, elevated levels of urinary nitrate were associated with increased risk of gastric cancer. The multivariate-adjusted odds ratios for the second and third tertiles of nitrate were 3.27 (95% confidence interval = 0.76-14.04) and 4.82 (95% confidence interval = 1.05-22.17), respectively, compared with the lowest tertile (P for trend = 0.042). There was no statistically significant association between urinary levels of nitrite or N-nitroso compounds and risk of gastric cancer. Urinary NMTCA level was significantly associated with consumption of alcohol and preserved meat and fish food items. CONCLUSION The present study demonstrates that exposure to nitrate, a precursor of N-nitroso compounds, may increase the risk of gastric cancer among individuals without a history of H. pylori infection.

BACKGROUND: The relationship between the alcohol policy environment (ie, the combined effectiveness and implementation of multiple existing alcohol policies) and youth drinking in the United States has not been assessed. We hypothesized that stronger alcohol policy environments are inversely associated with youth drinking, and this relationship is partly explained by adult drinking. METHODS: Alcohol Policy Scale (APS) scores that characterized the strength of the state-level alcohol policy environments were assessed with repeated cross-sectional Youth Risk Behavior Survey data of representative samples of high school students in grades 9 to 12, from biennial years between 1999 and 2011. RESULTS: In fully adjusted models, a 10 percentage point increase in APS scores (representing stronger policy environments) was associated with an 8% reduction in the odds of youth drinking and a 7% reduction in the odds of youth binge drinking. After we accounted for youth-oriented alcohol policies, the subgroup of population-oriented policies was independently associated with lower odds of youth drinking (adjusted odds ratio 0.94; 95% confidence interval 0.92-0.97) and youth binge drinking (adjusted odds ratio 0.96; 95% confidence interval 0.94-0.99). State-level per capita consumption mediated the relationship between population-oriented alcohol policies and binge drinking among youth. CONCLUSIONS: Stronger alcohol policies, including those that do not target youth specifically, are related to a reduced likelihood of youth alcohol consumption. These findings suggest that efforts to reduce youth drinking should incorporate population-based policies to reduce excessive drinking among adults as part of a comprehensive approach to preventing alcohol-related harms. Future research should examine influence of alcohol policy subgroups and discrete policies.

AIMS: Steady increases in alcohol consumption and related problems are likely to accompany China's rapid epidemiological transition and profit-based marketing activities. We reviewed research on health promotion interventions and policies to address excessive drinking and to guide health-care reform. METHODS: We searched Chinese- and English-language databases and included 21 studies in China published between 1980 and 2013 that covered each policy area from the World Health Organization (WHO) Global Strategy to Reduce the Harmful Use of Alcohol. We evaluated and compared preventive interventions to the global alcohol literature for cross-national applicability. RESULTS: In contrast with hundreds of studies in the global literature, 11 of 12 studies from mainland China were published in Chinese; six of 10 in English were on taxation from Taiwan or Hong Kong. Most studies demonstrated effectiveness in reducing excessive drinking, and some reported the reduction of health problems. Seven were randomized controlled trials. Studies targeted schools, drink-driving, work-places, the health sector and taxation. CONCLUSIONS: China is the world's largest alcohol market, yet there has been little growth in alcohol policy research related to health promotion interventions over the past decade. Guided by a public health approach, the WHO Global Strategy and health reform experience in Russia, Australia, Mexico and the United States, China could improve its public health response through better coordination and implementation of surveillance and evidence-based research, and through programmatic and legal responses such as public health law research, screening and early intervention within health systems and the implementation of effective alcohol control strategies.

We use injury-level data from the 1997-2013 Integrated Health Interview Series (IHIS) to describe the prevalence of injuries, causes of injuries, and where they occurred among community-dwelling elders. We also describe the outcomes of these injuries, in terms of whether elders were hospitalized and how many days of work were lost due to injury.