A meta-analysis of overall effects of weight loss interventions delivered via mobile phones and effect size differences according to delivery mode, personal contact, and intervention intensity and duration.

Weight loss interventions are delivered through various mediums including, increasingly, mobile phones. This systematic review and meta-analysis assesses whether interventions delivered via mobile phones reduce body weight and which intervention characteristics are associated with efficacy. The study included randomised controlled trials assessing the efficacy of weight loss interventions delivered via mobile phones. A meta-analysis to test intervention efficacy was performed, and subgroup analyses were conducted to determine whether interventions' delivery mode(s), inclusion of personal contact, duration and interaction frequency improve efficacy. Pooled body weight reduction (d = -0.23; 95% confidence interval = -0.38, -0.08) was significant. Interventions delivered via other modes in addition to the mobile phone were associated with weight reduction. Personal contact and more frequent interactions in interventions were also associated with greater weight reduction. In conclusion, the current body of evidence shows that interventions delivered via mobile phones produce a modest reduction in body weight when combined with other delivery modes. Delivering interventions with frequent and personal interactions may in particular benefit weight loss results.

Community-Based Surveys for Determining the Prevalence of HIV, Chlamydia, and Gonorrhoea in Men Having Sex with Men in Hong Kong.

Background. Community sampling of men having sex with men (MSM) for human immunodeficiency virus (HIV) and sexually transmitted infections prevalence studies poses challenges in view of problems in logistics and the hidden nature of MSM population. Methods. MSM in Hong Kong were recruited through social venues and the Internet. All participants were invited to complete a behavioural questionnaire and submit a urine specimen for HIV, Chlamydia, and gonorrhoea testing. Results. Totally, 994 MSM were recruited. No differences between venue and online-recruited respondents were identified regarding their demographics and infection status. The prevalence of HIV, Chlamydia, and gonorrhoea was 3.6% (95% CI: 2.6-5.0%), 4.7% (95% CI: 3.6-6.2%), and 0.2% (95% CI: 0.1-0.7%), respectively. Of all HIV cases, only 8.3% were aware of the infection; reflecting newly infected MSM were probably overrepresented. Some 58.3% had had HIV test within the past year, and 11.1% had CT/NG coinfection. HIV infection was associated with group sex [aOR: 2.67 (1.03-6.92)], receiving money for anal sex [aOR: 4.63 (1.12-19.18)], and unprotected anal sex with nonregular partners [aOR: 3.047 (1.16-8.01)]. Conclusion. Difference between venue- and online-recruited MSM was observed. A combination of sampling methods is complementary for epidemiology purpose. Overall, risk behaviours practised by undiagnosed HIV-positive MSM remains a cause for concern.