Assessing the potential for bias in direct observation of adult commuter cycling and helmet use.

OBJECTIVES: Bicycling and helmet surveillance, research, and programme evaluation depend on accurate measurement by direct observation, but it is unclear whether weather and other exogenous factors introduce bias into observed counts of cyclists and helmet use. METHODS: To address this issue, a time series was created of cyclists observed at two observation points in Washington, DC, at peak commuting times and locations between September 2012 and February 2013. Using multiple linear regression with Newey-West SEs to account for possible serial correlation, the association between various factors and cyclist counts and helmet use was investigated. RESULTS: The number of cyclists observed per 1 h session was significantly associated with predicted daily high temperature, chance of rain, and actual rain. Additionally, fewer cyclists were observed on Fridays. Helmet use was significantly lower during evening commutes than morning and also lower on Fridays. Helmet use was not associated with weather variables. Controlling for observable cyclists characteristics weakened the association between helmet use and the time of day and day of the week, but it did not eliminate that association. CONCLUSIONS: Direct observation to measure commuter cycling trends or evaluate interventions should control for weather and day of week. Measurement of helmet use is unlikely to be meaningfully biased by weather factors, but time of day and day of week should be taken into account. Failing to control for these factors could lead to significant bias in assessments of the level of, and trends in, commuter cycling and helmet use.

Promoting prevention through the affordable care act: workplace wellness.

Public health in the United States can be improved by building workplace "cultures of health" that support healthy lifestyles. The Affordable Care Act (ACA), which includes the Prevention and Public Health Fund, will support a new focus on prevention and wellness, offering opportunities to strengthen the public's health through workplace wellness initiatives. This article describes the opportunity the ACA provides to improve worker wellness.

Helmet wearing among users of a public bicycle-sharing program in the district of columbia and comparable riders on personal bicycles.

Bicycle-sharing programs are increasingly popular and have the potential to increase physical activity and decrease air pollution, but anecdotal evidence suggests helmet use is lower among users of bicycle-sharing programs than cyclists on private bicycles. We conducted a cross-sectional study to assess helmet use among users of a bicycle-sharing program in Washington, DC. Helmet use was significantly lower among cyclists on shared bicycles than private bicycles, highlighting a need for targeted helmet promotion activities.

Cyclists' helmet usage and characteristics in central and southern Malawi: a cross-sectional study.

The objective of this study was to determine the prevalence of, and factors associated with, bicycle helmet usage in southern and central Malawi. This study was across-sectional observation of public behaviour. The urban and rural roadways in southern and central Malawi were studied during the dry season. In total, 1900 bicyclists were observed along the roadways of southern and central Malawi over a four-day period. Observer ascertainment of cyclists' helmet status, approximate age, sex and bicycle operator or passenger status were measured. Of the 1900 cyclists observed, no cyclist was identified as wearing a helmet (exact 95% CI: 0.0-0.2%). There was no variation by age, sex or operator/passenger status. Nearly, 91.5% of observed cyclists were males and 87.7% were operating the bicycle. The sizeable majority of male cyclists were classified as young adults from adolescence to 25 years old (47.2%) or adults over age 25 (44.9%); 7.9% of male cyclists were pre-adolescent. Passengers were more likely to be female than operators (39.1% versus 4.2%), though, even for passengers, a higher proportion were males than females (p < 0.001). In Malawi, helmet usage is so rare as to be non-existent. This suggests an opportunity for significant improvement. Based on the observed cyclists' characteristics, interventions should be targeted to adult and young adult males.

Planning for pre-exposure prophylaxis to prevent HIV transmission: challenges and opportunities.

There are currently several ongoing or planned trials evaluating the efficacy of pre-exposure prophylaxis (PrEP) as a preventative approach to reducing the transmission of HIV. PrEP may prove ineffective, demonstrate partial efficacy, or show high efficacy and have the potential to reduce HIV infection in a significant way. However, in addition to the trial results, it is important that issues related to delivery, implementation and further research are also discussed. As a part of the ongoing discussion, in June 2009, the Bill & Melinda Gates Foundation sponsored a Planning for PrEP conference with stakeholders to review expected trial results, outline responsible educational approaches, and develop potential delivery and implementation strategies. The conference reinforced the need for continued and sustained dialogue to identify where PrEP implementation may fit best within an integrated HIV prevention package. This paper identifies the key action points that emerged from the Planning for PrEP meeting.