Karen Pfeffer

Dr. Karen Pfeffer


Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications


25 March 2013 in Traffic Injury Prevention
Verified
Journal Article
Closed access
KPKaren Pfeffer
Karen Pfeffer
EHE. Hunter
E. Hunter
Objective: Adolescence is a high-risk period for pedestrian injury. It is also a time of heightened susceptibility to peer influence. The aim of this research was to examine the effects of peer influence on the pedestrian road-crossing decisions of adolescents. Methods: Using 10 videos of road-crossing sites, 80 16- to 18-year-olds were asked to make pedestrian road-crossing decisions. Participants were assigned to one of 4 experimental conditions: negative peer (influencing unsafe decisions), positive peer (influencing cautious decisions), silent peer (who observed but did not comment), and no peer (the participant completed the task alone). Peers from the adolescent's own friendship group were recruited to influence either an unsafe or a cautious decision. Results: Statistically significant differences were found between peer conditions. Participants least often identified safe road-crossing sites when accompanied by a negative peer and more frequently identified dangerous road-crossing sites when accompanied by a positive peer. Both cautious and unsafe comments from a peer influenced adolescent pedestrians’ decisions. Conclusions: These findings showed that road-crossing decisions of adolescents were influenced by both unsafe and cautious comments from their peers. The discussion highlighted the role that peers can play in both increasing and reducing adolescent risk-taking.

31 March 2010 in Traffic Injury Prevention
Verified
Journal Article
Closed access
KPKaren Pfeffer
Karen Pfeffer
HFH. P. Fagbemi
H. P. Fagbemi
SSS. Stennet
S. Stennet
Objective: Pedestrian injuries are a major cause of morbidity and mortality to children, especially boys. Adults serve as pedestrian role models and provide learning opportunities for children when walking to school. The research objectives were to investigate adult pedestrian behavior when accompanying boys and girls. Methods: Behavioral observation of 140 adult pedestrians accompanying 4- to 9-year-old children was done in British residential locations. Observations took place at light-controlled crossings, speed-restricted school safety zones, and mid-block unmarked crossing sites. Behaviors observed included stopping at the curb, waiting at the curb, looking left and right before and during road crossing, holding hands, talking, and walking straight across. Results: In general, adults modeled safe road crossing behaviors. Adult safe behavior scores were higher when accompanying girls than when accompanying boys. No statistically significant differences were found by child age group. The fewest safe pedestrian behaviors were observed at light-controlled crossings. Conclusions: Adult pedestrians behave differently when with boys and girls and at different types of road crossing site. Interventions aimed at reducing pedestrian injuries to children may need to take these different everyday experiences into consideration.

MDMirena Dimolareva
Mirena Dimolareva
Nancy GeeNancy Gee
Nancy Gee
KPKaren Pfeffer
Karen Pfeffer
LMLaetitia Marechal
Laetitia Marechal
KPKyla Pennington
Kyla Pennington
KMKerstin Meints
Kerstin Meints
The collection of salivary cortisol has been chosen as one of the least intrusive, easiest to collect, analyze, and store methods of obtaining information on physiological changes. It is, however, not clear what the best practice is when collecting salivary cortisol from children within the school setting. The aim of this systematic review is to evaluate the feasibility of cortisol collection in schools for future research and to make recommendations for best practice. The review included 25 peer-reviewed articles from seven databases. The hypotheses of the included studies vary, but they all use cortisol as a diurnal, baseline, or acute measure, or to measure the effect of an intervention. Two methods of salivary cortisol collection were preferred by most of the research, i.e., passive drool or cotton Salivettes. The review has concluded that cortisol is a physiological marker that can be successfully measured in school-based research. However, there are discrepancies across studies when evaluating the collection guidelines, protocols, and instructions to participants as well as transparency of the success rate of obtaining all samples. Recommendations are made for future research to address and avoid such discrepancies and improve cross-study comparisons by implementing standard protocol guidelines.

1 May 2019 in Safety
Verified
Journal Article
Open access
PDF file
ABAmal Baswail
Amal Baswail
LALesley Allinson
Lesley Allinson
PGPaul Goddard
Paul Goddard
KPKaren Pfeffer
Karen Pfeffer
Phones and other portable technology can be a distraction for pedestrians, affecting their ability to cross a road safely. This study focused on adolescents and investigated whether using a phone distracts attention while crossing the road. A field observation outside a secondary school in the north of England was carried out over a four-week period in 2018 with permission from the school. Observations included recording what accessories the pedestrian was carrying (phone, headphones or another electronic device) and their associated action (whether they were holding the device, speaking into a phone, looking at it, holding it to their ear or interacting with it manually). We observed whether the pedestrian looked (or failed to look) left and right before crossing the road, whether they crossed when the pedestrian light was on green or red, and whether they crossed within the cross-walk. We found that 31.37% of road crossings were made by adolescents with a phone or other device. They looked left and right before crossing less frequently when they had an electronic device with them, when looking at the screen and when texting or swiping. In conclusion, the safety of adolescent pedestrians is affected by mobile phones and music players.