title: Evaluating the Effect of a Mechanical Adjunct to Improve the Installation of Child Restraint Systems to Vehicles.
abstract: OBJECTIVE
  We explored if an alternative CRS design that utilized a mechanical adjunct to amplify the force applied to the adult seat belt (intervention CRS) results in more accurate and secure attachment between the CRS and the vehicle compared to similar CRS models that use LATCH or the existing adult seat belt. We conducted three separate studies to address this question and additionally explored: (1) the contribution of prior CRS installation experience (Study 1), (2) the value-added of CRS labeling (Study 2), and (3) paper-based vs. video instructions (Study 3).
  
  
  METHODS
  In Studies 1 and 2 we assessed a forward facing combination CRS design (intervention CRS) compared to a commercially available LATCH equipped model (control CRS) and in Study 3 we conducted a similar study using a convertible model of both the intervention and control CRS. Participants installed both CRS in a contemporary minivan and could choose which type of attachment to use for the control CRS (LATCH or seat belt); order of installation was counter-balanced. Evaluators systematically examined installations for accuracy and security.
  
  
  RESULTS
  Study 1: A greater proportion of participants in both the experienced and inexperienced groups was able to securely install the intervention CRS compared to the control CRS: (45% vs. 16%, p =.0001 for experienced) and (37% vs. 6%, p =.003 for inexperienced). No differences between the CRS were observed for accuracy of installation in either user group. Study 2: A greater proportion of participants were able to securely install the enhanced intervention CRS compared to the control CRS: (62% vs. 9%, p =.001). The intervention CRS demonstrated reduced installation accuracy: (30% vs. 61%, p =.001). Study 3: A greater proportion of participants was able to securely install the intervention CRS compared to the control CRS: 79% vs. 66% p =.03, but this effect was smaller than in the previous studies. Participants were less likely to achieve an accurate installation with the intervention CRS compared to the control CRS: 54% vs. 79%, p =.004. Common accuracy errors in each study included twisting or misrouting the seatbelt when installing the intervention CRS.
  
  
  CONCLUSIONS
  Our results suggest that novel CRS designs that utilize mechanical advantage to facilitate attachment of the CRS to the vehicle result in a tighter installation compared to LATCH equipped models, but an increase in accuracy errors occurred.
authors.affiliation: a Division of Adolescent Medicine, Department of Pediatrics , The Children's Hospital of Philadelphia , Philadelphia , Pennsylvania.|b Center for Injury Research and Prevention , The Children's Hospital of Philadelphia , Philadelphia , Pennsylvania.
authors.forename: Jessica H
authors.initials: JH
authors.lastname: Mirman
authors.affiliation: c Minnesota Health-Solutions, Saint Paul, Minnesota.
authors.forename: Sara J
authors.initials: SJ
authors.lastname: Seifert
authors.affiliation: b Center for Injury Research and Prevention , The Children's Hospital of Philadelphia , Philadelphia , Pennsylvania.|d Division of Emergency Medicine, Department of Pediatrics , The Children's Hospital of Philadelphia , Philadelphia , Pennsylvania.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Zonfrillo
authors.affiliation: b Center for Injury Research and Prevention , The Children's Hospital of Philadelphia , Philadelphia , Pennsylvania.
authors.forename: Kristi
authors.initials: K
authors.lastname: Metzger
authors.affiliation: b Center for Injury Research and Prevention , The Children's Hospital of Philadelphia , Philadelphia , Pennsylvania.|d Division of Emergency Medicine, Department of Pediatrics , The Children's Hospital of Philadelphia , Philadelphia , Pennsylvania.
authors.forename: Dennis R
authors.initials: DR
authors.lastname: Durbin
authors.affiliation: b Center for Injury Research and Prevention , The Children's Hospital of Philadelphia , Philadelphia , Pennsylvania.|d Division of Emergency Medicine, Department of Pediatrics , The Children's Hospital of Philadelphia , Philadelphia , Pennsylvania.
authors.forename: Kristy B
authors.initials: KB
authors.lastname: Arbogast
mesh_terms: D000293:Adolescent; D000328:Adult; D057207:Child Restraint Systems / Q000706:statistics & numerical data*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D018986:Motor Vehicles; D012622:Seat Belts; D055815:Young Adult
keywords: child passenger safety; child restraints; injury; motor vehicle crash; parenting; pediatric injury