Back to Annual Meeting

Back to Annual Meeting

Abstract #149435

J. Michael Bowling, PhD¹, Carolyn E. Crump, PhD², Margaret M. Cannon, MPH³, and Robert J. Letourneau, MPH². (1) Health Behavior and Health Education, University of North Carolina Chapel Hill, CB #7440, Chapel Hill, NC 27599-7440, 919 302 8166, jbowling@EMAIL.UNC.EDU, (2) Health Behavior and Health Education, University of North Carolina at Chapel Hill, 137 E. Franklin Street, Suite 21, CB #7506, Chapel Hill, NC 27599, (3) NC Institute of Public Health, University of North Carolina at Chapel Hill, Campus Box 8165, Chapel Hill, NC 27599

Background: American Indians/Alaska Native (AI/AN) mortality due to motor vehicle crashes is 3.3. times that of the overall U.S. rate. The Indian Health Service encourages implementation and evaluation of interventions to increase seatbelt use. Considerable variability exists in methods used to identify AI/AN seatbelt use rates. This project developed and reports a uniform means for AI/AN communities to conduct seatbelt surveillance. Methods: Retrospectively, we determined observational data collection methods and seatbelt use rates for 12 Tribes. SUDAAN analysis was used to estimate design effects from the clustered observational survey data. Prospectively, 17 tribes assessed traffic volume, identified a sampling frame, and conducted quarterly observational surveys at seven randomly selected locations. SAS Surveyfreq was used to calculate design effects (DEFF), intraclass correlations (ICC), and 95% confidence intervals of rates of seatbelt use. Results: Driver DEFF ranged from 2.2 to 31.9 (n=10,712 observations) in the retrospective phase and .7 to 13.7 in the prospective phase (n= 28,684 observations). Prospectively, driver ICC ranged from -.002 to .14. Seatbelt use varied considerably across tribes for drivers (22% to 72%) and passengers (11% to 75%). Average driver use was 54% (95% CI=52%-57%) and passenger use 48% (95% CI=45%-51%). Conclusions: Observation location selection procedures are important and the implications of ignoring design effects could be substantial. The final protocol recommends using a probability based sample (determined by average cluster size) that estimates seatbelt use rates with 95% CIs. Lower AI/AN seatbelt use rates highlight the disparity when compared to All-U.S. seatbelt use rates of approximately 80%.

Learning Objectives:

• 1. Describe the importance of developing an observational seat belt survey protocol specific to American Indian/Alaska Native communities.
• 2. Discuss statistical methods used to analyze cluster design observational seat belt surveys.
• 3. Identify key elements of the final observational seat belt survey protocol and recommendations for the protocol’s dissemination and application.

Keywords: Injury Prevention, Data Collection

Presenting author's disclosure statement:

Any relevant financial relationships? No
Any institutionally-contracted trials related to this submission?

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.