H. Observation Guidelines For The Duval County Bicycle Helmet Use And Behavioral Survey
Observation guidelines for the Duval County Bicycle Helmet Use and Behavioral Survey was established by the Duval County Health Department/The Injury Prevention Program Office and was fashioned along the lines of helmet-use observation studies conducted in Florida, Maryland, Michigan, Texas and Washington. We adapted it to facilitate our study purposes.
Observation Site Selections:
Duval County Observed site were broken down into three groups:
To determine our sample for the elementary schools we did a random stratified sample. We divided the 103 middle schools into seven parts of town by zip codes. We then randomly took 30% from each stratum. We have a total of 33 elementary schools being observed.
We did the same for the middle schools but randomly took 50% of the schools because the difference in elementary and middle schools. The total number of middle school being observed is twelve (12).
For the non-school sites we have three sites that we observe. We observe these sites three different times, one time during the week and two times on the weekends (one morning and one afternoon) to capture more bicyclists. The total number of observed sites in the non-school sites is nine (9).
The form to capture all the data was created on Teleform 6.1 by Radley Remo. This will eliminate the time it takes to enter the information into a database. Form is enclosed. Three people from DCHD/TIPPO are assigned to collect all the data. They have been trained on how to use the form and how to observe. We constructed inter-reliability tests to maintain consistency. This allowed all data collectors to discuss what they saw and justify it. Two variables stuck out, helmet properly worn and bright visible clothing. We addressed this by requiring each variable to meet certain criteria.
For the properly worn helmet bicyclist must 1) have helmet level on head with no more that two fingers from eyebrows 2) have chin straps connected snug (no more that a finger under straps) and 3) have v-straps under bicyclist's ears. (depends on the type of helmet)
For bright visible clothing we took into account all of the bicyclist clothing. We also determined that the upper body (torso) will account for 75% of the bicyclist's body and the legs will account for 25%. So to determine if the bicyclist is wearing bright visible clothing he/she must 1) have 75% of clothing to be bright (shirt or jacket).
Changes from Past Studies
We have made some significant changes to the age variable. In the past, age was broken down by these subgroups:
<6 = Child
We felt that these subgroups were not appropriate for our studies and change the subgroups to:
<5 = Child
Past Years Sample Site Size and Selection
In the past we observed 43 elementary schools, 3 middle schools and 9 non-school sites for a total of 55 observed sites. For 2000 we will observe 33 elementary schools, 12 middle schools and 9 non-school sites for a total of 54 sites. We changed the sample selection to capture more bicyclists in our new target population (middle schools).