Justification of Questions

Justification for Qualifying and Activity Items

Qualifying Items:

Item 1 (Car ownership)

This question assesses whether the respondent has a vehicle he/she regularly drives. The vehicle must be available to the volunteer for use in the study.

Item 2 (License status)

Participants must have a valid license without restrictions that would constrain driving exposure (e.g., nighttime only).

Item 3 (Date of Birth)

This item asks the respondent his/her date of birth to ensure that he/she meets study inclusion criteria.

Item 4 (Driving frequency)

This question asks how many days a week the respondent drives. Participants must drive at least three times a week to be considered sufficiently active drivers for inclusion in the study.

Item 5-6 (medical conditions, adaptive equipment)

These questions will ensure that potential participants have not been diagnosed with medical conditions, or use adaptive equipment in their vehicles (e.g., pedal extenders, hand speed and brake controls) that would make them ineligible for this study.

Item 7 (In the area)

This question asks whether the potential participant will be available to take part in data collection activities during the data collection phase of the study, and that they plan to drive as usual (as opposed to taking an extended trip) during that time.

Activity Level Items:

The questionnaire proposed to assess potential volunteers’ activity level, Phone-FITT, was designed to measure the dimensions of physical activity – frequency, intensity, time and type (American College of Sports Medicine, 2000ⁱ; Gill et al., 2008ⁱⁱ). The instrument was designed to be a simple instrument, easy to administer by telephone to older adults, for use in fall injury prevention research. This instrument is a good fit for the proposed study as it has undergone reliability and validity testing for measuring activity levels in older adults.

The first part of the questionnaire covers frequency and duration of household chores and activities (e.g., housework, meal preparation and cleanup, shopping). The second part explores recreational and exercise activities (e.g., walking, lifting weights, stretching or balance exercises), as well as seasonal activities (golf and gardening), and other regular physical activities not already covered. Responses will provide a global measure of participants’ activity levels that will allow appropriate activity-level group assignments for the study.

Items A – F (Household activities)

Responses to these questions will provide information about the amount of time potential participants spend each week on household chores such as cooking, cleaning, maintenance and providing care for others. Some older adults spend a good deal of time on activities such as these that are often not measured in self-reported measures of physical activity.

Items G – O (Recreational and conditioning activities)

Responses to these items provide information about more traditional physical activities, such as aerobic, strength and flexibility classes or programs.

Items P – R (Seasonal and other activities)

Responses to this section cover activities that potential participants may participate in, but are not covered in the other sections.

i American College of Sports Medicine. (2000). Guidelines for Exercise Testing and Prescription (6th edition). Baltimore: Lippincott Williams & Wilkins.

ii Gill, D. P., Jones, G. R., Zou, G. Y., & Speechley, M. (2008). The Phone-FITT: A brief physical activity interview for older adults. Journal of Aging and Physical Activity, 16, 292-315.

2