Driving Cessation: What Older Former Drivers Tell Us

Download Driving Cessation: What Older Former Drivers Tell Us

Post on 06-Jul-2016

213 views

Category:

Documents

0 download

Embed Size (px)

TRANSCRIPT

  • JAGS 49:431435, 2001 2001 by the American Geriatrics Society 0002-8614/01/$15.00

    Driving Cessation: What Older Former Drivers Tell Us

    Ann M. Dellinger, PhD, MPH,* Meena Sehgal, MPH,* David A. Sleet, PhD,* andElizabeth Barrett-Connor, MD

    OBJECTIVES:

    To understand why older drivers living ina community setting stop driving.

    DESIGN:

    A cross-sectional study within a longitudinalcohort.

    SETTING:

    A geographically defined community in south-ern California.

    PARTICIPANTS:

    1,950 respondents age 55 and older whoreported ever being licensed drivers.

    MEASUREMENTS:

    A mailed survey instrument of self-reported driving habits linked to prior demographic, health,and medical information.

    RESULTS:

    Of the 1,950 eligible respondents, 141 hadstopped driving within the previous 5 years. Among thosewho stopped, mean age was 85.5 years, 65.2% were fe-male, and the majority reported they were in very good(43.4%) or good (34.0%) health. Nearly two-thirds re-ported driving less than 50 miles per week prior to stop-ping and 12.1% reported a motor vehicle crash during theprevious 5 years. The most common reasons reported forstopping were medical (41.0%) and age-related (19.4%).In bivariate analyses, age and miles driven per week wereeach associated with cessation (

    P

    #

    .001). Medical condi-tions, crashes in the previous 5 years, and gender did notreach statistical significance at the

    P

    #

    .05 level. Logisticregression results found that the number of medical condi-tions was inversely associated with driving cessation.

    CONCLUSION:

    The relationship between medical condi-tions and driving is complex; while medical conditions werethe most common reason given for driving cessation, thosewho stopped had fewer medical conditions than currentdrivers. This suggests that a broader measure of generalhealth or functional ability may play a dominant role in de-cisions to stop driving.

    J Am Geriatr Soc 49:431435, 2001.Key words: driving cessation; older drivers; motor vehicle

    T

    he safety of older drivers has received increased atten-tion in recent years. The structure of our population

    is changing so that the proportion of older persons is in-creasing. The population age 65 and over grew 11-foldfrom 1900 to 1994, while the population under 65 grewjust threefold. U.S. Census Bureau projections estimatethat by the year 2050 the population age 65 and overcould be as large as 80 million.

    1

    If just 75% of these per-sons are licensed to drive, we can expect 60 million olderlicensed drivers in 2050. Evidence suggests that the pro-portion of older persons licensed to drive is rising,

    2

    largelythe result of more older women driving.

    3

    Older drivers have among the highest motor vehiclecrash death rates per vehicle mile traveled.

    4

    Each year, ap-proximately 3,000 older drivers are killed and more than100,000 are nonfatally injured in traffic crashes. Fatal motorvehicle crash rates per 100 million vehicle miles traveled fol-low a U-shaped curve, with the highest rates among theyoungest and oldest drivers. In 1998, people 65 and olderrepresented 13% of the population, but constituted 17% ofall traffic fatalities.

    5,6

    These elevated crash statistics among older driverspersist even though many older drivers stop driving volun-tarily (i.e., without legal intervention). Because little isknown about the predictors of voluntary driving cessationamong older adults, this study was conducted to under-stand why active older drivers living in a community set-ting stop driving. A better understanding of the factorsthat influence older drivers to stop driving may help publichealth and medical practitioners advise those who need tostop driving or are considering it for safety reasons.

    METHODS

    Study Design

    This was a cross-sectional study in a longitudinal cohort ofcommunity-dwelling adults in southern California. The co-hort was originally established in 19721974 as part of theLipid Research Clinics Prevalence Studies. Eighty-two percentof the adult residents age 50 to 79 living in a geographicallydefined community, Rancho Bernardo, were enrolled at thattime. The cohort was largely white and middle to upper-mid-dle class. Enrollees were recruited by telephone and surveyedin person for a variety of demographic and health status mea-sures.

    7

    The cohort is seen intermittently for health and medi-cal assessment and mailed a short annual survey designed

    From the *National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia and

    University of Cali-fornia, San Diego, School of Medicine, Department of Family and Preven-tive Medicine, San Diego, California.Address correspondence to Ann M. Dellinger, PhD, MPH, National Centerfor Injury Prevention and Control, Centers for Disease Control andPrevention, 4770 Buford Highway NE, Mailstop K-63, Atlanta, GA 30341.

  • 432

    DELLINGER ET AL

    . APRIL 2001VOL. 49, NO. 4 JAGS

    to determine vital status and to address specific researchquestions. This study was part of a health survey mailed in1994. Approximately 69% responded by the end of 1995.

    The present sample consisted of 1,950 respondentsage 55 and older who reported ever being licensed drivers.We asked about miles driven, In an average week, abouthow many miles do/did you drive? motor vehicle crashes,In the last 5 years, have you had any automobile accidents,even minor ones, when you were driving? and why they hadstopped driving, If you have STOPPED driving, what is themain reason? Respondents were asked to check one of thefollowing categories for stopping: licensing or license renewalproblems, costs of keeping an automobile, someone else canalways drive me, medical problems, changes due to aging, orother reason. We also matched information on driving tomedical data and health status measures collected during in-person interviews from 1992 and 1995. As an indication ofcomorbidity, we summed the number of serious self-reportedmedical conditions including angina, heart problems, highblood pressure, diabetes mellitus, arthritis, and osteoporosis.

    Medical, health status, and comorbidity data were col-lected on all drivers, but analyses focused on the 141 driverswho reported they had stopped driving within the previous5 years. Our analysis excluded 92 persons who reportedstopping more than 5 years before the survey, four personswho reported their age at stopping as greater than their ageat the time of the survey, and six persons who reportedstopping within the previous 5 years but who also reportedbeing current drivers. Additionally, we excluded 29 personswho reported that they had never been licensed drivers.

    Data Analysis

    We used Statistical Analysis System (SAS) software to gen-erate all statistics.

    8

    Frequency of stopping was reported bydemographic characteristic. Reasons for stopping drivingwere grouped into six categories: (1) licensing or licenserenewal problems, (2) costs of keeping an automobile, (3)someone else can always drive me, (4) medical problems,(5) changes due to aging, and (6) other. The self-reportedlevel of general health was categorized as excellent, verygood, good, fair, or poor.

    Pearson chi-square tests were used to: (1) assess theassociation between driving cessation in the previous 5years and present age, health, gender, miles previouslydriven in an average week, number of medical conditions,and number of motor vehicle crashes in the previous 5years; (2) compare those persons who stopped driving inthe previous 5 years to current drivers; and (3) comparemen and women who stopped driving.

    In order to simultaneously control for multiple variablesof interest, we used a logistic regression modeling procedureto explore the association of several independent variables(age, gender, miles previously driven in an average week,number of crashes in previous 5 years, and number of medi-cal conditions) with the dependent variable (stopped driving).

    RESULTS

    All Drivers

    Surveys were sent to 3,988 participants and 2,770 re-sponded for a response rate of 69%. There were 1,950 re-spondents who had ever been licensed drivers, all were age

    55 and older, with a mean age of 73.8 years, 58.7% werefemale. Most (91.7%) reported that they were in excellent,very good, or good health. Only 8.3% reported fair orpoor health, but one-third reported one or more of the co-morbid conditions. Two hundred seventy-five (14.6%) re-spondents reported at least one motor vehicle crash in theprevious 5 years while they were driving (Table 1).

    Drivers Who Stopped in the Previous 5 Years

    Nearly two-thirds of the 141 persons who stopped drivingwithin the previous 5 years were female (65.2%), their meanage was 85.5 years. Age at time of stopping ranged from 65to 95 years. Just 2% stopped in their 60s, 18% in their 70s,63% in their 80s and 17% in their 90s. This represents 0.6%of those respondents in their 60s, 4.2% of those in their 70s,15.8% of those in their 80s, and 23.3% of those in their 90s.The majority reported very good (43.4%) or good (34.0%)health. Nearly two-thirds reported driving less than 50 milesper week prior to stopping, although 73% had none of theserious comorbid conditions. Of those who stopped driving,12.1% reported a motor vehicle crash in the previous 5 yearswhile driving (Table 1). Driving cessation did not vary bygender, and there were no statistically significant differences

    Table 1. Characteristics of the Sample

    Characteristic

    EverDrivers

    n

    5

    1,950

    DrivingNow

    n

    5

    1,686*

    StoppedLast 5 Years

    n

    5

    141

    %

    Age

    5564 24.2 27.6 0.96574 28.5 31.4 5.97584 32.5 32.5 33.1

    $

    85 14.8 8.5 61.0Gender

    Male 41.0 42.8 34.8Female 58.7 57.2 65.2

    Self-reported healthExcellent 22.3 23.9 5.7Very good 43.1 43.6 43.4Good 26.3 25.3 34.0Fair 7.3 6.4 15.0Poor 1.0 0.8 1.9

    Miles driven per week

    ,

    50 34.7 31.2 64.950100 33.8 35.2 21.1

    .

    100 31.5 33.6 14.0Selected medical

    conditions

    0 65.7 65.1 73.11 22.0 22.8 17.72 8.8 8.8 5.73

    1

    3.5 3.3 3.5Motor vehicle crash

    last 5 years 14.6 15.2 12.1

    *

    Ever drivers less those who stopped at any time in the past, those who reportedcurrently driving and stopping, and those who gave other inconsistent answers.

    Statistically significant at the

    P

    ,

    0.05 level.

    Sum of the number of medical conditions reported including angina, heart prob-lems, high blood pressure, diabetes mellitus, arthritis, and osteoporosis.

  • JAGS APRIL 2001VOL. 49, NO. 4

    DRIVING CESSATION: WHAT OLDER FORMER DRIVERS TELL US

    433

    between men and women who stopped driving with respectto number of miles driven before stopping, number of medi-cal conditions, or the number of crashes in the previous 5years while driving. Nevertheless, there were differences intheir reasons for stopping (

    P

    #

    .04); compared with men,women more frequently reported licensing problems, costs ofkeeping an automobile, and that someone else could drivethem.

    Respondents who stopped driving were asked tocheck one of six categories for the

    main

    reason theystopped driving; 139 respondents indicated at least onereason. Medical problems (41.0%) and changes due to ag-ing (19.4%) were the most common categories checked,followed by licensing or license renewal problems (12.2%)and other reasons (12.1%) (Table 2). The survey alsoasked the respondent to specify (i.e., write in) the mainmedical, age-related, or other reason for stopping if theyhad checked one of these boxes. Although respondentswere asked to choose one main reason for stopping, 13(9%) of 139 participants who responded to this questionwrote in more than one reason or diagnosis. Thus, Table 2gives the percentage of respondents who checked off eachcategory, and Table 3 gives their specified responses.

    Of the 57 persons checking medical problems as theirmain reason for stopping, 52 wrote in 60 different reasonsfor stopping. The most common reason was vision (n

    5

    20) followed by cardiovascular conditions (9), Parkinsonsdisease (6), arthritis (4), slow reactions or slow driving (3),accidents (2), and 16 persons wrote in other reasons suchas sciatica, leg numbness, or osteoporosis (Table 3). Of the27 persons checking changes due to aging as their mainreason for stopping, the most common reasons given werevision (7), slow reactions or slow driving (3), and time tostop or not safe (3). For the 17 persons who checked li-censing or license renewal problems as their main reasonfor stopping there was no area to write in a specific re-sponse (see Table 2 for question format). Nevertheless,eight persons wrote in ten responses. A similar result oc-curred in the someone else can always drive me categorywhere four persons gave six reasons for stopping (Table 3).

    Of the 139 persons who specified any reason for stop-ping, 5.0% (n

    5

    7) indicated accidents and an additional8.6% (n

    5

    12) indicated they might be unsafe drivers.Where drivers who stopped within the previous 5

    years were compared with current drivers (Table 1), thosewho stopped were more likely to be older (

    P

    #

    .001) andin poorer health (

    P

    #

    .003) than those driving at the timeof the survey. There were no differences in the number ofmotor vehicle crashes (

    P

    #

    .33), or the number of medicalconditions (

    P

    #

    .21).We performed Pearson chi-square tests to measure the

    association between demographic characteristics and driv-ing cessation. Age and miles driven per week were eachstatistically significant at the

    P

    #

    .001 level. Medical con-ditions, crashes in the previous 5 years, and gender did notreach statistical significance at the

    P

    #

    .05 level.A logistic regression model containing number of

    medical conditions, crashes in the previous 5 years, gen-der, age, and miles driven per week was used to assess theindependent associations of each variable with driving ces-sation. Results were similar to the bivariate analyses inthat age (

    P

    #

    .0001) and miles driven per week (

    P

    #

    .0001) were statistically significant, gender (

    P

    #

    .55) andcrashes (

    P

    #

    .90) were not. The one difference in the logis-tic regression results was that the number of medical con-ditions became significantly associated with driving cessa-tion (

    P

    #

    .02) but this relationship was in an unexpecteddirectionthe more medical conditions, the less likely aperson was to have stopped driving.

    DISCUSSION

    We found that respondents who had stopped driving inthe previous 5 years tended to be older and female, al-though gender differences did not reach statistical signifi-cance. Medical problems were the most commonly reportedreason for driving cessation, and those who stopped drivingwere twice as likely to report fair or poor health. Neverthe-less, those who stopped had fewer medical conditions thanthose who continued to drive and logistic regression re-sults found that the number of medical conditions was in-versely related to cessation. These seemingly inconsistentresults may be explained by a broader or more general no-tion of health. In this case, people who stopped drivinghad fewer medical conditions but lower levels of self-reported health than current drivers. This paradox may il-lustrate the less-than-perfect match be...

Recommended

View more >