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AM. J. DRUG ALCOHOL ABUSE, 4(1), pp. 91-100 (1977)
Driving Records Before and During Methadone Maintenance
JAMES F. MADDUX," M.D. Professor Department of Psychiatry The University of Texas Health Service Center San Antonio, Texas 78284
T. R. WILLIAMS, M.A. J. A. ZIEGLER, M.A. Southwest Research Institute San Antonio, Texas 78284 ABSTRACTS We compared the motor vehicle driving records of 104 former heroin users during 1 year of heroin use before admission to methadone maintenance with their records during 1 year after admission while they were maintained on methadone. We found a statistically significant increase in convictions for speeding from the year on heroin to the year on methadone, but no significant change in convictions for negligent collision, other moving violations, driving without a license, and in accidents. The results suggest that heroin users have slightly better driving records on heroin than they d o on methadone, possibly because on heroin they drive with special care to avoid arrest. The frequency with which our subjects were involved in accidents did not differ significantly from that of all Texas licensed drivers. On the basis of this study we recommend no restriction of the driving privilege of persons maintained on methadone.
*To whom requests for reprints should be addressed at the University of Texas Health Science Center a t San Antonio, 7703 Floyd Curl Drive, San Antonio, Texas 78284. 91
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Do the motor vehicle driving records of heroin users become better or worse when they enter methadone maintenance? Do their driving records while on heroin and while on methadone differ from those of drivers in general? The few studies directed to these questions have given somewhat ambiguous results. In 1968 Crancer and Quiring [ l ] compared driving records of persons arrested for illegal drug use in King County (Seattle), Washington, with the records of licensed drivers having the same age and sex distribution. Eighty percent of the 100 narcotic users in the drug using sample, but only 47% of the comparison subjects, had one or more recorded violations or accidents during the 7-year study period. The narcotic users apparently had worse driving records than the comparison subjects. These results were confirmed in New York State by Babst and associates [2] in 1969. These investigators found that 77% of 1,245 heroin users who had a driver license or a driving record had one or more driving violation convictions or accidents on their driving records. In contrast, only about 20% of all New York State motor vehicle operators had any conviction or accident on their driving records. Two subsequent more carefully designed studies suggested that heroin users who enter methadone maintenance have driving records which do not differ significantly from those of other drivers. Blomberg and Preusser [3] collected data through interviews and from driver records on 1,562 methadone maintenance patients in New York State. They found driver records for 718 (46%) of the subjects, and compared these with records of a comparison group consisting of 579 peers of the methadone patients. The annual moving violation rates and accident rates did not differ significantly from the period on heroin to the period on methadone. Subjects on heroin during 1970 had 0.171 accidents per driver per year; subjects on metahdone during 1971 had 0.198 accidents per driver per year. Both of these rates slightly exceeded the accident rate of the comparison subjects: during 1971 the comparison subjects had 0.154 accidents per driver per year. In 1973, Babst and associates [4] reported similar findings. They found driving records for 448 (28%) of 1,576 patients admitted to methadone maintenance in New York City during a period nearly 5 years in duration, from 1965 to 1969. The driving records of these subjects were compared with a sample of 182 New York City male drivers. Within specific age and sex groups, the annual driving conviction and accident rates before admission to methadone maintenance were similar to those after admission. For males aged 25 and older, who composed 78% of the methadone patients studied, the rate of convictions and accidents increased slightly from the period before to the period
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after admission. During the 5-year study period before and after admission to methadone, 33% of the methadone patients and 29% of the comparison subjects had recorded accidents.
METHOD We obtained driving history interviews with 174 patients who on September 30, 1972, had been continuously maintained on methadone for 1 year or longer in the Drug Dependence Program of the Bexar County Mental Health Retardation Center. An additional 60 patients had been maintained for 1 year or longer in the program, but we failed to obtain interviews with them because of limited time of the interviewers or temporary absence of the patients. In addition to the data from interviews, we collected data from clinical records and from driver records. The data obtained from clinical records included sex, ethnic background, education, principal occupation, marital status, drug use history, and evidence of any problem due to excessive use of alcohol during 1972. Subjects were paid $5.00 for providing the information requested in the driving history questionnaire. The interview took about 10 minutes. No subject refused to answer any of the questions, but some were unable to recall specific information about past driving experience. Practically all subjects seemed interested and cooperative. Information about driving experience during three periods was obtained: (1) before heroin use, (2) during heroin use, and (3) during methadone maintenance. For each period the subject was asked to estimate his annual mileage in one of the following five categories: none; some, less than 5000 miles, 5,000 to 9,999 miles, 10,000 to 14,999 miles, and 15,000 miles and over. Then for each period the subject was asked how many of specified types of driving violation convictions and accidents he had. During the interview the interviewer asked for the driver license number if the subject had a driver license. Only 105 (60%) of the 174 subjects had driver licenses. For the 105 who had licenses, we requested the driver records from the Texas Department of Public Safety. We obtained driver records for 104 subjects; no record existed for one license number that we submitted. We attempted to obtain a comparison group for study by asking each subject for the name and address of a friend or acquaintance who never used heroin and whom we might interview. In the early interviews the subjects declined to give us names of friends or acquaintances, and we abandoned the effort to obtain a comparison group.
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The driving violations and accidents were coded into five categories: (1) speeding; (2) negligent collision; (3) other moving violations (running through stop device, improper turn, driving on wrong side, driving on sidewalk, driving while intoxicated); (4) driving without a license; and (5) accidents. An “accident” means an event that results in unintended injury or property damage attributable to motion of a motor vehicle: A few convictions for habitual violator, improper lights, and no vehicle inspection sticker were excluded from the convictions coded. We report in this paper only the rates based on the official driver records. Because the driver records are maintained for only 5 years, we limited the periods for analysis of the data to 1 year before and 1 year after admission to methadone maintenance. We computed the annual rate per 100 subjects in each category for the year of heroin use before admission and for the year on methadone following admission. In addition to computing annual rates for the year before and the year after admission, we approximately controlled for mileage. Using the midpoints, rounded to the nearest 1,000 miles, of the annual mileage range estimated by subjects, we obtained the sum of miles of driving by all subjects for the year on heroin and for the year on methadone. For the mileage estimate of less than 5,000 miles, we assigned an artificial midpoint of 3,000 miles; for the mileage estimate of 15,000 miles and over, we assigned an artificial midpoint of 18,000 miles. For each category in each year we divided the sum of convictions or accidents in that category by the sum of miles during the corresponding year and multiplied by 100,000. This produced a rate per 100,000 miles. We did not consider these rates suitable for parametric tests of significance of change, primarily because the distributions had a J shape. T o test the signiftcance of changes from the period of heroin use to the period of methadone maintenance, we applied the McNemar test [5]. To use this test we classified each subject in a dichotomy of none versus one o r more in each of the five categories of convictions and accidents for the year on heroin and for the year on methadone. Then for each category a 2 X 2 table was set up to show the frequencies of change from the heroin year to the methadone year. The 5% level of confidence was accepted for statistical significance. To determine whether convictions or accidents during heroin use predicted convictions or accidents during methadone maintenance, we cross-tabulated the frequencies of the dichotomized categories during heroin use with those during methadone maintenance, and computed phi coefficients. Also by crosstabulations we analyzed the association of alcohol problems to the convictions and accidents.
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RESULTS In Table 1 is shown a comparison of the characteristics of the entire group of 174 subjects with those of the 104 subjects who had driver records. The subjects with driver records closely resembled the entire group. Nearly all subjects were male, and nearly all were Mexican-American. Most failed to complete high school, and most worked at manual labor occupations. As shown in Table 2, the subjects with driver records began heroin use at the mean age of 19 and were admitted to methadone maintenance at the mean age of 30. They began driving at the mean age of 15, range 1 1 to 21. The mean of estimated miles of driving, rounded t o the nearest 1,000 miles, was 12,000 for the year on heroin and 10,000 for the year on methadone. In Fig. 1 are shown the annual rates per 100 subjects of the five categories of convictions and accidents for the year on heroin before admission and for Table 1. Comparison of AU Subjects with Those Who Had Driver Records Entire group ( N =174) Characteristic
Subjects with records (N= 104)
(%I
(%)
87 13
96 4
Sex
Male Female Ethnic background Mexican-American
95
92
Anglo
3
5
Black
2
3
Education Completed high school Less than high school
18 82
20 80
Marital status Never married Currently married Common f'aw Other
10 40 21 29
6 50 18 26
Occupation Small business, clerical, sales Skilled manual Semiskilled Unskilled Unemployed Other
7 20 19 22 20 11
10 22 25 17 20
6
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MADDUX, WILLIAMS, AND ZIECLER
Table 2. Drug Use History of Subjects Maintained on Methadone (N= 104)
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Mean
Range
Age of first heroin use
19
Age at admission to methadone maintenance
30
11-37 19-44
Methadone dosage 1 year after admission
81
10-150
HEROIN
SPEEDING NEGLIGENT COUJSlON
OTHER MCMNG vKKATK)NS
DRMNG WITHOUT LICENSE
ACCloENTS
Fig. 1. Annual rates per 100 subjects of driving violation convictions and accidents during heroin use and during methadone maintenance for 104 subjects. From driver records of the Texas Department of Public Safety.
the year on methadone after admission. In all categories a trend of increased rates from the year on heroin to the year on methadone appears. In Fig. 2 are shown the rates per 100,000 miles of driving. Again, in all categories, a trend of increased rates from the year on heroin to the year on methadone is seen. By the McNemar test the increase was found statistically significant in only one category, conviction for speeding; this is shown in Table 3. In Table 4 are shown the phi coefficients of correlation between convictions and accidents on heroin with those on methadone. A statistically significant
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DRIVING RECORDS BEFORE AND DURING METHADONE MAINTENANCE
"
SPEEDING MGUGENT
OTHER WNG
cowsKmvK)IATIoNs
DRMNG WmWwT LICENSE
ACCIDENTS
Fig. 2. Driving violation convictions and accidents per 100,000 miles during heroin use and during methadone maintenance for 104 subjects. From driver records of the Texas Department of Public Safety.
Table 3. Subjects with None vs One or More Convictions for Speeding During 1 Year of Heroin Use and During 1 Year of Methadone Maintenance (N= 104) Heroin Methadone
None
One or more
Both
One or more
19
None
71
I I
78
Total
90
14
104
aMcNemar x2 = 4.7, df = 1, p
26
< .05.
correlation was found in one category, conviction for speeding. However, when we computed the coefficient for conviction or accident in any category, we found a significant correlation between the heroin and methadone periods. From evidence in the clinical records we classified 27 (26%) of the 104 subjects as problem drinkers. During the year on methadone the problem drinkers had convictions and accidents a little more frequently than the others, with one exception: they had fewer convictions for speeding. None of these differences had statistical
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MADDUX, WILLIAMS, AND ZIEGLER
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Table 4. Correlationsof Frequencies of Driving Violation Convictions and Accidenta during 1 Year o f Heroin Use with Those during 1 Year of Methadone Maintenance (N= 104) Category Speeding Negligent collision Other moving violations Driving without license Accident Any conviction or accident
Phi coefficients
.23*
-.Ol .14 .02
.oo
.31**
*p < .05. **p < .01.
significance. During the year on heroin one of the 104 subjects was convicted for driving while intoxicated; during the year on methadone, one different subject was convicted for driving while intoxicated. We could not obtain a comparison group, but we did compare the frequency of subjects who had accidents with that of all Texas licensed drivers. During the year on heroin, 7 of the 104 subjects had one or more accidents. During the year on methadone, 15 subjects had one or more accidents. Although the number having accidents more than doubled from the year on heroin to the year on methadone, the numbers were small and the increase was not statistically significant. During 1972, 7,038,307 residents of Texas had Texas driver licenses [6] . During the same year, 744,699 drivers were involved in reported accidents in Texas. Nine percent of these drivers did not reside in Texas, or they resided but were not licensed in Texas. Eliminating this 9% leaves 677,676 Texas residents with Texas licenses involved in accidents during 1972. Dividing this number by the number of licensed drivers and multiplying by 104, we find that the expected frequency of drivers having accidents among 104 Texas licensed drivers amounts to 10. The observed frequency of subjects having accidents during the year on heroin did not differ significantly from the expected frequency (x2 = 0.9). Also the observed frequency of 15 having accidents during the year on methadone did not differ significantly from the expected frequency (x2 = 2.5). Since age tends to be inversely associated with frequency of accidents, we should note that our study group was somewhat younger than all Texas licensed drivers, and therefore should have somewhat more accidents. Fifty-five percent of our subjects were under 30, but only 36% of Texas licensed drivers are under 30.
DRIVING RECORDS BEFORE AND DURING METHADONE MAINTENANCE
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DISCUSSION We found a statistically significant increase from the year on heroin to the year on methadone only in convictions for speeding. In the other categories of convictions and accidents, we found small and nonsignificant increases. The two previous studies in New York of driving records of methadone patients showed small and nonsignificant increases in,accidents [3] or in convictions and accidents [4] from the period on heroin to the period on methadone. Considered together, the trends in the findings of the two previous studies and of our study suggest that heroin users have slightly better driving records while using heroin than while maintained on methadone. Some persons using heroin may drive with special care. Blomberg and Preusser [3] reported that about one-third of their subjects stated that, when driving after using heroin, the main thing on their mind was driving well enough to avoid being stopped by the police. All patients maintained on methadone do not violate the drug laws daily, and perhaps they drive less carefully than they do while using heroin. Even if some persons drive more carefully on heroin than on methadone, our data provides some evidence that the persons who drive poorly on heroin continue to drive poorly on methadone. While maintained on methadone our subjects were involved in accidents at a frequency which did not differ significantly from that of all Texas licensed drivers. This finding agrees with the findings of the two previous studies in New York. Those studies indicated that methadone patients have motor vehicle accidents with approximately the same frequency as that of comparison drivers. Fraser and associates [7] reported that psychornotor performance was not impaired during addiction to heroin, and Gordon [8] reported that reaction time was not impaired in subjects maintained on methadone. The results of these studies suggest that psychomotor skill required for driving would not be impaired by dependence on heroin or methadone. However, one daily oral dose of methadone does not maintain a completely smooth dependence, and some temporary sedation might reduce attention or concentration. Martin and associates [9] found that some sedative effect of methadone persisted through 15 weeks of chronic methadone administration. Although alcoholism among patients maintained on methadone has become a noteworthy problem [ 101, and one-fourth of our subjects were classified as problem drinkers, problem drinking apparently did not significantly affect their driving records. We know that some of our problem drinkers do their drinking in the evenings at home or at nearby taverns, and consequently do little or no driving while intoxicated.
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MADDUX, WILLIAMS, AND ZIEGLER
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On the basis of this study we recommend no restriction of the driving privilege of persons maintained on methadone.
ACKNOWLEDCMENTS We gratefully acknowledge the assistance of Ruth Steinfeld, D. P. Desmond, Lillian Norton, Josefma Benito, J. R. Shelton, and W. J. Logsdon.
REFERENCES Crancer, A., and Quiring, D. L., Driving Records of Persons Arrested for Illegal Drug Use, Report No. 011, State of Washington, Department of Motor Vehicles, 1968. Babst, D. V., Inciardi, J. A,, Raeder, P. K., and Negri, D. B., Driving Records of Heroin Addicts, Research Report No. 1969-11, New York State Narcotic Addiction Control Commission and New York State Department of Motor Vehicles, December 1969. Blomberg, R. D., and Preusser, D. F., Drug Abuse and Driving Performance, Final Report DOTIHS-800754,Dunlap and Associates, Darien, Connecticut, 1972. Babst, D. V., Newman, S., Gordon, N. B., and Warner, A., Driving records of methadone maintenance patients in New York State, J. Drug Issues 3:285-292 (1973). Siegel, S., Nonparametric Statistics for the Behavioral Sciences, McGraw-Hill, New York, 1956, pp. 63-67. Motor Vehicle l’kaffic Accidents, 1972, Texas Department of Public Safety, Austin, Texas. Fraser, H. F., Jones, B. E., Rosenberg, D. E., and Thompson, A. K., Effects of addiction to intravenous heroin on patterns of physical activity in man, Clin. Pharmacol. Ther. 4:188-196 (1963). Gordon, N. B., Reaction-times of methadone treated ex-heroin addicts, Psychopharmacologia 16:337-344 (1970). Martin, W. R., Jasinski, D. R., Haertzen, C. A., Kay, D. C., Jones, B. E., Mansky, P. A., and Carpenter, R. W., Methadone-A reevaluation, Arch. Cen. PsychLtry 28~286-295(1973). Maddux, J. F., and Elliott, B., Problem drinkers among patients on methadone, Am. J. Drug Alcohol Abuse 2:245-254 (1975).
AM. J. DRUG ALCOHOL ABUSE, 4(1), pp. 91-100 (1977)
Driving Records Before and During Methadone Maintenance
JAMES F. MADDUX," M.D. Professor Department of Psychiatry The University of Texas Health Service Center San Antonio, Texas 78284
T. R. WILLIAMS, M.A. J. A. ZIEGLER, M.A. Southwest Research Institute San Antonio, Texas 78284 ABSTRACTS We compared the motor vehicle driving records of 104 former heroin users during 1 year of heroin use before admission to methadone maintenance with their records during 1 year after admission while they were maintained on methadone. We found a statistically significant increase in convictions for speeding from the year on heroin to the year on methadone, but no significant change in convictions for negligent collision, other moving violations, driving without a license, and in accidents. The results suggest that heroin users have slightly better driving records on heroin than they d o on methadone, possibly because on heroin they drive with special care to avoid arrest. The frequency with which our subjects were involved in accidents did not differ significantly from that of all Texas licensed drivers. On the basis of this study we recommend no restriction of the driving privilege of persons maintained on methadone.
*To whom requests for reprints should be addressed at the University of Texas Health Science Center a t San Antonio, 7703 Floyd Curl Drive, San Antonio, Texas 78284. 91
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Do the motor vehicle driving records of heroin users become better or worse when they enter methadone maintenance? Do their driving records while on heroin and while on methadone differ from those of drivers in general? The few studies directed to these questions have given somewhat ambiguous results. In 1968 Crancer and Quiring [ l ] compared driving records of persons arrested for illegal drug use in King County (Seattle), Washington, with the records of licensed drivers having the same age and sex distribution. Eighty percent of the 100 narcotic users in the drug using sample, but only 47% of the comparison subjects, had one or more recorded violations or accidents during the 7-year study period. The narcotic users apparently had worse driving records than the comparison subjects. These results were confirmed in New York State by Babst and associates [2] in 1969. These investigators found that 77% of 1,245 heroin users who had a driver license or a driving record had one or more driving violation convictions or accidents on their driving records. In contrast, only about 20% of all New York State motor vehicle operators had any conviction or accident on their driving records. Two subsequent more carefully designed studies suggested that heroin users who enter methadone maintenance have driving records which do not differ significantly from those of other drivers. Blomberg and Preusser [3] collected data through interviews and from driver records on 1,562 methadone maintenance patients in New York State. They found driver records for 718 (46%) of the subjects, and compared these with records of a comparison group consisting of 579 peers of the methadone patients. The annual moving violation rates and accident rates did not differ significantly from the period on heroin to the period on methadone. Subjects on heroin during 1970 had 0.171 accidents per driver per year; subjects on metahdone during 1971 had 0.198 accidents per driver per year. Both of these rates slightly exceeded the accident rate of the comparison subjects: during 1971 the comparison subjects had 0.154 accidents per driver per year. In 1973, Babst and associates [4] reported similar findings. They found driving records for 448 (28%) of 1,576 patients admitted to methadone maintenance in New York City during a period nearly 5 years in duration, from 1965 to 1969. The driving records of these subjects were compared with a sample of 182 New York City male drivers. Within specific age and sex groups, the annual driving conviction and accident rates before admission to methadone maintenance were similar to those after admission. For males aged 25 and older, who composed 78% of the methadone patients studied, the rate of convictions and accidents increased slightly from the period before to the period
DRIVING RECORDS BEFORE AND DURING METHADONE MAINTENANCE
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after admission. During the 5-year study period before and after admission to methadone, 33% of the methadone patients and 29% of the comparison subjects had recorded accidents.
METHOD We obtained driving history interviews with 174 patients who on September 30, 1972, had been continuously maintained on methadone for 1 year or longer in the Drug Dependence Program of the Bexar County Mental Health Retardation Center. An additional 60 patients had been maintained for 1 year or longer in the program, but we failed to obtain interviews with them because of limited time of the interviewers or temporary absence of the patients. In addition to the data from interviews, we collected data from clinical records and from driver records. The data obtained from clinical records included sex, ethnic background, education, principal occupation, marital status, drug use history, and evidence of any problem due to excessive use of alcohol during 1972. Subjects were paid $5.00 for providing the information requested in the driving history questionnaire. The interview took about 10 minutes. No subject refused to answer any of the questions, but some were unable to recall specific information about past driving experience. Practically all subjects seemed interested and cooperative. Information about driving experience during three periods was obtained: (1) before heroin use, (2) during heroin use, and (3) during methadone maintenance. For each period the subject was asked to estimate his annual mileage in one of the following five categories: none; some, less than 5000 miles, 5,000 to 9,999 miles, 10,000 to 14,999 miles, and 15,000 miles and over. Then for each period the subject was asked how many of specified types of driving violation convictions and accidents he had. During the interview the interviewer asked for the driver license number if the subject had a driver license. Only 105 (60%) of the 174 subjects had driver licenses. For the 105 who had licenses, we requested the driver records from the Texas Department of Public Safety. We obtained driver records for 104 subjects; no record existed for one license number that we submitted. We attempted to obtain a comparison group for study by asking each subject for the name and address of a friend or acquaintance who never used heroin and whom we might interview. In the early interviews the subjects declined to give us names of friends or acquaintances, and we abandoned the effort to obtain a comparison group.
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The driving violations and accidents were coded into five categories: (1) speeding; (2) negligent collision; (3) other moving violations (running through stop device, improper turn, driving on wrong side, driving on sidewalk, driving while intoxicated); (4) driving without a license; and (5) accidents. An “accident” means an event that results in unintended injury or property damage attributable to motion of a motor vehicle: A few convictions for habitual violator, improper lights, and no vehicle inspection sticker were excluded from the convictions coded. We report in this paper only the rates based on the official driver records. Because the driver records are maintained for only 5 years, we limited the periods for analysis of the data to 1 year before and 1 year after admission to methadone maintenance. We computed the annual rate per 100 subjects in each category for the year of heroin use before admission and for the year on methadone following admission. In addition to computing annual rates for the year before and the year after admission, we approximately controlled for mileage. Using the midpoints, rounded to the nearest 1,000 miles, of the annual mileage range estimated by subjects, we obtained the sum of miles of driving by all subjects for the year on heroin and for the year on methadone. For the mileage estimate of less than 5,000 miles, we assigned an artificial midpoint of 3,000 miles; for the mileage estimate of 15,000 miles and over, we assigned an artificial midpoint of 18,000 miles. For each category in each year we divided the sum of convictions or accidents in that category by the sum of miles during the corresponding year and multiplied by 100,000. This produced a rate per 100,000 miles. We did not consider these rates suitable for parametric tests of significance of change, primarily because the distributions had a J shape. T o test the signiftcance of changes from the period of heroin use to the period of methadone maintenance, we applied the McNemar test [5]. To use this test we classified each subject in a dichotomy of none versus one o r more in each of the five categories of convictions and accidents for the year on heroin and for the year on methadone. Then for each category a 2 X 2 table was set up to show the frequencies of change from the heroin year to the methadone year. The 5% level of confidence was accepted for statistical significance. To determine whether convictions or accidents during heroin use predicted convictions or accidents during methadone maintenance, we cross-tabulated the frequencies of the dichotomized categories during heroin use with those during methadone maintenance, and computed phi coefficients. Also by crosstabulations we analyzed the association of alcohol problems to the convictions and accidents.
DRIVING RECORDS BEFORE AND DURING METHADONE MAINTENANCE
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RESULTS In Table 1 is shown a comparison of the characteristics of the entire group of 174 subjects with those of the 104 subjects who had driver records. The subjects with driver records closely resembled the entire group. Nearly all subjects were male, and nearly all were Mexican-American. Most failed to complete high school, and most worked at manual labor occupations. As shown in Table 2, the subjects with driver records began heroin use at the mean age of 19 and were admitted to methadone maintenance at the mean age of 30. They began driving at the mean age of 15, range 1 1 to 21. The mean of estimated miles of driving, rounded t o the nearest 1,000 miles, was 12,000 for the year on heroin and 10,000 for the year on methadone. In Fig. 1 are shown the annual rates per 100 subjects of the five categories of convictions and accidents for the year on heroin before admission and for Table 1. Comparison of AU Subjects with Those Who Had Driver Records Entire group ( N =174) Characteristic
Subjects with records (N= 104)
(%I
(%)
87 13
96 4
Sex
Male Female Ethnic background Mexican-American
95
92
Anglo
3
5
Black
2
3
Education Completed high school Less than high school
18 82
20 80
Marital status Never married Currently married Common f'aw Other
10 40 21 29
6 50 18 26
Occupation Small business, clerical, sales Skilled manual Semiskilled Unskilled Unemployed Other
7 20 19 22 20 11
10 22 25 17 20
6
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MADDUX, WILLIAMS, AND ZIECLER
Table 2. Drug Use History of Subjects Maintained on Methadone (N= 104)
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Mean
Range
Age of first heroin use
19
Age at admission to methadone maintenance
30
11-37 19-44
Methadone dosage 1 year after admission
81
10-150
HEROIN
SPEEDING NEGLIGENT COUJSlON
OTHER MCMNG vKKATK)NS
DRMNG WITHOUT LICENSE
ACCloENTS
Fig. 1. Annual rates per 100 subjects of driving violation convictions and accidents during heroin use and during methadone maintenance for 104 subjects. From driver records of the Texas Department of Public Safety.
the year on methadone after admission. In all categories a trend of increased rates from the year on heroin to the year on methadone appears. In Fig. 2 are shown the rates per 100,000 miles of driving. Again, in all categories, a trend of increased rates from the year on heroin to the year on methadone is seen. By the McNemar test the increase was found statistically significant in only one category, conviction for speeding; this is shown in Table 3. In Table 4 are shown the phi coefficients of correlation between convictions and accidents on heroin with those on methadone. A statistically significant
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DRIVING RECORDS BEFORE AND DURING METHADONE MAINTENANCE
"
SPEEDING MGUGENT
OTHER WNG
cowsKmvK)IATIoNs
DRMNG WmWwT LICENSE
ACCIDENTS
Fig. 2. Driving violation convictions and accidents per 100,000 miles during heroin use and during methadone maintenance for 104 subjects. From driver records of the Texas Department of Public Safety.
Table 3. Subjects with None vs One or More Convictions for Speeding During 1 Year of Heroin Use and During 1 Year of Methadone Maintenance (N= 104) Heroin Methadone
None
One or more
Both
One or more
19
None
71
I I
78
Total
90
14
104
aMcNemar x2 = 4.7, df = 1, p
26
< .05.
correlation was found in one category, conviction for speeding. However, when we computed the coefficient for conviction or accident in any category, we found a significant correlation between the heroin and methadone periods. From evidence in the clinical records we classified 27 (26%) of the 104 subjects as problem drinkers. During the year on methadone the problem drinkers had convictions and accidents a little more frequently than the others, with one exception: they had fewer convictions for speeding. None of these differences had statistical
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Table 4. Correlationsof Frequencies of Driving Violation Convictions and Accidenta during 1 Year o f Heroin Use with Those during 1 Year of Methadone Maintenance (N= 104) Category Speeding Negligent collision Other moving violations Driving without license Accident Any conviction or accident
Phi coefficients
.23*
-.Ol .14 .02
.oo
.31**
*p < .05. **p < .01.
significance. During the year on heroin one of the 104 subjects was convicted for driving while intoxicated; during the year on methadone, one different subject was convicted for driving while intoxicated. We could not obtain a comparison group, but we did compare the frequency of subjects who had accidents with that of all Texas licensed drivers. During the year on heroin, 7 of the 104 subjects had one or more accidents. During the year on methadone, 15 subjects had one or more accidents. Although the number having accidents more than doubled from the year on heroin to the year on methadone, the numbers were small and the increase was not statistically significant. During 1972, 7,038,307 residents of Texas had Texas driver licenses [6] . During the same year, 744,699 drivers were involved in reported accidents in Texas. Nine percent of these drivers did not reside in Texas, or they resided but were not licensed in Texas. Eliminating this 9% leaves 677,676 Texas residents with Texas licenses involved in accidents during 1972. Dividing this number by the number of licensed drivers and multiplying by 104, we find that the expected frequency of drivers having accidents among 104 Texas licensed drivers amounts to 10. The observed frequency of subjects having accidents during the year on heroin did not differ significantly from the expected frequency (x2 = 0.9). Also the observed frequency of 15 having accidents during the year on methadone did not differ significantly from the expected frequency (x2 = 2.5). Since age tends to be inversely associated with frequency of accidents, we should note that our study group was somewhat younger than all Texas licensed drivers, and therefore should have somewhat more accidents. Fifty-five percent of our subjects were under 30, but only 36% of Texas licensed drivers are under 30.
DRIVING RECORDS BEFORE AND DURING METHADONE MAINTENANCE
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DISCUSSION We found a statistically significant increase from the year on heroin to the year on methadone only in convictions for speeding. In the other categories of convictions and accidents, we found small and nonsignificant increases. The two previous studies in New York of driving records of methadone patients showed small and nonsignificant increases in,accidents [3] or in convictions and accidents [4] from the period on heroin to the period on methadone. Considered together, the trends in the findings of the two previous studies and of our study suggest that heroin users have slightly better driving records while using heroin than while maintained on methadone. Some persons using heroin may drive with special care. Blomberg and Preusser [3] reported that about one-third of their subjects stated that, when driving after using heroin, the main thing on their mind was driving well enough to avoid being stopped by the police. All patients maintained on methadone do not violate the drug laws daily, and perhaps they drive less carefully than they do while using heroin. Even if some persons drive more carefully on heroin than on methadone, our data provides some evidence that the persons who drive poorly on heroin continue to drive poorly on methadone. While maintained on methadone our subjects were involved in accidents at a frequency which did not differ significantly from that of all Texas licensed drivers. This finding agrees with the findings of the two previous studies in New York. Those studies indicated that methadone patients have motor vehicle accidents with approximately the same frequency as that of comparison drivers. Fraser and associates [7] reported that psychornotor performance was not impaired during addiction to heroin, and Gordon [8] reported that reaction time was not impaired in subjects maintained on methadone. The results of these studies suggest that psychomotor skill required for driving would not be impaired by dependence on heroin or methadone. However, one daily oral dose of methadone does not maintain a completely smooth dependence, and some temporary sedation might reduce attention or concentration. Martin and associates [9] found that some sedative effect of methadone persisted through 15 weeks of chronic methadone administration. Although alcoholism among patients maintained on methadone has become a noteworthy problem [ 101, and one-fourth of our subjects were classified as problem drinkers, problem drinking apparently did not significantly affect their driving records. We know that some of our problem drinkers do their drinking in the evenings at home or at nearby taverns, and consequently do little or no driving while intoxicated.
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On the basis of this study we recommend no restriction of the driving privilege of persons maintained on methadone.
ACKNOWLEDCMENTS We gratefully acknowledge the assistance of Ruth Steinfeld, D. P. Desmond, Lillian Norton, Josefma Benito, J. R. Shelton, and W. J. Logsdon.
REFERENCES Crancer, A., and Quiring, D. L., Driving Records of Persons Arrested for Illegal Drug Use, Report No. 011, State of Washington, Department of Motor Vehicles, 1968. Babst, D. V., Inciardi, J. A,, Raeder, P. K., and Negri, D. B., Driving Records of Heroin Addicts, Research Report No. 1969-11, New York State Narcotic Addiction Control Commission and New York State Department of Motor Vehicles, December 1969. Blomberg, R. D., and Preusser, D. F., Drug Abuse and Driving Performance, Final Report DOTIHS-800754,Dunlap and Associates, Darien, Connecticut, 1972. Babst, D. V., Newman, S., Gordon, N. B., and Warner, A., Driving records of methadone maintenance patients in New York State, J. Drug Issues 3:285-292 (1973). Siegel, S., Nonparametric Statistics for the Behavioral Sciences, McGraw-Hill, New York, 1956, pp. 63-67. Motor Vehicle l’kaffic Accidents, 1972, Texas Department of Public Safety, Austin, Texas. Fraser, H. F., Jones, B. E., Rosenberg, D. E., and Thompson, A. K., Effects of addiction to intravenous heroin on patterns of physical activity in man, Clin. Pharmacol. Ther. 4:188-196 (1963). Gordon, N. B., Reaction-times of methadone treated ex-heroin addicts, Psychopharmacologia 16:337-344 (1970). Martin, W. R., Jasinski, D. R., Haertzen, C. A., Kay, D. C., Jones, B. E., Mansky, P. A., and Carpenter, R. W., Methadone-A reevaluation, Arch. Cen. PsychLtry 28~286-295(1973). Maddux, J. F., and Elliott, B., Problem drinkers among patients on methadone, Am. J. Drug Alcohol Abuse 2:245-254 (1975).
