Respondent characteristics are shown in Table 1. The mean age of the respondents was 49.45 (±16.41) years. There were 275 respondents (22.9%) with a history of medication side effects such as sleepiness, lightheadedness, and dizziness, and 925 respondents (77.1%) with no history of side effects. There were 207 respondents (17.3%) who drove for work and 993 respondents (82.7%) who did not.
Awareness regarding medications
When asked what medication(s) they were taking, 179 (14.9%) respondents answered, “Do not know.” The remaining 1021 respondents entered the name of the medication(s) they were taking.
Groups listed according to medication impact on their driving
The risk when driving a car is high, and groups were classified into those who take medicines that prohibit driving (n = 370, 30.8%), those whose medications do not prohibit driving (n = 650, 54.2%), and those taking unknown medications or who gave inaccurate medicine descriptions (n = 180, 15%).
Therapeutic classes of medications taken by all respondents
Medications were extracted from those being taken by all respondents. These medications are shown in Fig. 2, grouped by therapeutic class.
The most commonly taken medicines by respondents were for the cardiovascular system (n = 506) and the central nervous system (n = 505).
Classes of Medications Taken by Respondents that Prohibit Driving.
Figure 3 shows the classification of medicines based on their high risk on driving and the frequency of medication.
The most common class was neuropsychiatric medications, which are prescribed for conditions such as schizophrenia (151 responses), followed by sedatives and anxiolytics (145 responses) and antiepileptic medications (40 responses).
Awareness regarding effects of medication on driving
Participants’ awareness of the effects of medication on driving is shown in Table 2.
The effects of medication on driving were recognized by 81.8% of the respondents. The degree of awareness regarding the effects of medication on driving was significantly higher among respondents taking medications that prohibit driving than among respondents taking medications that did not prohibit driving or those taking unknown medications (p < 0.01). There was also a link between health literacy and awareness of the impact of medicines on driving impairment (r = 0.172; p < 0.01).
Warnings provided by healthcare professionals to respondents taking medications that prohibit driving
Table 3 shows the content of warnings provided by healthcare professionals to respondents taking medications that prohibit driving. Among respondents taking medications that prohibit driving, 65.5% were warned about the effect on driving by a healthcare professional, 25.7% were not, and 8.8% did not know or could not recall whether they had received a warning. More than a quarter of the respondents stated that they are inexperienced or did not understand the associated risks and concerns.
Multiple responses were permitted because respondents may have used multiple pharmacies. The most common warning to prohibit driving was to “practice caution while driving,” which was received by 33.2% of respondents, followed by 29.4% who were warned to “refrain from driving” and 19.8% who were warned to “avoid driving”; as can be seen, these messages are euphemistic and rather unclear expressions. Meanwhile, only 16.0% were given direct messages not to drive.
Respondents taking medications that prohibit driving: medication-taking and driving behavior after being warned
The medication-taking and driving behaviors of respondents taking medications that prohibit driving after being warned are shown in Table 4.
The results indicated that 22.0% of the respondents stopped taking the medication, reduced the dose, adjusted the frequency of the medication, or made some other adjustment at their discretion; moreover, 39.5% of respondents maintained treatment compliance according to physicians’ instructions but continued driving. In contrast, 25.2% of respondents took medication and stopped driving according to a physician’s instructions, and 11.4% consulted a physician, pharmacist, nurse, or another healthcare professional.
The relationship between the classification of the efficacy of prohibited medicines and medication driving behavior is shown in Table 5.
Consultation with a healthcare professional, medication, and not driving according to physicians’ instructions were all defined as positive behaviors adopted after being warned, regardless of the type of prohibited medicines.
The data revealed the following. Fewer than half of the respondents were taking what they considered to be the correct response regardless of the type of prohibited medication. Antiepileptic drugs had the highest percentage of positive behaviors at 40%, while antipyretic analgesics and anti-inflammatory drugs had the lowest percentage of positive behaviors at 21.4%. Antihistamines had the highest rate of self-decisional discontinuation at 23.1%.
Dose adjustment was 0% for antiepileptic drugs and antipyretic analgesics. The highest rate of spacing of doses was 11% for hypnotic sedatives/anxiolytics. The rate of “take as directed by healthcare professionals but continue driving” was very high for antipyretic analgesics and anti-inflammatory drugs (64.3%). Almost the same number of respondents in the other drug groups as the response considered correct also indicated that they would take the medication as directed by the physician but would continue driving.
This could be because accidents caused by epilepsy patients have been reported and medical professionals are highly aware of the effects of car-driving accidents on patients with epileptic seizures.
This indicates poor communication of medicine-related risks by healthcare workers. In addition, there is a possibility that providing information on driving prohibition using ambiguous expressions from several health professionals may mislead patients’ judgments. It was shown that patients’ understanding of driving bans was inadequate and they often dealt with it on the basis of their judgment in most cases.
Respondents taking medications that prohibit driving: analysis of factors affecting driving and medication-taking behavior (logistic regression analysis)
The results of the analysis of factors affecting driving and medication-taking behavior among respondents taking medications that prohibit driving (logistic regression analysis) are shown in Table 6.
Our analysis of the respondents’ positive behaviors revealed no association with age, sex, history of side effects, health literacy, educational history, or number of medications. There was a significant association between negative behavior and the need to drive for work.
Further, participants explained the reasons for continuing to drive after taking medications despite being warned. First, they believed that despite being drowsy, they would not cause an accident. Second, they were unaware of the extent to which the medicines they are taking affect their ability to drive.