The Quality, Readability, and Accuracy of the Information on Google About Cannabis and Driving: Quantitative Content Analysis

Background The public perception of driving under the influence of cannabis (DUIC) is not consistent with current evidence. The internet is an influential source of information available for people to find information about cannabis. Objective The purpose of this study was to assess the quality, readability, and accuracy of the information about DUIC found on the internet using the Google Canada search engine. Methods A quantitative content analysis of the top Google search web pages was conducted to analyze the information available to the public about DUIC. Google searches were performed using keywords, and the first 20 pages were selected. Web pages or web-based resources were eligible if they had text on cannabis and driving in English. We assessed (1) the quality of information using the Quality Evaluation Scoring Tool (QUEST) and the presence of the Health on the Net (HON) code; (2) the readability of information using the Gunning Fox Index (GFI), Flesch Reading Ease Scale (FRES), Flesch-Kincaid Grade Level (FKGL), and Simple Measure of Gobbledygook (SMOG) scores; and (3) the accuracy of information pertaining to the effects of cannabis consumption, prevalence of DUIC, DUIC effects on driving ability, risk of collision, and detection by law enforcement using an adapted version of the 5Cs website evaluation tool. Results A total of 82 web pages were included in the data analysis. The average QUEST score was 17.4 (SD 5.6) out of 28. The average readability scores were 9.7 (SD 2.3) for FKGL, 11.4 (SD 2.9) for GFI, 12.2 (SD 1.9) for SMOG index, and 49.9 (SD 12.3) for FRES. The readability scores demonstrated that 8 (9.8%) to 16 (19.5%) web pages were considered readable by the public. The accuracy results showed that of the web pages that presented information on each key topic, 96% (22/23) of them were accurate about the effects of cannabis consumption; 97% (30/31) were accurate about the prevalence of DUIC; 92% (49/53) were accurate about the DUIC effects on driving ability; 80% (41/51) were accurate about the risk of collision; and 71% (35/49) were accurate about detection by law enforcement. Conclusions Health organizations should consider health literacy of the public when creating content to help prevent misinterpretation and perpetuate prevailing misperceptions surrounding DUIC. Delivering high quality, readable, and accurate information in a way that is comprehensible to the public is needed to support informed decision-making.

effects; the route of administration determines how fast the effect begins and how long it lasts (smoke/vape is quicker to take effect, less duration; oral is slower to take effect, longer duration) • THC blood levels depend on the amount ingested or smoked, the concentration of THC in cannabis, the amount of body fat, and the extent of experience with cannabis [1] • Smoking/vaporizing: onset in 5-10 min; duration of effect 2-4 hours; peak 10-30 mins [2] • Oral: onset in 1-3 hours; duration of effect 6-8 hours; peak 2-4 hours [2] • Evidence suggests that regular cannabis users can develop tolerance to the impairment effects of cannabis [3]

Prevalence of Cannabis Use and Driving
The practice of driving after cannabis use is common; it is also common for people to ride as passengers in vehicles driven by cannabis users.
• In the past 12 months, 15% of individuals with a valid driver's license who use cannabis admitted driving within 2 hours of using cannabis [4].
• Cannabis use and driving were more prevalent among men than among women [4].
• Passengers are commonly found riding in a vehicle driven by someone who has used cannabis [5] • The prevalence of cannabis use among nighttime drivers is higher than that of alcohol [6].
• Many young Canadians do not necessarily perceive their driving ability as adversely affected by cannabis use; this may contribute to the prevalence of driving after cannabis use [6].

Effects of Cannabis on Driving Performances
Cognitive tasks, such as tracking, reaction time, visual function, concentration, short-term memory, response time, and divided attention, are negatively affected by cannabis, depending on the amount, strength, experience with cannabis, frequency, and experience of the driver; the impact is magnified by the combination of cannabis with alcohol or other drugs.
• A driver's ability to operate a vehicle safely is also adversely affected by cannabis use [7].
• It is likely that the extent of the adverse effects of cannabis use will depend on the amount of cannabis used, the strength, experience with cannabis, and frequency and experience of the driver [1].
• Increased variability in lateral position in the lane [8] • Impaired performance on divided attention tasks [9] • Produce greater variability in steering wheel adjustments [1] • In addition to greater variability in speed and following distance, cannabis-using drivers have a slower reaction time when sudden changes occur in the environment [1] • As a result of overestimating the degree of impairment due to cannabis, drivers may try to compensate by driving slower and leaving longer following distances [1] • As driving demands increase, impairment becomes increasingly evident [1] • Driving skills were negatively affected by cannabis and alcohol when combined [8]

Risk of Collision after Using Cannabis
Combined with alcohol and at high doses, cannabis can increase the risk of a crash; cannabis is the most common psychoactive substance found in deceased and injured drivers in Canada; cannabis-related fatalities and injuries are more prevalent among 16-34-year-olds.
• Among drivers involved in serious accidents, cannabis is frequently found [6].
• The risk of collisions has not increased significantly in some studies [10] • Researchers have also shown that low levels of cannabis use increase crash risk, and crash risk increases with dose [11][12][13].
• According to meta-analytic research, cannabis doubles the chances of being involved in a crash [14].
• There is a significantly increased risk of collision for drivers who consume cannabis and alcohol at the same time [11,15,16].
• In Canada, cannabis is among the most commonly found psychoactive substances among dead and injured drivers [17].
• In addition, young adults aged 16 -34 made up 59% of the cannabis-attributable injuries, as well as 68% of the cannabis-attributable property damage only (PDO) collisions [18].

Detection of Cannabis use by Impaired Drivers
Trained officers can accurately detect impairment by cannabis.
• Young people believe it is difficult for law enforcement officers to detect and charge drivers who are under the influence of cannabis [19,20].
• An officer trained in drug identification has a 95% accuracy rate in identifying the type of drug causing impairment [21].