Clinical Research Directory

Validating a Novel Driving Simulation-based MWT Against the Standard MWT in an OSA-cohort Challenged by CPAP-withdrawal

In brief, the proposed study will evaluate a recently proposed naturalistic, driving simulation test to identify and measure sleepiness behind the wheel, one of the most underestimated causes of road accidents. The proposed test offers higher ecological validity and might complement somnological tests that are standard, but rarely performed. Thus, the test might provide traffic medicine and sonologists with an effective tool, that can also directly convey the risks of excessive daytime sleepiness to drivers and thus, in combination, effectively aid in traffic medicine's mandate to avoid preventable road fatalities. Excessive daytime sleepiness (EDS) is a symptomatic condition resulting from too little or compromised sleep, caused by psycho-social stress (shiftwork, lifestyle) or medical conditions (obstructive sleep apnoea (OSA), narcolepsy). Driving with untreated EDS might lead to sleepy/drowsy driving and microsleep, which is considered to be one of the highest-ranking causes of road accidents. Sleepiness and its dangers on the wheel might subjectively not be registered by the affected drivers. Also, subjective sleepiness might not correlate with somnological measurements that are also crucial for legally determining the fitness to drive (FTD). There exists a variety of partially complementary tools to evaluate the extent of EDS. Mean sleep latency obtained in the maintenance of wakefulness test (MWT) is widely, but not uniformly, considered to be one of the most objective measures to evaluate EDS, especially in the context of driving performance. However, there is inconsistent or insufficient evidence for MWTs to reliably predict the FTD in general, potentially as its result might be strongly influenced by motivation. Moreover, patients might not relate low mean MWT-latencies to their own and other's risks in traffic. A need for improved tools to measure EDS was formulated. It remains open, whether the MWT should be replaced or complemented by, for example, future road-side metabolomics-tests detecting sleepiness in traffic or whether the MWT should be adapted to better convey a.) the risks of EDS in traffic and b.) its meaning for the determination of the FTD. With this need in mind the investigators proposed furnishing the maintenance of wakefulness test with improved ecological validity to provide an improved tool for the assessment of the effect of excessive daytime sleepiness on the fitness to drive: recently published results from an exploratory feasibility study suggested it to be well possible to transfer the MWT-paradigm to a driving simulator (DS) with high user acceptance. The published result's implication and relevance was well received: the new test, DS-MWT, might complement somnological MWTs in pneumology and neurology. I might provide a naturalistic and relatable tool to determine EDS in traffic medicine, who is institutionally responsible for determining the FTD. This is also desirable, because prohibitively high cost - in time, money and instrumentation - often prevent a standard MWT in standard care of sleep-related medical conditions. Potentially, the use of the DS-MWT might help reduce the number of preventable road fatalities by more often identifying sleepy individuals before they get behind the wheel. However, for this goal to be achieve, it remains to be evaluated whether the latencies obtained in classical or simulation conditions are comparable and whether obtained latencies actually reflect other clinical parameters of EDS relating to underlying medical conditions, such as for example OSA. This represents a significant gap of evidence for both medical experts in pneumology and traffic medicine, but also for affected drivers. This gap will be filled by systematically comparing classical and simulation-based MWTs by means of their resulting latencies. In a within-study setup of 36 highly adherent OSA-patients, experiments will be related to a main medical comparator, a ≥7-day continuous positive airway pressure (CPAP)-withdrawal (W) and subsequent -resumption or continuation (C), respectively. There will be a control group of 18 healthy participants for comparison.

Exploring Parameters of Driving Simulation in Relation to Drug Holidays in ADHD Patients

Attention deficit hyperactivity disorder (ADHD) or syndrome (ADHS) is a symptomatically defined condition that - if untreated - is linked to a significantly increased risk of traffic accidents. In a recent umbrella review, where data from reviews and meta-analyses on 21.142.129 adults was assessed, a pooled prevalence of 3.1% of ADHD in adults was estimated. Considering that globally around 1.35 million people lose their lives and more than 50 million are suffering from injuries or disabilities due to road accidents, the fraction of car accidents caused by ADHD as a risk factor is considerable and needs to be addressed. This risk is largely presumed to be caused by an elevated level of inattentiveness in affected persons. Compounds of different groups, which can be classified in stimulants - formulations of methylphenidate and amphetamine - and non-stimulants - atomoxetin, guanfacine and clonidine -, have been shown to be effective in alleviating negative effects of ADHD, including inattentiveness. Under well-established but individually managed medication regimes, affected individuals can consequently lead a largely "unirritated" life and are not subject to fundamental restriction with respect to driving anymore. In children and adolescents, documented negative effects of stimulant medication include loss of appetite and decreased growth rates. It could however be shown that short-term interruptions (weekend, school holidays, and alike), introduced to alleviate aforementioned effects, do not affect the drug's beneficial effects in functional use (e.g., school). Such monitored medication breaks are often called "drug holidays" (D). They have become standard procedure in well-monitored treatment, predominantly including behavioral therapy. Based on own experience in childhood and or hearsay, also a fraction of affected adults under stimulant medication expresses the desire to take drug holidays and "be themselves" from time to time. With the predominant fraction of medication being fast acting drugs in extended-release formulation and typical patients being not only highly compliant but also extremely informed and adherent, these so-called "drug holidays" are reported an accepted in therapeutically accompanied settings of adults by now. However, while the overall positive effect of stimulant treatment on driving performance has been confirmed in a row of excellent on road- and/or simulation studies using integrated driving scores (IDS), so far there is no study available addressing the effect of drug holidays in adult drivers on driving performance. This represents a significant gap of evidence for both medical experts and affected. The proposed study will address this gap by exploring parameters of driving simulation in relation to drug holidays in ADHD patients.