Summary of the main findings of included studies stratified by condition
| Prevalence | Crash association | Diagnostic/intervention strategies | Economic impact |
|---|---|---|---|
| Sleep disorders | |||
| ▸ Sleep disorder diagnoses were present in about 19.2% (n=2674); however. OSA constituted the main sleep disorder diagnosed in these studies ▸ Although the prevalence of sleep apnoea distribution differed between studies, yet higher prevalence was observed in commercial vehicle drivers than general populations, with and without associated risk factors ▸ Drivers with a reported history of hypertension were 2.5 times more likely to have OSA as compared with those with a normal blood pressure (OR 2.57 CI 1.67 to 3.96)25 Hypertension correlated with feeling tired or postsleep fatigue (p<0.05)26 | ▸ The presence of sleep disorders was found to increase risk of crashes ▸ Obesity with BMI≥25 is associated with a 14-fold increased risk of OSA (OR 13.64)41 and BMI≥30 had more than a 25-fold increased risk of OSA (OR 26.86).25 Obesity with BMI≥25 is associated with an increase of 2.5 times in sleep apnoea≥2 days/month (OR 2.53, CI 1.44 to 4.59) and correlated with snoring loudness (the louder the snoring, the greater likelihood of obesity; p<0.05)26 ▸ BMI in commercial drivers was found to be associated with increased risk of OSA (Spearman and Pearson correlation coefficients were 0.41 and 0.30 respectively)34 | ▸ The Berlin questionnaire predicted strong correlation between sleepy driving and the severity of snoring and witnessed apnoea, while witnessed apnoea had no correlation with BMI, gender or hypertension.26 ▸ 4% ODI4 revealed strong correlation with OSA severity (Spearman Rank 0.86 and Pearson correlation coefficients 0.95)34 ▸ MAP index had the 2nd strongest correlation with OSA severity after ODI4 (Spearman Rank and Pearson correlation coefficients were 0.59 and 0.53, respectively)44 ▸ CVHR using automated ECG might help screening moderate-to-severe SDB23 ▸ The Multivariable Apnoea Prediction Index showed poor agreement with the home-monitor detected sleep apnoea (AUC 0.58, 95% CI 0.49 to 0.62). only 12% of drivers reported daytime sleepiness (Epworth Sleepiness Scale score>10)22 | ▸ Gurubhagavatula et al51 estimated the cost of crashes involving commercial drivers to support screening and treatment of OSA, the total costs per driver of programmes arising from comprehensive screening, treatment of identified cases of OSA, and crashes varied based on treatment acceptance rates and stages of diagnosis screening—if treatment acceptance is 100%, then the total costs per driver are; do nothing: US$689; one-stage screening: US$562; two-stage screening: US$587 and with polysomnography US$920 |
| Diabetes mellitus | |||
| ▸ 16 138 drivers enrolled with 33.4% having a diagnosis of diabetes mellitus9 25 38 ▸ Prevalence rate of collisions or crashes at 25% ▸ Average BMI was 30.5±6 kg/m² ▸ In two studies,9 38 68% of total drivers with diabetes were on insulin and about 40% reported diabetes with complications | ▸ Truck drivers with diabetes were found to have more accidents than a control group (t-statistic 2.42, coefficient 0.84) ▸ Levels of severe hypoglycaemia requiring outside assistance that showed almost quadrupled relative risk of crash (OR=4.07, 95% CI 2.35 to 7.04)38 ▸ Crash risk increased in ST drivers group of uncomplicated patients of diabetes who were not using insulin when compared to a healthy cohort (RR 1.68, CI 1.27 to 2.24); but with none of the AT drivers group9 | ▸ Low HbA1c quartiles correlated with higher relative risk of adverse consequences and increased crashes risk in adults with diabetes mellitus (OR=1.27, 95% CI 1.04 to 1.55) after adjusting to confounders ▸ Levels of blood sugar, especially the diagnosis of severe hypoglycaemia was found with drivers with increased risk of accidents | ▸ NR |
| Hypertension | |||
| ▸ In 1000 commercial drivers in three studies, 23% had a hypertension diagnosis ▸ The mean age of drivers was 43, with a mean BMI≥30 kg/m² | ▸ Hypertension had no effect on crash rates6; however, Nadaeu et al in a follow-up study, the same authors found that bus drivers with hypertension were involved in more severe crashes in comparison to healthy bus drivers9 | ▸ Studies applied the DownShift program intervention to their population to examine the effect size31 44 ▸ 58% of 208 drivers were controlled to BP<140=90, compared to 38% at baseline (p<0.001)31 ▸ There were significantly fewer employees having uncontrolled blood pressure according to FMCSA guidelines (17.2%) than they had before DownShift program implementation (26.1%, p<0.01), even in drivers with other concomitant comorbidities44 | ▸ Greene et al40 studied the economic impact of the 2-year BP DownShift program and reported a 16.3% reduction in costs for a sample of 499 CDL employees over 2 years (pre-BP DownShift: US$3 312 220; post-BP DownShift: US$2 771 094). ▸ Cost savings to the utility company from implementation of the BP DownShift program for these 499 employees was US$541 126 over the 2 years or about US$271 000 annually |
| Alcohol or illicit drugs misuse | |||
| ▸ A total of 0.3% of surveyed commercial drivers was found to be positive for alcohol or drug levels24 32 ▸ Gjerde et al24 reported that levels of alcohol and drugs were lower among commercial drivers in comparison to non-commercial drivers | ▸ Riva et al32 reported no statistical significance between drug consumption and decreasing accidents or minimising the risk on public safety | ▸ Spicer et al47 the implementation of support and peer-focused substance abuse intervention programmes was found to help minimising workplace injuries ▸ The detection of a psychoactive substance in a sample from a truck driver compared with car or van driver was 0.29 (95% CI 0.17 to 0.53). The adjusted OR for the detection of an illegal drug was 0.42 (95% CI 0.18 to 0.82), and the adjusted OR for the detection of alcohol was 0.13 (95% CI 0.02 to 1.10)24 ▸ Employee alcohol-involved injury safety and prevention programmes are likely to be helpful to minimise employer fringe costs without reducing employees’ benefits45 | ▸ Zalonshnja et al45 found that the annual employer cost of motor vehicle crashes in which at least one driver was alcohol impaired was over US$9 billion, including wage-risk premiums; of this, only US$3.1 billion comes from job-related alcohol involvement and 30% of it was directed towards paying for legal liabilities ▸ The annual employer cost of alcohol-involved workplace violence-related injuries was more than US$8.5 billion, including wage-risk premiums; of this, more than 52% covered wage replacement costs and another 40% covered wage premiums |
| Obesity or BMI-related status | |||
| ▸ BMI of 25 kg/m² or greater was found in 78.4% of commercial drivers, and 45.2% had BMI≥30 kg/m² ▸ Obese drivers were more likely to have snoring loudness, and reported drowsy driving (p<0.05)26 | ▸ Wiegand et al7 found obese that drivers were at greater risk to be involved in safety-threatening event in comparison with non-obese drivers (OR 1.37; CI=1.19 to 2.18) | ▸ The obese drivers demonstrated signs of fatigue when involved in at-fault incidents (OR 1.99; CI 1.02 to 3.88) ▸ Body mass index (BMI) in commercial drivers was found to be associated with increased risk of OSA (Spearman and Pearson correlation coefficients were 0.41 and 0.30, respectively)34 ▸ Elevated BMI was found to be correlated with increased risk of sleep aponea.48 BMI≥25 associated with 14-fold increased risk of OSA (OR 13.64)41 BMI≥30 had more than a 25-fold increased risk of OSA (OR 26.86)25 | ▸ Martin et al42 found that in 2849 truckers had a mean annual total healthcare cost of US$1785. Unadjusted trimmed total cost for overweight participants (US$1613) and obese participants (US$1792) were significantly higher than for normal weight participants (US$1012; p<0.05) ▸ Adjusted total costs of obese and overweight participants had on average, US$591 (p=0.031) and US$383 (p=0.188) were than normal weight participants |
AT, articulated-truck; AUC, area under the curve; BMI, body mass index; CVHR, cyclic variation of heart rate; MAP, Mean arterial pressure; ODI, oxygen desaturation index; OSA, obstructive sleep apnoea; SDB, sleep-disordered breathing; ST, single-truck.