Elsevier

Sleep Medicine Reviews

Volume 15, Issue 5, October 2011, Pages 301-310
Sleep Medicine Reviews

Clinical Review
Nasal continuous positive airway pressure (nCPAP) treatment for obstructive sleep apnea, road traffic accidents and driving simulator performance: A meta-analysis

https://doi.org/10.1016/j.smrv.2010.10.002Get rights and content

Summary

We used meta-analysis to synthesize current evidence regarding the effect of nasal continuous positive airway pressure (nCPAP) on road traffic accidents in patients with obstructive sleep apnea (OSA) as well as on their performance in driving simulator. The primary outcomes were real accidents, near miss accidents, and accident-related events in the driving simulator. Pooled odds ratios (ORs), incidence rate ratios (IRRs) and standardized mean differences (SMDs) were appropriately calculated through fixed or random effects models after assessing between-study heterogeneity. Furthermore, risk differences (RDs) and numbers needed to treat (NNTs) were estimated for real and near miss accidents. Meta-regression analysis was performed to examine the effect of moderator variables and publication bias was also evaluated. Ten studies on real accidents (1221 patients), five studies on near miss accidents (769 patients) and six studies on the performance in driving simulator (110 patients) were included. A statistically significant reduction in real accidents (OR = 0.21, 95% CI = 0.12–0.35, random effects model; IRR = 0.45, 95% CI = 0.34–0.59, fixed effects model) and near miss accidents (OR = 0.09, 95% CI = 0.04–0.21, random effects model; IRR = 0.23, 95% CI = 0.08–0.67, random effects model) was observed. Likewise, a significant reduction in accident-related events was observed in the driving simulator (SMD = −1.20, 95% CI = −1.75 to −0.64, random effects). The RD for real accidents was −0.22 (95% CI = −0.32 to −0.13, random effects), with NNT equal to five patients (95% CI = 3–8), whereas for near miss accidents the RD was −0.47 (95% CI = −0.69 to −0.25, random effects), with NNT equal to two patients (95% CI = 1–4). For near miss accidents, meta-regression analysis suggested that nCPAP seemed more effective among patients entering the studies with higher baseline accident rates. In conclusion, all three meta-analyses demonstrated a sizeable protective effect of nCPAP on road traffic accidents, both in real life and virtual environment.

Introduction

Obstructive sleep apnea (OSA) is a common chronic disorder that affects approximately 20% of the general population if defined as an apneae hypopnea index (AHI) ≥ 5 events/h, or 2–9% if defined as an AHI ≥ 5 events/h accompanied by at least one symptom that is known to respond to treatment, such as daytime sleepiness.*1, *2, 3 The high prevalence rates are disturbing taking under consideration that OSA patients have an increased risk of morbidity and mortality, particularly due to cardiovascular disease or involvement in road traffic accidents. Indeed, OSA patients are often sleepy during daytime causing traffic accidents and work injuries.*4, 5 If left untreated, OSA leads to excessive daytime sleepiness, cognitive dysfunction, impaired work performance, and decrements in quality of life.6

Many treatment modalities have been proposed for the treatment of OSA including dietary and lifestyle management, pharmacological agents, oral appliance devices and surgical interventions (nasal reconstruction, various uvulopalatopharyngo-glossoplasty techniques, maxillomandibular manipulations, and tracheotomy). Despite the variety of alternative choices, nasal continuous positive airway pressure (nCPAP) device remains the gold standard of treatment.*1, *7 It is indicated for mild to severe OSA patients, and it has proved to be efficient in improving symptoms and reducing the severity of a pleiad of medical conditions related to upper airway obstruction during sleep.8

The purpose of this meta-analysis is to estimate the extent to which nCPAP treatment affects real and near miss road traffic accident rates in OSA patients, as well as the extent to which nCPAP affects their performance in driving simulator. We also sought to estimate the number needed to treat (NNT) to avoid road traffic accidents.

Section snippets

Data collection

The present meta-analysis was conducted in accordance to the “preferred reporting items for systematic reviews and meta-analyses” (PRISMA) guidelines.9 A combined computerized and manual systematic database search of medical literature was performed and the respective publications were retrieved from electronic search engines (Medline, Embase, Scopus, Google Scholar, Ovid and the Cochrane Library). “Bibliosleep”, a subject specific electronic database including sleep and sleep-related

Results

As shown in the flow diagram (Fig. 1), after extraction and review of the abstracts, 19 articles were eventually deemed eligible out of a total of 549 potentially relevant articles of interest; out of these, in the subsequent detailed evaluation, three were found to have been performed on mutually overlapping populations20, 21, 22 and were therefore, also excluded. A fourth article was by necessity excluded, as no distinction was made between real and near miss accidents and the corresponding

Discussion

In the current meta-analysis comprising of 1221 OSA subjects, the application of nCPAP treatment was associated with an estimated statistically significant 55% reduction of the reporting involvement in real accidents within a specified time period (IRR = 0.45). A comparable, sizeable finding emerged for the reduction of near miss accidents (IRR = 0.23). More importantly, it has been estimated for the first time that five and two OSA patients should be treated with nCPAP to prevent one patient

Conclusion

In conclusion, this meta-analysis provides support to nCPAP treatment as a highly effective and cost-effective intervention for the prevention of road traffic accidents among OSA patients, whereas it also portrays the driving simulator as a useful tool for assessing the improvement in driving before an OSA patient is involved in real driving situations.

Practice points

  • 1)

    A growing body of evidence supports the efficacy of nCPAP treatment in a) reducing real and near miss accidents and b) improving

Acknowledgment

The study was partially supported by the National and Kapodistrian University of Athens. The authors would like to thank Nick Dessypris for the statistical comments and remarks on the manuscript. We would also like to thank Theodoros Michelakos for his remarks on the text.

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