Although definitive assessment of cost effectiveness may require long-term evidence from randomized trials, it is important to begin to estimate likely cost effectiveness early in the life cycle of new technologies . Such estimates can help prioritize internal development plans, indicate which parameters need further research and inform early adopters of the technology [1,2,3]. Single-use flexible video bronchoscopes is one such new technology in an area with limited evidence.
Bronchoscopes give healthcare professionals both visualization of and access to the affected tissue to investigate symptoms, confirm diagnoses or treat a patient. For instance, the instrument allows for visual orientation into an individual lobe or segment bronchi or allows for bronchoalveolar lavage. Estimates indicate 500,000 bronchoscopic procedures take place per year in the USA alone . Bronchoscopic procedures are common in clinical settings because they are generally recognized as safe . Complications associated with flexible bronchoscopy are usually minor and relate to procedure or sedation . Common complications include bleeding, pneumothorax and infection; however, other risks, such as sore throat, heart attack and fever, also exist [6,7,8].
A single-use flexible video bronchoscope would eliminate any given risk of cross-contamination. The decision as to whether or not a hospital should buy and implement the new and possibly better technology requires economical, ethical and clinical considerations. This study provides a health economic perspective on the issue by conducting a cost-effectiveness analysis (CEA) of single-use flexible video bronchoscopes and comparing this with reusable flexible video bronchoscopes when applied in a typical intensive care unit (ICU). ICUs are characterized by patients with generally low immune responses, and they often rely on mechanical ventilation, bypassing normal immune responses in the upper airways. This patient group is therefore particularly prone to infection. However, the risk of cross-contamination and infection is not well investigated. Given the limited clinical evidence, this study should be interpreted as an early assessment of the likely cost effectiveness of single-use flexible video bronchoscopes.
Reprocessing of Reusable Flexible Bronchoscopes
When a procedure is completed, the standard reusable flexible bronchoscope needs to be reprocessed prior to reuse. All parts of the reusable technology are reused. Flexible bronchoscopes initially receive manual cleaning (removing organic debris and microorganisms) at the site before being moved to a designated reprocessing work area for leak testing and possible automated cleaning. Depending on the device material, it undergoes either disinfection (the elimination of all microorganisms other than a small number of bacterial spores) or sterilization (the complete destruction of all forms of microbiological life) . When this reprocessing has been performed according to the approved labelling from the manufacturer, the flexible bronchoscopes are stored in an appropriate storage cabinet. Each flexible bronchoscope requires a specific reprocessing regime. This results in a range of different instructions on product labels, such as the varying use of detergents . Some healthcare facilities also use automated endoscope reprocessors (AERs) to implement a mechanical disinfection method. Since the bronchoscopes are in contact with mucous membranes and have a moderate degree of infection risk if contaminated at the time of use, they are categorized as semi-critical devices  and should therefore optimally be sterilized. However, the device materials do not always permit this reprocessing method. If the reusable bronchoscope is heat-labile, low-temperature reprocessing should be applied, such as high-level disinfection (HLD) . HLD procedures vary  but commonly involve the elimination of certain microorganisms to an acceptable extent. The US FDA maintains an updated list of approved sterilants and high-level disinfectants for this purpose .
Risks of Cross-Contamination and Post-Endoscopic Infection
The risk of adverse events due to inappropriate cleaning, disinfection or rinsing, or lack of leak testing and drying as a cause of cross-contamination is well described in the literature [13,14,15]. Some of these failures are associated with human error and some suggest additional or improved training as part of the solution . Yet some of these cases involving inadequate cleaning might be due to difficult conditions for personnel .
Biofilm formation is of special concern in reprocessing [18, 19]. A biofilm can be defined as a microbially derived sessile community characterized by cells that are irreversibly attached to a substratum, interface or each other and that are embedded in a matrix of extracellular polymeric substances that produce and exhibit an altered phenotype with respect to growth rate and gene transcription . The structure and physiological attributes of biofilms make microorganisms in biofilms, in contrast to a normal planktonic state, very resistant to antimicrobial agents, whether antibiotics, disinfectants or germicides .
Outbreaks of post-endoscopic infection and cross-contamination related to biofilm development inside endoscope channels and AERs have been reported in the literature [15, 21]. Biofilms can be removed from artificial surfaces by physical methods, e.g. thorough brushing of bronchoscope channels combined with chemical treatment . Unfortunately, because of the composition and nature of the flexible bronchoscope construction, it is difficult to consistently brush and clean properly [21,22,23]. This is particularly so when the bronchoscope is damaged [19, 24]. It is difficult to know whether the flexible bronchoscope is damaged [18, 21, 22, 24], and therefore a potential risk exists for bacterial colonization of cracks, grooves and pits.
The resistance of microorganisms in biofilms to decontamination is an issue of concern not only for the bronchoscopes but also for the AERs. If a contaminated reusable bronchoscope is introduced to an AER, it could allow the formation of biofilm in the AER itself. This AER could then contaminate the next, originally sterile, reusable bronchoscope being reprocessed, thereby acting as a source of contamination . In addition, bacterial spores are not necessarily eliminated by exposure to disinfectants . A few disinfectants, termed chemical sterilants, are able to kill bacterial spores after prolonged exposure (3–12 h) .
Although much effort is being put into reprocessing reusable bronchoscopes, reports are continually being published showing problems with cross-contamination despite strict adherence to reprocessing labelling instructions [15, 18]. Complications during these procedures are a reality in which clinicians work and to which patients are compelled to submit. Nonetheless, the risk of cross-contamination of a pathogen from one patient to another as a result of inadequate bronchoscope reprocessing might be preventable. However, research in this context is still sparse, and no direct quantified risk has been identified in the literature. In 2015 alone, the FDA published new guidelines for reprocessing, issued safety communications on bronchoscopes and AERs, required manufacturers to conduct post-marketing surveillance studies and sent warning letters to at least three major manufactures [26,27,28]. It is in the interests of patients, clinicians and suppliers in this industry to further investigate the reality. Until then, we are dealing with uncertainty.
In an effort to minimize this risk of cross-contamination, a range of alternative pathways could be taken, such as the use of single-use protective sheets, thorough and repetitive education of healthcare personnel or further development of reusable bronchoscope materials and AERs . Still, these methods of dealing with risk will only minimize, not eliminate, the uncertainty.