## 10 Implications  
From a research perspective, studies are needed to improve the standardisation of methods used to diagnose OSA in practice through direct comparisons of tools used in different practice settings and a thorough evaluation of their value. Based on the results of these studies, it may be possible to streamline OSA diagnosis in practice, including outside of specialist sleep units, as appropriate, thereby reducing diagnostic costs [84].  
Further, super-simplified methods can be utilised, which rely on one or two channels (pulse oximetry and/or respiratory flow) and automatic analysis for interpretation. This method has been proposed as a useful diagnostic tool in primary care [45]. As an alternative to PSG for diagnosing OSA, respiratory polygraphy has been shown to be cost-effective [93], and should be considered as the first option for diagnosing OSA in patients with high pre-test probability (patients with referred symptoms of OSA and/or risk factors such as obesity, hypertension, and snoring).  
In addition, further research is required to determine the most effective approaches to improving PAP therapy adherence as well as to supporting PAP therapy withdrawal in patients with OSA. Nurse-led interventions should be considered specifically in this context, given the key role of nurses in the primary care management of OSA [92]. It is clear that nurses play an essential role in supporting adherence to PAP therapy, and more should be done to support nurses in this role by providing evidence-based strategies and facilitating primary care staff engagement with patients in the primary care settings. There should be nursing involvement in services devoted to OSA diagnosis, patient follow up, and educating patients about OSA [94].  
The use of telemedicine to facilitate follow-up in the community and to promote assessment of treatment efficacy provides nurses with the opportunity to guide care of patients with OSA in the community, thus reducing the need for specialist care [95]. E-health technology can be used by nurses to monitor and motivate patients with OSA through virtual educational programmes, visits, and remote monitoring; however, more research needs to be conducted to find out whether e-health technologies are cost-effective, whether patient education via e-health tools is effective, and whether patients accept receiving education and monitoring via e-health tools. Furthermore, research is necessary to support the role of nurses in caring for patients with OSA, including qualitative evaluations of barriers to care as well as quantitative evaluations of nurse-led care over the long- and medium-term, focusing on clinically significant outcomes [86].  
There are important implications for nurses working in both specialist and primary care settings as a result of the transition. Specialist services may benefit from nurse-led care and assessments as they become more standardised, and there is evidence supporting comparisons between nurse-led and physician-led care. In primary health care, nurses appear to be best positioned to provide effective patient follow-up and education, using diverse techniques such as telemedicine to facilitate patient assessment and prevent treatment escalation. It is necessary, however, to raise concerns regarding the global shortage of nurses as well as whether nurses are prepared to cope with the growing number of patients.