## 5 Role of Nurses in the Diagnosis of Obstructive Sleep Apnoea  
Comprehensive patient history and the use of validated questionnaires: according to [PERSON] et al. (2016), it is imperative to begin OSA management and diagnosis in a primary care setting [43]. It is likely that nurses will screen the patients as they are the first point of contact within the healthcare system. The use of screening tools can reduce OSA-related mortality and morbidity rates. However, screening has several challenges, such as the lack of knowledge regarding how to identify OSA, the best OSA screening tool, how to diagnose OSA, and follow-up procedures for patients who are diagnosed with OSA in different settings [68]. It has been indicated that inadequate training and knowledge of OSA screening tools is a barrier to OSA screening in primary care settings [68]. As a result of the study, it was determined that nurses and primary care physicians would benefit from additional training about OSA detection and its impact on health [68]. The development of a number of OSA screening measures has been designed to facilitate the quick screening of patients for OSA either in hospital or primary care settings [68]. The use of sensitive and specific screening measures provides a cost-effective method of detecting OSA and determining whether to refer the patient to a sleep specialist [68].  
The studies have demonstrated that the screening tools are effective in detecting OSA among high-risk patients. Primary care nurses and physicians have received training on OSA risk factors, symptoms, associated comorbidities, and treatment options, as well as using screening tools to ensure early diagnosis. Studies have shown that nurses employed a variety of screening tools/questionnaires in primary care settings as well as in sleep units including STOP-BANG [43], five-dimensions questionnaire (EQ-5D) [38; 42], the SF-36 questionnaires [62; 63; 67] and the Epworth Sleepiness Scale [38; 42; 43; 62; 63; 67; 69]. A more comprehensive sleep history should be taken as soon as possible after a positive OSA screening or when the physician determines that further evaluation is necessary. In addition to the body mass index (BMI) and neck circumference, blood pressure is a measure of health that falls under the responsibility of nurses [68].  
Facilitating the OSA diagnostic tests/sleep studies: It is generally acknowledged that PSG is the gold standard method for diagnosing OSA, although it must often be carried out in a controlled, specialist setting [64]. Indeed, PSG is an intricate and technical procedure that may be difficult to perform outside of specialised sleep units, which might prohibit its use in primary care or other settings. Therefore, suspected OSA patients may experience long wait times before being diagnosed and able to receive medical therapy [43].  
In recent years, HSAT has become increasingly popular, as it provides a cost-effective and effective diagnostic tool, especially when combined with electroencephalography (EEG) readings [64]. It may be beneficial to refine algorithms using HSAT with or without EEG readings in order to facilitate simple and effective diagnosis of OSA, thus preventing the need for PSG and costly assessments in sleep clinics [64]. Home respiratory polygraphy (HRP) is a simplified, portable monitor that measures air flow, respiratory efforts, pulse oximmetry, and body position. Furthermore, HRP has been shown to be a cost-effectivealternative for detecting OSA especially in patients with high pre-test OSA suspicion [43]. It has been concluded, however, that some diagnostic procedures are difficult to carry out in primary care, but other procedures may be considered in patients without OSA comorbidities [43]. A further consideration has been that all levels of medical care must be involved. There must be coordination and collaboration between the healthcare team in primary care (i.e., nurses, physicians) as well as the healthcare team in sleep units [43].