## 1 Introduction  
Sleep-related breathing disorders (SRBDs) represent a series of disorders compromising the quality of life of patients, especially paediatric patients. They are characterised by habitual snoring and a series of daytime-related symptoms such as hyperactivity, drowsiness and poor school performance. Obstructive sleep apnoea syndrome (OSAS) is the most severe spectrum of SRBDs. It is characterised by repeated episodes of complete and/or partial and/or prolonged obstruction of the upper airways during sleep, normally associated with a reduction in blood oxygen saturation. Patients with breathing disorders related to obstructive sleep apnoea are considered to be at high-risk for other health complications such as obesity or being overweight, hypertension, and cardiovascular and metabolic diseases [1; 2]. To manage OSAS early, especially in order to reduce the psychological and functional complications related to these disorders, it is essential to adopt large-scale screening measures as effectively as possible. To this end, several paediatric screen questionnaires have been proposed. Sleep Clinical Record (SCR), OSA-18, Brouilette Score (BS), \"I'm sleep\", Sleeping Sleepless Sleepy Disturbed Rest (SSSDR) and Paediatric Sleep Questionnaire (PSQ) are several examples of the most widely used paediatric screening questionnaires [3; 4; 5; 6]. Among these, only SCR, in addition to the question-based survey, includes a fairly detailed physical examination of the child, attributing a diagnostic value to the tool [7]. For these reasons, it is considered the most complex and time-consuming diagnostic questionnaire, and it is not easy to use. Both OSA-18 and BS, because of their low sensitivity and specificity, have been poorly classified in the current guidelines of the European Respiratory Society Task Force [3]. \"I'm sleep\" has a relatively high sensitivity (82%), given the simplicity of the tool, while the specificity is equal to 50% [4]. SSSDR is a new survey that promotes greater knowledge of healthy sleep and helps in the early identification of different and widely defined sleep disorders, including obstructive SRBDs [5]. Due to its recent introduction into the international scientific community, it has not yet been included in the current guidelines of the European Respiratory Society Task Force. Finally, the Paediatric Sleep Questionnaire (PSQ) [6] has its sensitivity and specificity evaluated at 78% and 72%, respectively, with reliability at Class I and Class II, according to the classification of the American Academy of Neurology (AAN) [1]. The 22-item questionnaire can be filled in easily by the parents of subjects aged between 2 and 18 using only the answers \"yes\", \"no\", and \"I do not know\". The questionnaire, divided into 10 sections, investigates different aspects of the quality of the sleep, from snoring to diurnal and nocturnal behavioural habits. A very recent and helpful comparison of the questionnaires used in the screening of obstructive SRBD in children was performed by [PERSON] et al. [5] in order to help in the choice of the best tool for early identification and management of patients' conditions. As reported by the authors, in the current guidelines of the European Respiratory Society Task Force, PSQ is defined as a \"useful tool\" to predict OSAS, with an apnoea-hypopnea index (AHI) of \(>\)5, detecting the neurobehavioral consequences associated with OSAS and/or evaluating their regression after adenotosillectomy, which is considered the first choice for OSAS treatment in children [5]. For these reasons, it is one of the most used and validated screening tools, appearing at least as effective as or better than PSG (polysomnography) [1; 5; 6]. The inclusion of PSQ in the European guidelines and its use in many literature articles that have translated and rewritten the questions in different languages has made PSQ the most suitable questionnaire in the last twenty years, according to the literature [8; 9; 10].