In this study, the CHASE-OSA score was developed to predict moderate-to-severe pediatric OSA using a large dataset from our sleep-study center. The score incorporates key clinical predictors, primarily based on anatomical and functional abnormalities that predispose children to OSA, including age 1–5 years, upper airway phenotypes with craniofacial abnormalities, adenotonsillar hypertrophy, and obesity. OSA-related symptoms such as snoring more than 5 nights/week, stopping breathing or awakening during sleep, and excessive daytime sleepiness were also included. Our findings demonstrate that the CHASE-OSA score has good predictive ability, with internal validation showing potential for accurately identification of moderate-to-severe OSA.

Unlike mild OSA, children with moderate and severe OSA are at higher risk of multi-organ morbidity, are less likely to recover without treatment, and are more likely to require prolonged supplemental oxygen, experience respiratory complications, and need extended postoperative monitoring following surgery [2, 3, 21]. Therefore, all children suspected of having the condition should be screened [22]. Due to the limited availability of PSG, questionnaire-based screening tools should be utilized [1]. To maximize the identification of true cases, the screening tool should prioritize the detection of moderate-to-severe OSA rather than excluding it. An effective screening test should have a high level of sensitivity to detect most cases of moderate-to-severe OSA, along with a high negative predictive value (NPV) to ensure that a negative result reliably indicates the absence of the condition [7].

Various screening methods and questionnaires for the prediction of pediatric OSA severity exist but are limited. A recent meta-analysis compared the sensitivity and specificity of the PSQ (22-item parent questionnaire) and the OSA-18 (18-item quality-of-life assessment completed by parents) for the prediction of pediatric OSA [7]. For moderate and severe OSA, the PSQ showed higher sensitivity (82% and 89%) compared to the OSA-18 (69% for both), but both tools had low specificity: PSQ (43% and 26%) and OSA-18 (33% and 53%) [7]. Therefore, the PSQ may be the most effective questionnaire-based tool to triage children with moderate and severe OSA. However, its 22-item format, typically completed by parents, can be time-consuming and burdensome, especially in a busy or urgent settings [8].

Several short-form questionnaires have been developed to provide simple, quick, and accurate screening for moderate-to-severe OSA. The Sleep Clinical Record (SCR), which combines OSA-related symptoms, physical exams, and hyperactivity/attention deficit, is endorsed by the European Respiratory Society with a cutoff score of ≥ 6.5 for diagnosis of pediatric OSA [2]. In a study of 273 children aged 2–16 years, with a 17% prevalence of moderate-to-severe OSA, an SCR cutoff of 8.25 (AuROC = 0.81) predicted moderate-to-severe OSA with 83% sensitivity, 95% NPV, 70% specificity, and 36% positive predictive value (PPV) [4]. Soh et al. [23] developed a 5-question tool (OSA-5), derived from the OSA-18 questionnaire, using retrospective data from 368 children. The tool predicted moderate-to-severe OSA, with 17.4% of children diagnosed, resulting in high sensitivity (88%) and NPV (88%) but low specificity (44%) and PPV (42%). In a subsequent external validation of 123 children, with 29.5% diagnosed with moderate-to-severe OSA, the OSA-5 showed high sensitivity (82%) and NPV (81%), though specificity and PPV remained low [23]. Both SCR and OSA-5 show potential as screening tools for moderate-to-severe OSA; however, the low prevalence of the condition in these studies may limit their generalizability. Additionally, the need for multi-domain evaluations and sub-score calculations may reduce the practicality of SCR in clinical settings.

In 2016, Raman et al. [24] developed a six-item questionnaire, adapted from the SRBD scale component of the PSQ, to predict moderate-to-severe OSA. In a study of 636 children aged 6–16 years, the tool demonstrated high sensitivity (85.7%) but low specificity (51.3%) with a cutoff score of 2/5 (AuROC = 0.74), predicting moderate-to-severe OSA in 55.9% of cases [24]. They suggested it may be useful for preoperative risk stratification. However, its applicability may be limited by its restriction to children aged ≥ 6 years, affecting its generalizability.

The CHASE-OSA score is a practical and effective tool for distinguishing between normal to mild and moderate-to-severe OSA for children aged 1–18, based on key elements of medical history and physical examination findings related to OSA severity. The score ranges from 0 to 14 and includes three cutoff points, each offering different levels of sensitivity and specificity to accommodate various clinical contexts. Higher scores indicate a greater likelihood of moderate-to-severe OSA. All CHASE-OSA cutoff points demonstrated high sensitivity for predicting moderate-to-severe OSA, similar to the PSQ [7]. A cutoff of ≥ 5 provides high sensitivity and NPV but lower specificity, making it suitable for hospitals with ample resources and easy access to PSG. For prioritization of true positive cases, a cutoff of ≥ 7 is ideal, as it increases specificity, which is advantageous in resource-limited environments where PSG is harder to obtain. With a cutoff of ≥ 6, the CHASE-OSA score shows robust diagnostic performance, achieving a sensitivity of 85.8%, specificity of 69.9%, PPV of 85.0%, and NPV of 71.3%. These metrics reflect a reliable overall accuracy compared to other commonly used screening tools [4, 7, 23, 24]. This cutoff point may be particularly useful in settings where overnight sleep tests are costly or unavailable.

Our study suggests that the CHASE-OSA score offers wide potential benefits in clinical practice. For children with a high CHASE-OSA score, a comprehensive evaluation for OSA, including consultation with a pediatrician or otolaryngologist, is recommended. Expedited referral to a sleep physician for PSG and further management is advised. In emergency surgical cases, anesthesiologists should be alerted to the potential complications and ensure appropriate preoperative preparation, intraoperative management, and postoperative care planning [21]. For elective surgery, an overnight sleep study is recommended to confirm the diagnosis and optimize perioperative care. The CHASE-OSA score also helps educate parents about the associated risks and available treatment options. Children with a low CHASE-OSA score should have regular follow-up assessments to monitor OSA symptoms. Promoting a healthy lifestyle and addressing underlying conditions, such as obesity and allergies, may reduce the risk of developing OSA. If symptoms persist, referral to a sleep specialist remains recommended.

The CHASE-OSA score could streamline clinical workflows with its straightforward calculation and minimal training requirements, enabling rapid risk stratification and likely encouraging high provider adoption. By efficiently identifying high-risk cases, CHASE-OSA could reduce PSG wait times (typically three to eight months at our center), supporting improved perioperative planning and long-term outcomes. In our country, access to sleep studies is often limited by high costs (PSG: USD 200–250; nocturnal pulse oximetry: USD 100–150) and specialist scarcity. Implementing the CHASE-OSA score could offer economic advantages by reducing both institutional and patient expenses. Patients may save up to USD 300 per visit in travel and accommodation costs, while healthcare providers could reduce unnecessary studies and optimize resource allocation.

This study had several limitations. First, there was potential selection bias in including children with snoring symptoms from retrospective data, which may have contributed to the high prevalence of OSA observed. However, this limitation is mitigated by the large sample size, which helps offset the bias and strengthens the reliability of the findings. Second, OSA severity was assessed using two non-overlapping diagnostic methods, PSG, and nocturnal pulse oximetry, which are not directly comparable [25]. Nevertheless, nocturnal pulse oximetry has proven to be a reliable alternative with a 97% PPV for the detection of pediatric OSA [26]. Given the limitations of our resources and the need to include children unsuitable for PSG, nocturnal pulse oximetry provided practical benefits [18, 27]. To unify the results, we employed multivariable regression analysis, allowing us to control for confounding factors and assess independent predictors of moderate and severe OSA across both diagnostic methods. Finally, although the CHASE-OSA score has undergone internal validation, future studies are needed for external validation to confirm its accuracy and applicability across diverse populations.