OSA-18生活品質問卷無法偵測兒童阻塞性睡眠呼吸中止症
作者：Fran Lowry
出處：WebMD醫學新聞
December 23, 2009 — 根據一項線上發表於12月21日兒科醫學期刊的新研究結果，OSA-18生活品質問卷無法準確偵測兒童阻塞性睡眠呼吸中止症，且不應該用於取代多重睡眠電圖。
來自加拿大魁北克Montreal兒童醫院的Evelyn Constantin醫師表示，多重睡眠電圖是目前擁有診斷兒童阻塞性睡眠呼吸中止最好的工具。然而，多重睡眠電圖相對不容易取得且費用昂貴，因此需要研究來評估其他診斷方法。曾有人提議OSA-18是個有用的工具，且可用於取代多重睡眠電圖。
在這項研究中，Constantin醫師想要確定OSA-18問卷是不是偵測中重度阻塞性睡眠呼吸中止症準確的方法，就如用於兒童的McGill氧氣飽和計分數一樣。
OSA-18是一個有18項問題的問卷，以李克特型式的計分系統，包括5項睡眠品質次項，分別是睡眠障礙、生理症狀、情緒症狀、日常功能以及照護者擔憂。分數可從18分，代表對生活品質無影響，到126分，代表有重大負面效應。分數超過60分以上被認為是異常。
Constantin醫師進行一項斷面性研究，使用包括334位年齡介於2~10歲的兒童資料，這些資料包括流行病學、醫療史、併存疾病、睡眠習慣、睡眠症狀、對OSA-18與氧氣飽和計的反應。所有兒童都在2005年4月到2006年3月之間接受在家過夜脈衝式氧氣飽和計的檢查。
她發現平均OSA-18分數為52.9±19.0分。整體看來，99位兒童的McGill氧氣飽和計分數異常，這些兒童中有40位OSA-18分數大於等於60分。OSA-18問卷的敏感度為40%。
在217位OSA分數低於60分的受試者，158位McGill氧氣飽和計分數並沒有結論，陰性預測值為73%。
Constantin醫師在將試驗族群分成類似數目的三組後，進行敏感度與陰性預測值的事後分析，這三組分別為2~3歲、4~5歲、與6~10歲。她報告這些年齡族群的敏感度與陰性預測值一樣不好。
作者們寫到，這項研究一個重要限制是使用夜間脈衝式氧氣飽和計作為參考基準。考慮準確評量如何改變OSA-18被判定比更敏感的方法：實驗室內，進行多重睡眠電圖，是很具有教育意義的。
她也附帶表示，包括大部分已經被耳鼻喉科醫師轉介的病患試驗族群，以及比較少部分的家醫科醫師與次專科醫師，因而被認為不能代表一般小兒病患族群。
Constantin醫師寫到，雖然OSA-18問卷並不能有效地偵測兒童中重度阻塞性睡眠呼吸中止症，這可能在決定這些狀況如何影響兒童生活與家庭環境上是有用的，且可能在描述確實無法僅由多重睡眠電圖偵測的面向上扮演角色。
這項研究發現應該讓依賴OSA兒童主觀檢驗的內科與外科醫師停下腳步來。她的結論是，由於取得多重睡眠電圖的困難，需要更多的研究來發展與確效簡化且正確偵測兒童OSA的方法。
Constantin醫師表示接受Fonds de la recherche en sante du Quebec、Montreal兒童醫院研究機構以及加拿大兒童健康臨床醫師科學計畫的獎學金。她目前由Fonds de la recherche en sante du Quebec研究職業獎助資助。
OSA-18 Quality-of-Life Questionnaire Does Not Detect Obstructive Sleep Apnea in Children
By Fran Lowry
Medscape Medical News
December 23, 2009 — The OSA-18 Quality-of-Life Questionnaire does not accurately detect obstructive sleep apnea in children and should not be used in place of polysomnography, according to new research published online December 21 in Pediatrics.
"Polysomnography is the best tool available for diagnosing obstructive sleep apnea...in children. However, polysomnography is relatively inaccessible and costly, and studies are needed to evaluate other diagnostic approaches," writes Evelyn Constantin, MD, from the Montreal Children's Hospital, Quebec, Canada. "It has been suggested that the [OSA-18] is a useful measure that could replace polysomnography."
In this study, Dr. Constantin sought to determine whether the OSA-18 questionnaire was an accurate measure for the detection of moderate to severe obstructive sleep apnea, as indicated by an abnormal McGill oximetry score, in children.
The OSA-18 is an 18-item questionnaire that uses a Likert-type scoring system that includes 5 subscales of sleep quality, including sleep disturbance, physical symptoms, emotional symptoms, daytime function, and caregiver concerns. Scores can range from 18, meaning no effect on quality of life, to 126, meaning major negative effect. A value of 60 or more is considered abnormal.
Dr. Constantin performed a cross-sectional study using a database that contained information on 334 children aged 2 to 10 years, including demographics, medical history, comorbidities, sleep habits, sleep symptoms, responses to questions from the OSA-18, and oximetry metrics. All children had been tested with overnight home pulse oximetry between April 2005 and March 2006.
She found that the mean OSA-18 score was 52.9 ± 19.0. In all, 99 children had an abnormal McGill oximetry score, and 40 of these children had an OSA-18 score equal to or greater than 60. The sensitivity of the OSA-18 was 40%.
Of the 217 participants who had an OSA-score less than 60, 158 had an inconclusive McGill oximetry score, which resulted in a negative predictive value of 73%.
Dr. Constantin also performed a posthoc analysis for sensitivity and negative predictive value after stratifying the study population into 3 age groups of similar size as follows: 2 to 3 years old, 4 to 5 years old, and 6 to 10 years old. She reports that the sensitivity and negative predictive value for each of these age groups were equally poor.
An important limitation to the study is the use of a nocturnal pulse oximetry–based test as the reference standard, the authors write. "It is instructive to consider how accuracy measures could have changed had the OSA-18 been judged against a more sensitive standard: in-laboratory, attended polysomnography."
She also adds that the study population consisted of patients who had been referred mostly by otolaryngologists and to a lesser extent by family physicians and subspecialists, and as a result cannot be considered to be representative of the general pediatric population.
Although the OSA-18 is not useful for detecting moderate-to-severe obstructive sleep apnea in children, it may useful in determining how the condition affects the child's life and the family environment and may play a role "in addressing dimensions that certainly cannot be addressed by polysomnography alone," Dr. Constantin writes.
The study findings should give pause to physicians and surgeons "who would rely on subjective testing for children with OSA. Because of the obstacles of obtaining polysomnography, additional studies are needed to develop and validate measures that would simply and accurately detect OSA in children," she concludes.
Dr. Constantin has reported that she was supported by a fellowship from the Fonds de la recherche en sante du Quebec, the Montreal Children's Hospital Research Institute, and the Canadian Child Health Clinician Scientist Program. She is currently funded by a research career award from the Fonds de la recherche en sante du Quebec.
Pediatrics. Published online December 21, 2009.
