Among 110 resident physicians, 69 (62.8 %) residents were junior and 41 (37.2%) residents were senior. Fifty percent of junior residents and 51.2 % of senior residents were female. The mean age of junior residents was 28.7 years with standard deviation of 2.4 and the mean age of senior residents was 29 with standard deviation of 2.9 (table 1). Descriptive statistics was done for the individual questions of OSAKA (table 2) and OSAKA-KIDS (table 3). Cronbach alpha for junior and senior residents were 0.42 and 0.72, respectively for OSAKA, and 0.38 and 0.76, respectively for OSAKA-KIDS.
Knowledge part of OSAKA and OSAKA-KIDS
The questions with less than 50% correct answer among the juniors were "Uvulopalatopharyngoplasty is curative for majority of the patients" (40%), "treatment with continuous positive airway pressure (CPAP) can result in nasal congestion" (25%), "Alcohol at bedtime improves obstructive sleep apnea" (46%), "obstructive sleep apnea is more common in women than men" (27%), and "less than 5 apnea/hypopnea is normal in adults " (49%) in OSAKA, and "about 10% of children snore at a regular basis" (45%), "severity of snoring correlates with severity of obstructive sleep apnea in children" (32%), "children younger than 2 years should have polysomnography prior to obstructive sleep apnea surgery" (45%), and "cardiorespiratory monitor can reliably detect central and obstructive apnea in infants" (17%) in OSAKA-KIDS.
The questions with less than 70% correct answer among the seniors were "treatment with CPAP can result in nasal congestion" (34%), "The most common cause of obstructive sleep apnea in children is the presence of large tonsil and adenoid" (53%), "Alcohol at bedtime improves obstructive sleep apnea" (61%), "collar size 43 cm or more in men is associated with obstructive sleep apnea" (58%), "obstructive sleep apnea is more common in women than men" (56%), and "less than 5 apnea/hypopnea is normal in adults" (63%) in OSAKA, and "about 10% of children snore at a regular basis" (51%), "about 2% of children have obstructive sleep apnea" (49%), "Polysomnogram is needed to differentiate primary snoring from obstructive sleep apnea syndrome in children" (68%), "severity of snoring correlates with severity of obstructive sleep apnea in children" (61%), "excessive upper airway muscle tone loss during sleep contributes to obstructive sleep apnea in children" (58%), "snoring is most frequently reported at ages 2-8 years" (56%), "cardiac arrhythmia may be associated with untreated obstructive sleep apnea" (66%), "children with sickle cell disease are at increased risk of obstructive sleep apnea" (29%), "children younger than 2 years should have polysomnography prior to obstructive sleep apnea surgery" (34%), "significant OSA can occur without snoring in children" (63%), and " cardiorespiratory monitor can reliably detect central and obstructive apnea in infants" (44%) in OSAKA-KIDS.
Inferentially, significant difference was found between junior and senior residents in correct answering of the following questions based on Pearson chi-square test: For OSAKA, "uvulopharyngoplasty surgery is curable for most of the patients" (P <0.001; better answer in the seniors), "overnight sleep study is the diagnostic gold standard of obstructive sleep apnea" (P =0.047; better answer in the seniors), "loosing of tonicity of upper airway muscles during sleep helps formation of obstructive sleep apnea" (P =0.004; better answer in the seniors), "enlarged palatine tonsil and enlarge adenoid are the most prevalent reasons of obstructive sleep apnea in children" (P =0.032; better answer in the seniors), "examination of pharynx, facial bones and cranial bones is useful in a patient suspected to obstructive sleep apnea", (P =0.032; better answer in the seniors), "lack of treatment of obstructive sleep apnea is associated with increased driving accidents" (P =0.008; better answer in the seniors), and "obstructive sleep apnea is more common in women than men" (P =0.003; better answer in the seniors) (table 2); for OSAKA-KIDS, "about 2% of children have obstructive sleep apnea" (P =0.018; better answer in the juniors), "severity of snoring is correlated with severity of obstructive sleep apnea in children" (P =0.003; better answer in the seniors), "children with sickle cell anemia have more risk of obstructive sleep apnea" (P =0.028; better answer in the juniors), and "cardiopulmonary monitoring can confidently detect central and obstructive apnea in infants" (P =0.003; better answer in the seniors) (table 3).
Attitude part of OSAKA and OSAKA-KIDS
In the following cases, for OSAKA, attitude of the juniors and the seniors were different based on Pearson chi-square test in 2 by 5 tables: "obstructive sleep apnea from the viewpoint of a clinical disease" (P =0.004), "Identifying patients with possible obstructive sleep apnea" (P =0.002), "I have enough self-confidence to find a patient who is at risk of obstructive sleep apnea" (P =0.001), and "I have enough ability to be involved with patients with obstructive sleep apnea" (P =0.003). No significant difference was observed for "I have enough ability to treat the patients with CPAP" (P =0.290). In the following cases, for OSAKA-KIDS, attitude of the juniors and the seniors were different based on Pearson chi-square test in 2 by 5 tables: "obstructive sleep apnea from the viewpoint of a clinical disease" (P =0.002), "finding the diseases resulting in obstructive sleep apnea" (P =0.002), "I have enough self-confidence to find a patient who is at risk of obstructive sleep apnea" (P =0.003), and "I have enough ability to be involved with patients with obstructive sleep apnea" (P =0.002). No significant difference was observed for "I have enough ability to treat the patients with CPAP" (P =0.051) (table 4).
Total score of knowledge and its association with attitude
Total score of knowledge was compared between the juniors and the seniors. Senior residents had significantly higher total knowledge score for OSAKA based on independent t test (12.73±3.13 VS 10.52±2.63; P <0.001) (table 2). No significant difference was observed for OSAKA-KIDS (11.31±3.59 VS 10.69±2.49; P =0.288) (table 3). Association of total score of knowledge with attitude status was analyzed using Kruskal Wallis test. According to this, for OSAKA, total knowledge score was associated with attitude from the viewpoint of clinical importance of sleep apnea in both junior (P =0.025) and senior (P =0.003) residents, total knowledge score was associated with attitude from the viewpoint of clinical importance of finding patients with obstructive sleep apnea in both junior (P =0.006) and senior (P =0.034) residents, total knowledge score was associated with self-attitude to ability of finding patients with obstructive sleep apnea in both junior (P <0.001) and senior (P =0.001) residents, total knowledge score was associated with self-attitude to ability to be involved with patients with obstructive sleep apnea in junior (P =0.028) residents however not in the seniors (P =0.052), and no significant association was observed for self-attitude to ability to treat the patients with CPAP in junior (P =0.141) and senior (P =0.139) residents. For OSAKA-KIDS, total knowledge score was associated with attitude from the viewpoint of clinical importance of sleep apnea in senior (P =0.029) but not in junior (P =0.290) residents, total knowledge score was associated with attitude from the viewpoint of clinical importance of finding patients with obstructive sleep apnea in senior (P =0.013) but not in junior (P =0.216) residents, no significant association was observed for self-attitude to ability of finding patients with obstructive sleep apnea in junior (P =0.081) and in senior (P =0.392) residents, no significant association was observed for self-attitude to ability to be involved with patients with obstructive sleep apnea in junior (P =0.117) and in senior (P =0.478) residents, and no significant association was observed for self-attitude to ability to treat the patients with CPAP in junior (P =0.495) and senior (P =0.838) residents.
Correlation of total knowledge score in OSAKA with total knowledge score in OSAKA-KIDS was determined in junior and senior residents. According to this, positive correlation was found for both junior and senior residents (P <0.001).
Choosing the first lines of treatment
Effect of being junior or senior on choosing the first lines of treatment was analyzed using Pearson chi-square. According to this, significant association was found for first (P =0.006) and third lines (P =0.014) however not in second line (P =0.274). The most frequent choice for the first line was CPAP (63.8%) and weight loss (41.5%) among junior and senior residents, respectively. The most frequent choice for the third line was weight loss (29.0%) and surgery (22.0%) among junior and senior residents, respectively.