Obstructive sleep apnea (OSA) is a respiratory condition commonly found in children, which is characterized by the collapse of the airway when one is asleep. If the OSA condition is untreated, it can lead to severe cardiovascular, somatic growth, and neuro-cognitive consequences. It has been established that adenotonsillar hypertrophy is one of the major determinants of OSA condition in children. The studies on the relationship between tonsil size and OSA conditions have rather contributed fewer facts regarding the condition, which remains an issue of controversy. Researchers Kang, Chou, Weng, Lee, and Hsu (2012) conducted a study to determine the association between adenonotonsillar hypertrophy, age, and obesity in children with obstructive sleep apnea. This paper is intended to be an analysis of the research process followed by the study conducted by Kang et al.
In the study presented by Kang et al, the literature review presented is not extensive; however, there is a clear summary in the abstract detailing a few research activities that have been conducted that are related to the study’s main objective. The authors of the article review one study on the relationship between tonsil size and OSA, which concluded there was a weak association, subjective to pediatric tonsil size. By reviewing the works of other authors that reveal methodological inadequacy and disparities in adenoid size evaluation, Kang et al (2012) connect what may have been missing in the previous research to help the research team answer the main objective of the study. To incorporate age as a factor in the study, Kang et al. review the work of another group of researchers who concluded that the association between adenoid size and OSA is more common among pre-school children than in school going children. A review of a research work that found out an association between adenotonsullar and apnea innon-obese children also gave light to the research conducted by Kang et al to include all these factors in the study. Even though the literature review is not extensive, it is important to acknowledge the fact that the few literature reviews give an insight into the study objective.
Data collection process is a vital component in any research process, and therefore, the need to collect data that helps the investigator answer the research hypothesis is key (Friedman, Furberg, and DeMets, 2010). Even though the informed consent form was not used in the study, the concerned authorities approved the data collection process for this retrospective study, which in this case was the ethics committee of the national Taiwan hospital university. This clearly shows that a research protocol was followed during the study process. Considering the objective of the study, the data source was of great importance, and Kang et al did a recommendable job with the data collection procedures that would give sufficient and relevant data for the study. For instance,by recruiting children from different departments that includes psychiatric, pediatric, otolaryngology and respiratory clinics makes it possible to obtain data that is relevant to the researchmain objective. We can observe from the study that ethical procedures were also followed when the data collection process was conducted by experts from the various departments the sample population was drawn. The study data was collected from a sample population of 495 divided into different age groups and relevant data to the research question obtained from the study participant. To analyze the data, multi logistic regression was used.
From the study conducted by Kang et al, it is clear that the data collection process followed a laid out procedure with detailed and specific information to be collected from the study participants. It is important to note that children under one year were excluded from the study because sleep patterns and disorders vary considerably in this age group. Other exclusion criteria were put in place to avoid collecting data that might have significant negative impact on the study. Such kinds of procedures are referred to quality controls measures that are as well important during a data collection process. Detailed histories and physical examination were done on study participant and thus ensuring the collection of data that is relevant to the research question. Moreover, dividing the study participants into different age groups would enable the research team answer age-related research question. Screening of the participants for the OSA was an important procedure to the study as it enabled the research team to collect data on polysomnographic sleep study, which forms part of the research question.
Methodology and results
The study utilized a sample population of 495 participants divided into different age groups. While assessing the adenoid and tonsil size, the ratio of adenoidal-nasopharyngeal (AN) was obtained in the form of the ration of adenoidal depth to the diameter of nasopharyngeal. If the AN ration was higher than 0.67, then it was classified as adenoidal hypertrophy. Assessments on tonsillar were divided into four different categories depending on size on an ascending order. From grade three and above, the conclusion was the presence of tonsillar hypertrophy.Polysomnography (PSG) was conducted throughout the night in a sleeping lab. If the continued respiratory effort associated with a greater than 90% decrease in the airflow in a span of greater or equal to 2, then the case was considered as obstructive apnea. If the same was greater or equal to 50% in the same airflow span then it was defined as hypopnea. The presence of an apnea/hypopnea index >=1 event within an hour in the polysomnographic was defined as OSA.Polysomnographic assessment followed the procedures provided by the American Academy of Sleep Medicine and was conducted by a professional in the field.
To analyze the collected data, SPSS was used, which is a good statistical software for analyzing such categorical data. Continuous data in this study by Kang et al (2012) was expressed as the mean plus the standard deviation whereas the categorical as percentages. The relationships between AHI and adenoid size in the different groups were studied using the Pearson’s correlation. The authors of the article used logistic regression to analyze OSA risk. A multi logistic regression model was fitted to determine the degree of association between the OSA risks and the demographics. The model was considered statistically significant at a p-value less than 0.05.From the results presented, most of the results are statistically significant considering the p-value and Pearson’s correlation. For instance, from the multivariate regression model employed to analyze the association between the demographics and the OSA risk, it is clear that age and gender does not have a significant correlation with OSA in pediatric whereas obesity, tonsillar hypertrophy and adenoidal hypertrophy have a statistically significant correlation with OSA. From the results of the assessment of adenotonsillar size in non-obese and obese, tonsil grade has a positive correlation to the AHI for both non- obese and obese children.The results from the assessment of adenotonsillar size in the different age groups are all statistically significant except for the adolescence group.
Discussion and Conclusion
The conclusion presented in this study asserts that the major determinants in OSA in children are obesity, tonsillar hypertrophy, and adenoidal hypertrophy. From the results, the authors of the article conclude that adenotonsillar sizes differ between the different age group but rather do not have a relationship with obesity. The conclusion that adenoid size decreases in adolescent is concurrent with the results presented from the group assessments. For instance, form the table, it was evident that asage increases, the adenotonsillar size influence decreases. The results and conclusion of this study answers the research question or objective presented by the authors of the article. Based on the p-value and the Pearson’s correlation, the results of the study based on the collected data answers the research question. However, as an individual I feel that there is need to do further research on the issue to include other factors that contribute to OSA in children that may influence the study factors.
In summary, an individual may base an argument on the sample size in relation to the population size. The authors of the article did not provide more information regarding the population of children with OSA. However, conclusively, the authors of the research article did a great work especially in data collection and the analysis of this study to arrive to the conclusion. The inclusion of experts in the data collection activity increased the data accuracy, which is fundamental to any research undertaking. The data analysis procedure used in this article was appropriate for the type of data that was collected. I think the information given is enough to make conclusion on the research question, however more research should be done to determine other factors contributing OSA.
Kang, K., Chou, C., Weng, W., Lee, P., & Hsu, W. (2012). Association between Adenotonsillar Hypertrophy, Age, and Obesity in Children with Obstructive Sleep Apnea.
Friedman, L., Furberg, C., & DeMets, D. (2010). Fundamentals of clinical trials. New York: Springer.