Connecting the Dots: Analysing the Relationship Between AHI and ODI in Obstructive Sleep Apnea

In the lab type-1 Polysomnography (PSG) is the gold standard for the diagnosis of Obstructive sleep apnea (OSA). But in view, the increasing prevalence, highly expensive, and the presence of a pandemic state make it sometimes impractical to perform PSG in all patients suspected of OSA. The objective of our study was to compare the correlation between the gold standard Autoscored Apnea Hypopnea Index (AHI) and Oxygen desaturation index (ODI) based classification of the severity of OSA. It was a single-centered hospital-based cross-sectional study in which a total of 176 Subjects suspected of OSA were recruited and underwent overnight 7 channels of in-lab polysomnography at AIIMS Patna. Demographic details, comorbidities, and lab data were collected for all enrolled patients. BMI, STOP-BANG score, and Epworth sleepiness score (ESS) were also calculated for all subjects. They were categorized into mild, moderate, and severe OSA based on AHI and ODI values of 5–14.9, 15–29.9, and ≥ 30 events per hour, respectively. Recordings of polysomnography (PSG) were presented with descriptive statistics. Data is presented as the “mean ± standard deviations” for continuous variables and percentage frequencies for categorical variables. The Chi-square test was used to compare the discrete variables. Statistical significance was set at an alpha level of 0.05 with P < 0.05, with a two-tailed probability. Spearman's rank correlation analysis was used to test the strength and direction of the association between OSA severity (using AHI classification) and the Oxygen Desaturation Index. The Mean (SD) age of patients enrolled in our study was 47.42(12.60) years with 57.95