Predictors of oxygen saturation ≤95% in a cross-sectional population based survey

Summary Background Pulse oximetry has become an important tool in evaluating, and monitoring pulmonary diseases, but the knowledge about arterial oxygen saturation (SpO 2 ) values in a general population is limited. The aim of this study was to describe the distribution of low pulse oximetry values in a general adult population and their association with certain predictors. Methods A cross-sectional population based survey was performed in Tromso, Norway, in 2007–2008. Valid SpO 2 and pre-bronchodilator spirometry was recorded in 6317 participants aged 38–87 years (57% women). Resting SpO 2 ≤95% was defined as an abnormal value. Predictors of SpO 2 ≤95% with p Results The prevalence of SpO 2 ≤95% was 6.3%. The strongest predictors in the logistic regression were increased body mass index (BMI) (OR of BMI ≥35 = 6.2, CI(4.2, 9.2)), and reduced forced expiratory volume in 1 s (FEV 1 ) % predicted (OR of FEV1% predicted p p p Conclusion Airflow limitation and other known signs of pulmonary diseases were, as expected, strongly associated with decreased oxygen saturation. Obesity was also a strong predictor of low SpO 2 , and should be included among possible explanations when low SpO 2 values are encountered.