Abstract: | In this study we investigated whether the diagnosis of sleep apnoea syndrome (SAS), based on night-time polysomnography (NPSG), can be predicted or excluded by a one-hour daytime polysomnography (DPSG). The results of 306 NPSGs were compared with DPSGs, which were performed the day before. Treated patients were excluded. In the 89 patients with SAS (Apnoea index (AI)>/=5) 59 showed apnoeas during the DPSG and 30 did not. In the 217 without SAS 25 showed apnoeas daring DPSG and 192 did not. Sensitivity for detecting SAS was 66%, the specificity was 88%, the positive predictive value (PPV) 70% and the negative predictive value (NPV) 86%. For relevant SAS (AI>/=10) the NPV would be 95%. We conclude that the one-hour DPSG is not sufficient for diagnosing or excluding SAS with certainty. It can be used to make the presence of relevant SAS unlikely. |