Fig 1.
Flow diagram of the study protocol.
The study follows a nested case-control design. The cases correspond to the hospitalizations of adults patients with a SA co-diagnosis. The controls correspond to hospitalizations without coded SA in patients matching the cases 1:1 for age, gender and month of hospitalization.
Fig 2.
Characteristics of SA hospitalizations in Switzerland.
The evolution of the annual number of SA hospitalizations between 2002 and 2018 is shown in panel A. The number of hospitalizations with a co-diagnosis of SA increases steadily over the years. The age distribution per gender is depicted in panel B.
Table 1.
Baseline characteristics of hospitalized cases with SA compared to age and sex-matched controls without diagnosis of SA (1:1 nested case-control design).
Table 2.
List of comorbidities significantly over-represented in SA compared to the matched-control population.
The simplified ICD-10-GM codes including 2 digits are presented together with a short description and the associated odds-ratios.
Fig 3.
Principal component analysis (PCA) biplot of comorbidities associated with sleep apnea.
SA hospitalization cases are reported in smoothed blue density areas, whereas comorbidities (ICD-10-GM codes) are depicted by framed labels. Comorbidities lying in the same direction are correlated. Comorbidities lying far away from the center of the plot are the most influential comorbidities. As a help for interpretation, the upper left inset represents external explanatory variables fitted to the PCA plot. The association between comorbidities and explanatory variables is given by the direction of the arrows.
Fig 4.
Survival benefit of coded sleep apnea in patients hospitalized with 47 conditions with highest in-hospital mortality.
The odds-ratios (and 95% confidence intervals) comparing the in-hospital mortality between SA cases and matched controls are displayed using a forest plot. The estimates are represented by dots whose size is proportional to the prevalence of the condition. Comorbidities significantly associated with a lower rate of in-hospital mortality are shown in green. Comorbidities not significantly associated with in-hospital mortality are shown in gray. The simplified ICD-10-GM codes including 2 digits are presented.