Researchers in Norway studied sleep apnea patients to determine if they were less healthy than the general population.
Obstructive sleep apnea is becoming an important health issue in society today. Not only is it becoming more common, affecting as much as 6-23% of all adult women and 13-50% of all adult men, but it can also lead to serious health issues, such as cardiovascular disease.
Many studies have shown that sleep apnea negatively affects an individual’s health status, which is a multi-dimensional measure of a person’s health and well-being including mental and social aspects. However, in many countries, the association between health status and sleep apnea is not well known.
First study examining the association between sleep apnea and health status in Norway
With this knowledge gap in mind, researchers in Norway recently studied the link between sleep apnea and health status, as there is a limited understanding of this relationship in the country. The overall goal was to compare the health status of sleep apnea patients to that of the general population. To the researchers’ knowledge, no previous study of this kind had ever been done in Norway. Their results were recently published in Scientific Reports.
Comparing sleep apnea patients to the general population using the SF-36 tool
The study subjects were selected to meet the following criteria:
- Suspected by their clinician (e.g. family doctor) of having obstructive sleep apnea.
- Age of 18 years old or older.
- Referred to Akershus University Hospital between October 2003 and December 2007 for an overnight sleep study to ascertain an OSA diagnosis.
- Successfully completed this overnight sleep study.
- Fully completed the SF-36 health status questionnaire. The SF-36 is a widely used tool to assess HS. Higher scores on the SF-36 indicate better HS.
These criteria resulted in a sleep study population of 418.
To represent the general population, the researchers used data collected from the Norwegian Lifestyle Survey, by Statistics Norway. This survey consisted of both home and telephone interviews of subjects 16 years of age or older. After the interviews, the participants of this survey completed a postal survey, which also included the SF-36 health status questionnaire. These postal surveys were mailed between November 15, 2002, and May 15, 2003. From this data, the researchers gathered a sample of 5,000 people.
The sleep-study group showed lower health status than the general population
For the participants in the sleep study group, there was no difference in health status between those patients showing some sleep apnea, and those showing no sleep apnea. As an overall population, however, the subjects in the sleep study group, of which 47% showed no sign of sleep apnea, had lower health status scores than the general population group. Thus, factors other than sleep apnea may account for the sleep studies patients’ lower health status.
The researchers noted some limitations in their study. First, the selection of participants was challenging, and varied over time, leading to a potential sampling bias. Second, the measurement of sleep apnea during the sleep study was not consistent across the patients, with more than 80% of the sleep studies measured using a method which may underestimate sleep apnea.
Physicians must consider all factors when diagnosing sleep apnea
The application to physicians is that the lower health status seen in sleep apnea patients may not be caused by the same factors that cause obstructive sleep apnea, or which affect the severity of obstructive sleep apnea. Thus, physicians need to examine all aspects of their patients’ health, such as alternative sleep disorders, and mental conditions, in order to accurately assess whether a diagnosis of obstructive sleep apnea is a possibility.
Written by Raymond Quan, MASc, MBA
Reference: Beiske et al., “Health status in subjects with suspected obstructive sleep apnea and comparison with a general population.” Scientific Reports (2018) 8:5579.
