OSAHS Screening in Diverse Populations

• This is a multi-center study spans China, engaging many hospitals and research institutions. It involves community residents, patients with hypertension, COPD, and other specific diseases, as well as special populations like university teachers and students, and company employees. The study is still recruiting and 2,185 subjects have been included currently.
• This study employs rigorous randomization methods to ensure the representativeness of the sample and the reliability of the results. For community residents, cluster sampling is first applied. A random number table method is used to select several communities within the designated research area. The research team then obtains a complete list of registered residents in these communities as the sampling frame. A computer-based random number generator is utilized to randomly select target residents. Those selected are contacted by telephone for the screening questionnaire. If telephone contact fails, interviewers visit the residents' homes to conduct the survey, ensuring every selected resident has an equal chance of participation.
• For individuals categorized into OSA high - risk and low - risk groups based on the screening questionnaire, computer - based numbering and randomization are used. Specifically, the information of individuals in each group is entered into a computer system, which assigns a unique number to each individual. Random number - generation software then produces a random sequence of numbers. Individuals are selected for subsequent PSG or PM based on this sequence. This method ensures the scientific and unbiased selection of the sample.
• The sample size is determined based on OSA's expected prevalence (23.6%). To estimate the 95% confidence interval with a 5% precision level, at least 277 participants are needed for diagnostic monitoring. Considering a 30% dropout rate and an 80% response rate for the screening questionnaire, the total sample size is set at 100,000 for questionnaires and 10,000 for PSG or PM.
• Missing data will be handled through multiple imputation. The reasons for missing data are recorded, and sensitivity analyses assess its impact on results. Data checks verify that entries meet predefined rules for range and consistency, identifying and correcting anomalies promptly.
• SOPs cover all aspects of registry operations, ensuring consistency and quality in data collection and management. All questionnaires were manually entered into the electronic system. The reports of PSG or PM were manually interpreted by two professional sleep physicians. In case of disputes, a third person was invited to intervene.

Inclusion criteria

• Sign the informed consent form before participating in the study
• Complete independent behaviour and cognitive abilities
• Ability to answer the questionnaire completely and accurately

Exclusion criteria

• Incomplete answers to the scale
• Patients with severe diseases and acute infections or those requiring long-term home oxygen therapy
• Patients with severe mental and psychological disorders
• Patients with severe organ failure
• patients with a total sleep time <240 min by PSG or PM