Identification of quality-of-life clusters by the Quebec sleep questionnaire in sleep apnea patients

Patients with obstructive sleep apnea (OSA) may present different symptoms. The clinical importance of symptom clustering is supported by the difference in the incidence of cardiovascular diseases between hypersomnolent and non-hypersomnolent sleep apnea patients. The objective of this study was to determine if quality-of-life clusters could be identified from the Quebec Sleep Questionnaire (QSQ) in OSA patients. Latent class analysis was used to identify clusters in a multivariate analysis of dichotomic variables (presence or absence of symptoms) for each item the QSQ obtained from 147 patients who fulfilled the questionnaire during its validation and subsequent trials (75.5% males, age: 53 ± 11 years, body mass index (BMI): 30.4 ± 4.7 kg/m², apnea/hypopnea index (AHI): 31.3 ± 14.8/h). Three clusters were identified. Quality of life was preserved in patients of cluster 1 (20.4% of patients). Patients of cluster 2 (32.6% of patients) had a moderately impaired quality of life, mainly due to daytime somnolence and poor sleep quality. Patients with impaired quality of life (cluster 3, 46.9% of patients) had an important impact in every domain of the QSQ with the highest sleepiness and daytime symptom impairments. Gender, BMI, and AHI did not differ between the three clusters. In conclusion, different quality-of-life clusters can be identified from the QSQ in sleep apnea patients. These clusters are similar to those reported previously. Further studies are needed to validate these clusters in larger and independent cohorts, to evaluate how they respond to OSA treatment, and their relationship with incident outcomes.