Insomnia symptoms and CPAP compliance in OSAS patients: A descriptive study using Data Mining methods.

Background: Obstructive Sleep Apnoea Syndrome (OSAS) and insomnia are common pathologies sharing a high comorbidity. CPAP is a cumbersome treatment. Yet, CPAP compliance must remain optimal in order to reverse excessive daytime sleepiness and prevent the cardiovascular consequences of OSAS. But chronic insomnia could negatively affect CPAP compliance.

Objective: To assess the consequences of insomnia symptoms on long-term CPAP use.

Methods: A prospective study was conducted on 148 OSAS patients (RDI=39.0+/-21.3/h), age=54.8+/-11.8years, BMI=29.1+/-6.3kg/m(2), Epworth Score=12.2+/-5.4, on CPAP. Using the Insomnia Severity Index (ISI) as an indicator of insomnia (ISI14=moderate to severe insomnia) and baseline data (anthropometric data, sleeping medication intakes, CPAP compliance, Epworth, Pittsburgh Sleep Quality and ISI scores, polygraphic recording data), Data Mining analysis identified the major rules explaining the features "High" or "Low ISI" and "High" or "Low Use" in the groups defined, according to the median values of the ISI and the 6th month-compliance, respectively.

Results: Median ISI was 15 and median 6th month-compliance was 4.38h/night. Moderate to severe insomnia complaint was found in 50% of patients. In the "High" and "Low ISI," the 6th month-compliance was not significantly different (3.7+/-2.3 vs 4.2+/-2.3h/night). In the classification models of compliance, the ISI was not a predictor of CPAP rejection or of long-term use, the predictor for explaining CPAP abandonment being the RDI, and the predictor of the 6th month-compliance being the one month-compliance.

Conclusion: Insomnia symptoms were highly prevalent in OSAS patients, but had no impact on CPAP rejection or on long-term compliance.