Psychological variables as predictors of adherence to treatment by continuous positive airway pressure

Study objectives: We examined whether psychological variables enable us to predict adherence to CPAP in order to construct a predictive model to identify patients at risk of abandoning treatment. Method: One hundred and twenty-two Obstructive Sleep Apnoea (OSA) patients were studied before and one month after beginning CPAP treatment. All patients completed four psychological evaluation instruments before CPAP treatment: a health perception questionnaire (Nottingham Health Profile: NHP), a mental health rating scale (Hospital Anxiety and Depression Scale: HADS) and two disease-specific questionnaires that measure the patient's understanding of OSA and its treatment (Apnea Knowledge Test: AKT) and his attitudes to OSA and CPAP (Apnea Beliefs Scale: ABS). Results: Thirty percent of the participants were non-adherent at one month. Decision-tree analysis indicated that it was possible to correctly classify 85.7% of non-adherent patients using three baseline factors (Emotional reactions score [NHP], age, and total score on ABS). Logistic regression analyses confirmed these two psychological variables as independent predictors of adherence. Conclusion: Assessing psychological well-being and subjective health status at onset of CPAP enables the identification of patients at risk of abandoning CPAP treatment. This subgroup could then be targeted early to receive supportive and educational measures to improve adherence rates. (c) 2009 Elsevier B.V. All rights reserved.