Clinical outcomes and cost-effectiveness of continuous positive airway pressure to manage obstructive sleep apnea in patients with type 2 diabetes in the U.K.

OBJECTIVE: To assess clinical outcomes and cost-effectiveness of using continuous positive airway pressure (CPAP) to manage obstructive sleep apnea (OSA) in patients with type 2 diabetes (T2D) from the perspective of the U.K.'s National Health Service (NHS). RESEARCH DESIGN AND METHODS: Using a case-control design, 150 CPAP-treated patients with OSA and T2D were randomly selected from The Health Improvement Network (THIN) database (a nationally representative database of patients registered with general practitioners in the U.K.) and matched with 150 OSA and T2D patients from the same database who were not treated with CPAP. The total NHS cost and outcomes of patient management in both groups over 5 years and the cost-effectiveness of CPAP compared with no CPAP treatment were estimated.
RESULTS: Using CPAP was associated with significantly lower blood pressure at 5 years and increasingly lower HbA1c levels over 5 consecutive years compared with untreated OSA patients. At 5 years, the HbA1c level in the CPAP-treated group was 8.2% (66.0 mmol/mol) vs. 12.1% (108.4 mmol/mol) in the control group (P < 0.03). Use of CPAP significantly increased patients' health status by 0.27 quality-adjusted life years (QALYs) per patient over 5 years (P < 0.001) and NHS management costs by £4,141 per patient over 5 years; the cost per QALY gained with CPAP was £15,337.
CONCLUSIONS: Initiating treatment with CPAP in OSA patients with T2D leads to significantly lower blood pressure and better controlled diabetes and affords a cost-effective use of NHS resources. These observations have the potential for treatment modification if confirmed in a prospective study.