Health utilities in evaluating intervention in the sleep apnoea/hypopnoea syndrome

Formulating a rational health policy necessitates the ability to compare between different healthcare interventions and disease scenarios. Continuous positive airway pressure (CPAP) therapy with a conservative lifestyle strategy in sleep apnoea/hypopnoe syndrome (SAHS) was evaluated using health utility and quality-adjusted life years (QALYs) as outcome measures. A total 71 SAHS (apnoea/hypopnoea index ≥15 h^-1) patients completed a randomised, parallel group study over 3 months using utilities derived by the standard gamble approach (Usg) and European quality of life questionnaire (Euroqol) (Ueq). The severely impaired health status at baseline improved by 23% (Usg 0.32 to 0.55) adding 8 QALYs in the CPAP group, compared to a 4% improvement with 4.7 QALYs added in the lifestyle group (Usg 0.31 to 0.35). The Ueq showed a marginal change with CPAP (0.73 to 0.77) but did not demonstrate any improvement with lifestyle intervention. The health status impairment in sleep apnoea/hypopnoea syndrome patients is markedly improved by continuous positive airway pressure compared to a modest improvement with conservative lifestyle strategies using the standard gamble utility, which may be incorporated in effectiveness and economic analyses. The European quality of life questionnaire did not reflect a similar degree of impact and is probably not useful in this population.