Split-night versus full-night studies for sleep apnoea/hypopnoea syndrome

Investigation and treatment of sleep apnoea/hypopnoea syndrome (SAHS) is pl acing increasing demands on healthcare resources. This workload may be redu ced by using split-night studies instead of the standard full-nights of dia gnostic polysomnography and continuous positive airway pressure (CPAP) titr ation. Split-night studies involve polysomnography in the first half of the night followed, if there is an abnormal frequency of apnoeas and hypopneas , by CPAP titration for the remainder of the night. The authors' database of all patients prescribed a CPAP trial 1991-1997 was used to compare long-term outcomes in all 49 (46 accepting CPAP) patients prescribed split-night studies with those in full-night patients, matched 1 :2 using an apnoea/hypopnoea index (AHI) of +/-15% and Epworth score of +/- 3 units. Classical symptoms of SAHS were the main reason for the split-night studies (n=27). There were no differences between the groups in long-term CPAP use , median nightly CPAP use (split-night 6.0 h.night(-1), interquartile range (IQR) 3.8-7.4, fullnight; 6.2 h.night(-1) IQR 3.7-7.0, p=0.9) post-treatme nt Epworth scores and frequency of nursing interventions/clinic visits requ ired. The median time from referral to treatment was less for the split-nig ht patients (13 months, IQR 11-20 months) than for full-night patients (22 months, IQR 12-34 months; p=0.003), Split-night studies, in selected patients, result in equivalent long-term c ontinuous positive airway pressure use to full-night studies with shorter t reatment times and less healthcare utilization.