USE OF HOME SLEEP STUDIES FOR DIAGNOSIS OF THE SLEEP APNOEA HYPOPNOEASYNDROME/

Background - A study was undertaken to test the hypothesis that unsupe rvised domiciliary limited sleep studies do not impair the accuracy of diagnosis when used to investigate the sleep apnoea/hypopnoea syndrom e (SAHS) and can be cheaper than laboratory polysomnography. Methods - For validation, 23 subjects with suspected SAHS underwent laboratory polysomnography and a home study (EdenTec 3711) on successive nights. All subjects with >15 apnoeas+hypopnoeas (A+H)/hour on polysomnography showed >30 A+H/hour on their home study. Thereafter, in a prospective trial 150 subjects had a home study as the initial investigation and studies showing >30 events/hour were regarded as diagnostic of SAHS. T hose showing fewer events were investigated with polysomnography if ne cessary. Time to treatment, outcome, and costs of this protocol were c ompared with those of 75 patients investigated initially with polysomn ography. Results - Of the prospective trial subjects, 29% had >30 A+H/ hour and proceeded directly from home study to treatment; 15% without daytime sleepiness were not investigated further. Polysomnography was undertaken to establish a diagnosis in 56% of cases, including 18% who se home studies were unsuccessful. Compared with the 75 control patien ts, this protocol gave a diagnosis faster (median 18 (range 0-221) ver sus 47 (0-227) days, p<0.001) and more cheaply (mean (SD) pound 164 (1 04) versus pound 210 (0), p<0.001). The proportions offered CPAP (61% versus 67%) and subsequent objective CPAP usage (mean 4.7 (2.4) versus 5.0 (2.4) hours/night) were not different. Conclusions - Use of home sleep studies has benefits in time and cost. For diagnostic reliabilit y a further sleep study was required in 56% of cases.