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.