Sleep in the laboratory and sleep at home II: Comparisons of middle-aged insomnia sufferers and normal sleepers

Study Objectives: The study compared adaptation responses and sloop pattern differences shown by normal sleepers and insomnia sufferers during lab (LP SG) and home (HPSG) polysomnography. Design: A counter-balanced, matched-group design was used. Participants und erwent 3 consecutive nocturnal LPSG's and 3 consecutive nocturnal PSG's in their homes (HPSG's). Setting: The sleep disorders laboratories at affiliated VA and university m edical centers. Participants: Thirty-five (18 women) middle-aged (40 to 59 years) noncompla ining normal sleepers and an age-matched sample of 33 (17 women) individual s who met structured interview criteria for persistent primary insomnia wer e the study participants. Measurements and Results: A series of multivariate and univariate analyses were conducted with 9 common sleep parameters to address study objectives. Bed partner influences were controlled by conducting separate sets of analy ses for those with and without routine home bed partners. The interaction o f participant type (normal vs. insomnia), sleep setting, and PSG sequence ( HPSG list vs. LPSG 1st) affected first night values of sleep efficiency and stage 2 sleep among those without routine bed partners, and REM latency an d sleep efficiency among those with routine bed partners. Analyses which co ntrolled for first night and sequencing effects showed a significant partic ipant type x sleep setting interaction among those with bed partners. These latter analyses suggested that LPSG's may underestimate the home sleep tim e of insomnia sufferers and overestimate the sleep continuity of normal sle epers, at least among those who routinely sleep with a bed partner. Conclusions: The nocturnal recording site may influence adaptation effects and sleep pattern differences noted between insomnia sufferers and normal s leepers.