Sleep, 15(6):571-575
© 1992 American Sleep Disorders Association and Sleep Research Society
Concordance Between Habitual Sleep Times and Laboratory Recording Schedules Charles F. Reynolds III, Victoria J. Grochocinski, Timothy H. Monk, Daniel J. Buysse, Donna E. Giles, Patricia A. Coble, Jeannette V. Matzzie, Jack Doman, James Monahan and David J. Kupfer Sleep and Chronobiology Center, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, U.S.A.
Summary: The validity of laboratory-based studies of sleep depends, in part, upon good concordance between habitual sleep schedule and laboratory recording schedule. Without good concordance, error variance due to the circadian misplacement of sleep and to different amounts of time in bed is probable. In an assessment of scheduling concordance in 1,762 research patient nights over two time intervals, we observed good concordance «3D-minute discrepancy) in 71.2-77.3% of bedtimes and waketimes, discrepancy (difference of ::::30 minutes) in 14.9-24.2% of bedtimes and waketimes, and missing data in 4.6-7.5% of times. Waketime differences were consistently in the direction of earlier laboratory than habitual waketimes, whereas differences in bedtime were about equally divided between earlier and later (laboratory vs. habitual). Subjects with schedule discordance averaged 19.5 minutes less time in bed during laboratory sessions as compared with their habitual sleep schedule, whereas subjects with schedule concordance averaged only 3.6 minutes less (p < 0.001). Our experience suggests that it may be more difficult to achieve higher rates of concordance among young adult and middle-aged subjects than among elders and that patient requests related to external constraints on scheduling were a frequent reason for discrepancy. We strongly recommend a policy of routinely including data on laboratory versus habitual sleep times in peer-reviewed publications. Key Words: Habitual sleep schedule-Laboratory schedule-Polysomnography-Circadian rhythms.
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Although the stated policy of many sleep research laboratories and sleep disorder centers is to estimate the usual or habitual sleep schedules of research subjects and sleep disorder patients, the extent of concordance between usual sleep schedules and the timing of recording sessions has not been reported. Such a gap in methodological knowledge is regrettable because the importance of attending to habitual sleep-wake schedules is central to the current understanding of circadian rhythm sleep disorders (1); the effects of aging on sleep and circadian rhythms (2); and non pharmacologic approaches, such as sleep restriction therapy (3), to the treatment of several sleep-wake disorders. Furthermore, the validity oflaboratory-based sleep recordings depends, in part, upon good concordance between subjects' habitual sleep schedules and laboratory recording schedules. This notion is reflected in decisions to exclude subjects who show marked instability of sleepwake schedule, may be experiencing jet lag, or are shift
workers. The belief is also demonstrated in descriptions within methods sections of research articles that subjects are recorded at, or close to, their "habitual" or "usual" sleep-wake schedules. Typically, however, methods of ascertaining habitual sleep-wake schedule and data on habitual sleep-wake schedule versus actual time of polysomnography are not reported. Despite the apparent prevalence of this policy regarding the conduct of sleep research, we know of no published data actually addressing the concordance between habitual sleep schedules and laboratory recording time. For 15 months, we collected such data in order to determine how well our performance matches laboratory policy. Our goals were three-fold: 1) to ascertain the frequency and severity of discrepancies; 2) to determine reasons for discrepancy; and 3) to develop a system for reducing the incidence of discrepancy.
Accepted for publication July 1992. Address correspondence and reprint requests to Dr. Charles F. Reynolds III, Western Psychiatric Institute and Clinic, 3811 O'Hara Street, Pittsburgh, Pennsylvania 15213, U.S.A.
Data were collected and analyzed for two different time intervals: 1) December 15, 1990 to April 15, 1991 (time interval!); and 2) April 16, 1991 to November
METHODS
571 Downloaded from https://academic.oup.com/sleep/article-abstract/15/6/571/2749349 by guest on 04 March 2018
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C. F. REYNOLDS III ET AL. SUBJECT NAME =, ***example*** Study Startin9 Date = 19920129 10 = 12345 DATE = 19920105 HABITUAL BEDTIME= 2330 HABITUAL WA¥:ETIME= 710 HABITUAL MINUTES IN BEO= 461 19 20 21 22 HABITUAL TIMES ACTUAL NIGHTS
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How many Night 1 Night 2 Night 3 Night 4 Night 5 Night 6 Night 7 Night 8 Night 9 Night 10 Night 11 Night 12 Night 13 Night 14
nights? 14 bedtime 2200 bedtime 2300 bedtime 2330 bedtime 5 bedtime 10 bedtime* 330 bedtime* 200 bedtime 2250 bedtime 2200 bedtime 2345 bedtime 2305 bedtime 30 bedtime 130 bedtime 2330
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© 1992 American Sleep Disorders Association and Sleep Research Society
Concordance Between Habitual Sleep Times and Laboratory Recording Schedules Charles F. Reynolds III, Victoria J. Grochocinski, Timothy H. Monk, Daniel J. Buysse, Donna E. Giles, Patricia A. Coble, Jeannette V. Matzzie, Jack Doman, James Monahan and David J. Kupfer Sleep and Chronobiology Center, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, U.S.A.
Summary: The validity of laboratory-based studies of sleep depends, in part, upon good concordance between habitual sleep schedule and laboratory recording schedule. Without good concordance, error variance due to the circadian misplacement of sleep and to different amounts of time in bed is probable. In an assessment of scheduling concordance in 1,762 research patient nights over two time intervals, we observed good concordance «3D-minute discrepancy) in 71.2-77.3% of bedtimes and waketimes, discrepancy (difference of ::::30 minutes) in 14.9-24.2% of bedtimes and waketimes, and missing data in 4.6-7.5% of times. Waketime differences were consistently in the direction of earlier laboratory than habitual waketimes, whereas differences in bedtime were about equally divided between earlier and later (laboratory vs. habitual). Subjects with schedule discordance averaged 19.5 minutes less time in bed during laboratory sessions as compared with their habitual sleep schedule, whereas subjects with schedule concordance averaged only 3.6 minutes less (p < 0.001). Our experience suggests that it may be more difficult to achieve higher rates of concordance among young adult and middle-aged subjects than among elders and that patient requests related to external constraints on scheduling were a frequent reason for discrepancy. We strongly recommend a policy of routinely including data on laboratory versus habitual sleep times in peer-reviewed publications. Key Words: Habitual sleep schedule-Laboratory schedule-Polysomnography-Circadian rhythms.
'
..
Although the stated policy of many sleep research laboratories and sleep disorder centers is to estimate the usual or habitual sleep schedules of research subjects and sleep disorder patients, the extent of concordance between usual sleep schedules and the timing of recording sessions has not been reported. Such a gap in methodological knowledge is regrettable because the importance of attending to habitual sleep-wake schedules is central to the current understanding of circadian rhythm sleep disorders (1); the effects of aging on sleep and circadian rhythms (2); and non pharmacologic approaches, such as sleep restriction therapy (3), to the treatment of several sleep-wake disorders. Furthermore, the validity oflaboratory-based sleep recordings depends, in part, upon good concordance between subjects' habitual sleep schedules and laboratory recording schedules. This notion is reflected in decisions to exclude subjects who show marked instability of sleepwake schedule, may be experiencing jet lag, or are shift
workers. The belief is also demonstrated in descriptions within methods sections of research articles that subjects are recorded at, or close to, their "habitual" or "usual" sleep-wake schedules. Typically, however, methods of ascertaining habitual sleep-wake schedule and data on habitual sleep-wake schedule versus actual time of polysomnography are not reported. Despite the apparent prevalence of this policy regarding the conduct of sleep research, we know of no published data actually addressing the concordance between habitual sleep schedules and laboratory recording time. For 15 months, we collected such data in order to determine how well our performance matches laboratory policy. Our goals were three-fold: 1) to ascertain the frequency and severity of discrepancies; 2) to determine reasons for discrepancy; and 3) to develop a system for reducing the incidence of discrepancy.
Accepted for publication July 1992. Address correspondence and reprint requests to Dr. Charles F. Reynolds III, Western Psychiatric Institute and Clinic, 3811 O'Hara Street, Pittsburgh, Pennsylvania 15213, U.S.A.
Data were collected and analyzed for two different time intervals: 1) December 15, 1990 to April 15, 1991 (time interval!); and 2) April 16, 1991 to November
METHODS
571 Downloaded from https://academic.oup.com/sleep/article-abstract/15/6/571/2749349 by guest on 04 March 2018
572
C. F. REYNOLDS III ET AL. SUBJECT NAME =, ***example*** Study Startin9 Date = 19920129 10 = 12345 DATE = 19920105 HABITUAL BEDTIME= 2330 HABITUAL WA¥:ETIME= 710 HABITUAL MINUTES IN BEO= 461 19 20 21 22 HABITUAL TIMES ACTUAL NIGHTS
23
24
1
2
3
4
5
6
(12) (11) 7
8
9
10
11
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How many Night 1 Night 2 Night 3 Night 4 Night 5 Night 6 Night 7 Night 8 Night 9 Night 10 Night 11 Night 12 Night 13 Night 14
nights? 14 bedtime 2200 bedtime 2300 bedtime 2330 bedtime 5 bedtime 10 bedtime* 330 bedtime* 200 bedtime 2250 bedtime 2200 bedtime 2345 bedtime 2305 bedtime 30 bedtime 130 bedtime 2330
12
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waketime 705 waketime 700 waketime 645 waketime 715 waketime 6~;0 waketime*1130 waketime*1000 waketime 6~;5 waketime 630 waketime 6~15 waketime 700 waketime 700 waketime*1030 waketime 9
