Brief Report: Sleep in Parents of Children with Autism Spectrum Disorders

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1 Brief Report: Sleep in Parents of Children with Autism Spectrum Disorders Lisa J. Meltzer, PHD Department of Pediatrics and Division of Pulmonary Medicine, University of Pennsylvania and The Children s Hospital of Philadelphia Objective To examine sleep quality and sleep wake patterns in parents of children with autism spectrum disorders (ASDs) and parents of typically developing (TD) children. Methods Thirty-five mothers and 22 fathers completed the Pittsburgh Sleep Quality Index, a 7-day sleep diary, and wore an actigraph for 1 week. Results Parents of children with ASDs reported poorer sleep quality compared to the TD group. In addition, parents of children with ASDs had objectively different sleep patterns, with an earlier wake time and shorter total sleep time than parents of TD children. Finally, regardless of group, fathers had significantly shorter sleep time compared to mothers. Conclusions This study is one of the first to demonstrate poorer sleep quality and shorter sleep quantity in parents of children with ASDs using validated measures of sleep. Future studies should examine the relationship between chronic sleep loss and stress in parents of children with ASDs. Key words autism; children; fathers; mothers; sleep. A number of studies have reported disrupted sleep patterns (i.e., frequent night wakings, early morning wake time, and shorter total sleep time) in children with autism spectrum disorders (ASDs) (Allik, Larsson, & Smedje, 2006b; Doo & Wing, 2006; Hering, Epstein, Elroy, Iancu, & Zelnik, 1999; Patzold, Richdale, & Tonge, 1998; Polimeni, Richdale, & Francis, 2005; Wiggs & Stores, 2004). Because almost all of these sleep disruptions have been reported by parents, it is logical to assume that parent sleep patterns are also disrupted, resulting in poorer sleep quality. One study found that over two-thirds of parents of children with autism or Asperger s disorder reported their own sleep was disrupted due to their child s sleep (Polimeni et al., 2005), yet no studies have included either a validated self-report measure of sleep quality or an objective measure of sleep wake patterns in parents of children with ASDs. An earlier morning wake time has been consistently found in children with ASDs compared to typically developing (TD) children by subjective report and actigraphy (Allik et al., 2006b; Hering et al., 1999; Wiggs & Stores, 2004), a well-validated objective measure of sleep wake patterns (Sadeh & Acebo, 2002). As most parents of children with ASDs will rise when their child wakes for the day, it is likely that parents of these children also have an earlier wake time and shorter total sleep time compared to parents of TD children. Over time, this shorter sleep duration can result in chronic partial sleep deprivation (CPSD). The consequences of CPSD include negative mood, elevated stress, and increased fatigue (see Dinges, Rogers, & Baynard, 2005 for review), outcomes often reported by parents of children with ASDs (Allik, Larsson, & Smedje, 2006a; Doo & Wing, 2006; Weiss, 1991). When examining any aspect of functioning in parents, it is important to include fathers, and distinguish between maternal and paternal experiences (Phares, Lopez, Fields, Kamboukos, & Duhig, 2005). While mothers tend to be the primary caregivers of children, in recent years fathers have taken an increasing role in caregiving (Cabrera, Tamis-LeMonda, Bradley, Hofferth, & Lamb, 2000). Studies of families of children with ASDs have suggested that mothers are at greater risk than fathers for stress, sleepiness, and poor physical health All correspondence concerning this article should be addressed to Lisa J. Meltzer, PhD, The Children s Hospital of Philadelphia, 3535 Market Street, 14th Floor, Philadelphia, PA 19104, USA. meltzerl@ .chop.edu Journal of Pediatric Psychology 33(4) pp , 2008 doi: /jpepsy/jsn005 Advance Access publication February 4, 2008 Journal of Pediatric Psychology vol. 33 no. 4 ß The Author Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please journals.permissions@oxfordjournals.org

2 Sleep in Parents 381 related to a child s sleep problems (Allik et al., 2006a; Polimeni, Richdale, & Francis, 2007). Yet, no studies have examined differences in sleep between mothers and fathers of children with ASDs. While it would be expected that mothers have poorer sleep quality and sleep less than fathers due to their primary caregiver role, actigraphy studies of healthy adults in the general population have found that women have an earlier bedtime, shorter sleep onset latency, and longer total sleep time than men (Jean- Louis, Mendlowicz, von Gizyki, Zizi, & Nunes, 1999; Reyner & Horne, 1995). Thus, the purpose of this exploratory study was to examine sleep quality and sleep wake patterns in parents of children with and without ASDs. Based on the existing literature, it was hypothesized that (a) parents of children with ASDs would have poorer sleep quality and more disrupted sleep patterns (earlier morning wake time, more night wakings, and shorter total sleep time) compared to parents of TD children, (b) regardless of group, mothers would have poorer sleep quality and more disrupted sleep patterns compared to fathers due their general primary caregiver role, and (c) mothers of children with ASDs would have poorer sleep quality and more disrupted sleep patterns compared to mothers of TD children and fathers in both groups due to the additional caregiving demands of having a child with an ASD. Methods Participants and Procedure This study was approved by the Institutional Review Board at a large tertiary care children s hospital. Families of children with ASDs were recruited through websites, list serves, and community newsletters for families of children with ASDs. Families of TD children were recruited through flyers placed in two primary care pediatricians offices. Both groups were screened by telephone for exclusion criteria (see below), and then a home visit was scheduled at a time convenient for the family (with both parents/ caregivers present in two-parent families). Parents were asked to provide written documentation of the child s ASD diagnosis at the home visit, including a letter or report from a physician or psychologist, an individualized education plan (IEP), or other behavioral treatment plan. In addition, all families completed the Social Communication Questionnaire (SCQ), a validated screening measure for symptoms of ASDs (Rutter, Bailey, & Lord, 2003). During the home visit informed consent was obtained, participants completed a series of questionnaires, and were given instructions on care of the actigraph and how to keep complete the daily sleep diary. A second home visit was done after 7 days to collect the actigraphs and sleep diaries. Families were included if they had a child ages 4 10 years and lived within a 90 mile radius of the children s hospital. Children with an ASD were required to have a score of >15 on the SCQ, while children in the TD group were required to have a score of <15 on the SCQ. Families were excluded if either the child or parent had obstructive sleep apnea, narcolepsy, or restless legs syndrome (n ¼ 5), as these can affect both sleep quality and quantity independent of the child s or parent s sleep patterns; if the typically developing child had any type of chronic physical or developmental disorders (n ¼ 3); or if there was a second child in the home with a chronic physical or developmental disorder (n ¼ 4). An attempt was made to match TD children on age and sex with the ASD participants. Sixty-eight participants (43 females, 25 males) were enrolled in the study, representing 24 families of children with autism spectrum disorders (ASD) and 17 families of TD children. Data for 11 participants (four ASD mothers, four ASD fathers, three TD mothers) were lost due to either technical problems with the actigraphy, not enough valid days to score, or participant noncompliance. The only significant demographic difference between participants with valid data or lost data was the child s age, t(40,8) ¼ 2.52, p ¼.02, with participants whose data was lost having younger children than participants with valid actigraphy data (5.4 vs. 6.4 years). The final sample included 57 participants. Selfdesignated primary caregivers (20 ASD, 15 TD) were all mothers, and self-designated secondary caregivers (12 ASD, 10 TD) were all fathers or live-in boyfriends. Diagnoses for children with ASDs were autism (n ¼ 13), Asperger s (n ¼ 5), and pervasive developmental disorder not otherwise specified (PDD-NOS) (n ¼ 6). Complete demographic information can be found in Table I. Measures Pittsburgh Sleep Quality Index (PSQI) The PSQI is a well-validated 19-item self-report measure of sleep quality in adults over the previous month (Buysse, Reynolds, Monk, Berman, & Kupfer, 1989). The PSQI provides a global score of sleep quality and seven subscale scores (Table I). A total score of 5 has been recommended as clinically significant in terms of poor sleep quality. The PSQI has demonstrated good validity and reliability (Cronbach s a >0.8) (Carpenter & Andrykowski, 1998). Participants completed the PSQI at the initial home visit, prior to wearing the actigraphy.

3 382 L. J. Meltzer Table I. Demographic and Sleep Variables for Caregivers ASD TD Variable Mothers (n ¼ 20) Fathers (n ¼ 12) Mothers (n ¼ 15) Fathers (n ¼ 10) Age (mean, SD) 37.5 (4.9) 40.1 (5.3) 39.3 (6.6) 40.8 (5.4) Range Years of education (mean, SD) 14.9 (2.5) 15.5 (3.5) 15.5 (2.6) 15.1 (3.2) Range Race Caucasian 17 (85.0%) 11 (91.7%) 12 (80.0%) 8 (80.0%) Black/African-American 2 (10.0%) 1 (8.3%) 2 (13.3%) 2 (20.0%) Other 1 (5.0%) 1 (6.7%) Marital status Married 12 (60.0%) 10 (83.3%) 12 (80.0%) 10 (100%) Not married 8 (40.0%) 2 (16.7%) 3 (20.0%) Employment status Full-time 10 (50.0%) 12 (100%) 4 (26.7%) 9 (90.0%) Part-time 4 (20.0%) 6 (40.0%) 1 (10.0%) Not currently working 6 (30.0%) 5 (33.3%) Child age (SD) 6.3 (2.1) 6.4 (2.2) 6.5 (2.4) 6.7 (2.5) Range Child sex Male 15 (75.0%) 10 (83.3%) 9 (60.0%) 7 (70.0%) Female 5 (25.0%) 2 (16.7%) 6 (40.0%) 3 (30.0%) SCQ score (n, SD) Autism 21.0 (10, 4.5) 20.7 (6, 4.0) Asperger s disease 18.0 (4, 1.4) 18.7 (3,.6) PDD-NOS 18.7 (6, 6.4) 19.3 (3, 4.0) Subjective sleep variables PSQI sleep quality 1.33 (.73) 1.33 (.65) 1.13 (.52).90 (.99) PSQI sleep onset latency 1.15 (.99) 1.00 (.95) 1.00 (.85).90 (1.20) PSQI sleep duration 1.55 (1.14) 1.50 (.90) 1.10 (.88) 1.70 (.82) PSQI sleep efficiency.65 (.88).33 (.49).73 (1.03).70 (.82) PSQI sleep disturbances 1.30 (.47) 1.50 (.52) 1.40 (.51).90 (.57) PSQI sleep medications.10 (.31).08 (.29).60 (1.12).50 (1.08) PSQI daytime functioning 1.35 (.88) 1.33 (.65).87 (.83) 1.20 (.79) PSQI total score 7.43 (3.41) 7.08 (2.15) 6.80 (3.99) 6.80 (5.09) Diary sleep quality 51.2 (16.8) 57.0 (16.3) 57.4 (13.8) 67.6 (10.9) Objective sleep variables (Actigraphy) Bedtime 23:36 (66) 23:28 (50) 23:38 (78) 23:59 (68) Wake time 6:35 (49) 5:54 (45) 7:12 (55) 6:42 (42) Time in bed (min) 418 (52) 387 (38) 455 (58) 403 (62) Actual sleep time (min) 349 (40) 304 (37) 401 (69) 330 (87) Sleep efficiency (%) 84.2 (8.2) 79.2 (7.9) 87.9 (8.7) 81.3 (13.3) Longest sleep period (min) (55) 90.8 (24) (70) (83) Night waking frequency (median) 2.6 (1.8) 2.7 (0.9) 2.2 (1.6) 2.3 (1.8) Night waking duration (median min) 13.1 (10.0) 12.2 (2.0) 10.7 (3.8) 14.1 (6.0) Possible range for the PSQI subscales is 0 3 for each scale, with possible range for Total Score Higher scores for all scales represent poorer sleep. Possible range for Diary Sleep Quality is Actigraphy bedtime and wake time expressed by 24 h clock, SD expressed in minutes. Actigraphy An actigraph (MicroMini-Motionlogger, Ambulatory Monitoring Inc., Ardsley, NY, USA) is a wrist-watch sized motion detector that has been shown to be highly valid and reliable for differentiating sleep from wakefulness (Jean-Louis et al., 1996; Sadeh & Acebo, 2002), as well as recording total sleep time (r ¼.97 compared to polysomnography) (Jean-Louis et al., 1996). Participants wore an

4 Sleep in Parents 383 actigraph for 7 consecutive nights on their nondominant wrist. Sleep patterns were estimated using the validated Sadeh scoring algorithm developed for adults and adolescents (Sadeh, Sharkey, & Carskadon, 1994). Actigraphic sleep measures included: (a) sleep onset/ bedtime; (b) sleep offset/wake time, (c) time in bed (minutes from sleep onset to sleep offset), (d) actual sleep time (number of sleep minutes between sleep onset and sleep offset), (e) sleep efficiency (actual sleep time divided by time in bed, expressed as a percent), (f) longest sleep period (longest consecutive period scored as sleep without any identified awakening), (g) median number of nighttime wakings (at least 5 consecutive minutes), and (h) median length of nighttime wakings Sleep Diary During the week participants wore the actigraph, they were asked each morning to rate their previous nights sleep using a visual analog scale (VAS, 100 mm line, 0 ¼ very poorly, 100 ¼ excellent). These VAS sleep quality ratings were averaged over the week, providing a sleep quality score for the same week as the objective actigraphy data. Results Demographic variables No significant differences were found between the two groups (ASD and TD) on any demographic variable (Table I). Similarly, no significant demographic differences were found between the three ASD diagnosis groups (autism, AD, and PDD-NOS). Subjective Sleep Quality To examine differences in sleep quality between groups (hypothesis 1), parents (hypothesis 2), and the interaction between parent and group (hypothesis 3), a 2 2 multiple analysis of variance (MANOVA) was performed on eight dependent variables (DV; PSQI subscales and diary sleep quality). The combined DVs were significantly affected by group, F(8,46) ¼ 3.12, p ¼.007, partial Z 2 ¼.35, but not by parent, F(8,46) ¼ 1.26, p ¼.29, partial Z 2 ¼.18, or the interaction between group and parent, F(8,46) ¼ 1.79, p ¼.10, partial Z 2 ¼.24. A post hoc one-way ANOVA showed poorer diary sleep quality for the ASD group compared to the TD group, while parents of TD children took sleep medications more frequently than the ASD group (Table II). Table II. Means, Standard Deviations, and Analysis of Variance (ANOVA) Results for Sleep Variables as a Function of Group and Parent Group Dependent Variable ASD (n ¼ 32) TD (n ¼ 25) F (1,55) Mothers (n ¼ 35) Fathers (n ¼ 22) F (1,55) Subjective sleep PSQI sleep quality 1.33 (.69) 1.04 (.73) (.64) 1.14 (.83).33 PSQI sleep onset latency 1.09 (.96).96 (.98) (.92).95 (1.04).22 PSQI sleep duration 1.53 (1.05) 1.32 (.90) (1.10) 1.59 (.85) 1.18 PSQI sleep efficiency.53 (.76).72 (.94) (.93).50 (.67).57 PSQI sleep disturbances 1.38 (.49) 1.20 (.58) (.48) 1.23 (.61) 1.16 PSQI sleep medications.09 (.30).56 (1.08) 4.82*.31 (.80).27 (.77).08 PSQI daytime functioning 1.34 (.79) 1.00 (.82) (.88) 1.27 (.70).51 PSQI total score 7.30 (2.96) 6.80 (4.36) (3.62) 6.95 (3.68).03 Diary sleep quality (16.56) (13.44) 4.20* (15.6) (14.8) 3.75 Objective sleep (Actigraphy) Bedtime 23:33 (60) 23:46 (73).83 23:37 (70) 23:42 (59).13 Wake time 6:19 (51) 7:00 (51) 9.99** 6:51 (54) 6:16 (49) 6.91** Time in bed (min) (49) (63) (56) (49) 8.22** Actual sleep time (min) (44) (83) 5.90* (59) (64) 12.97*** Sleep efficiency (%) 82.3 (8.4) 85.2 (11.0) (8.5) 80.2 (10.5) 5.11* Longest sleep period (min) (52) (74) (61) (61) 4.69* Night waking frequency (median) 2.6 (1.5) 2.3 (1.6) (1.7) 2.5 (1.3).05 Night waking duration (median min) 12.8 (7.9) 11.8 (4.9) (7.9) 13.0 (4.2).23 Possible range for the PSQI subscales is 0 3 for each scale, with possible range for Total Score Higher scores for all scales represent poorer sleep. Possible range for Diary Sleep Quality is Actigraphy bedtime and wake time expressed by 24 h clock, SD expressed in minutes. *p.05; **p.01; **p.001. Parent

5 384 L. J. Meltzer Although no significant difference was found for the PSQI total score, the means for both groups were above the suggested clinical cutoff of 5. When the sample was divided into above and below the cutoff, a chi-squared analysis revealed a group difference for PSQI total score, w 2 (1, n ¼ 57) ¼ 3.72, p ¼.05, with more ASD parents having elevated PSQI scores compared to TD parents (66 vs. 40%). No difference was found between the percent of mothers and fathers with scores above and below the PSQI cutoff, w 2 (1, n ¼ 57) ¼.32, n.s. Objective Sleep Patterns To examine differences in sleep patterns between groups (hypothesis 1), parents (hypothesis 2), and the interaction between parent and group (hypothesis 3), a 2 2 MANOVA was performed on eight dependent variables (actigraphic sleep variables). The combined DVs were significantly affected by group, F(8,46) ¼ 3.24, p ¼.005, partial Z 2 ¼.36, and by parent, F(8,46) ¼ 2.62, p ¼.02, partial Z 2 ¼.31, but not the interaction between group and parent, F(8,46) ¼.65, p ¼.73, partial Z 2 ¼.10. Post hoc ANOVAs (Table II) showed an earlier wake time and shorter actual sleep time for parents in the ASD group compared to the TD group. Regardless of group, fathers had an earlier wake time, shorter time in bed, shorter actual sleep time, lower sleep efficiency, and shorter longest sleep period compared to mothers. Relationship Between Subjective and Objective Sleep Measures To explore whether the subjective and objective sleep measures were examining the same or different constructs, Pearson correlations were used. Although the PSQI total score was significantly related to the diary sleep quality (r ¼.47, p <.001), there were no significant relationships found between the PSQI or diary sleep quality and any of the objective sleep variables (r s range.17 to. 08). Discussion This exploratory study is one of the first to measure both sleep quality and sleep wake patterns in parents of children with and without ASDs using validated measures. As expected, compared to parents of TD children, parents of children with ASDs reported poorer sleep quality as well as an earlier morning wake time and shorter sleep duration. These results are consistent with previous studies that have found poorer sleep quality and more sleep disruptions in parents of children with intellectual disabilities including ASDs (Allik et al., 2006b; Didden, Korzilious, Aperlo, Overloop, & Vries, 2002; Polimeni et al., 2005; Wiggs & Stores, 2001). This study extends the current literature by focusing only on parents of children with ASDs and by using validated measures of sleep quality and sleep wake patterns. Over time, the poorer sleep quality and shorter sleep duration experienced by parents of children with ASDs may result in CPSD, and contribute to or exacerbate the stress related to raising a child with an ASD (Polimeni et al., 2007; Wiggs & Stores, 2004). Contrary to the hypothesis, fathers in both groups had significantly earlier wake times and shorter sleep duration than mothers. While unexpected, these findings are consistent with studies of men and women in the general population. It is possible that fathers in this study were waking earlier for reasons other than caring for their child (e.g., work schedule, stress). However, the question of differences between parents may have been limited by the small sample size and lack of power to detect significant interactions. For example, when examining the descriptive data (Table I), it is notable (and clinically meaningful) that mothers of children with ASDs woke 37 min earlier and got an average of 51 min less sleep per night compared to mothers of TD children. Future studies should include larger samples and more information about reasons for wake times and sleep disruptions (e.g., caring for child, stress about child, or bed partner snoring). Finally, consistent with previous studies of sleep in children with developmental disorders, including ASDs (Corkum, Tannock, Moldofsky, Hogg-Johnson, & Humphries, 2001; Hering et al., 1999), subjective sleep quality was not directly related to objective sleep wake patterns. It is possible that the temporal differences between the PSQI (reporting on the previous month) and actigraphy (prospectively measuring sleep over 1 week) contributed to this lack of a relationship. However, the sleep quality rating from the diary was measuring the same week as the actigraph, with no direct relationship found between sleep quality and quantity. Some investigators have suggested that after dealing with a child s challenging behaviors during the day, disrupted sleep patterns may be reported as more severe by parents of children with autism (Hering et al., 1999; Schreck & Mulick, 2000). As subjective and objective measures of sleep address different constructs (sleep quality vs. sleep patterns), both types of measures should be included in future research to maximize the understanding of sleep quality and sleep wake patterns in parents of children with ASDs. There are a number of strengths and limitations in this study. A primary strength is the inclusion of fathers.

6 Sleep in Parents 385 As family-centered care has become the standard of practice in many pediatric medical communities, it is important to consider that fathers of children with ASDs may also experience sleep disruptions related to their child. The recruitment of families from the community rather than an autism treatment clinic was both a strength and limitation. While the families in this study may be a more representative sample of the population than a clinical sample, the small sample size in this study has limited the generalizability of the results. In addition, there may have been a selection bias as participants in both groups responded to advertisements to participate in a study of parent and child sleep. Anecdotally, some families in the ASD group asked if they could participate even if their child did not currently have significant sleep problems, while some families in the TD group stated a desire to participate due to their child s ongoing sleep problems. Thus, sleep quality and sleep disturbances in parents of children with ASDs may have been diminished or negated by this sample bias. Further, the higher rates of medication usage in the TD group may have contributed to their longer total sleep time. This confound should be controlled in future studies. Finally, although written documentation was provided, and the SCQ was used as a screener, no diagnostic reassessment of the child s autism was performed. Despite these limitations, this study provides a significant contribution to the literature, demonstrating that along with poorer sleep quality, parents of children with ASDs sleep less than parents of TD children. In addition, self-report questionnaires and actigraphy should both be included in studies of parent and child sleep, as these measures focus on different aspects of sleep. Future research should examine the direct relationship between child and parent sleep, and consider improved parent sleep as an outcome of interventions designed to improve sleep problems in children with ASDs (Wiggs & Stores, 1998, 2001). While it remains to be determined in parents of children with ASDs, improvements in parent sleep may contribute to less parental stress and improved daytime functioning for the entire family. Acknowledgments This study was supported by the Sleep Research Society Foundation. I would like to thank the families who participated in this study, and my research assistants, Kelly Ann Davis, Christine Leas, Lisa Levandoski, Raymond Morris, and Allison Reamy, who helped with data collection and entry. In addition, I thank the network of primary care physicians for their contribution to clinical research through the Pediatric Research Consortium (PeRC) at The Children s Hospital of Philadelphia. Conflicts of interest: None declared. Received May 2, 2007; revisions received January 9, 2008; accepted January 10, 2008 References Allik, H., Larsson, J., & Smedje, H. (2006a). Healthrelated quality of life in parents of school-aged children with Asperger syndrome or high-functioning autism. Health and Quality of Life Outcomes, 4. Allik, H., Larsson, J. O., & Smedje, H. (2006b). Sleep patterns of school-age children with Asperger syndrome or high-functioning autism. Journal of Autism and Developmental Disorders, 36, Buysse, D. J., Reynolds, C. F., Monk, T. H., Berman, S. R., & Kupfer, D. J. (1989). The Pittsburgh Sleep Quality Index: A new instrument for psychiatric practice and research. Psychiatry Research, 28, Cabrera, N. J., Tamis-LeMonda, C. S., Bradley, R. H., Hofferth, S., & Lamb, M. E. (2000). Fatherhood in the twenty-first century. Child Development, 71, Carpenter, J. S., & Andrykowski, M. A. (1998). Psychometric evaluation of the Pittsburgh Sleep Quality Index. Journal of Psychosomatic Research, 45, Corkum, P., Tannock, R., Moldofsky, H., Hogg-Johnson, S., & Humphries, T. (2001). Actigraphy and parental ratings of sleep in children with attention-deficit/hyperactivity disorder (ADHD). Sleep, 24, Didden, R., Korzilius, H., van Aperlo, B., van Overloop, C., & de Vries, M. (2002). Sleep problems and daytime problem behaviours in children with intellectual disability. Journal of Intellectual Disability Research, 46, Dinges, D. F., Rogers, N. L., & Baynard, M. D. (2005). Chronic sleep deprivation. In M. H. Kryger, T. Roth, & W. C. Dement (Eds.), Principles and practice of sleep medicine (4th ed., pp ). Philadelphia, PA: Elsevier Saunders. Doo, S., & Wing, Y. K. (2006). Sleep problems of children with pervasive developmental disorders: Correlation with parental stress. Developmental Medicine and Child Neurology, 48,

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