Gender Differences in Sleep, Fatigue, and Daytime Activity ina Pediatric Oncology Sample Receiving Dexamethasone
Stacy D. Sanford, PHD, James O. Okuma, MS, Jianmin Pan, PHD, Deo Kumar Srivastava, PHD,Nancy West, BSN, Lynne Farr, PHD and Pamela S. Hinds, PHD, FAANSt Jude Children’s Research Hospital, Memphis
Objective To examine gender differences in sleep, fatigue, and daytime activity in a sample of childrenwith acute lymphoblastic leukemia (ALL).
Participants included 88 children in maintenance
treatment for ALL (34 girls; 54 boys). Participants wore an actigraph for 10 consecutive days (5 dayspre-dexamethasone and 5 days during dexamethasone administration). Fatigue instruments were alsoadministered.
Girls napped more and had less fragmented night sleep than boys did. Wake time
after sleep onset was sensitive to dexamethasone administration, revealing a differential direction ofresponse for girls and boys. No gender differences were observed for subjective fatigue or daytime activityin the total sample.
Our preliminary findings support gender differences in the sleep of
children with cancer after controlling for differences in age, treatment, and risk group. Future researchthat focuses on the etiology of gender differences and developing interventions will help clarify the clinicalapplication of our findings.
actigraphy; acute lymphoblastic leukemia; dexamethasone; fatigue; gender differences;
Within the conceptual framework of the biopsychosocial
disturbing treatment-related symptom in children with
model of illness, gender differences are important as they
cancer in two longitudinal studies (Hinds et al., 2000;
may permeate all three aspects of the model including
Hinds, Scholes, Gattuso, Riggins, & Heffner, 1990).
biological sex differences, psychological gender identity,
Activity levels are of interest as inactivity may represent a
and societal gender expectations or stereotypes (Engel,
mechanism underlying fatigue in survivors of ALL
1977). Gender-specific medicine has gained relevance as
(Meeske, Siegel, Globe, Mack, & Berstein, 2005).
the scientific community continues to recognize gender
Finally, poor sleep may compromise immune functioning,
differences in normal human functioning, pathophysiol-
endocrine functioning, and other health-related outcomes
ogy, treatment response, and disease manifestation.
(Lee, Cho, Miaskowski, & Dodd, 2004; Spiegel, Leproult,
Consequently, it is important that pediatric medicine
& Van Cauter, 1999); therefore, assessment and treat-
verify the existence of gender differences, ascertain the
ment of disturbed sleep, fatigue, and inactivity are vital in
mechanisms underlying such differences, and facilitate
populations with cancer. Moreover, within the context of
the development of treatment modalities or adjustments
gender-specific medicine, ascertaining the presence of
tailored to patient gender. Accordingly, this study aimed
gender differences in their behavioral manifestation is
to examine gender differences in sleep, fatigue, and
daytime activity in children receiving maintenance treat-
Previous studies have shown administration of
ment for acute lymphoblastic leukemia (ALL). These
prednisone, an anticancer steroidal medication, negatively
symptoms are of interest in this population as studies of
affects sleep and daytime functioning in children with
persons with cancer suggest that they are prevalent
cancer (Drigan, Spirato, & Gelber, 1992; Harris, Carel,
(Theobald, 2004). Indeed, fatigue was rated the most
Rosenberg, Joshi, & Leventhal, 1986). Similarly, data
All correspondence concerning this article should be addressed to Stacy Sanford, PhD, St Jude Children’s ResearchHospital, 332 N. Lauderdale St MS, 740, Memphis TN 38105, USA. E-mail: [email protected]
Journal of Pediatric Psychology 33(3) pp. 298–306, 2008
Advance Access publication November 17, 2007
Journal of Pediatric Psychology vol. 33 no. 3 ß The Author 2007. Published by Oxford University Press on behalf of the Society of Pediatric Psychology.
All rights reserved. For permissions, please e-mail: [email protected]
Gender Differences in Pediatric Oncology Sleep
presented here were collected as part of a larger study that
fatigue than boys (Hockenberry et al., 2003). Two studies
aimed to establish the relations between systemic exposure
of childhood cancer survivors found females to have
to dexamethasone (also an anticancer steroidal medication)
higher self-reports of fatigue than males did (Meeske
and adverse behavioral effects on sleep and fatigue in
et al., 2005; Mulrooney et al., 2004;). Meeske et al.
children receiving maintenance treatment for ALL (Hinds,
(2005) posited that inactivity represents a mechanism
2007a). Dexamethasone was specifically targeted for this
underlying fatigue in ALL survivors; thus this aspect of
study because it is central to contemporary treatment of
daytime functioning should be assessed.
ALL, is more potent than prednisone when given at a
Evidence supports gender differences in daytime
conventional dosage, and is associated with serious adverse
activity levels of healthy children, but the extent to which
events including osteonecrosis and changes in sleep and
age and maturity interact with these differences is clouded
fatigue (Bostrom et al., 2003; Drigan et al., 1992; Harris
by the variability in methodology (e.g., subjective ratings
et al., 1986; Kaspers, Pieters, & Veerman, 1997). Results
of activity vs. objective measures such as actigraphy or
of the published primary analysis revealed a significant
assessment of biological vs. chronological age). A study
decrease in nocturnal awakening and increases in subjective
that used accelerometers with healthy children found boys
fatigue, total sleep time, and duration of daytime naps after
to be more active than girls across age groups, with overall
dexamethasone administration. Despite some variability
activity levels decreasing for both genders as they approach
with respect to age and ALL risk group, the authors
adolescence (Riddoch et al., 2004). In contrast, a study
concluded that dexamethasone treatment adversely altered
using self-report measures of activity found gender
sleep and fatigue in children and adolescents with ALL, the
differences in daytime activity to dissipate after controlling
effect being cumulative over the 5-day drug study period.
for biological versus chronological age (Thompson, Baxter-
Our work is a secondary analysis that will not only clarify the
Jones, Mirwald, & Bailey, 2003).
relationship of gender with sleep, fatigue, and daytime
Our aim was to examine gender differences in sleep,
activity in this sample but also determine whether
fatigue, and daytime activity in a sample of children with
dexamethasone administration influences any observed
cancer that is homogenous in terms of diagnosis, time point
in treatment, and receipt of dexamethasone. The following
Gender differences in the physiology and behavioral
hypotheses were tested: (a) sleep variables differ by gender,
manifestations of sleep have been previously documented
with boys demonstrating more disturbed sleep (in terms of
more nocturnal awakenings and wake time after sleep
Guilleminault, & Vitiello, 2004). There is evidence to
onset) and girls demonstrating longer duration of sleep
support gender differences in sleep across the develop-
(in terms of greater total sleep time); (b) fatigue scores differ
mental lifespan, but few studies have focused on gender
by gender, with girls having higher levels of subjective
differences in children’s sleep. Within existing studies,
fatigue than boys; (c) girls demonstrate greater daytime
there are differences in the samples and methodology.
napping as additional support for gender differences in the
Previous studies on healthy children from Israel and Japan
fatigue experience; and (d) daytime activity level differs by
have found gender differences in sleep by using an
gender, with boys demonstrating greater daytime activity
actigraph, a nonintrusive, wristwatch-style device that
than girls. Also, interactions between gender and dexa-
objectively records movement and is accompanied by
methasone administration on variables of sleep, fatigue, and
software that produces a number of quantitative activity
activity were examined. Data were explored within and
and sleep variables. One such study of 13- to 14-year-old
across risk groups as group differences on study variables
Japanese school children (Gaina, Sekine, Hamanishi, Chen,
were anticipated due to known differences in dosage and
& Kagamimori, 2005) indicated that girls performed better
treatment (e.g., more aggressive treatment for standard-risk
than boys on sleep indicators, with boys having more
groups). To our knowledge, no studies have examined
inefficient sleep and more awakenings. Sadeh, Raviv, and
gender differences in sleep, fatigue, and daytime activity in
Gruber (2000) reported similar results in 140 healthy Israeli
children (2nd, 4th, and 6th graders), with girls havinglonger and more motionless sleep than boys.
With respect to fatigue, gender differences have been
reported in children with cancer as well as cancer
survivors. A study of 149 children receiving chemother-
To be eligible for participation, children (and parents)
apy for cancer found girls to self-report more frequent
had to be English speaking, 5- to 17-years old, available
Table I. Demographic Characteristics of 88 Children with ALL
to participate at the designated time point in treatment,
and willing to give assent (children) and consent
Participants were recruited from the three sites and from
(parents). Participants initially included 100 children
three large cancer treatment protocols. Participants at
with low- or standard-risk ALL, all of which were in the
St Jude Children’s Research Hospital were treated on the
same maintenance period of treatment, and receiving
Total XV protocol; participants at the Texas Children’s
the same continuation therapy at one of three sites:
Cancer Center and the Hospital for Sick Children were
St Jude Children’s Research Hospital, Memphis, TN,
treated on Children’s Oncology Group (COG) 9904 and
USA; Texas Children’s Cancer Center, Houston, TX, USA;
COG 9905 studies. COG is a multisite international
or the Hospital for Sick Children, Toronto, Canada. The
pediatric cancer cooperative group. The Total XV and
study was approved by the institutional review board at
COG protocols aim to increase the cure rate in children
all three study sites. Because 12 of the 100 participants
and adolescents with ALL. The therapy used in these
in the primary study lacked actigraphy data due to
protocols is risk directed; that is, the appropriate intensity
equipment failure or insufficient recordings, the sample
of treatment is matched to disease severity and patient
size for the secondary analysis was reduced to 88.
characteristics. Disease characteristics were precisely
This 12% reduction is less than that reported in previous
determined and confirmed by early response to therapy.
pediatric actigraphy studies (28%; Acebo et al., 1999).
Dexamethasone dosing differed by risk group for the
The distribution of participants by age, gender, ethnicity,
Total XV protocol and the COG protocols: Total XV
and risk group is presented in Table I. The distribution
participants [low risk: (8 mg/m2/day)/TID for 5 days (total
of age was significantly different among the four risk
pulse 40 mg/m2); standard risk: (12 mg/m2/day)/TID for
groups (younger mean age in low-risk groups) and boys
5 days (total pulse 60 mg/m2)] received higher doses than
were significantly younger than girls. Both these differ-
COG participants [low and standard risk: (6 mg/m2/day)/
ences were expected because of known differences in
BID for 7 days (total pulse 42 mg/m2; 5-day pulse,
risk factors and prevalence rates of ALL by gender and
age. However, gender did not differ by risk group.
In the prospective repeated-measures study, partici-
Eighty-four eligible participants declined to enroll
pants served as their own control. Participation was
in the study (refusal rate 45%), with more girls declining
voluntary and no compensation was provided. The
than boys (52 vs. 40%) and more adolescents declining than
timing of the 10-day period of data collection (after week
children (50 vs. 44.6%). Refusal rates were similar across
50 of treatment) was selected because of (a) similarity
ethnicities. The participant burden for the primary study
in treatment across risk groups by clinical trial, (b) low
was considerable, including blood sampling for assessing
intensity of treatment demands on participants and
pharmacokinetics. The refusal rate for this study was not
families, (c) availability of participants and parents
discrepant from other studies that have involved similar
for scheduled follow-ups and assessments, and (d)
patients, methods (blood sampling), and burden (Gattuso,
Hinds, Tong, & Srivastava, 2006).
(the participants’ home) for the two 5-day study periods.
Gender Differences in Pediatric Oncology Sleep
Recruitment was based on planned follow-up visits;
therefore, nurse coordinators for the protocols could
Fatigue was assessed by three respondent-specific scales
notify study personnel when an eligible patient was
(child, adolescent, and parent). While developing these
scheduled to return during the data collection weeks.
scales, qualitative data from respondents indicated that
Research staff then contacted eligible patients and their
the fatigue experience differs between children and
parents. Enrolled patients had the actigraph applied in
adolescents; therefore, development of and assessment
the outpatient clinic. During the first 5 days, participants
with differing instruments was warranted. For children,
did not receive dexamethasone (pre-dex), and during
fatigue is defined as a profound sense of being weak or
the second consecutive 5 days they received dexamethasone
tired or of having difficulty with movement as measured
(on-dex) at the doses previously presented. Variables of
by the FS-C. The FS-C was designed for children aged
activity/rest and sleep/wake were measured with a 24-hr
7–12 years. This self-report instrument consists of 14
wrist actigraph (dominant wrist), worn by participants
items that describe the intensity of the participant’s
for all 10 consecutive days. Participants at least 7-years
fatigue on a 5-point Likert scale in the past 24 hr.
old completed a self-report fatigue instrument on days 2
Intensity ratings range from 0 (no fatigue symptoms) to 70
and 5 of each treatment week. A parent-report fatigue
(high fatigue). The FS-C has been reviewed for face,
instrument was also administered on the same days for
content, and construct validity (Hinds & Hockenberry-
Hockenberry et al., 2003). It has been completed by150 children with cancer in the most recent testing and
found to be internally consistent (a ¼ .84). Alpha
coefficients ranged from .72 to .81 in our investigation.
The Mini Motionlogger AAM-32 (Ambulatory MonitoringInc., Ardsley, NY, USA) is a nonintrusive wristwatch-style
device that objectively records movement or physical
For adolescents, fatigue is defined as a complex changing
activity. It contains a biaxial piezoelectric sensor and a
state of exhaustion that may be a physical condition,
microprocessor with programmable epoch length. Data-
a mental or emotional state, or a combination of physical,
storage capacity is determined by the epoch length;
mental, and emotional tiredness as measured by the FS-A.
for this study, the epoch length was 1 min, as suggested
This self-report instrument similar to the FS-C but
by Littner et al. (2003). The system’s accompanying
designed for adolescents aged 13–18 years. It is
software was used to extract several quantitative activity/
composed of a 14-item scale in which the intensity of
rest and sleep/wake variables. Sleep was estimated by
each fatigue item is rated on a 5-point Likert scale,
the algorithm reported by Sadeh, Sharkey, and Carskadon
with intensity ratings ranging from 14 (no fatigue
(1994), which has been validated within samples of
symptoms) to 70 (high fatigue) in the past 24 hr. The
children and adolescents; our 10-day study design
FS-A has demonstrated good reliability (a ¼ .67–.95) as
exceeds the criterion for number of nighttime recordings
well as face, content, and construct validity (Hinds
necessary for reliable actigraph assessments (Acebo et al.,
& Hockenberry-Eaton, 2001; Hinds et al., 2007b;
1999). For a detailed review of practice parameters
Hockenberry-Eaton & Hinds, 2000; Hockenberry et al.,
and the role of actigraphy in the study of sleep, see
2003). Alpha coefficients ranged from .89 to .95 in our
Littner et al. (2003). Nocturnal variables extracted for this
study were (a) number of awakenings (NWAK), (b) waketime after sleep onset (min) (WASO), and (c) total night
sleep time (min). Daytime variables were (a) mean
For parents, fatigue is defined as a state of diminished to
daytime activity (min), (b) total day sleep time (min),
complete loss of energy that is influenced by disease
(c) number of naps, (d) mean nap duration (min),
state, nutritional, emotional, environmental, personal/
and (e) day sleep percent or percentage of the wake
behavioral, family, and treatment-related factors as
period spent sleeping. These key terms were recom-
measured by the FS-P. The FS-P consists of 17 items
mended via Berger et al. (2007) via the National Cancer
that measure parents’ perception of their child’s fatigue in
Institute State of the Science Conference on Sleep/
the past 24 hr on a 5-point Likert scale, with intensity
Wake Disturbances in People with Cancer and Their
scores ranging from 17 (no fatigue) to 85 (high fatigue).
The FS-P has been completed by 150 parents with
Table II. Descriptive Statistics for Night Sleep/Wake, Day Rest/Activity, and Fatigue Variables
n, number of participants; NWAK, number of awakenings; WASO, wake time after sleep onset; Pre-dex, week prior to administration of dexamethasone; On-dex, duringadministration of dexamethasone.
children of all ages and has acceptable internal consis-
differences within each risk group, since the four risk
tency (a ¼ .87; Hinds & Hockenberry-Eaton, 2001;
groups were not homogeneous with regard to treatment
Hockenberry-Eaton & Hinds, 2000; Hockenberry et al.,
(including dexamethasone dose) and age. Such analyses
2003). Alpha coefficients ranged from .91 to .92 in our
were not conducted for the COG low-risk group because
of its relatively small sample size (n ¼ 13). Please notethat the risk group analyses were exploratory as we lackedsufficient power to draw firm conclusions. Stratified two-
sample Wilcoxon–Mann–Whitney tests were completed
Independent longitudinal analyses using a Linear Mixed
for each fatigue instrument to test for gender differences
Effect model as described in Diggle, Heagerty, Liang, and
Zeger (2005) were completed to assess the effects ofgender on each night sleep/wake and day activity/restvariable. We used the PROC MIXED procedure from thestatistical software package SAS 9.1 (SAS Institute Inc.,
2000). Longitudinal analysis in which actigraphy data is
examined for every 24-hr time period as opposed to
Table II provides means and standard deviations for each
considered superior for such data as it considers the
night sleep/wake and day activity/rest variable. Generally
correlation among the observations of the same patient
speaking children had very disturbed sleep with an
over time. It is also relevant to our data because previous
average of 12 awakenings or more per night and WASO
studies show that the effects of dexamethasone are
of 1 hr or more. Even so, their total sleep time was not
cumulative (Hinds et al., 2007a). Longitudinal analyses
indicative of inadequate sleep duration as they slept as a
were completed with each of the night sleep/wake and
group >8 hr per night on average. Table III summarizes
day activity/rest variables modeled as dependent variables.
the longitudinal regression analyses. The r2 used here is
Week of treatment (pre-dex vs. on-dex) and gender (male
the generalization of R2 for linear regression framework to
vs. female) were entered into the model as were covariates
the linear mixed-effects model proposed by Xu (2003).
of age (years) and risk group. We aimed to specifically
This value represents the explained variation in the
evaluate gender differences for each sleep/fatigue variable
comprehensive model including covariates of age and risk
after adjusting for these other covariates given known
group. Main effects for gender were found with boys
variations in risk group and age (Hinds et al., 2007a)
having significantly more NWAK and WASO than girls
We also performed an exploratory analysis on gender
did across treatment periods. For WASO, there was also
Gender Differences in Pediatric Oncology Sleep
Table III. Longitudinal Regression Results for All Participants
r2, the total variance explained by the comprehensive model that includes variables as seen above as well as covariates of risk group and age; NWAK, number of awakenings;WASO, wake time after sleep onsetBold values signify statistical significance. *p < .05, **p < .01, ***p < .001.
an interesting interaction between gender and week of
differences on the parent, child, or adolescent fatigue
treatment, with WASO decreasing in girls and increasing
scales after adjusting for risk group. However, these
in boys during the on-dex treatment period. There was no
results must be interpreted with caution because after risk
gender difference in total night sleep time. Boys and girls
group adjustment, some of the comparisons were based
did not differ in mean daytime activity level; however,
on very few participants. Because of these concerns, we
girls had significantly higher total day sleep time, number
did not explore gender differences within risk groups or
of naps, mean nap duration, and day sleep percent than
by age. Further, risk groups were significantly different by
age and fatigue measures were also age dependent.
Sleep/Wake and Activity/Rest Resultsby Risk Group
The following is a summary of the results from theexploratory longitudinal regression analyses completed by
The findings presented herein are supportive of gender
risk group. Results for the COG standard-risk group
differences in daytime and nocturnal sleep in children
were most similar to that of the total sample. Girls had
receiving treatment for ALL. The preliminary nature of
significantly fewer NWAK than boys did [F(1,22) ¼
this work prohibits us from drawing empirical conclu-
10.43, p < .01]. There was an interaction between
sions about how best to apply this knowledge in the
clinical setting; however, these findings are informative to
p < .05]. Specifically, girls had lesser WASO when on-
future research. From the perspective of gender-specific
dex (M ¼ 44.76; SD ¼ 21.91) than pre-dex (M ¼ 66.18;
medicine, because gender differences were found with
SD ¼ 55.25) and boys showed the opposite trend, with
some being sensitive to drug administration, researchers
more WASO on-dex (M ¼ 90.73; SD ¼ 63.17) than pre-
can develop and test new hypotheses regarding the
dex (M ¼ 76.24; SD ¼ 43.81). Girls had considerably
mechanisms that underlie these differences, be they
more daytime sleep than boys did across treatment
psychological (e.g., differential mood disturbance), social
periods by way of total day sleep time [F(1,22) ¼ 11.04,
(e.g., differential expectations regarding sleep/activity
p < .01], number of daytime naps [F(1,22) ¼ 13.36,
behavior), and/or biological (e.g., differential drug meta-
p < .01], mean nap duration [F(1,22) ¼ 8.38, p < .01],
bolism) in nature. Establishment of mechanisms may
and day sleep percent [F(1,22) ¼ 14.07, p < .01]. No
contribute to development of gender-specific interven-
gender differences were observed for the Total XV low- or
tions for sleep and fatigue (e.g., gender-specific sleep
(e.g., differential drug dosing) to ultimately improve
functioning and health-related quality of life in this
Table II gives means and standard deviations for each
population. Furthermore, the longitudinal effects of sleep
fatigue variable. There were no significant gender
disturbances and fatigue during treatment for ALL are
currently unknown, although there is evidence in the
to be conducted separately for the three instruments
survivorship literature that sleep problems and fatigue
(child, adolescent, and parent), thus resulting in small
are common in these individuals (Meeske et al., 2005;
sample sizes for fatigue analyses (e.g., only 13 partici-
Mulrooney et al., 2004; Mulrooney et al., 2007). The
pants in adolescent analysis). Consequently, statistical
degree to which their prevalence or severity are more
power may have been insufficient. Often, much larger
manifest in survivors of cancer than in healthy sibling
sample sizes are required to detect individual differences
controls is unclear; however, this does raises questions
such as gender differences. Another limitation is that
for future research as to why these symptoms might
there is currently no well-established cut score for these
persist including whether or not the etiology of these
instruments; therefore, it is unclear what score is
symptoms are the same from the point of treatment in
indicative of clinically significant fatigue.
childhood as they are as an adult survivor of cancer. The
We further anticipated daytime activity levels to
gender differences observed herein and within the
differ by gender, with boys having greater mean daytime
survivorship literature further supports the inclusion of
activity than girls; however, this hypothesis did not
gender-specific investigations in this line of inquiry.
hold true for the total sample. Although this result did
Finally, the implications of prolonged sleep disturbance
not support our hypothesis, literature on this topic is
and/or fatigue for health-related outcomes in persons with
conflicting (Riddoch et al., 2004; Thompson et al., 2003);
cancer are a matter for future investigation.
therefore, our result is not entirely unexpected. However,
The results of this preliminary work only partially
chronobiology studies on the impact of pediatric cancer
supported our hypotheses. The r2-values (Table III)
treatment on circadian rhythms in boys and girls may be
indicate that despite including many variables, relatively
more informative about and more sensitive to differences
little variance was accounted for within our comprehen-
in daytime activity and sleep patterns than was the
sive models. This is surprising and further study is
examination of distinct sleep and activity variables
required to determine the reason for the larger proportion
of observed variance especially given the magnitude of
Our exploratory analyses by risk group revealed
sleep disturbance experienced by the children. For
some gender differences on day and night sleep variables.
example, our sample experienced on average 11–17
There was variability among risk groups for several
awakenings per night. In contrast, a study of healthy
variables, including age, dexamethasone dosage, and
2nd, 4th, and 6th grade children revealed only one or
disease characteristics. Sample characteristics for the
two awakenings per night, as assessed by actigraph
COG and Total XV standard-risk groups were similar;
recordings (Sadeh et al., 2000). Boys in our sample
however, the gender effects observed for the COG group
showed more disturbed sleep than girls did both before
do not hold true for the Total XV group. The Total XV
and during administration of dexamethasone; however,
risk group received a much higher dose of dexamethasone
girls did not have more total nocturnal sleep time as
than the COG groups. The potent effects of higher
expected. Observed differences in WASO were particu-
doses of dexamethasone might overshadow gender
larly sensitive to dexamethasone administration and
differences observed in children receiving lower doses.
revealed a differential response for girls and boys.
Our future studies will focus on pharmacokinetics in this
Despite having less disturbed nocturnal sleep,
sample, which may help further elucidate the variance we
objectively girls demonstrated greater daytime napping
observed. Another interesting characteristic of the COG
in the total sample. This result suggests that gender
standard-risk group is that this is the only risk group that
differences may exist in the fatigue experience. Contrary
had a nearly equal number of boys and girls; the other
to this finding, gender differences were not found in
risk groups had considerably more boys than girls.
subjective fatigue. Gender differences in subjective fatigue
Results for this group more closely matched those of
may not exist in our sample because of the significant
the total sample than did the other risk groups and the
differences found in sleep disruption and daytime
difference in gender distribution may have contributed.
compensatory behavior (e.g., napping). Gender differ-
A discrete treatment difference may have contributed to
ences observed in other populations might be suppressed
this discrepancy, or the discrepancy might simply be a
in our sample by the more disturbed nocturnal sleep in
statistical anomaly. We can only speculate why sleep,
boys and higher rate or duration of napping in girls. In
fatigue, and daytime activity variables differed among risk
contrast, this null finding may have been due to
groups; however, these unique findings will guide future
limitations of our fatigue instrumentation. Analyses had
research on these observed differences.
Gender Differences in Pediatric Oncology Sleep
Our data include a relatively large number of
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longitudinal measurements on a specific pediatric medical
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Dexamethasone versus prednisone and daily oral
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