Women's Health Initiative Insomnia Rating Scale Research Articles

0030 Insomnia is associated with lower serum antioxidants in the Hispanic Community Health Study/Study of Latinos

Abstract Introduction Insomnia is associated with neurodegenerative diseases. Concentration levels of some metabolites are associated with pathophysiologic changes, possibly in a sex-specific manner. Thus, serum metabolite levels are useful for understanding insomnia-related pathophysiological changes and how they potentially relate to neurodegenerative disease. Methods The Hispanic Community Health Study/Study of Latinos (HCHS/SOL) is a longitudinal cohort study following self-reported Hispanic/Latino individuals in the U.S. At baseline, insomnia symptoms were captured using the Women Health Initiative Insomnia Rating Scale (WHIIRS), insomnia being defined as WHIIRS≥9. Metabolites were measured using blood serum from the baseline exam in independent discovery and replication datasets. In discovery, metabolite associations with WHIIRS and with insomnia were estimated in linear regression. Significant associations (FDR p-values< 0.05) were tested in the replication dataset and considered replicated if their p-value< 0.05 and the direction of association matched with the discovery analysis. Associations were further studied for gender interaction. All analyses were adjusted for age, self-reported gender, study center, and Hispanic/Latino background. Results 3,895 individuals participated in the discovery analysis, and 2,121 in replication analysis. Female individuals were aged 46.5 on average (SD 15.1) and 35% had insomnia, while male individuals were aged 44.8 (14.8) and 24% had insomnia. After quality control, 767 metabolites were tested for association. Six metabolites were associated with WHIIRS (FDR< 0.05) in the gender-combined analysis. Three were xenobiotics which were on the benzoate or salicylic acid metabolism pathway. Of the 6 metabolite associations, two replicated (p-value< 0.05): hydrocinnamate and indolepropionate. These two metabolites had spearman correlation of 0.44. Higher levels of both metabolites were associated with lower WHIIRS, showing stronger associations in females (interaction p-value =0.04 for hydrocinnamate and p-value=0.13 for indolepropionate). Associations remained essentially unchanged in a model further adjusting for hypertension and diabetes. When removing 534 individuals who self-reported using sleeping pills at least once a week, the associations attenuated slightly: from an effect estimates of -0.0075 to -0.0069 (hydrocinnamate) and from -0.0082 to -0.0068 (indolepropionate). Conclusion Among the HCHS/SOL target population, insomnia symptom severity is associated with a lower concentrations of some plasma metabolite levels which are important antioxidant needed in preventing oxidative stress and neurodegeneration. Support (if any) R01HL161012.

A Longitudinal Study of Sleep Habits and Leukemia Incidence Among Postmenopausal Women.

We sought to assess the relationship between sleep duration, sleep disturbance, and leukemia incidence among postmenopausal women. This study included 130,343 postmenopausal women aged 50-79 years who were enrolled in the Women's Health Initiative (WHI) during 1993-1998. Information on self-reported typical sleep duration and sleep disturbance was obtained by questionnaire at baseline, and sleep disturbance level was defined according to the Women's Health Initiative Insomnia Rating Scale (WHIIRS). WHIIRS scores of 0-4, 5-8, and 9-20 comprised 37.0%, 32.6%, and 30.4% of all women, respectively. After an average of 16.4 years (2,135,109 cumulative person-years) of follow-up, 930 of the participants were identified as having incident leukemia. Compared with women with the lowest level of sleep disturbance (WHIIRS score 0-4), women with higher sleep disturbance levels (WHIIRS scores of 5-8 and 9-20) had 22% (95% confidence interval (CI): 1.04, 1.43) and 18% (95% CI: 1.00, 1.40) excess risks of leukemia, respectively, after multivariable adjustment. A significant dose-response trend was found for the association between sleep disturbance and leukemia risk (P for trend = 0.048). In addition, women with the highest level of sleep disturbance had a higher risk of myeloid leukemia (for WHIIRS score 9-20 vs. WHIIRS score 0-4, hazard ratio = 1.39, CI: 1.05, 1.83). Higher sleep disturbance level was associated with increased risk of leukemia, especially for myeloid leukemia among postmenopausal women.

Correlates of daytime sleepiness and insomnia among adults in Samoa

To describe daytime sleepiness and insomnia among adults in Samoa and identify modifiable factors associated with these measures. Cross-sectional analysis of data from the Soifua Manuia ("Good Health") study (n = 519, 55.1% female); Upolu island, Samoa. Daytime sleepiness and insomnia were assessed with the Epworth Sleepiness Scale (ESS) and the Women's Health Initiative Insomnia Rating Scale (WHIIRS), respectively. Detailed physical, sociodemographic, and behavioral factors were collected. Sleep measures were characterized using multiple linear regression with backwards elimination and a bootstrap stability investigation. Excessive daytime sleepiness (ESS>10) and insomnia (WHIIRS>10) were reported by 20% and 6.3% of the sample, respectively. ESS scores were higher in individuals reporting more physical activity (Estimate=1.88; 95% CI=1.12 to 2.75), higher material wealth (0.18; 0.09 to 0.28), and asthma (2.85; 1.25 to 4.51). ESS scores were lower in individuals residing in periurban versus urban regions (-1.43; -2.39 to -0.41), reporting no work versus day shift work (-2.26; -3.07 to -1.41), and reporting greater perceived stress (-0.14; -0.23 to -0.06). WHIIRS scores were lower in individuals reporting "other" shift work (split/irregular/on-call/rotating) versus day shift work (-1.96; -2.89 to -1.14) and those who perceived their village's wealth to be poor/average versus wealthy (-0.94; -1.50 to -0.34). Participants had a generally higher prevalence of excessive daytime sleepiness, but lower prevalence of insomnia, compared with individuals from high-income countries. Factors associated with sleep health differed compared with prior studies, emphasizing potential cultural/environmental differences and the need for targeted interventions to improve sleep health in this setting.

Personality and insomnia symptoms in older adults: the Baltimore Longitudinal Study of Aging.

To examine associations of personality dimensions and facets with insomnia symptoms in a community sample of older adults. We studied 1049 participants aged 60-97 years in the Baltimore Longitudinal Study of Aging. Personality was assessed by the Revised NEO Personality Inventory (NEO-PI-R), and insomnia symptom severity was measured by the Women's Health Initiative Insomnia Rating Scale (WHIIRS). Adjusting for demographic characteristics, higher neuroticism, lower conscientiousness, and lower extraversion were associated with greater insomnia symptom severity. These associations remained significant for neuroticism and conscientiousness when further adjusting for depressive symptoms and comorbidities. Higher scores on neuroticism facets Anxiety, Angry Hostility, and Depression, and lower scores on conscientiousness facets Competence, Order, and Achievement Striving and on agreeableness facet Altruism were associated with greater insomnia symptom severity in fully adjusted models. Results were similar among cognitively normal older adults (N = 966), except higher scores on extraversion facets Warmth and Assertiveness associated with lower insomnia symptom severity, and agreeableness facet Altruism was unassociated. Among older adults, insomnia symptoms appear partially related to personality, with persons higher in neuroticism experiencing greater insomnia symptom severity, and those higher in conscientiousness experiencing lower insomnia symptom severity. Exploring facets of the Big-Five dimensions may provide additional insight regarding the etiology and resolution of sleep disturbance, and some of these associations may differ based on cognitive status. Future studies should investigate the hypothesis that sleep impairment mediates part of the association between specific personality traits and health-related outcomes.

Disrupted Sleep Architecture Is Associated With Incident Bone Loss in Indian Postmenopausal Women: A Prospective Study.

Inadequate sleep has been shown to be detrimental to several body systems, including the bone. We proposed to study the impact of insomnia on bone health in Indian postmenopausal women. In a 2-year prospective study, ambulant community-dwelling postmenopausal women aged >50 years were recruited through simple random sampling. Sleep duration was recorded based on self-reported sleep duration and sleep quality using the Women's Health Initiative Insomnia Rating Scale (WHIIRS). Anthropometry, bone biochemistry including bone turnover markers (C-terminal telopeptide of type 1 collagen [CTX], N-terminal telopeptide of type 1 pro-collagen [P1NP]), bone mineral density (BMD), and trabecular bone score (TBS) were assessed at baseline and at the end of 2 years. Among 190 postmenopausal women with mean (SD) age of 58.2 (6.9) years, 65/190 (34.2%) had insomnia (WHIIRS ≥ 9) and 20/190 (10.5%) developed osteoporosis at any site on follow-up. The percentage decline over 2 years in BMD in women with insomnia was significantly (p < 0.001) higher at femoral neck (2.9 [1.6] versus 1.2 [1.2]%) and lumbar spine (4.5 [2.0] versus 1.6 [1.1]%). The decrement in TBS was also significantly higher (p < 0.001) in women with suboptimal sleep (1.5 [2.1] versus 0.5 [1.0] %) when compared with those with adequate sleep. The increment in CTX (46.4 [32.2] versus 18.9 [26.4]) and decrement in P1NP (35.4 [9.1] versus 16.7 [18.9]), respectively, were also greater (p < 0.001) in women with insomnia compared with those without. On multivariate analysis, insomnia was the sole factor that was predictive (adjusted odds ratio [OR]= 9.3; 95% confidence interval [CI] 2.9-29.6; p < 0.001) of incident osteoporosis. In conclusion, poor sleep quality was associated with incident osteoporosis in Indian postmenopausal women. Optimal sleep may help to retard ongoing bone loss that results from sleep deprivation and requires further research. © 2022 American Society for Bone and Mineral Research (ASBMR).

Abstract P6-12-02: Racial/ethnic differences in sleep quality and duration among breast cancer survivors: Results from the women's health initiative (WHI)

Abstract BACKGROUND: Sleep is a crucial factor for optimal health, but breast cancer survivors often report poor sleep quality. It is estimated 20-70% of survivors have at least one sleep problem, which contribute to quality of life and health differences among survivors. Minority groups tend to have poorer sleep quality and shorter sleep duration than Non-Hispanic Whites (NHW). African-Americans (AA) with breast cancer have a poorer prognosis than NHW for each stage-specific diagnosis and are twice as likely as NHW to report short sleep duration, yet survivor studies are still lacking in AA participants. The purpose of this study was to examine sleep quality and duration patterns before and after cancer diagnosis by race/ethnicity among WHI breast cancer survivors. METHODS: There were 12,098 postmenopausal women diagnosed with invasive breast cancer after WHI enrollment who were eligible for this secondary analysis. Baseline demographic and clinical characteristics were described. The WHI Insomnia Rating Scale (WHIIRS) was measured at multiple time points pre- and post-diagnosis. A higher WHIIRS scores (0-20 points) indicates greater sleep disturbance and ≥9 points identifies clinical insomnia. A linear mixed model was fit to the WHIIRS sleep quality data to examine if the trend in sleep quality with time changed following a cancer diagnosis. For short (&amp;lt;6hrs) and long (≥9hrs) sleep duration, we fit a logistic regression model with multilevel mixed effects. RESULTS: The majority of participants were NHW (87.4%), mean age at diagnosis was 70.3 years, and 75% had localized breast cancer at diagnosis. At baseline, 30% of women had insomnia. The lowest average WHIIRS score was 5.6 among Asians, and the highest was 6.6 among American-Indians and NHWs (p=0.02). AAs had the most women sleeping ≤5 hrs/night and NHW had the least (19.6% vs 5.7%, p&amp;lt;0.01). At diagnosis, the average WHIIRS score was 7.2. After diagnosis, sleep quality improved in the overall study population (p=0.03). Short sleep duration ranged from 6% before diagnosis, 9% at diagnosis and 11% after diagnosis (p=0.29). Long sleep duration ranged from 3% before diagnosis, 6% at diagnosis and 15% after diagnosis (p=0.43). There was no difference in sleep quality across race after diagnosis (p=0.53). The probability of short sleep and long sleep after diagnosis did not differ significantly across race (p=0.12, p=0.90), however racial minorities tended to have higher probabilities of short sleep at diagnosis compared to NHWs. DISCUSSION: Sleep is an appealing area to target for improvement due to the multiple ways it can be treated. With increasing survival rates, there is an emphasis on improving quality of life in survivors. Our results span 20 years pre-diagnosis to 15 years post-diagnosis and are similar to shorter follow-up studies which found most women's sleep problems resolve within a few years of treatment completion. The lack of difference by race was an unexpected finding in another similar longitudinal study, which suggested most differences are seen in cross-sectional sleep studies. This study adds to the literature on longitudinal sleep data, especially to the little data on sleep trajectories in minority breast cancer survivors. Citation Format: Beverly CM, Naughton M, Foraker R, Pennell M, Young G, Hale L, Crane T, Pan K, Danhauer S, Feliciano E, Paskett E. Racial/ethnic differences in sleep quality and duration among breast cancer survivors: Results from the women's health initiative (WHI) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-12-02.

Subjective insomnia symptoms and sleep duration are not related to hypothalamic-pituitary-adrenal axis activity in older adults.

Insomnia symptoms are highly prevalent in depressed older adults. This study investigates the association between hypothalamic-pituitary-adrenal (HPA) axis activity and symptoms of insomnia, respectively, sleep duration among 294 depressed and 123 non-depressed older adults of the Netherlands Study of Depression in Older people (NESDO) study. Insomnia symptoms were defined as clinically relevant when having a score ≥10 points on the Women's Health Initiative Insomnia Rating Scale (WHIIRS). Sleep duration was categorized in short (≤6h per night), normal (7-8h per night) and long (≥9h per night) duration. Salivary cortisol levels were used to assess the following cortisol parameters for HPA axis activity: area under the curve with respect to the increase (AUCi) and to the ground (AUCg), diurnal slope, evening cortisol level and dexamethasone suppression ratio. Clinically relevant insomnia symptoms were present in 46% of the participants. Thirty-two per cent of the participants were short sleepers, whereas 16% were long sleepers. However, univariate analyses showed no differences in any of the HPA axis parameters between people with and without insomnia symptoms or between the three groups with different sleep duration. In addition, no significant interaction was found between a diagnosis of depression or the severity of depressive symptoms and any of the cortisol parameters in relation to insomnia symptoms or sleep duration.

Sleep quality, duration, and breast cancer aggressiveness.

Epidemiological studies suggest that short sleep duration and poor sleep quality may increase breast cancer risk. However, whether sleep is associated with breast tumor aggressiveness characteristics has largely been unexplored. The study included 4171 non-Hispanic whites (NHW) and 235 African Americans (AA) diagnosed with incident, primary, invasive breast cancer in the Women's Health Initiative (WHI) Observational Study (1994-2013). We used logistic regression to examine the association of baseline sleep (sleep duration, sleep quality, WHI Insomnia Rating Scale) with tumor grade, stage, hormone receptor status, HER2 status. In NHW, women who reported 6h of sleep/night were more likely to have tumors classified as regional/distant stage at diagnosis compared to women who slept 7-8h/night (adjusted odds ratio (OR): 1.25, 95% confidence interval (CI): 1.05-1.48). AA women who reported their typical night's sleep as 'average quality' or 'restless or very restless sleep' were more likely to be diagnosed with triple-negative tumors than those who reported 'sound or restful' sleep (adjusted ORs: 2.91 (1.11, 7.63) and 3.74 (1.10, 12.77), respectively). Our findings provide indications that aspects of sleep (sleep duration and quality), partially modifiable health behaviors, may be associated with development of aggressive tumor characteristics in postmenopausal women. The role of these sleep attributes may differ for NHW and AA women; however, further study in robust, racial diverse samples is needed. This study provides evidence that facets of sleep behavior are associated with the development of aggressive tumor features and these associations differ by race.

Association Between Non-Iron-Deficient Anemia and Insomnia Symptoms in Community-Dwelling Older Adults: The Baltimore Longitudinal Study of Aging.

Anemia is associated with poorer sleep in children, and clinically, anemia is linked to insomnia. However, the association between anemia and insomnia in older adults is understudied. We examined the cross-sectional association between anemia and insomnia in 1,053 adults (71.4 ± 10.6 years) in the Baltimore Longitudinal Study of Aging. Participants were classified as nonanemic, non-iron-deficient anemic, or iron-deficient anemic based on hemoglobin, ferritin, transferrin saturation, and mean cell volume. Insomnia symptoms were evaluated by the Women's Health Initiative Insomnia Rating Scale (WHIIRS). A total score (range 0-20) was generated, and participants were also classified as having 0, 1, or 2+ symptoms. Overall, 10.5% of participants had non-iron-deficient anemia, 0.9% had iron-deficient anemia, and 88.5% had no anemia. Due to its low prevalence, the iron-deficient anemic group was dropped from analyses. In models adjusted for demographics, number of medical conditions, and Center for Epidemiologic Studies Depression Scale score, non-iron-deficient anemic individuals had significantly higher WHIIRS total scores, indicating greater insomnia severity, compared to those without anemia (predicted adjusted mean WHIIRS of 7.24 [95% confidence interval (CI): 6.40-8.08] vs 5.92 [95% CI: 5.65-6.19]). They also had twice the risk of reporting ≥2 insomnia symptoms (vs 0 symptoms; relative risk ratio = 2.20, 95% CI: 1.25-3.89). Results suggest that individuals with non-iron-deficient anemia are more likely to experience insomnia symptoms than those who are nonanemic. These results may have implications for insomnia treatment or the identification of underlying frailty in individuals with sleep problems.

Abstract MP082: Sleep Duration and Insomnia as Risk Factors for Coronary Heart Disease among Postmenopausal Women: Findings from the Women's Health Initiative

Background Several prospective studies have reported a positive association for both long and short sleep duration with coronary heart disease (CHD) risk. Insomnia may also be a CHD risk factor. Our aims were to identify whether sleep duration and insomnia symptoms are associated with greater incident CHD among postmenopausal women. Methods Participants were 86,329 postmenopausal women, aged 50-79 at enrollment into the Women's Health Initiative (WHI) observational study, who reported information regarding sleep habits at baseline (1993-1998) and were followed for first occurrence of a coronary event. Cox proportional hazards models were developed using sleep duration and insomnia as the primary exposures. Person-years of follow up were calculated from the screening visit through August 2009. Results Compared to mid-range sleep duration (7-8 hours) women reporting shorter sleep (≤5 hours) and longer sleep (≥10 hours) had higher incident CHD (HR=1.21, 95% CI 1.09-1.33; HR=1.51, 95% CI 1.08-2.11), respectively, after adjusting for age and race. Only longer sleep remained significantly associated with incident CHD in fully adjusted models (HR=1.53, 95% CI 1.09-2.14). Women that scored high (≥9) for insomnia on the WHI Insomnia Rating Scale (WHIIRS) demonstrated the highest risk of CHD (HR=1.35, 95% CI 1.24-1.47, age- and race-adjusted; HR=1.18, 95% CI 1.08-1.30, fully adjusted models). When the analyses are stratified by the WHIIIRS, among those with high insomnia scores (≥9), long sleep almost doubled the risk of CHD (HR=1.97, 95% CI 1.18-3.30) versus mid-range sleep duration, whereas among those with lower WHIIRS scores (&lt;9), long sleepers have a relatively lower increased risk of CHD (HR=1.49, 95% CI 1.08-2.06). Conclusions Women reporting ≥10 hours of sleep per night with high insomnia scores had a higher risk for incident CHD. A significant interaction between sleep duration and insomnia was observed (p&lt;0.02), and both long sleep duration and a high insomnia score were associated with greater risk of CHD. Table 1. Cox proportional hazards models - sleep duration and incident CHD * among WHI participants stratified by level of insomnia Cases N High level of perceived insomnia (WHIIRS ≥ 9) Model adjusted for age, race Model fully adjusted † HR 95% CI P-value HR 95% CI P-value Sleep time ≤5 h 347 4580 1.16 1.02, 1.32 0.03 1.05 0.93, 1.18 0.46 6 h 679 9610 1.08 0.97, 1.20 0.14 1.00 0.91, 1.10 0.98 7-8 h (ref) 734 10919 REF REF REF REF REF REF 9 h 48 517 1.38 1.03, 1.85 0.03 1.26 0.97, 1.65 0.08 ≥10 h 12 114 1.98 1.12, 3.51 0.02 1.97 1.18, 3.30 0.01 Cases N Low level for perceived insomnia (WHIIRS &lt; 9) Model adjusted for age, race Model fully adjusted † HR 95% CI P-value HR 95% CI P-value Sleep time ≤5 h 130 2209 1.12 0.96, 1.31 0.16 0.92 0.77, 1.09 0.34 6 h 768 13,416 0.99 0.92, 1.07 0.88 0.94 0.87, 1.02 0.12 7-8 h (ref) 2418 41347 REF REF REF REF REF REF 9 h 171 2934 1.06 0.93, 1.21 0.38 0.98 0.85, 1.13 0.73 ≥10 h 23 357 1.67 1.22, 2.28 0.01 1.49 1.08, 2.06 0.02 * Outcome includes myocardial infarction, CHD death, percutaneous transluminal coronary angioplasty, coronary artery bypass grafting or hospitalized angina † Model adjusted for age, race, education, income, smoking, BMI, physical activity, alcohol intake, depression, diabetes, high blood pressure, cholesterol medication, comorbid conditions

Marital Happiness and Sleep Disturbances in a Multi-Ethnic Sample of Middle-Aged Women

Previous research suggests that divorced individuals, particularly women, have higher rates of sleep disturbances as compared to married individuals. Among the married, however, little is known about the association between relationship quality and sleep. The present study examined the association between marital happiness and self-reported sleep disturbances in a sample of midlife women drawn from the Study of Women's Health Across the Nation (SWAN), a multi-site, multi-ethnic, community-based study (N = 2,148). Marital happiness was measured using a single item from the Dyadic Adjustment Scale, and sleep disturbance was assessed using 4 items from the Women's Health Initiative Insomnia Rating Scale (WHIIRS). After controlling for relevant covariates, maritally happy women reported fewer sleep disturbances, with the association evident among Caucasian women and to a lesser extent among African American women.

Validation of the Women’s Health Initiative Insomnia Rating Scale in a Multicenter Controlled Clinical Trial

The objective of this study was to evaluate the construct validity of the five-item Women's Health Initiative Insomnia Rating Scale (WHIIRS) by comparing women taking hormone therapy (HT) versus those taking a placebo and by comparing women known to differ in vasomotor symptoms. The WHIIRS was included in two phase III randomized trials intended to evaluate the efficacy of a combination estradiol plus and norethindrone acetate transdermal delivery system in reducing vasomotor symptoms. In all, 850 healthy postmenopausal women participated in these studies. Both trials were double-blind, one was placebo-controlled and the other was positive-controlled. The former trial admitted women with > or =8 hot flashes/day and lasted 12 weeks with data collected on the WHIIRS at baseline, 4, 8, and 12 weeks. The other trial had no entry criteria pertaining to hot flashes and lasted 52 weeks with WHIIRS data collected at baseline, 12, 24, and 52 weeks. The WHIIRS was sensitive to the effect of HT on sleep disturbance over time. The WHIIRS also detected differences in self-reported sleep disturbance between women with mild vasomotor symptoms compared with those with moderate to severe symptoms. As expected, the study using a positive control revealed that sleep improved over time (p <.0001). Also as predicted, the study using a placebo control found that sleep disturbance in the treatment groups improved at a faster rate than in the control groups (p = .035). The construct validity of the WHIIRS was supported because it was successfully used to detect self-reported sleep disturbance differences in women taking HT versus those taking a placebo as well as in groups known to differ in severity of their vasomotor symptoms.

Reliability and validity of the Women's Health Initiative Insomnia Rating Scale.

The reliability and construct validity of the 5-item Women's Health Initiative Insomnia Rating Scale (WHIIRS) were evaluated in 2 studies. In Study 1, using a sample of 66,269 postmenopausal women, validity of the WHIIRS was assessed by examining its relationship to other measures known to be related to sleep quality. Reliability of the WHIIRS was estimated using a resampling approach; the mean alpha coefficient was .78. Test-retest reliability coefficients were .96 for same-day administration and .66 after a year or more. Correlations of the WHIIRS with the other measures were in the predicted directions. Study 2 used a sample of 459 women and compared the WHIIRS with objective indicators of sleep quality. Results showed that differences in the objective indicators could be detected by the WHIIRS. Findings suggest that a between-group mean difference of approximately 0.50 of a standard deviation on the WHIIRS may be clinically meaningful.

Factor structure and measurement invariance of the Women's Health Initiative Insomnia Rating Scale.

As part of the Women's Health Initiative Study, the 5-item Women's Health Initiative Insomnia Rating Scale (WHIIRS) was developed. This article summarizes the development of the scale through the use of responses from 66,269 postmenopausal women (mean age = 62.07 years, SD = 7.41 years). All women completed a 10-item questionnaire concerning sleep. A novel resampling technique was introduced as part of the data analysis. Principal-axes factor analysis without iteration and rotation to a varimax solution was conducted for 120,000 random samples of 1,000 women each. Use of this strategy led to the development of a scale with a highly stable factor structure. Structural equation modeling revealed no major differences in factor structure across age and race-ethnic groups. WHIIRS norms for race-ethnicity and age subgroups are detailed.

Relationship between sleep characteristics and depressive symptoms in last trimester of pregnancy.

Sleep problems during pregnancy may cause many complications that reduce quality of life. This study aims to determine the relationship between pregnant women's sleep characteristics and depressive symptoms. A hospital-based, cross-sectional study was conducted. Pregnant women were selected from the population by using the an improbable random sampling method. This study sample included 436 pregnant women who met the study's inclusion criteria. To collect data, this study used an information form that was developed by the researcher after reviewing relevant literature, the Women's Health Initiative Insomnia Rating Scale (WHIIRS), and the Beck Depression Inventory (BDI). The researchers used face-to-face interviews method to collect data from the participants, pregnant women who were examined in the polyclinic. This study found that 36% of participating pregnant women reported insomnia, and 38.1% experienced depressive symptoms. It also determined that participants who had problems with insomnia, who experienced a change in sleep habits, and who did not wake up feeling rested experienced depressive symptoms 1.64, 2.79, and 2.59 times more than those who didn't have these problems, respectively. who experienced a decrease in sleep, who experienced an increase in sleep, and who did not wake up feeling rested experienced depressive symptoms 1.61, 3.22, 3.53, and 2.59 times more, respectively, than those who did not have insomnia, who did not experience a change in sleep habits in pregnancy, and who woke up feeling rested, respectively. This study determined that there is a relationship between insomnia and depressive symptoms and that pregnant women experiencing insomnia presented with more depressive symptoms.