Psychometric properties of the Insomnia Severity Index in cancer survivors

Psychometric Evaluation of the Insomnia Severity Index in Nurses

OBJECTIVES

Examine psychometric properties of the Insomnia Severity Index (ISI) in a sample of nurses.

METHOD

In a sample of day shift nurses (N = 289), a confirmatory factor analysis (CFA), convergent and discriminant validity analyses, and a test-retest reliability analysis were performed.

RESULTS

CFA showed that a two-factor model provided the best fit. The ISI had moderate to poor convergent validity with sleep diary parameters, and moderate convergent validity with the Sleep Condition Indicator (r = -.66), Pittsburgh Sleep Quality Index (r = .66), and PROMIS Sleep-Related Impairment measure (r = .67). The ISI demonstrated good discriminant validity with the measures Composite Scale of Morningness (r = -.27), Nightmares Disorder Index (r = .25), PTSD Checklist for DSM-5 (sleep items removed; r = .32), and Perceived Stress Scale (r = .43). The ISI had weaker discriminant validity with the PHQ-9 (r = .69) and Generalized Anxiety Disorder Screener (r = .51). The ISI demonstrated a good test-retest reliability (ICCs = .74-.88).

CONCLUSIONS

The ISI is a psychometrically strong measure for the assessment of insomnia severity in day shift nurses. Overlap with psychological symptoms, primarily anxiety and depression, suggests caution while interpreting these constructs.

Comparing sleep measures in cancer survivors: self-reported sleep diary versus objective wearable sleep tracker

PURPOSE

Cancer survivors are increasingly using wearable fitness trackers, but it is unclear if they match traditional self-reported sleep diaries. We aimed to compare sleep data from Fitbit and the Consensus Sleep Diary (CSD) in this group.

METHODS

We analyzed data from two randomized clinical trials, using both CSD and Fitbit to collect sleep outcomes: total sleep time (TST), wake time after sleep onset (WASO), number of awakenings (NWAK), time in bed (TIB), and sleep efficiency (SE). Insomnia severity was measured by Insomnia Severity Index (ISI). We used the Wilcoxon signed rank test, Spearman's rank correlation coefficients, and the Mann-Whitney test to compare sleep outcomes and assess their ability to distinguish insomnia severity levels between CSD and Fitbit data.

RESULTS

Among 62 participants, compared to CSD, Fitbit recorded longer TST by an average of 14.6 (SD = 84.9) minutes, longer WASO by an average of 28.7 (SD = 40.5) minutes, more NWAK by an average of 16.7 (SD = 6.6) times per night, and higher SE by an average of 7.1% (SD = 14.4); but shorter TIB by an average of 24.4 (SD = 71.5) minutes. All the differences were statistically significant (all p < 0.05), except for TST (p = 0.38). Moderate correlations were found for TST (r = 0.41, p = 0.001) and TIB (r = 0.44, p < 0.001). Compared to no/mild insomnia group, participants with clinical insomnia reported more NWAK (p = 0.009) and lower SE (p = 0.029) as measured by CSD, but there were no differences measured by Fitbit.

CONCLUSIONS

TST was the only similar outcome between Fitbit and CSD. Our study highlights the advantages, disadvantages, and clinical utilization of sleep trackers in oncology.

Comparing sleep measures in cancer survivors: Self-reported sleep diary versus objective wearable sleep tracker

Purpose

Cancer survivors are increasingly using wearable fitness trackers, but it's unclear if they match traditional self-reported sleep diaries. We aimed to compare sleep data from Fitbit and the Consensus Sleep Diary (CSD) in this group.

Methods

We analyzed data from two randomized clinical trials, using both CSD and Fitbit to collect sleep outcomes: total sleep time (TST), wake time after sleep onset (WASO), number of awakenings (NWAK), time in bed (TIB) and sleep efficiency (SE). Insomnia severity was measured by Insomnia Severity Index (ISI). We used the Wilcoxon Singed Ranks Test, Spearman's rank correlation coefficients, and the Mann-Whitney Test to compare sleep outcomes and assess their ability to distinguish insomnia severity levels between CSD and Fitbit data.

Results

Among 62 participants, compared to CSD, Fitbit recorded longer TST by an average of 14.6 (SD = 84.9) minutes, longer WASO by an average of 28.7 (SD = 40.5) minutes, more NWAK by an average of 16.7 (SD = 6.6) times per night, and higher SE by an average of 7.1% (SD = 14.4); but shorter TIB by an average of 24.4 (SD = 71.5) minutes. All the differences were statistically significant (all p < 0.05), except for TST (p = 0.38). Moderate correlations were found for TST (r = 0.41, p = 0.001) and TIB (r = 0.44, p < 0.001). Compared to no/mild insomnia group, participants with clinical insomnia reported more NWAK (p = 0.009) and lower SE (p = 0.029) as measured by CSD, but Fitbit outcomes didn't.

Conclusions

TST was the only similar outcome between Fitbit and CSD. Our study highlights the advantages, disadvantages, and clinical utilization of sleep trackers in oncology.

Insomnia Severity Index: A reliability generalisation meta-analysis

The aim of the current study was to conduct a reliability generalisation (RG) meta-analysis of Cronbach's alpha for the Insomnia Severity Index (ISI). A systematic search of three databases (PubMed, Scopus, and Web of Science) from inception to 12 March 2021 was performed. Publications that reported Cronbach's alpha for the total ISI score were included. Only psychometric-focussed studies were considered. Meta-analysis was carried out using a random-effects model to derive a pooled estimate of Cronbach's alphas. The number of participants in the included publications ranged from 25 to 12,056, with 33 studies (42 estimates) comprising internal consistency coefficients, and a combined sample size of N = 29,688. The age range of the included publications was from 13.4 to 74.3 years. Data extraction implied 33 publications out of 706 found through the database search. Cronbach's alphas ranged from 0.65 to 0.92. The majority of the reported coefficients were ≥0.7 and presented a low risk of bias (n = 32). The pooled alpha coefficient was 0.83 (IC [0.81-0.85]; SE = 0.009) with high heterogeneity among the included publications (I²  = 97%). Subgroup analyses including moderators such as continent, setting, risk of bias, and age did not affect significantly the overall result. In general, the cumulative estimate of Cronbach's alpha for the ISI is good. However, this finding should be interpreted with caution since there is a high heterogeneity level and some of the studies might not have checked the assumptions underlying Cronbach's alphas.

The effect of a combined treatment of foot soak and lavender oil inhalation therapy on the severity of insomnia of patients with cancer: Randomized interventional study

OBJECTIVES

This three-arm randomized intervention study was carried out with the aim to evaluate the effects of a combined foot soak and lavender oil inhalation therapy on the severity of insomnia of patients with cancer.

METHOD

This research was carried out in oncology and palliative services. Forty-five patients were randomly assigned to three groups. Throughout a 14-day period, 20 min of foot soak treatment was applied to the patients in the F group, patients in the L group were applied lavender oil inhalation therapy for 5 min and a combined treatment of foot soak and lavender oil inhalation therapy were applied to the patients in the FL group. Insomnia severity of the patients in all groups were evaluated twice using the Insomnia Severity Index at the baseline and on the fifteenth day.

RESULTS

The severity of the insomnia of the patients in all groups was found to be moderate. The severity of the insomnia in the second evaluation was found to be statistically significantly lower in the L and FL groups (p<0.05) compared to the baseline evaluation within the group, however no significant difference was found in the F group (p>0.05). The effect size of a combined treatment of foot soak and lavender oil inhalation therapy on the severity of insomnia of patients in the FL group was higher and moderate (d = 0.684) compared to merely foot soak and merely lavender oil inhalation therapy.

CONCLUSION

A combined treatment of foot soak and lavender oil inhalation therapy shall mitigate the severity of a moderate level of insomnia of patients with cancer.

Mental distress, quality of life and physical symptoms in Chinese women with ovarian cancer receiving olaparib treatment during the COVID-19 pandemic

OBJECTIVES

Women with ovarian cancer (OC) have experienced unprecedented challenges since the novel coronavirus disease-2019 (COVID-19) outbreak in China. We aim to evaluate the experience of psychological status, physical symptoms and quality of life (QoL) and investigate the impact of COVID-19 pandemic on OC patients receiving olaparib.

METHODS

The survey was conducted online from April 22 to May 12 in 2020. Demographic and clinical questions were listed to collect general information. The degree of insomnia, depression, anxiety, stress symptoms and QoL were assessed by the Chinese versions of the Insomnia Severity Index, the Patient Health Questionnaire-9, the Generalized Anxiety Disorder-7, the Impact of Event Scale-Revised, and the General Functional Assessment of Cancer Therapy, respectively. Multivariate logistic regression analysis was conducted to analyze the risk factors for mental distress and QoL.

RESULTS

A total of 56 respondents coming from 15 various provinces in China participated in the survey. The prevalence of insomnia, depressive, anxiety, stress symptoms and reduced QoL were 37.5, 51.8, 37.5, 30.4, and 51.8%, respectively. Unfavorable disease status, shorter period of olaparib administration, adverse events of olaparib and delay in cancer care were correlated with mental health problems. Reduced QoL was also significantly associated with psychological distress.

CONCLUSIONS

This study emphasized that mental health problems and reduced QoL should gain more attention in women with OC who are receiving oral olaparib at home. Appropriate psychological healthcare strategies are necessary for OC patients during the COVID-19 pandemic.

Structural validity of the Insomnia Severity Index: A systematic review and meta-analysis

The factor structure of the Insomnia Severity Index (ISI) is discussed, with examples being drawn from about 13 disparate reported models. A systematic appraisal of procedural details of studies investigating the dimensionality of the ISI was performed. The databases CINAHL, Cochrane Library, Embase, Medline, and PsycINFO were searched thoroughly, and all articles in English, published, and/or available online as of 14th March 2019, were included. Meta-analyses of Cronbach's alpha and structural validity measures were performed. Several inadequacies or omissions were found in analyses using the three groups of measures. Fifteen out of 20 studies did not employ either EFA or CFA, 10 studies did not report CFA, while five did not report EFA. The most common omissions related to multivariate normality, final model selection based on consideration of fit indices, parsimony, and failure to consider the theoretical construct in the final model selection. Meta-analysis showed that CFA outcome is more robust compared to EFA, two-factor solution is the vigorous presentation of dimensionality compared to a three-factor solution, and ISI has a high pooled Cronbach's alpha. Further validation of the disparate models of the ISI is needed with more comprehensive reporting guidelines, such as the one suggested in the present review.

A population-based psychometric analysis of the insomnia severity index in black women with and without a history of cancer

Black women are under-represented in insomnia research. Further, cancer treatments increase the risk of late effects, thus affecting the sleep of psychologically and medically vulnerable cancer survivors. The Insomnia Severity Index (ISI) is widely used, but has not been researched in black women, and research in cancer survivors is limited. Prior studies demonstrate that psychometric properties of the ISI are not consistent across samples. This study examined the internal consistency and factor structure of the ISI in 29,500 participants from the Black Women's Health Study, an epidemiological study of black women in the United States. This cohort included 28,214 women without a cancer history and 1,286 cancer survivors. Exploratory, confirmatory and multigroup analyses were conducted to determine the psychometric properties of the ISI in these groups. The mean ISI score was 7.18 (standard deviation [SD] = 6.82). Findings supported the internal consistency reliability of the ISI in black women with (Ω = 0.896) and without (Ω = 0.892) a cancer history. Exploratory factor analyses supported a one-factor structure. Confirmatory factor analyses indicated that fit of this one-factor model was not robust in survivors (Satorra-Bentler chi-square [χSB² (14)] = 197.78, comparative fit index [CFI] = 0.928, root mean-square error of approximation [RMSEA] = 0.143) or in women with no cancer history (χSB² (14) = 2,887.93, CFI = 0.945, RMSEA = 0.121), but the alternative models we examined were not superior. Although factor structures in previous studies have varied considerably, we found a one-factor structure. Although internal consistency reliability was strong, factor analytic results did not further support the ISI. Inconsistencies in ISI measurement properties across studies may reflect differences in sample sizes and populations.

Assessment of sleep problems with the Insomnia Severity Index (ISI) and the sleep item of the Patient Health Questionnaire (PHQ-9) in cancer patients

Objective

The objectives of this study were to examine sleep problems in cancer patients, to test the psychometric properties of the Insomnia Sleep Index (ISI) in comparison with the sleep item of the Patient Health Questionnaire-9 (PHQ-9), and to analyze disrupting factors which might cause the sleep problems.

Methods

A sample of 1026 mixed-site cancer patients in treatment at a German oncological rehabilitation clinic was examined.

Results

The reliability of the ISI was very good (Cronbach’s alpha = 0.92), and the results of the confirmatory factor analysis were acceptable. Females reported worse sleep quality (ISI mean: 13.7 ± 6.6) than males (10.7 ± 6.4). Sleep problems as measured with the PHQ-9 sleep item were markedly higher than those in the general population (effect size d = 1.15).

Patients reported that, of the factors that disrupted their sleep, psychological factors (brooding, worries) were more relevant than symptom factors (pain, nocturnal urination, or restless legs).

Conclusions

The ISI is effective in detecting sleep problems in cancer patients. Normative studies with the ISI would be helpful for assessing ISI mean scores. Sex differences should be taken into account when groups of patients are compared. The sleep item of the PHQ-9 can be used in epidemiological studies.

Does the guided online cognitive behavioral therapy for insomnia "i-Sleep youth" improve sleep of adolescents and young adults with insomnia after childhood cancer? (MICADO-study): study protocol of a randomized controlled trial

BACKGROUND

Adolescents and young adults who had childhood cancer are at increased risk for insomnia, due to being critically ill during an important phase of their life for the development of good sleep habits. Insomnia is disabling and prevalent after childhood cancer (26-29%) and negatively impacts quality of life, fatigue, pain, and general functioning and is often associated with other (mental) health problems. Insomnia and a history of childhood cancer both increase the risk of adverse health outcomes, posing a double burden for adolescents who had childhood cancer. The first-line treatment for insomnia is cognitive behavioral therapy for insomnia (CBT-I). However, access to this type of care is often limited. The guided online CBT-I treatment "i-Sleep" has been developed to facilitate access via online care. i-Sleep is shown effective in adult (breast cancer) patients, but it is unknown if iCBT-I is effective in pediatric oncology.

METHODS/DESIGN

We developed a youth version of i-Sleep. Our aim is to evaluate its effectiveness in a national randomized-controlled clinical trial comparing iCBT-I to a waiting-list control condition at 3 and 6 months (n = 70). The intervention group will be also assessed at 12 months to see whether the post-test effects are maintained. Adolescents and young adults aged 12-30 years with insomnia, diagnosed with (childhood) cancer, currently at least 6 months since their last cancer treatment will be eligible. Outcomes include sleep efficiency (actigraphic), insomnia severity (self-report), sleep and circadian activity rhythm parameters, fatigue, health-related quality of life, perceived cognitive functioning, chronic distress, depressive and anxiety symptoms, and intervention acceptability.

DISCUSSION

Insomnia is prevalent in the pediatric oncology population posing a double health burden for adolescents and young adults who had childhood cancer. If guided iCBT-I is effective, guidelines for insomnia can be installed to treat insomnia and potentially improve quality of life and the health of adolescents and young adults who had childhood cancer.

TRIAL REGISTRATION

NL7220 (NTR7419; Netherlands Trial register). Registered on 2 August 2018.

Psychometric properties of the Insomnia Severity Index in a sample of family dementia caregivers

STUDY OBJECTIVES

Family caregivers of people with dementia frequently report sleep problems that are linked to depressive and anxious symptoms. However, data are needed regarding the psychometric properties of specific measures of sleep problems in caregiving populations. The aim of this study is to analyse the psychometric properties of the Insomnia Severity Index (ISI; Morin, 1993) in a Spanish dementia caregiver sample.

METHODS

271 participants took part in face-to face interviews where, along with sociodemographic variables, caregivers' sleep problems, depressive and anxious symptoms were measured. The psychometric properties of the ISI were analysed through Confirmatory Factor Analysis (CFA) and analysis of the internal consistency and convergent and criterion validity.

RESULTS

The Spanish version of the Insomnia Severity Index showed adequate indices of internal consistency (Cronbach's alpha = 0.78) in our sample of family caregivers of people with dementia. A one-factor structure provided a better fit to the data than two- and three-factor structures. The ISI was significantly associated with lower sleep quality, less average sleep time per day and lower self-perception of vitality, as well as with higher depressive and anxious symptoms. Differences in ISI scores were found between people with and without depressive and anxious symptoms. Statistically significant gender-based differences in sleep problems were also found, with female caregivers showing higher sleep problems.

CONCLUSIONS

The ISI is a reliable and valid instrument to assess the subjective severity of sleep problems in the family dementia caregiver population and may be a useful instrument in intervention and research settings. Additional evidence was also provided of the importance of considering sleep problems in the studied population.

Predictors of increased risk for early treatment non-adherence to oral anti-estrogen therapies in early-stage breast cancer patients

PURPOSE

Non-adherence to the oral anti-estrogen therapies (AET) tamoxifen and aromatase inhibitors in early-stage hormone receptor-positive breast cancer is associated with numerous negative clinical outcomes. Prior studies have identified that non-adherence is associated with psychological and menopause-related factors which are present during AET, but the presence of these characteristics prior to AET initiation has not been investigated.

METHODS

Psychological and menopause symptoms (depression, generalized anxiety, insomnia, somatosensory amplification, hot flash frequency, and hot flash-related interference) were assessed pre-AET initiation as predictors of subsequent non-adherence in 73 participants (M_age = 55.0, SD = 10.1 years). Participants self-reported treatment adherence after three and 6 weeks on AET. Participants who did not initiate treatment were excluded from the analysis.

RESULTS

Discriminant function analyses revealed that the hypothesized set of psychological and menopause symptoms at baseline (pre-AET) together statistically distinguished between those who were non-adherent (n = 19; 26.0%) from adherent (n = 54; 74.0%) at 6 weeks. Model classification accuracy was statistically significant (Wilks' ƛ = 0.782, χ²(6) = 15.50, p = 0.017) at the 6-week timepoint. Results were consistent at 3 weeks. Pre-AET psychological and menopause symptoms correctly classified 6-week treatment adherence 77.9% of the time. Depression contributed most to distinguishing between adherers and non-adherers.

CONCLUSIONS

The presence of a composite profile of psychological and menopause symptoms prior to AET initiation may help to identify early treatment non-adherence. Results can be used to identify patients at risk for non-adherence and to guide psychological and symptom management interventions.