A systematic review of patient-reported outcome instruments measuring sleep dysfunction in adults

Validation of self-reported sleep against actigraphy

BACKGROUND

Self-report remains the most practical and cost-effective method for epidemiologic sleep studies involving large population-based samples. Several validated questionnaires have been developed to assess sleep, but these tools are lengthy to administer and may be impractical for epidemiologic studies. We examined whether a 3-item sleep questionnaire, similar to those typically used in epidemiologic studies, closely corresponded with objective measures of sleep as assessed using actigraphy monitoring.

METHODS

Eligible participants were Western Australian women aged 18 to 80 years. Participants completed a sleep questionnaire, wore a wrist actigraph for 7 nights, and completed a brief daily sleep log. Objective actigraphy measurements for 56 participants were summarized by mean and mode and compared with the subjective reports, using weighted kappa and delta.

RESULTS

Data collected from the questionnaire showed poor agreement with objectively measured sleep, with kappas ranging from -0.19 to 0.14.

CONCLUSIONS

Our results indicate that sleep questions typically used in epidemiologic studies do not closely correspond with objective measures of sleep as assessed using actigraphy. The findings have implications for studies that have used such sleep questions. A means of appropriately measuring sleep as a risk factor in epidemiologic studies remains to be determined.

Poor sleep at baseline predicts worse mood outcomes in patients with co-occurring bipolar disorder and substance dependence

BACKGROUND

Sleep problems are common in patients with bipolar disorder and have been shown to predict subsequent mood symptoms. Sleep problems have also been shown to lead to worse substance use outcomes in individuals with substance use disorder. However, the relationship between sleep and clinical outcomes in a population with co-occurring bipolar disorder and substance use disorder is unclear.

METHOD

This secondary analysis included 60 outpatients (mean age = 38.1 years; recruited via advertisements, fliers, clinician referrals, and hospital treatment programs) who met DSM-IV criteria for both bipolar disorder and substance use disorder (assessed with the Structured Clinical Interview for DSM-IV Axis I Disorders) and who participated in a randomized clinical trial comparing integrated group therapy for bipolar disorder and substance use disorder to group drug counseling for substance use disorder alone. A 12-week treatment period preceded a 24-week follow-up. Poor sleep was assessed with the Pittsburgh Sleep Quality Index, which provides 7 component subscores and an overall sleep score. Data were collected from August 2003 through April 2007.

RESULTS

When analyses were controlled for baseline mood, substance use, and treatment condition, baseline sleep score predicted mood over the course of the 12-week treatment (β = 0.28; P < .05) and 24-week follow-up (β = 0.46; P < .01): worse sleep was associated with worse mood outcomes. Sleep was not associated with substance use outcomes.

CONCLUSIONS

Impaired sleep is a prognostic factor for mood outcomes in patients with co-occurring bipolar and substance use disorders. Further investigation is warranted into the long-term clinical outcomes of poor sleep in this population with co-occurring bipolar disorder and substance use disorder so that appropriate interventions can be developed.

Reliability of a sleep quality questionnaire for use in epidemiologic studies

Background

The longer-term health impacts of poor sleep quality are of increasing interest, as evidence suggests that there are rising levels of sleep disturbance in the community. Studies have reported links between sleep quality and increased morbidity and mortality. However, the results of these studies are constrained by limitations in the measurement of sleep quality in epidemiologic studies. The Breast Cancer Environment and Employment Study (BCEES) has developed a sleep questionnaire that attempts to address some of the limitations of previous sleep questionnaires. The present study assessed the test-retest reliability of the sleep questionnaire used in the Breast Cancer Environment and Employment Study (BCEES).

Methods

Subjects for this reliability study were women who were participating as controls in the BCEES study. Test-retest reliability was evaluated for individual items, using weighted kappa for categorical variables and intraclass correlation coefficients (ICC) and limits of agreement for continuous variables.

Results

Most sleep questions showed good agreement, ranging from 0.78 to 0.45. The ICC was 0.45 (95% CI 0.32–0.59) for lifetime sleep loss per year and 0.60 (95% CI 0.49–0.71) for symptom severity.

Conclusions

The test-retest reliability of the general sleep questions was good, and future epidemiologic studies of sleep could reliably expand the number of assessed domains of sleep quality. However, reliability decreased as increasing detail was required from participants about specific periods of sleep disturbance, and changes to the questionnaire are warranted.

Assessing the quality of sleep in Greek primary caregivers of patients with secondary progressive multiple sclerosis: a cross-sectional study

CONTEXT

Several studies have investigated the prevalence of sleep disorders in patients suffering from multiple sclerosis (MS) and have shown that up to 54% of patients may have significantly more sleep problems than the general population. To our knowledge, however, no data are available about the quality of sleep of the primary caregivers of patients with MS.

OBJECTIVES

The objectives of the current cross-sectional study were to assess the quality of sleep in Greek primary caregivers of patients with MS and to investigate its relationship with the degree of caregivers' emotional distress.

METHODS

Twenty-two male and 13 female primary caregivers (mean age 47.3±12.4 years) of an equal number of patients with MS, who consented to participate, completed the validated Greek version of the Pittsburgh Sleep Quality Index (PSQI) and the validated Greek version of the Hospital Anxiety and Depression Scale (HADS). Thirty-five age-, gender-, and education-matched healthy controls were used for comparisons.

RESULTS

Caregivers experienced a higher degree of anxiety than depression. The mean score in the seven-item HADS-A subscale was 9.5±4 (range 3-15) and the mean score in the seven-item HADS-D subscale was 7.1±3.1 (range 2-14). The mean scores of caregivers on both HADS-A and HADS-D were significantly higher than those of controls (P<0.001). The PSQI scoring demonstrated that 19 (54.3%) caregivers had poor sleep quality (cut-off value of >5). The mean values of caregivers for the PSQI were 6.0±2.8 (range 2-12) compared with controls, who scored at a significantly lower level (1.5±0.8; P<0.001). Poor quality of sleep was significantly correlated with increased levels of anxiety (r=0.392; P=0.02) and depression (r=0.424; P=0.01). Among the PSQI components, the sleep duration and sleep latency were mostly influenced by the degree of emotional distress.

CONCLUSION

A significant proportion of primary caregivers of MS patients experience poor sleep quality. The degree of their emotional distress appears to significantly influence their quality of sleep. Appropriate psychopharmacological interventions may be required for those individuals.

Neuropsychological effects of sleep loss: implication for neuropsychologists

There is rapidly accumulating evidence of a close relationship between sleep loss and cognition. Neuropsychologists need to become aware of this body of knowledge as the effects of sleep loss on brain functions are significant. The current study (a) outlines the extent to which insufficient sleep affects performance on cognitive tasks in otherwise healthy people, (b) discusses the relationship between sleep and neurocognitive disorders, and (c) highlights key issues that merit consideration for neuropsychologists. This review shows that sleep loss has a measurable impact on performance through decreases in cognitive functions and effects on biological pathways that support cognitive performance. Sleep loss reliably produces reductions in speed of processing and attention. Higher order cognitive functions are affected to a lesser extent, and there is sparing on tasks of crystallized abilities. Deficits worsen with increasing time awake, but may be overturned after normal sleep is resumed. The review also shows that sleep disorders are a major feature of neuropsychological conditions contributing to the pattern of cognitive impairment. Overall, neuropsychologists must be alert to sleep problems in their clients, so that sleep interventions, or referrals, are put in place in the rehabilitation plan of individuals with cognitive dysfunctions. Recommendations also include routine screening of sleep as part of cognitive assessment.

Distress screening in allogeneic hematopoietic stem cell (HSCT) caregivers and patients

Family caregivers of allogeneic hematopoietic stem cell transplant (HSCT) patients are at risk for experiencing significant psychological distress yet screening caregivers has not been well studied.

OBJECTIVE

This analysis explored the psychometric characteristics of the Distress Thermometer (DT) by examining its relationship, sensitivity, and specificity relative to the Brief Symptom Inventory 18 (BSI-18) and the Multidimensional Fatigue Symptom Inventory (MFSI) in a sample of allogeneic HSCT caregivers and patients.

METHODS

Longitudinal data were drawn from an ongoing intervention study for HSCT caregivers and patients. Data from one hundred and fifty-six English-speaking adults where patients (n = 65) were receiving their first allogeneic HSCT with at least one adult caregiver (n = 91) were eligible for this analysis. Study questionnaires were administered at baseline, initial discharge, and 6 weeks following discharge.

RESULTS

Construct validity was supported by significant relationships (p<0.001) between the DT and the BSI-18 GSI and the MFSI-Emotional subscales for caregivers and patients. The diagnostic utility of the DT for patients was good (AUC = 0.85±0.05, p = 0.001), while for caregivers it was poor (AUC = 0.61±0.08, p = 0.28). A DT cut point of 5 was supported for patients (sensitivity = 1.0, specificity = 0.68), while for caregivers there was less confidence (sensitivity = 0.70, specificity = 0.52). Caregivers and patients reporting a higher number of problems had a greater level of distress (p<0.001).

CONCLUSIONS

These findings support the validity of the DT in screening for distress in HSCT caregivers and patients. Although the diagnostic utility of the DT for HSCT caregivers may be limited, understanding factors associated with distress can guide practice for this understudied population.

The societal costs of insomnia

OBJECTIVE

Insomnia can be broadly defined as difficulty initiating or maintaining sleep, or sleep that is not refreshing or of poor quality with negative effect on daytime function. Insomnia can be a primary condition or comorbid to an underlying disorder. Subjective measures of insomnia used in population studies, usually based on complaints of unsatisfactory sleep, put the prevalence at about 10%. Insomnia is more common in the elderly and in women, and is often associated with medical and psychiatric disorders. This review examines the measures used to assess quality of sleep (QOS) and daytime functioning and the impact of insomnia on society using these measures.

METHODS

Literature searches were performed to identify all studies of insomnia (primary and comorbid) in adults (aged 18-64 years) and the elderly (aged ≥ 65 years) with baseline and/or outcomes relating to QOS or daytime functioning. The impact of poor QOS on quality of life (QOL), psychomotor and cognitive skills, health care resource utilization, and other societal effects was examined.

RESULTS

Although definitions and measurement scales used to assess sleep quality vary widely, it is clear that the societal consequences of insomnia are substantial and include impaired QOL and increased health care utilization. The impact of poor QOS and impaired daytime functioning common in insomnia can lead to indirect effects such as lower work productivity, increased sick leave, and a higher rate of motor vehicle crashes.

CONCLUSIONS

Insomnia is associated with substantial direct and indirect costs to society. It is almost impossible to separate the costs associated with primary and comorbid insomnia. More studies are required which control for the severity of any primary disorder to accurately evaluate the costs of comorbid insomnia. Development of standardized diagnostic and assessment scales will enable more accurate quantification of the true societal burden of insomnia and will contribute to greater understanding of this disorder.

Development and validation of patient-reported outcome measures for sleep disturbance and sleep-related impairments

STUDY OBJECTIVES

To develop an archive of self-report questions assessing sleep disturbance and sleep-related impairments (SRI), to develop item banks from this archive, and to validate and calibrate the item banks using classic validation techniques and item response theory analyses in a sample of clinical and community participants.

DESIGN

Cross-sectional self-report study.

SETTING

Academic medical center and participant homes.

PARTICIPANTS

One thousand nine hundred ninety-three adults recruited from an Internet polling sample and 259 adults recruited from medical, psychiatric, and sleep clinics.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

This study was part of PROMIS (Patient-Reported Outcomes Information System), a National Institutes of Health Roadmap initiative. Self-report item banks were developed through an iterative process of literature searches, collecting and sorting items, expert content review, qualitative patient research, and pilot testing. Internal consistency, convergent validity, and exploratory and confirmatory factor analysis were examined in the resulting item banks. Factor analyses identified 2 preliminary item banks, sleep disturbance and SRI. Item response theory analyses and expert content review narrowed the item banks to 27 and 16 items, respectively. Validity of the item banks was supported by moderate to high correlations with existing scales and by significant differences in sleep disturbance and SRI scores between participants with and without sleep disorders.

CONCLUSIONS

The PROMIS sleep disturbance and SRI item banks have excellent measurement properties and may prove to be useful for assessing general aspects of sleep and SRI with various groups of patients and interventions.

Subjective perception of sleep, but not its objective quality, is associated with immediate postpartum mood disturbances in healthy women

STUDY OBJECTIVES

This study investigated whether there was a relationship between disrupted sleep and postpartum mood disturbances in women during the week after delivery.

DESIGN

Sleep and mood were measured during the third trimester (Time-1) and one week postpartum (Time-2) in a 2-stage longitudinal design.

SETTING

Participants were recruited from an antenatal clinic in a regional Melbourne hospital.

PARTICIPANTS

Forty-four healthy women at low risk for postpartum depression.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Objective sleep was measured by actigraphy and subjective sleep by the Pittsburgh Sleep Quality Index; mood was assessed by the Depression Anxiety Stress Scale, the Hospital Anxiety Depression Scale, and the Positive and Negative Affect Schedule. Sleep and mood questionnaires were administered at Time-1 and Time-2. Wrist actigraphy was collected for one week at both times. After delivery, both objective and subjective nighttime sleep significantly worsened with decreased total sleep time and sleep efficiency, while daytime napping behavior significantly increased. On average, mood improved across all scales after delivery, although 45.95% of the sample experienced deterioration of mood. Regression analyses showed little relationship between Time-1 and Time-2 objective nighttime sleep, and postpartum mood. Variables that related to both Time-1 and Time-2 subjective perception of sleep, including subjective nighttime sleep, sleep-related daytime dysfunction, and daytime napping behavior, were significant predictors of postpartum mood.

CONCLUSIONS

The perception of poor sleep, and the conscious awareness of its impact during wake-time, might share a stronger relationship with the occurrence of immediate postpartum mood disturbances than actual sleep quality and quantity.

Interpreting score differences in the Insomnia Severity Index: using health-related outcomes to define the minimally important difference

OBJECTIVE

To estimate the minimally important difference (MID) for the Insomnia Severity Index (ISI) by examining the association of score differences of the ISI with health-related outcomes including health-related quality of life, productivity, and fatigue.

METHODS

Data came from a randomized, placebo-controlled clinical trial evaluating the long-term efficacy of eszopiclone for primary insomnia (N = 828). Logistic regression models were used to characterize the relationship between ISI change scores (from baseline to 6 months post-treatment) and outcomes/anchors from the SF-36 Health Survey, Work Limitations Questionnaire (WLQ), and Fatigue Severity Scale (FSS). Odds ratios were derived from the regression coefficients to calculate the probability of a given outcome being associated with different ISI change scores. Convergence between anchor- and distribution-based estimates was assessed.

RESULTS

Higher ISI scores (indicating more severe insomnia) were significantly associated with higher probabilities of negative outcome in all models. Individuals with a 6-point score reduction in ISI scores (which corresponded to 1(1/2) standard deviations) were 48% less likely to report 'feeling worn out' (SF-36) at 6 months, 46% less likely to be 'unable to think clearly' (WLQ), and 52% less likely to report 'feeling fatigued' (FSS). Similar results were found across a broad spectrum of all selected anchors.

CONCLUSIONS

Based on results of the study, a 6-point reduction is recommended to represent a clinically meaningful improvement in individuals with primary insomnia. Research on generalizability of the recommended MID in this study to other patient populations and other type of treatment interventions is needed.

Approaches to measuring the effects of wake-promoting drugs: a focus on cognitive function

OBJECTIVES

In clinical drug development, wakefulness and wake-promotion may be assessed by a large number of scales and questionnaires. Objective assessment of wakefulness is most commonly made using sleep latency/maintenance of wakefulness tests, polysomnography and/or behavioral measures. The purpose of the present review is to highlight the degree of overlap in the assessment of wakefulness and cognition, with consideration of assessment techniques and the underlying neurobiology of both concepts.

DESIGN

Reviews of four key areas were conducted: commonly used techniques in the assessment of wakefulness; neurobiology of sleep/wake and cognition; targets of wake promoting and/or cognition enhancing drugs; and ongoing clinical trials investigating wake promoting effects.

RESULTS

There is clear overlap between the assessment of wakefulness and cognition. There are common techniques which may be used to assess both concepts; aspects of the neurobiology of both concepts may be closely related; and wake-promoting drugs may have nootropic properties (and vice versa). Clinical trials of wake-promoting drugs often, though not routinely, assess aspects of cognition.

CONCLUSIONS

Routine and broad assessment of cognition in the development of wake-promoting drugs may reveal important nootropic effects, which are not secondary to alertness/wakefulness, whilst existing cognitive enhancers may have underexplored or unknown wake promoting properties.

Optimizing circadian cycles and behavioral insomnia treatment in migraine

Sleep regulation may play a key role in headache management for individuals with migraine. At least among individuals with a predisposition to headache, episodes may be provoked by sleep deprivation or excess, as well as by sleep disorders. Chronobiological patterns have been identified in some forms of headache, including migraine. Insomnia is the most common sleep disorder in headache clinic populations, observed in half to two thirds of migraineurs. Recent evidence suggests migraine may improve with regulation of sleep. Because sleep represents a potentially modifiable vulnerability to headache, practitioners may wish to consider strategies that restore sleep homeostasis. Behavioral strategies are effective for regulation of sleep and may be abbreviated for headache medical practice settings. This article discusses the nature and prevalence of sleep complaints in migraineurs, conceptualization, and behavioral management of insomnia in the headache practice setting.

Evaluation of the methodological quality of systematic reviews of health status measurement instruments

A systematic review of measurement properties of health-status instruments is a tool for evaluating the quality of instruments. Our aim was to appraise the quality of the review process, to describe how authors assess the methodological quality of primary studies of measurement properties, and to describe how authors evaluate results of the studies. Literature searches were performed in three databases. One hundred and forty-eight reviews were included. The purpose of included reviews was to identify health status instruments used in an evaluative application and to report on the measurement properties of these instruments. Two independent reviewers selected the articles and extracted the data. Reviews were often of low quality: 22% of the reviews used one database, the search strategy was often poorly described, and in many cases it was not reported whether article selection (75%) and data extraction (71%) was done by two independent reviewers. In 11 reviews the methodological quality of the primary studies was evaluated for all measurement properties, and of these 11 reviews only 7 evaluated the results. Methods to evaluate the quality of the primary studies and the results differed widely. The poor quality of reviews hampers evidence-based selection of instruments. Guidelines for conducting and reporting systematic reviews of measurement properties should be developed.

A comparative study of the components of sleep quality in medical outpatients

Background. Almost any medical illness that causes significant pain or discomfort may negatively affect the quality of sleep. Moreover sleep disorders may coexist with medical disorders in people of all ages. Measuring sleep dysfunction is an area of active research, but few studies examined subjective ratings of sleep quality in medical patients Method. A total of 250 medical patients with various somatic complaints who attended the ENT, internal, neurology, orthopaedics and urology clinics participated in this study. The patients completed the Pittsburgh Sleep Quality Index (PSQI) which measures the quality of sleep in seven major domains and helps discriminate between individuals who experience poor sleep versus individuals who sleep well. A score ≥6 is considered as a significant sleep disturbance. Results. The PSQI score of the patients from all selected clinics were higher than the reported cut-off point (Mean = 8, SD = 3.42). Significant differences were found in sleep duration (component 3) and sleep disturbances (component 5) between clinics. Pain and worry were the major causes of sleep disturbances reported by the majority of the patients. Conclusion. Sleep disturbances in medically ill patients require careful evaluation for proper treatment that will alleviate the sleep problem without exacerbating concomitant illnesses. Essentially any condition that causes pain or discomfort may cause insomnia and must be considered in the overall treatment plan.

Headache and sleep disorders: review and clinical implications for headache management

Review of epidemiological and clinical studies suggests that sleep disorders are disproportionately observed in specific headache diagnoses (eg, migraine, tension-type, cluster) and other nonspecific headache patterns (ie, chronic daily headache, "awakening" or morning headache). Interestingly, the sleep disorders associated with headache are of varied types, including obstructive sleep apnea (OSA), periodic limb movement disorder, circadian rhythm disorder, insomnia, and hypersomnia. Headache, particularly morning headache and chronic headache, may be consequent to, or aggravated by, a sleep disorder, and management of the sleep disorder may improve or resolve the headache. Sleep-disordered breathing is the best example of this relationship. Insomnia is the sleep disorder most often cited by clinical headache populations. Depression and anxiety are comorbid with both headache and sleep disorders (especially insomnia) and consideration of the full headache-sleep-affective symptom constellation may yield opportunities to maximize treatment. This paper reviews the comorbidity of headache and sleep disorders (including coexisting psychiatric symptoms where available). Clinical implications for headache evaluation are presented. Sleep screening strategies conducive to headache practice are described. Consideration of the spectrum of sleep-disordered breathing is encouraged in the headache population, including awareness of potential upper airway resistance syndrome in headache patients lacking traditional risk factors for OSA. Pharmacologic and behavioral sleep regulation strategies are offered that are also compatible with treatment of primary headache.