Reliability and validity of the brief insomnia questionnaire in the America insomnia survey

Study Objectives:

To evaluate the reliability and validity of the Brief Insomnia Questionnaire (BIQ), a fully structured questionnaire developed to diagnose insomnia according to hierarchy-free Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR), International Classification of Diseases-10 (ICD-10), and research diagnostic criteria/International Classification of Sleep Disorders-2 (RDC/ICSD-2) general criteria without organic exclusions in the America Insomnia Survey (AIS).

Design:

Probability subsamples of AIS respondents, oversampling BIQ positives, completed short-term test-retest interviews (n = 59) or clinical reappraisal interviews (n = 203) to assess BIQ reliability and validity.

Setting:

The AIS is a large (n = 10,094) epidemiologic survey of the prevalence and correlates of insomnia.

Participants:

Adult subscribers to a national managed healthcare plan.

Intervention:

None

Measurements and Results:

BIQ test-retest correlations were 0.47-0.94 for nature of the sleep problems (initiation, maintenance, nonrestorative sleep [NRS]), 0.72-0.95 for problem frequency, 0.66-0.88 for daytime impairment/distress, and 0.62 for duration of sleep. Good individual-level concordance was found between BIQ diagnoses and diagnoses based on expert interviews for meeting hierarchy-free inclusion criteria for diagnoses in any of the diagnostic systems, with area under the receiver operating characteristic curve (AUC, a measure of classification accuracy insensitive to disorder prevalence) of 0.86 for dichotomous classifications. The AUC increased to 0.94 when symptom-level data were added to generate continuous predicted-probability of diagnosis measures. The AUC was lower for dichotomous classifications based on RDC/ICSD-2 (0.68) and ICD-10 (0.70) than for DSM-IV-TR (0.83) criteria but increased consistently when symptom-level data were added to generate continuous predicted-probability measures of RDC/ICSD-2, ICD-10, and DSM-IV-TR diagnoses (0.92-0.95).

Conclusions:

These results show that the BIQ generates accurate estimates of the prevalence and correlates of hierarchy-free insomnia in the America Insomnia Survey.

Citation:

Kessler RC; Coulouvrat C; Hajak G; Lakoma MD; Roth T; Sampson N; Shahly V; Shillington A; Stephenson JJ; Walsh JK; Zammit GK. Reliability and validity of the brief insomnia questionnaire in the america insomnia survey. SLEEP 2010;33(11):1539-1549.     

Auswirkungen passiver Änderungen des Bettklimas auf den Schlaf

Background

During sleep, a number of thermoregulatory processes that are important for the quality of sleep take place. In the literature, the endogenous reduction of the core body temperature during sleep has been described as a precondition for restful sleep. Most of the investigations on thermoregulatory aspects involve changes in the external temperature.

Methods

This investigation examined the effects of passive changes in the climate of the bed (temperature/humidity) on the quality of sleep in healthy subjects. With constant external conditions, two different blankets with different heat transfer and moisture dissipation characteristics were used to create different microclimates in the space between the mattress and the blanket. The effects of this passive change in climate on the quality of sleep were investigated on a polysomnographic basis in this pilot study under standardized, randomized, and double-blind conditions with 12 healthy subjects who each slept in the sleep laboratory for three consecutive nights. Measurements of the temperature and humidity of the room and the space between the mattress and the blanket were performed in six of the subjects. The subjects slept under one of the two bed covers in each case.

Results

The study blanket was better at dissipating temperature and humidity to the surroundings. The climate under the study blanket was drier and cooler. Total sleep time, sleep efficiency, and arousal tended to improve under the study blanket. None of the differences reached significance.

Conclusion

This pilot study indicated a tendency towards improvement (p<0.10) of sleep quality associated with a drier climate in the area of the bed between the mattress and the blanket. However, further investigations involving a larger number of test subjects are required to confirm these preliminary findings.     

Suprathreshold repetitive transcranial magnetic stimulation elevates thyroid-stimulating hormone in healthy male subjects.

Repetitive transcranial magnetic stimulation (rTMS) has been introduced as a new antidepressive treatment strategy. The mode of action by which the antidepressive effect is brought about is not yet clear. Other antidepressive treatment strategies such as sleep deprivation are associated with an increase of plasma thyroid-stimulating hormone (TSH) levels that correlate with clinical improvement. In the present study, the effect of left prefrontal suprathreshold (120% of motor threshold) rTMS on TSH plasma levels of 19 healthy male subjects was investigated in comparison with subthreshold (80% of motor threshold) and sham stimulation. Suprathreshold rTMS was followed by a significant relative increase of TSH levels 10 and 60 minutes after stimulation in comparison with subthreshold and sham stimulation. The more pronounced effect of suprathreshold rTMS on TSH plasma levels might be important for the determination of optimal stimulation parameters in the treatment of depressed patients.     

Nocturnal plasma melatonin levels in patients suffering from chronic primary insomnia

Abstract: Polysomnographic sleep patterns and melatonin secretion were investigated in 10 patients (age: 41.3 ± 9.5 years) who suffered from chronic primary insomnia and complained predominantly about difficulties in maintaining sleep and in five healthy controls (age 27.2 ± 0.7 years). Nocturnal plasma melatonin concentrations were obtained hourly, measured by direct radioimmunoassay and statistically compared between insomniacs and controls with age as a covariate. Plasma melatonin levels in the patient group tended to begin increasing earlier in the evening and were significantly (P ± 0.01) lower during the middle of the night (peak value 82.5 ± 26.5 pg/ml) than in the healthy controls (peak value 116.8 ± 13.5 pg/ml). Among the patients, the most severely reduced nocturnal plasma melatonin levels were found in those patients with a history of sleep disturbance lasting for longer than five years (N = 6; age 41.8 ± 11.7 years; duration 15.3 ± 5.9 years; peak value 72.1 ± 25.0 pg/ml); whereas those chronic insomniacs affected for fewer than five years had relatively higher nocturnal levels (N = 4; age 40.6 ± 6.5 years; duration 3.8 ± 1.5 years; peak value 98.2 ± 23.9 pg/ml). These results show that the circadian rhythm of melatonin secretion is disturbed in patients with chronic primary insomnia, and that the nocturnal plasma melatonin secretion is increasingly more affected the longer the patients are unable to maintain a regular sleep pattern.     

Epidemiology of severe insomnia and its consequences in Germany

This is the first nation-wide face-to-face survey on the prevalence of well-defined severe insomnia and its impact on quality of life in the general population of Germany. The survey was part of an international epidemiological study, which was also conducted in Belgium, Great Britain, Ireland and Sweden. A representative sample of 1913 adults aged 18 years and over were interviewed in all parts of Germany according to the quota method. Subjects with symptomatic insomnia were identified using an algorithm compatible with the principal criteria for severe insomnia defined in the fourth revision of the Diagnostic and Statistical Manual of Mental Diseases (DSM-IV). Subjects provided data on quality of life using the Short Form 36 Health Survey (SF-36) questionnaire and on health care consumption. Prevalence of severe insomnia in Germany was found to be 4 %, which was lower than in other European countries (6–22 %). Severe insomnia was more prevalent among women, the unemployed, those living alone after divorce or separation, and those in large cities, but not more frequently in the elderly (aged 65 years and over). The majority of subjects had chronic complaints, with 74 % of them suffering from severe sleep problems for over a year's duration (average 56 ± 23 months). Consultations with general physicians, medication usage, medical tests and hospitalisation were greater among severe insomniacs compared to subjects who had no sleep complaints. The question regarding overall appreciation of quality of life was rated as bad in 22 % and good in 28 % of severe insomniacs compared to 3 % (bad) and 68 % (good) in subjects with no sleep complaints. Despite this, only 55 % of severe insomniacs had ever discussed their sleep problem with a doctor and the proportion who consulted their doctor specifically regarding sleep problems in the previous 12 months was even lower (36 %). The vast majority (73 %) was not taking hypnotic or sedative medications. In conclusion, insomnia, even when severe, is a common and a chronic complaint in Germany. This trial suggests that while, on the one hand, sleep disorders have a significant impact on patient's quality of life and consumption of health care, it is, on the other hand, a condition that is poorly recognised and for which patients are, for unknown reasons, reluctant to seek treatment. Received: 23 November 1999 / Accepted: 23 August 2000     

Separation anxiety and actual separation experiences during childhood in patients with panic disorder.

OBJECTIVE: The association between separation anxiety in childhood and actual separation experiences during childhood has not yet been investigated in patients with panic disorder. METHODS: In 115 patients with panic disorder with or without agoraphobia and in 124 control subjects without a history of psychiatric illness, we assessed separation anxiety during childhood, retrospectively, using DSM-IV and ICD-10 criteria and the Separation Anxiety Symptom Inventory (SASI). In addition, actual separation experiences from age 0 to 15 years were assessed, retrospectively. RESULTS: A total of 22.6% of the patients and 4.8% of the control subjects fulfilled both DSM-IV and ICD-10 criteria for childhood separation anxiety (chi 2 = 11.8; P < 0.0001). Further, 57.4% of the patients and 37.9% of the control subjects reported actual separation experiences during their childhood (chi 2 = 9.09, P < 0.003). Separation anxiety and actual separation experiences, however, were independent of each other. CONCLUSION: These results suggest that separation anxiety during childhood is not a consequence of actual traumatic separation experiences in panic disorder patients.     

The influence of intravenous L-tryptophan on plasma melatonin and sleep in men

The sleep-inducing mechanisms of L-Tryptophan (L-Trp) are generally thought to be mediated by a central serotonergic activation. Evidence is presented that some effects of L-Trp on sleep may be mediated by melatonin, a Trp-metabolite with sedative properties. Trp effects on vigilance, sleep, and plasma-melatonin concentrations were measured after double-blind application of 0, 1, 3, and 5 g L-Trp in nine and five healthy probands during daytime and nighttime, respectively. A significant sleep-inducing effect was observed after L-Trp administration during daytime and nighttime. The infusions of L-Trp caused a massive elevation of plasma melatonin levels. This effect was significant both during the night and the day, indicating that the increment of circulating melatonin may be of extrapineal origin.