Elsevier

Sleep Medicine

Volume 3, Issue 2, March 2002, Pages 115-120
Sleep Medicine

Original article
Prevalence and consequences of insomnia disorders in the general population of Italy

https://doi.org/10.1016/S1389-9457(01)00158-7Get rights and content

Abstract

Objectives: To assess the prevalence of insomnia disorders using DSM-IV classification, and the consequences of insomnia in the Italian general population.

Methods: A representative sample of the Italian general population composed of 3970 individuals aged 15 years or older were interviewed by telephone using the Sleep-EVAL system (participation rate: 89.4%). Participants were interviewed about their sleep habits and sleep disorders. DSM-IV classification was used by Sleep-EVAL to determine the sleep disorder diagnosis.

Results: Insomnia symptoms were reported by 27.6% of the sample. Sleep dissatisfaction was found in 10.1% and insomnia disorder diagnoses in 7% of the sample. The use of sleep-enhancing medication was reported by 5.7% of the sample. Most of these subjects were using anxiolytics. Dissatisfaction with sleep was associated with daytime sleepiness. Middle-aged drivers dissatisfied with their sleep were three times more likely to have had a road accident in the previous year compared to other drivers. However, fewer than 30% of subjects dissatisfied with their sleep or with an insomnia disorder diagnosis had consulted a physician about their sleep problem.

Conclusions: As in other European and non-European countries, insomnia is widespread in Italy. The consequences are important. Appropriate recognition and treatment of insomnia should be part of an educational program for general practitioners everywhere.

Introduction

Insomnia is a distressing and disabling condition that affects a large part of the general population. Epidemiological studies performed in Western Europe, the USA, and Japan have reported a prevalence of insomnia symptoms ranging from 10 to 48% [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23]. This variation in the prevalence can be narrowed when more specific criteria are used. Frequent insomnia, defined as having difficulty initiating or maintaining sleep ‘often’ or at least three times per week, has a prevalence between 6 and 15% [9], [10], [11], [12], [13], [14], [15]. ‘Major complaints of insomnia’, ‘being bothered by insomnia’, and ‘having a great or a very great problem with insomnia’ have a prevalence between 7 and 12% [16], [17], [18]. Sleep dissatisfaction has a prevalence between 7 and 18% [5], [6], [7], [8], [20], [21], [22], [23]. Therefore, the large variability of insomnia prevalence among the different studies is not only due to cultural differences, but also because of the idiosyncratic ways of defining insomnia. Furthermore, there is no consensus on how to define insomnia and how to measure it in the general population.

Consequences of these sleep disturbances are numerous and bear important health and economical issues: increased hospitalizations, absenteeism at work, higher risks of road accidents, mortality and higher risk of developing a mental disorder.

This study aims to assess the prevalence of insomnia and its treatment in Italy using DSM-IV classification, and to assess the consequences of insomnia.

Section snippets

Sample

A representative sample of the Italian population was interviewed by telephone between December 1996 and April 1997 about its sleep habits, sleep disorders and mental disorders. The targeted population consisted of 46,332,282 inhabitants representing all non-institutionalized Italians aged 15 years or older. The sample was drawn according to a two-stage procedure. First, telephone numbers were pulled within each of the 18 geographical areas of Italy with respect to the population distribution

Description of the sample

The subjects were aged between 15 and 99 years; 18.3% were 65 years and older. Women represented 52% of the sample. Most of the subjects were married with the exception of the youngest, who were mainly single, and the oldest, who were frequently widowed (Table 1).

Dissatisfaction with sleep quality or quantity

Sleep dissatisfaction was reported by 10.1% (95% CI: 9.2–11.0%) of the sample. Women reported being dissatisfied with their sleep twice as much as men (12.0 vs. 6.8%; P<0.0001). The prevalence of sleep dissatisfaction significantly

Discussion

This study aimed to assess the prevalence of insomnia in Italy, its treatment and its association with daytime sleepiness and road accidents. Insomnia was assessed using three different measures as found in the literature: dissatisfaction with sleep quality or quantity, a symptom and a diagnosis. This provided different figures of prevalence. In this study, sleep dissatisfaction was reported by one Italian in ten. Insomnia symptoms, i.e. difficulty in initiating or maintaining sleep or NRS,

Acknowledgements

This study was supported by the FRSQ (#971067) and an unrestricted educational grant from the Sanofi-Synthelabo group.

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