Michel Paillard

Prevalence of insomnia in a survey of 12 778 adults in France

This study was an epidemiological questionnaire survey of a representative sample of the French population that included 12 778 individuals and in which adapted DSM‐IV criteria for the definition of insomnia were used. Our goals were not only to assess the prevalence of ‘insomnia’ using these criteria, but also to compare the results obtained with those of prior studies using different definitions of ‘insomnia’. The aim of this study was also to identify where areas of agreement and disaggreement existed, as we believe that it is important to emphasize these points because DSM‐IV recommendations are supposedly reflected in clinical practice. Seventy‐three per cent of the individuals surveyed complained of a nocturnal sleep problem, but only 29% reported at least one sleep problem three times per week for a month, and 19% (2428 subjects) had at least one sleep problem three times per week for a month and complained of daytime consequences (DSM‐IV criteria). Only 9% had two or more nocturnal sleep problems with daytime consequences and were classified as ‘severe insomniacs’. Our study indicates that if DSM‐IV criteria are used, the diagnosis of ‘insomnia’ is lower than in other epidemiological studies. The DSM criteria have an advantage in that they emphasize the daytime consequences of nocturnal sleep disturbances, which seem to be responsible for the most important socio‐economic costs of the problem.

SF-36: evaluation of quality of life in severe and mild insomniacs compared with good sleepers.

Objective Despite many studies, the impact of chronic insomnia on daytime functioning is not well understood. The aim of our study was to detect this impact by evaluating quality of life (QoL) using a validated instrument, the 36-item Short Form Health Survey of the Medical Outcomes Study (SF-36), in three matched groups of severe insomniacs, mild insomniacs, and good sleepers selected from the general population. Methods Three matched groups of 240 severe insomniacs, 422 mild insomniacs, and 391 good sleepers were recruited from the general French population after eliminating those with DSM-IV criteria for anxiety or depression. All subjects were asked to complete the SF-36. Scores for each QoL dimension were calculated and compared statistically among the three groups. Results Severe insomniacs had lower QoL scores in eight dimensions of the SF-36 than mild insomniacs and good sleepers. Mild insomniacs had lower scores in the same eight dimensions when compared with good sleepers. No dimension was significantly more altered than the other. Conclusions The mental health status and role of emotional QoL dimensions were worse in severe and mild insomniacs than in good sleepers. This result held even though we screened for psychiatric diseases, which shows a clear interrelation between insomnia and emotional state. General health status was also worse in severe and mild insomniacs than in good sleepers. However, we could conclude only that insomnia was related to a worse health status and not whether it was a cause or consequence of this worse health status. Finally, the degradation of QoL scores was correlated with the severity of insomnia.

Sleep disorders in children with blindness.

To evaluate the frequency and type of sleep disorders seen in blind children compared with matched controls, a 42‐item questionnaire was used on 156 children (77 blind children) ranging from 3 to 18 years of age. A total of 17.4% of blind children reported sleeping less than 7 hours per night on weekdays compared with 2.6% of controls, with blind children awakening much earlier. Blind children had more sleep complaints, and 13.4% of blind subjects had daily episodes of involuntary sleepiness compared with 1.3% of controls. Blindness has an impact on sleep and alertness that adds to the primary disability.