Study of Sleep Disorders among Young Children Using Hindi Translated and Validated Version of Pediatric Sleep Questionnaire

INTRODUCTION

Sleep disorders are not uncommon among school children, and it has been found the primary school children suffer from various sleep disorders, for example, difficulty falling asleep, restless sleep, teeth grinding, and daytime sleepiness.[1] Cultural and geographical differences have been observed in the prevalence of sleep disorders, sleep schedule, and the reasons that lead to daytime sleepiness among children.[1] Although the sleep disorders are common, still it has been found that many a times, parents remain oblivious of their child's sleep problems.[2] It has been reported that children from the Asian countries sleepless as compared to Western countries.[13] Sleep deprivation has also been reported among children, especially with relation to the homework schedule.[45] Diagnosis of sleep disorders and sleep deprivation is important in children as they have been found to be associated with daytime napping, cardiovascular morbidity, attention deficit hyperactivity disorder (ADHD), and obesity.[678]

Indian data using the sleep questionnaires suggests that around 13% of toddlers have sleep problems, most common being the night awakenings.[9] Another study reported that among 3–10 years old children, 43% had some kind of sleep disorder.[10] The most common disorder has been the nocturnal enuresis followed by sleep talking and bruxism.

A number of questionnaires have been developed to assess sleep disorders in children. These include Children Report of Sleep Habits (CRSH),[2] Children's Sleep Habits Questionnaire (CSHQ),[11] and Pediatric Sleep Questionnaire (PSQ).[12] Among these, CRSH is the self-reporting questionnaire, while the latter two are to be responded by the parents. A review of various sleep questionnaires has reported that PSQ-sleep disordered breathing subscale is a validated tool and possess' all psychometric properties. Of all the questionnaires, CSHQ has already been translated in Hindi.[13] However, CSHQ does not provide any diagnosis. Hence, the objective of this study was to assess sleep disorders among children falling in the age group of 4–9 years, especially the obstructive sleep apnea (OSA) using Hindi translation of PSQ.

METHODS

This study was done after obtaining permission from the Institutional Ethics Committee. It had two parts first, the translation of PSQ in Hindi and second, assessment of sleep disorders in children using the Hindi version.

RESULTS

Translation process of the scale in Hindi was made difficult by various cultural issues. In Hindi, we did not have expression for some of the phrases mentioned in original English version. For example, original version mentions “growing pains” in item numbers A13a and A13b. Since this did not have adequate translation in Hindi, after the consensus, another term which is given in original instrument “unexplained leg pains” was used, and it was translated as “akaaran dard.” Other terminologies where the alternate terminologies were used are depicted in Table 1. The kappa suggested a perfect agreement for most of the items of the scale [Table 2]. Item A15 had worst agreement, and hence, it was revised in the Hindi translation after consultation with participants.

Table 1 Hindi translation of English terminologies in Pediatric Sleep Questionnaire-Hindi version

Table 2 Kappa values of items of Pediatric Sleep Questionnaire-Hindi version

A total of 560 forms were distributed; out of which, 482 were returned (response rate = 86%). Out of these 482 forms, 47 forms had missing responses on 5 or more items, hence, they were excluded from the study. Thus, in the final analysis, 435 forms were included in the study.

The average age of subjects included in this study was 6.36 ± 1.61 years. This sample was dominated by girls (60.64%). Mean sleep latency in this group was 11.69 ± 9.14 min. None of the forms that were returned disclosed any medical condition among any of the participants.

4.14% children had difficult bedtime routine. Difficulty in falling asleep was reported in 1.93% children. Two or more awakenings in the night were reported in 3.01% children, and 1.94% had difficulty in falling asleep again. Early morning awakening was reported in 3.43% children. 6.38% children complained of nonrefreshing sleep, and napping was reported in 30.34% children. 30.34% children consumed caffeine during the day. Frequent change in bedtime was reported in 5.49% and a frequent change in wake time was observed by parents of 4.95% children. Table 3 depicts prevalence of various sleep disorders and their symptoms.

Table 3 Prevalence of various sleep disorders and their symptoms in children of 4-9 years (n=435)

DISCUSSION

This study suggested that sleep disorders are not uncommon in young school children. SRBD was reported in approximately 8% children, and at least, one out of three children was wetting the bed. “Restless legs” and “growing pains” were reported in 6% and 10% children, respectively. Among parasomnias, teeth grinding was most common, reported in 14% children. Hypersomnia and caffeine consumption was also common among young children. Thus, this study underlines the need for focusing our attention to the sleep of children.

Earlier studies have reported that sleep disorders are not uncommon among school children. At the age of 4 years, 19% children have been found to suffer from sleep disorders with insomnia being the most prevalent of all, reported in 17% of the subjects.[19] Another study has reported that insomnia and nightmares were the most prevalent sleep disorder among children who have just joined the school, having reported by 15% and 14% study sample.[20] An Indian study involving children falling between 1 and 3 years suggested that 81% had 1–3 awakenings at night and 13% were suffering from various sleep disorders.[9] Our results are more or less comparable with the data from other studies except the snoring, which has been reported by small group in the present study. Earlier it has been found that around 39% children snore with 4% having habitual snoring.[21] That study reported that habitual snoring was associated with restless sleep, witnessed pauses in breath during sleep and mouth breathing, and hyperactivity during the daytime.[21] Furthermore, sleep disorders and poor sleep have been found to impair academic performance and to produce symptoms similar to ADHD.[212223] Thus, sleep-related symptoms should not be ignored among children.

We found that sleep-related parents of 8% children reported SRBD-OSA. Adenotonsillar hypertrophy and obesity are the important predictors of OSA among children, and most of the time they are coexistent.[24] In addition to mimicking ADHD, OSA has been found to have multiple metabolic and cardiovascular complications among children. Studies have reported that OSA among children leads to lipid peroxidation;[25] increment of proinflammatory markers in body, for example, interleukin 6, interleukin 18, plasminogen activating factor, high-sensitivity-C reactive protein;[2627] insulin resistance;[28] endothelial dysfunction;[29] and an increase in blood pressure.[30] However, resolution of OSA by adenotonsillectomy or any other method has been reported to improve all consequences of OSA among children including ADHD and systemic inflammation.[26293031] Considering the high prevalence of OSA in this study among Indian children and multiple adverse consequences which are reversible, there is a need for improving the awareness among pediatricians regarding sleep disorders.

Worsening of growing pains at night was reported by parents of 3.22% subjects with repeated kicking in bed by 2.14%. Earlier studies have suggested a RLS has a prevalence of approximately 2% in Chinese children[32] and 3% among Turkish children and adolescents;[33] figures that are close to the prevalence found in this study. However, it should be noted that we did not assess the RLS by face-to-face interview. RLS among children is frequently associated with iron deficiency.[34] In addition, a number of children in this study had growing pains, and growing pains may be initial presentation of RLS among children.[35] Considering the impact of RLS on the daytime performance of children, sleep quality at night and considering the prevalence of iron deficiency in India, it would be worthwhile to assess the children for RLS.[36]

This study had few methodological limitations – first, sample size was small; second, this was a questionnaire-based study, and third, sleep and sleep disorders were not examined using objective measures. However, the strengths of the study lie in the fact that a Hindi translated version of a valid instrument was used that had earlier been found to have good correlation with objective measures.[12] In future, further studies with improved methodology are required to assess the extent of the problem among children and to analyze the effect of sleep disorder on scholastic performance, behavior, and health.

CONCLUSION

This study shows that a significant proportion of children aging between 4 and 9 years suffer from sleep disorders such as SRBD and RLS.