Journal of The Association of Physicians of India ■ Vol. 63 ■ October 2015
Original Article
A Cross-Sectional Observational Study to Determine the Prevalence of Insomnia amongst Indian Corporate Employees N Yardi1, S Adsule2
Abstract
Editorial Viewpoint
Objectives: To determine the prevalence of insomnia, co-morbid medical conditions, personal habits and impact of insomnia on various day-to-day activities among corporate employees.
• Today’s corporate culture has brought with it many illnesses, stress related insomnia being very common.
Design: This was a cross-sectional, observational study conducted in six corporate offices. Setting: A corporate office was defined as any organized body performing various business operations and working together to achieve a common goal. Participants: Six hundred and five office based employees of Indian nationality who were 18 years or above and working approximately 8 hours a day were enrolled for this study. Measurements and Results: The participant reported outcome (PRO) and the insomnia symptom questionnaire (ISQ) were used to assess various parameters in the participants. The ISQ was scored by the physician and subsequently shared with participants. Of the 602 participants included in the study, prevalence of insomnia was found to be to be 13.8%. Previously undiagnosed population was 96.4%. Common co-morbid conditions associated with insomnia were anxiety, hypertension and depression. Regarding personal habits, alcohol consumption was observed to be significantly higher in the sufferers of insomnia. Insomniacs agreed that insufficient sleep affected their health, performance at work, household duties, and relationship with family. Conclusions: Significant number of insomniacs as determined by ISQ was previously undiagnosed, thus indicating the lack of relevance given by healthcare professionals towards the condition. Insomnia was also associated with co-morbid conditions and impairment of day-to-day activities.
Introduction
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nsomnia is defined in the fifth edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-5) as difficulty in getting to sleep, staying asleep or having non-restorative sleep despite having adequate opportunity for sleep, together with associated
impairment of daytime functioning, with symptoms being present for at least 4 weeks. 1 Insomnia is the most common sleep-related complaint
• Insomnia was found to be in 14% of the study subjects and commonly associated with hypertension, anxiety and depression. • Insomnia directly affected work performance, both in the office and at home. w i t h a p r e va l e n c e o f 1 0 % - 4 8 % in the general population. 2,3 In South India, 18.6% of respondents reported insomnia.4 Insomnia is associated with substantial impairment in an individual’s quality of life, impacting health, w o r k a n d h e a l t h c a r e c o s t . 5,6 Insomnia in corporate employees needs due attention since they are more prone to sleep disturbances 7-9 and as they work for longer hours.10 Though the working hours of various Indian professionals vary hugely, their working hours are much longer than in the West. 10 Data on prevalence of insomnia amongst Indian employees is scarce. In this study, we aimed to determine the prevalence of
Consultant Epileptologist and Pediatric Neurologist, Associate Professor, KEM Hospital, Jehangir Hospital, Deenanath Mangeshkar Hospital, Yardi Hospital, Pune, Maharashtra; 2Senior Manager Medical Affairs, Abbott India Ltd., Mumbai, Maharashtra. Received: 02.06.2015; Revised: 08.07.2015; Accepted: 11.08.2015 1
Journal of The Association of Physicians of India ■ Vol. 63 ■ October 2015
insomnia among Indian corporate e m p l o y e e s . We a l s o a i m e d t o determine the association, if any between insomnia and chronic medical conditions. The study also assessed the personal habits related to sleep in those with insomnia. Impact of insufficient sleep on dayto-day activities was also studied.
Material and Methods Study Population and Design
T h i s wa s a c r o s s - s e c t i o n a l , observational study conducted in employees aged 18 years and above, working in Indian corporate offices. A corporate office was any organized body performing various business operations and working together to achieve a common goal. Six corporate offices in India were identified and selected (as study sites) for participation. The study was initiated after the corporate offices provided an authorization letter/memorandum of understanding for participation. An introductory email explaining the nature and objective of this questionnaire based survey (to be completed by participants) was sent to all employees by their respective human resource teams. Additionally, posters and banners were displayed and pamphlets were distributed to all employees. E m p l o ye e s we r e r e q u e s t e d t o nominate themselves to participate in the survey conducted at their office premises. Office based employees of Indian nationality who were working approximately 8 hours a day were selected for this study. Those employees who were working in shift duties were excluded. The entire study process and the material used for the study were approved by an Independent Ethics Committee. Two field physicians and two clinical research coordinators were assigned to each study site. This ‘execution team’ explained the study and the contents of the questionnaire to the participants. The participants were required
to sign the subject authorization form as a documentation of their consent to participate in the study. The participants answered the participant reported outcome (PRO) questionnaire. Participants who did not have insomnia diagnosed by a physician previously were requested the fill the Insomnia Symptom Questionnaire (ISQ). The field physician scored the completed ISQ and shared the score, its interpretation and the questionnaire copy with the participants. The PRO data was couriered to the data management team for data entry and further statistical analysis. No investigational product was administered to the participants during this study. Questionnaires
The PRO questionnaire captured general information of the participants such as demography, anthropometric measurements, marital status, and education. It included questions to document the daily average working hours, any current medical condition(s) (as diagnosed by their physician), personal habits (alcohol consumption, its type and quantity; smoking status, its frequency and duration; and daily tea/ coffee consumption) and the impact of insufficient sleep on day-to-day activities. The ISQ is a 13-item self-rated questionnaire designed to identify insomnia. It is based on the criteria defined by the American Psychiatric Association’s fourth edition of the Diagnostic and Statistical Manual (DSM-IV) for primary insomnia which are consistent with the American Academy of Sleep Medicine’s (AASM) Research Diagnostic Criteria (RDC).1 The ISQ items contain multiple choices on an ordinal scale to: (1) determine the presence of a complaint of difficulty initiating or maintaining sleep, or feeling that the sleep was nonrestorative or unrefreshing; (2) determine the frequency of complaints (questions 1-5) and
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duration of these symptoms; and (3) assess the extent to which the individual’s sleep complaints affect daytime activities (questions 6-13). 11 The ISQ scoring algorithm as described by Okun et al, results in a simple dichotomous outcome of insomnia (“present” or “absent”). Based on this algorithm, participants were assessed for the presence of insomnia. Statistical Analysis
The general consensus o n p r e va l e n c e o f i n s o m n i a i n the general population is approximately 10%.12 To be secured of sufficient precision, the desired width of the interval was set to 5% (= upper confidence limit minus lower confidence limit). Given the prevalence of insomnia in 10% of general population, a sample size of approximately 550 participants was arrived at. However, to increase the statistical power of the study; 605 participants were aimed to be enrolled. Descriptive statistics was used to summarize the data in this study. Demographic characteristics were presented as number (n), mean, median, standard deviation (SD), minimum, and maximum for the continuous data and frequencies and percentages for categorical data. The prevalence of insomnia wa s p r e s e n t e d a s p e r c e n t a g e . Sub-group analysis was performed to analyze data on the basis of presence or absence of insomnia. A paired t-test and the chi-square test were used to compare the continuous and the categorical variable respectively.
Results A total of 605 participants were enrolled in the study of which three participants were excluded as they did not meet the eligibility criteria (worked in shift duties). A total of 602 participants were included in the analysis set. The demographic and anthropometric measures of all
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Journal of The Association of Physicians of India ■ Vol. 63 ■ October 2015
Table 1: Demographic and anthropometric data of participants Variables Age (Years) Weight (Kg) Height (cm) BMI (Kg/m2) Gender Male Female
Marital status Married Unmarried Other* Education Graduate Postgraduate Undergraduate Other† No info
p value
All values number (%); p value is for with insomnia vs without insomnia by Chi-squared test. * other includes those separated or widowed; †other educational qualifications
Table 3: Co-morbid medical conditions in the participants Medical condition Anxiety Hypertension Depression Asthma Diabetes Coronary heart disease