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Prevalence of insomnia and its impact on daily function amongst Malaysian primary care patients

Prevalence of insomnia and its impact on daily function amongst Malaysian primary care patients Background: Insomnia is a common public health problem and the prevalence and impact of insomnia in primary care attendees is not well documented in the Asian population. Objectives: To determine the prevalence of self-reported insomnia symptoms amongst adult primary care attendees and the association with socio-demographic factors; to ascertain the impact of insomnia on daily functioning and to describe the psychological profile of patients with insomnia. Methods: In this cross-sectional survey, 2049 adult patients (≥18 year old) attending seven primary care clinics in Peninsular Malaysia, completed the questionnaire asking about symptoms of insomnia (defined according to the International Classification of Sleep Disorders and DSM IV criteria) daytime impairment and psychological symptoms (assessed by Hospital Anxiety and Depression Scale). Results: The response rate was 86.2%. A total of 60% reported insomnia symptoms, 38.9% had frequent insomnia symptoms (>3 times per week), 30.7% had chronic insomnia without daytime consequences and 28.6% had chronic insomnia with daytime dysfunction. Indian ethnicity (OR 1.79; 95%CI, 1.28-2.49), age ≥ 50 or older (OR 1.82; 95%CI, 1.10-3.01), anxiety symptoms (OR 1.65; 95%CI, 1.21-2.22) and depression symptoms (OR 1.65; 95%CI, 1.21-2.26) were risk factors for chronic insomnia with daytime dysfunction. Amongst those with chronic insomnia with daytime dysfunction, 47.8% had anxiety symptoms (OR, 2.01; 95%CI, 1.57-2.59) and 36.5% had depression symptoms (OR, 2.74; 95%CI, 2.04-3.68) based on HADs score. They also had tendency to doze off while driving and to be involved in road traffic accidents. Conclusions: A third of primary care attendees have insomnia symptoms and chronic insomnia, associated with significant daytime dysfunction and psychological morbidity. By identifying those at risk of having chronic insomnia, appropriate interventions can be commenced. Keywords: Insomnia, Psychological morbidity, Prevalence, Primary care, Malaysia Background chronic insomnia have more severe sleep complaints Insomnia is a common public health problem with an and poorer daytime functioning, and consulted more estimated prevalence in both Western and Asian general often [9]. Patients with insomnia have been reported to populations in the range of 11-50% [1-7]. The wide vari- have twice as many admissions to hospital, more visits ation of prevalence is due to differences in definitions of to GPs (increased 14%) and undergo more laboratory insomnia used, populations studied and research meth- testing (increased 9%). They were also noted to have odology. Studies conducted in Western settings have clinical consultations an average 12.87 times per year reported that primary care populations have a higher compared to 5.25 per year for the non insomnia patients prevalence of insomnia (64-69%) than the general popu- [8]. The strong association between insomnia and health lation [8-10]. Patients in primary care clinics with care utilisation persists even after adjustments for age, gender and chronic disease [10]. Insomnia has a significant impact on individual health * Correspondence: drzailina@yahoo.com particularly those with co-morbid conditions, it has been Department of Family Medicine, International Medical University, Jalan Rasah, Seremban, Negeri Sembilan 70300, Malaysia reported to be associated with chronic diseases such as Full list of author information is available at the end of the article © 2012 Zailinawati et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Zailinawati et al. Asia Pacific Family Medicine 2012, 11:9 Page 2 of 8 http://www.apfmj.com/content/11/1/9 ischemic heart disease and hypertension, morning head- study in the public clinics and consecutive patients were aches and depression [11-13]. Epidemiological studies recruited by the doctors in the private clinics. We col- have demonstrated that lack of sleep is associated with day- lected an equal number of patients from each setting. time consequences such as poor performance at work [14], Participants in the study were aged 18 years and above impaired memory and concentration [3,10]. Insomnia has attending the primary care clinics for any reason. Exclu- also been shown to be related to higher rates of work sion criteria were serious illness, impaired memory, those absenteeism and increased rates of motor vehicle and with mental illness, women who were either pregnant or workplace accidents [15]. All these have significant direct up to 6 weeks postpartum and illiterate patients, as they and indirect economic implications [8,10,14-16]. Simon may not be able to provide accurate responses which may et al. reported that those with insomnia used average 60% introduce bias to the study. higher of total health services compared those without insomnia. Despite the high reported prevalence and public Questionnaires health burden of insomnia worldwide, it remains a problem The self-administered questionnaire sought data on socio- that is widely under-recognized and under-treated [2,17]. demographic factors, sleep, lifestyle issues (cigarette use, In view of the significant impact on individuals and caffeine and alcohol consumption) and utilized the Epworth society, and primary care being the first patients’ en- Sleepiness Scale (ESS) [19] to measure daytime dysfunction counter, there is a need to explore this issue in primary (sleepiness) and the Hospital Anxiety and Depression Scale care settings further. To date, there have been no studies (HADs scale) to measure psychological symptoms [20]. on insomnia in Malaysian or any other Asian primary The study was conducted in English and Malay as most care settings. This study was conducted in seven primary Malaysians understand either of these languages. care clinics in Peninsular Malaysia. We aimed to docu- To evaluate their sleep pattern, respondents were asked ment the prevalence of self-reported insomnia symp- about difficulty in falling asleep (> 30 min to fall asleep), toms and sleep patterns amongst adult primary care maintaining sleep (> 3 night-time awakenings), early morn- attendees in Malaysia, to see if this was associated with ing awakening (waking between 2 to 5am) and complaints socio-demographic and clinical characteristics, to ascer- of un-refreshing sleep (waking non refreshed in the morn- tain the impact of insomnia on daily functioning and ing) and the frequency and duration of these events. to describe the psychological profile of patients with The presence of any of the above symptoms on at least insomnia. 3 days in a week was considered to be insomnia, based on the International Classification of Sleep Disorders Methods (ICSD 2001) [21] and DSM IV criteria [22]. Study design Daytime impairment was said to occur when the re- The study was a cross-sectional, self-administered ques- spondent answered positively to any of the following [23]: tionnaire survey, conducted in five private primary care trouble functioning during the day due to sleepiness, feel- clinics and two public primary care clinics in Malaysia. ing irritable, feeling anxious, feeling depressed, loss of It was conducted between January to November 2007. concentration, exhaustion, decreased work productivity, Primary care providers in Malaysia can be broadly classi- poor memory, Epworth Sleepiness Scale [19] is ≥ 11. fied into private and government sectors. Since there is The respondents with insomnia were classified into 3 no complete sampling frame for the private care provi- categories based on the Italian sleep study [8]: ders in Malaysia convenience sampling was employed. Purposive selection of the clinics was based on their 1) Level 1 - Insomnia (any of the insomnia symptoms varied geographical locations in the northern, central on at least 3 days of the week) with absence of and southern part of Peninsular Malaysia and to ensure daytime dysfunction representation of the different ethnic groups that make 2) Level 2 - Chronic insomnia (Level 1 insomnia) with up Malaysia’s multiethnic population. A pilot study was symptoms persisting for > than 4 weeks duration conducted to refine the questionnaire and study protocol 3) Level 3 - Chronic insomnia (Level 2 insomnia) with [18]. Ethical approval for the study was obtained from daytime impairment. the Human Ethics Committees of Monash University, Australia and International Medical University, Malaysia. Psychological symptoms were considered as absent if the HADs score was 0–7, mild if subjects scored 8–10, Sampling and enrollment criteria moderate if 11–14 and severe if 15–21. The scales used Due to the large difference in daily number of patients in this study have acceptable validity, reliability and test- seen in public primary care clinics (200–400 patients per retest reliability [20,24]. Several studies have shown that day) and private primary care clinics (20–30 patients per HADS is dependable, stable, and consistent in producing day), one in five patients was invited to participate in the the result and has been validated in Malaysia [24-26]. Zailinawati et al. Asia Pacific Family Medicine 2012, 11:9 Page 3 of 8 http://www.apfmj.com/content/11/1/9 Table 1 Socio-demographic data of participants Statistical analysis Data were analyzed using the Statistical Package for Variable n Percentage (%) Social Sciences (SPSS) version 11.0. Statistical compari- Gender son of categorical variables and continuous data was Male 908 44.3 undertaken using χ test and t-test respectively. For or- Female 1141 55.7 dinal variable where linear trend is expected, chi-square Age group test for linear-to-linear association (equivalent to chi- 18-29 694 34.0 square test for trend) was applied. Statistical significance was set at p< 0.05. In the univariate analysis, insomnia is 30-39 467 22.9 the dependent variable (this is classified at several levels: 40-49 369 18.1 insomnia, chronic insomnia, chronic insomnia with day- 50-59 301 14.7 time consequences). The independent variables are fac- > 60 212 10.4 tors such as sex, age group, employment status and Ethnic group lifestyle habits. Malay 1242 60.6 Result Chinese 401 19.6 Demographics and prevalence of insomnia in primary Indian 375 18.3 care patients Others 31 1.5 Of the 2400 questionnaires distributed, 2075 patients Marital status returned the survey but 26 incomplete questionnaires Single 548 29.3 were excluded. The response rate varied in different cen- Married 1306 65.6 ters from 50.2% to 100%, with an average of 86.2%. The mean age of the respondents was 39 years (SD ± 14.46), Separated/divorced/widow 102 5.1 and the majority were employed (70.2%) (Table 1). Employment status Sixty percent of the study population had at least one Employed 1436 70.2 of the insomnia symptoms, with 38.9% classified as level Unemployed 429 21.0 1 insomnia, 30.7% as level 2 insomnia and 28.6% as level Pensioner 130 6.4 3 insomnia. Chronic (or level 2) insomnia was more Others 50 2.4 prevalent among those aged ≥ 60 years, of Indian ethni- city, those who were separated, divorced or widowed, Household income* who earned less than RM 500 per month, who were un- <500 121 6.0 employed or who had a low educational level. There was 501-1000 479 23.7 no significant gender difference in any level of insomnia 1001-2000 720 35.7 (Table 2). Amongst all respondents only 6.3% (130) and 2001-3000 333 16.5 amongst those with insomnia only 14.2% (113) discussed 3001-4000 156 7.7 their sleep problems with their doctors. Private clinics attendees tended to have more insomnia 4001-5000 70 3.5 than patients attending public clinics (47.6% vs. 30.5%, >5000 140 6.9 p<0.001). However, there was significantly more chronic Educational Level insomnia in public compared to private clinics (61.9% Never attended school 46 2.3 vs. 47.9%, p<0.001) and more chronic insomnia with Primary school only 275 13.5 daytime dysfunction in public clinics (55.3% vs. 45.8%, Secondary school only 1076 52.7 p<0.001). Tertiary education 694 31.6 Pattern of insomnia in primary care patients * RM- Ringgit Malaysia, 1 USD = 3.4 RM. Among those who reported insomnia, difficulty initiating sleep and un-refreshed sleep were noted in 32.6% and respondents who were older than 60 years old with 36.4% respectively, while difficulty maintaining sleep chronic insomnia experienced more difficulty in initiat- (20.5%) and early morning awakening (14.8%) were less ing sleep, compared to those between 18 to 29 years old frequent. A total of 57.4% and 55.3% of those who had (47.2% vs. 71.7%, p<0.001). The younger age group chronic insomnia reported having difficulty initiating reported more of un-refreshed sleep compared to the sleep and un-refreshed sleep respectively. While 32.5% elderly (68.5% vs. 44.1%, p<0.001). of those with chronic insomnia had difficulty maintain- Those who had insomnia and chronic insomnia took ing sleep and 24.5% had early morning awakening. The an average of 45 min (SD ± 41.5), and those who did not Zailinawati et al. Asia Pacific Family Medicine 2012, 11:9 Page 4 of 8 http://www.apfmj.com/content/11/1/9 Table 2 Demographic characteristics of patients with different level of insomnia Level 1 Insomnia n = 798 n (%) Level 2 Insomnia n = 630 n (%) Level 3 Insomnia n = 587 n (%) Gender Male 353 (39.2) 262 (51.2) 243 (47.3) Female 445 (39.3) 368 (54.9) 344 (51.0) Chi-square test χ =1.17, df=1, p>0.05 Ethnic Group Indian 158 (42.8)* 143 (67.5)* 135 (63.1)* Non-Indian (46.4) Chi-square test χ =19.5, df=1, p<0.001 Age Group 18-29 260 (37.7) 189 (45.5) 178 (42.6) 30-39 186 (40.3) 137 (47.1) 128 (43.8) 40-49 144 (39.2) 117 (54.9) 108 (50.2) 50-59 124 (41.5) 116 (69.0) 109 (64.9) >60 80 (38.1) 67 (73.6)* 60 (65.9)* Chi-square for trend χ =33.0, df=1, p<0.001 Marital Status Single 218 (37.7) 158 (44.3) 151 (42.2) Married 499 (38.6) 406 (55.9) 375 (51.4) Separated/Divorced/Widow 54 (52.9)* 49 (74.2)* 44 (66.7)* Chi-square for trend χ =15.9, df=1, p<0.001 Household Income <500 62 (52.5) 54 (65.9)* 53 (63.9)* 501-1000 181 (38.1) 145 (57.1) 136 (52.9) 1001-2000 266 (37.2) 212 (52.9) 194 (48.3) 2001-3000 131 (39.8) 102 (51.5) 93 (47.0) 3001-4000 59 (38.1) 45 (46.9) 40 (41.7) 4001-5000 28 (40.0) 19 (44.2) 18 (40.9) >5000 52 (37.1) 38 (45.8) 38 (45.8) Chi-square for trend χ =8.2, df=1, p=0.004 Employment Status Employed 582 (39.5) 421 (48.3) 390 (44.6) Unemployed 168 (39.6) 153 (69.9) 146 (66.1)* Pensioner 44 (33.8) 39 (72.2)* 34 (63.0) Chi-square test χ =36.7, df=2, p<0.001 Educational Level Never attended school 28 (60.9)* 24 (77.4)* 23 (74.2)* Primary school 125 (46.1) 114 (67.9) 107 (62.6) Secondary school 386 (36.1) 309 (53.6) 286 (49.4) Tertiary education 250 (40.4) 182 (44.9) 170 (41.9) Chi-square for trend χ =27.7, df=1, p<0.001 * p< 0.05 is significant. Level 1 insomnia – any of the insomnia symptoms occurring more than 3 times per week. Level 2 insomnia – chronic insomnia (any of the insomnia symptoms occurring more than 3 times per week, persist more than 4 weeks). Level 3 insomnia – chronic insomnia with daytime consequences. Zailinawati et al. Asia Pacific Family Medicine 2012, 11:9 Page 5 of 8 http://www.apfmj.com/content/11/1/9 have insomnia took an average of 17.7 min, (SD ± 14.6) of them having an ESS score ≥11 (28.2% vs. 18.3%, to fall asleep. Chronic insomniacs range of sleep latency p<0.001). (duration of time from “lights out,” or bedtime, to the Those with insomnia were more likely to exhibit psy- onset of sleep) was from 1 min to 5 h. Those who had chological symptoms such as, easily irritable (50.8% vs. insomnia, slept significantly less (about 5.7 h per night) 35.4%, p<0.001), anxious (57.5% vs. 36.0%, p<0.001) and (SD ± 1.25), compared to those without insomnia about felt depressed (45.1% vs. 25.4%, p<0.001). They also 6.6 h per night (SD ± 1.00). About 14.5% of those with reported loss of concentration at work (37.9% vs. 21.8%, insomnia slept less than 4 h per night, and a total of p<0.001), they felt tired easily (72.1% vs. 60.7%, p<0.001 39.6% slept less than 5 h per night. and had poorer memory (43.8% vs. 29.8%, p<0.001). They perceived that they were less productive (37.4% vs. Lifestyle factors associated with insomnia pattern in 18.9%, p<0.001) and felt that they poorer health (8.1% primary care patients vs. 2.2%, p<0.001). Table 3 shows the association between lifestyle factors Those with chronic insomnia were more likely to report and the different levels of insomnia. Smokers were more driving while sleepy (42.5% vs. 35.5%, p=0.032, OR 1.12, likely to have un-refreshed sleep, (49.5% vs. 32.9%, 95%CI 1.01-1.25) and about one in five reported to dozing p<0.001). Those who drank more than 5 cups of caffein- off while driving (19.1% vs. 13.1%, p=0.016, OR 1.07, 95% ated drinks per day, tended to have more symptoms of CI 1.01-1.14). Four percent of those chronic insomniacs insomnia with more difficulty falling asleep, (68.6% vs. were involved in road traffic accidents due to sleepiness 31.4%, p<0.001) and more un-refreshed sleep (77.1% vs. (3.9% vs. 1.1%, p=0.007, OR 1.03, 95%CI 1.00-1.05). 22.9%, p<0.001). While only 3.9% of respondents consumed alcohol in this study there were no differences in sleep patterns The psychological profile of patients with insomnia between those who drank and those who did not. Of the 780 primary care attendees that had insomnia, a Respondents with insomnia take more sedatives (8.4% total of 47.8% (285) had anxiety symptoms based on HADS, vs. 1.2% p<0.001). The ‘sleep medication’ that they pre- with OR 2.01; 95%CI 1.57-2.59 (60.0% were categorised as sumed helped them included paracetamol, antihistamines, having mild symptoms, 29.1% moderate and 2.9% severe anti-depressants, anxiolytics and benzodiazepines (Table 3). anxiety symptoms). A total of 36.5% (285) were considered to have depression (OR 2.74; 95%CI 2.04-3.68), with 70.5% The impact of insomnia on daily function amongst of them categorised as mild, 27.4% moderate and 2.1% had primary care patients severe symptoms of depression. Further analysis in the The majority of those who had any level of insomnia different category of insomnia, either chronic insomnia or (83.3%) reported fair to poor quality of sleep. Those with those with daytime dysfunction showed that the percentage insomnia symptoms were more likely to report signifi- who were positive for both anxiety and depression were cant daytime sleepiness (66.2% vs. 52.2%, p<0.001) and almost the same. Interestingly, of those with anxiety, 74.4% this was supported by a significantly higher percentage experienced insomnia, as did 80.1% of those with depression. Table 3 Lifestyle of the respondents (non insomnia and the different level of insomnia) Non-insomniacs n=819 Level 1 insomnia n=798 Level 2 insomnia n=630 Level 3 insomnia n=587 n (%) n (%) n (%) n (%) Cigarette smoking 73 (17.6) 208 (26.1)* 153 (24.3)* 145 (24.7)* Consume caffeinated drinks 304 (73.3) 605 (76.0) 483 (76.9) 454 (77.5) Number of cups caffeinated drinks per day 1-2 248 (81.0) 428 (70.7) 343 (71.0) 318 (69.6) 3-5 56 (18.3) 143 (23.6) 112 (23.3) 110 (24.2) >5 2 (0.7) 34 (5.6)* 28 (5.8)* 27 (5.9)* Consume coffee 1 h before 28 (7.1) 93 (12.4)* 77 (13.0)* 74 (13.4)* Bedtime Alcohol 18 (4.4) 45 (5.7) 38 (6.1) 34 (5.8) Sedative use 5 (1.2) 67 (8.4)* 57 (9.1)* 56 (9.5)* * p<0.05 is significant. Level 1 insomnia – any of the insomnia symptoms occurring more than 3 times per week. Level 2 insomnia – chronic insomnia (any of the insomnia symptoms occurring more than 3 times per week, persist more than 4 weeks). Level 3 insomnia – chronic insomnia with daytime consequences. Zailinawati et al. Asia Pacific Family Medicine 2012, 11:9 Page 6 of 8 http://www.apfmj.com/content/11/1/9 Multivariate analyses the total burden of disease in Malaysia, which is the top Logistic regression analysis indicated that the likelihood of three, after ischaemic heart disease (9.8%) and cardiovas- someone having chronic insomnia with daytime conse- cular disease (6.4%) [30]. Malaysian government is addres- quences was independently associated with being Indian sing these issues actively to reduce road traffic accidents ethnicity, (OR 1.79; 95%CI 1.28-2.49), aged 50 or older, (OR [31]. However, there is a need to include widespread na- 1.82; 95%CI 1.10-3.01), having anxiety symptoms, (OR 1.65; tional campaigns to advocate enough sleep, create aware- 95%CI 1.21-2.22) and depression symptoms, (OR 1.65; 95% ness of the symptoms and effect of sleep deprivation and CI 1.21-2.26). promote help seeking in those suffering from insomnia. Besides insomnia and daytime sleepiness, reports of per- sonality change in subjects with insomnia and associated Discussion cognitive changes could also contribute to traffic accidents The study population was representative of the primary [32], however, there are many other causes of daytime care attendees in the selected primary care clinics in the sleepiness which were not explored in this study [23]. Peninsular Malaysia. In our study, almost half of the Chronic insomnia may be a symptom of a psychiatric patients attended the clinics of any reasons, experienced disorder or predispose or be a risk factor for these condi- at least one of the insomnia symptoms, and one third tions [12,33-35]. This study confirmed the association be- experienced chronic insomnia. This confirms that the tween chronic insomnia and symptoms of depression and prevalence of insomnia in primary care is higher com- anxiety. We also noted that there was no particular pattern pared to the general population in Malaysia [27,28] and of insomnia associated with depression supporting others other Asian [4-7] and Western countries [1-3,17] using who have noted that the classical ‘early morning wakening’ the same definition. In Malaysia, 33.8% of the general symptom is not necessarily linked to depression [12]. We population were reported to have insomnia symptoms believe therefore that where a patient is found to suffer and 12.2% had chronic insomnia [27]. The high preva- from any form of insomnia, be that difficulty falling asleep lence is probably due to the possible underlying physical or maintaining sleep, early wakening or waking up un- and mental health problem that brought them to the pri- refreshed further exploration of psychological symptoms mary care clinics. Primary care attendees presented with should be undertaken. Some authors even suggest that a variety of reasons for visits. Various studies suggest treatment of insomnia may reduce the risk of psychological that majority of those with insomnia seen in primary disorders [12,34]. care clinics have co-morbid conditions [12,13]. Hence Our findings related to the socio-demographic variables the new phrase of “comorbid insomnia’ emerged from associated with insomnia concur with the results of other the 2005 National Institutes of Health’s (NIH) confer- studies [1-7,17]. The high prevalence of chronic insomnia ence [13]. Comorbid insomnia refers to insomnia related amongst the elderly probably due to the progressive in- to certain medical conditions (psychiatric or medical dis- activity, dissatisfaction with social life and concurrent med- orders), medicines, and certain substances such caffeine. ical and psychiatric problems [2,10,17]. The lack of gender Unfortunately, the reason for visits and co-morbidities predilection for insomnia in Malaysian women further sub- for the sample population of this study is out of the stantiates the result of a meta-analysis [36] and confirms scope of this paper. result of the other local studies [27,28] which report that This study shows that chronic insomnia is highly Asian countries have less gender (female) predisposition to prevalent (30.7%) if compared to most studies in general insomnia than Western countries. In a sub-analysis (not population [2-7] which generally reported 9-15%. This shown) the Indian ethnicity were significantly unemployed, finding indicates that chronic insomnia is common had low educational status and reported more depressive among those seeking health care; perhaps because asso- symptoms based on HADs scoring; which may explain the association with the increase risk of having insomnia ciated co-morbidities such as medical or psychiatric dis- orders cause symptoms of insomnia. The importance of symptoms compared to other ethnic groups. chronic insomnia is the association with poor daytime Like other studies [1,9], not many of the patients with in- somnia consulted a physician for sleep problems. Despite functioning which may in turn affect work efficiency and productivity and may be detrimental if their working en- the high prevalence of symptoms, less than ten percent of vironment demands high cognitive skills and constant thosewithinsomniawereonany type of sedatives. Unfor- tunately, we did not know type of sedatives used by the alertness. Our finding that chronic insomnia is significantly asso- patients. This study is an important study in primary care ciated with daytime sleepiness and falling asleep whilst driv- population in both private and public clinics in Malaysia as it shows that insomnia is common, under-recognised and ing may lead to a higher risk of road traffic accidents, concurs with other studies [15,29] and is of serious public under-treated. We were however unable to establish a health concern. Road traffic accidents constitute 5.7% of causal link between insomnia and psychiatric disorders due Zailinawati et al. Asia Pacific Family Medicine 2012, 11:9 Page 7 of 8 http://www.apfmj.com/content/11/1/9 to the cross-sectional design and the lack of clinical inter- study on psychological problem in general health care. Eur Psychiatry 1996, 11(Supp 1):5S–10S. view for diagnosing disorders in this study. A longitudinal 2. 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Zailinawati AH, Ariff K, Nurjahan M, Teng CL: Epidemiology of insomnia in Malaysian adults: a community-based survey in 4 urban areas. Asia Pac J Public Health 2008, 20(3):224–233. References 1. Ustun TB, Privett M, Lecrubier Y: Form, frequency and burden of sleep 28. Kamil MA, Teng CL, Hassan SA: Snoring and breathing pauses during problem in general health care: a report from the WHO collaborative sleep in the Malaysian population. Respirology 2007, 12(3):375–380. Zailinawati et al. Asia Pacific Family Medicine 2012, 11:9 Page 8 of 8 http://www.apfmj.com/content/11/1/9 29. Nor’Aishah AB, Rampal KG: Study of fatigue amongst bus drivers. National University of Malaysia: Masters Thesis in Public health (Occupational Health); 2004. 30. Malaysia; health situation and trend. 2010. [cited 2011 29th September]; Available from: http://www.wpro.who.int/countries/maa/2010/ health_situation.htm. 31. Malaysian Institute of Road Safety Research (MIROS). 2010. [cited 2011 29th September]; Available from: http://www.miros.gov.my/web/guest/national. 32. Drowsy driving and automobile crashes. National Center on Sleep Disorders Research and National Highway Traffic Safety Administration; 1998. 33. Hohagen F, Rink K, Käppler C: Prevalence and treatment of insomnia in general practice: a longitudinal study. Eur Arch Psychiatry Clin Neurosci 1993, 242:329–336. 34. Fong SY, Wing YK: Longitudinal follow up of primary insomnia patients in a psychiatric clinic. Aust N Z J Psychiatry 2007, 41:611–617. 35. Vollrath M, Wicki W, Angst J, The Zurich study: VIII. Insomnia: association with depression, anxiety, somatic syndromes, and course of insomnia. Eur Arch Psychiatry Neurol Sci 1989, 239(2):113–124. 36. Zhang B, Wing YK: Sex differences in insomnia: a meta-analysis. Sleep 2006, 29:85–93. doi:10.1186/1447-056X-11-9 Cite this article as: Zailinawati et al.: Prevalence of insomnia and its impact on daily function amongst Malaysian primary care patients. Asia Pacific Family Medicine 2012 11:9. Submit your next manuscript to BioMed Central and take full advantage of: • Convenient online submission • Thorough peer review • No space constraints or color figure charges • Immediate publication on acceptance • Inclusion in PubMed, CAS, Scopus and Google Scholar • Research which is freely available for redistribution Submit your manuscript at www.biomedcentral.com/submit http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Asia Pacific Family Medicine Springer Journals

Prevalence of insomnia and its impact on daily function amongst Malaysian primary care patients

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Copyright © 2012 by Zailinawati et al.; licensee BioMed Central Ltd.
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Medicine & Public Health; General Practice / Family Medicine; Primary Care Medicine
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Abstract

Background: Insomnia is a common public health problem and the prevalence and impact of insomnia in primary care attendees is not well documented in the Asian population. Objectives: To determine the prevalence of self-reported insomnia symptoms amongst adult primary care attendees and the association with socio-demographic factors; to ascertain the impact of insomnia on daily functioning and to describe the psychological profile of patients with insomnia. Methods: In this cross-sectional survey, 2049 adult patients (≥18 year old) attending seven primary care clinics in Peninsular Malaysia, completed the questionnaire asking about symptoms of insomnia (defined according to the International Classification of Sleep Disorders and DSM IV criteria) daytime impairment and psychological symptoms (assessed by Hospital Anxiety and Depression Scale). Results: The response rate was 86.2%. A total of 60% reported insomnia symptoms, 38.9% had frequent insomnia symptoms (>3 times per week), 30.7% had chronic insomnia without daytime consequences and 28.6% had chronic insomnia with daytime dysfunction. Indian ethnicity (OR 1.79; 95%CI, 1.28-2.49), age ≥ 50 or older (OR 1.82; 95%CI, 1.10-3.01), anxiety symptoms (OR 1.65; 95%CI, 1.21-2.22) and depression symptoms (OR 1.65; 95%CI, 1.21-2.26) were risk factors for chronic insomnia with daytime dysfunction. Amongst those with chronic insomnia with daytime dysfunction, 47.8% had anxiety symptoms (OR, 2.01; 95%CI, 1.57-2.59) and 36.5% had depression symptoms (OR, 2.74; 95%CI, 2.04-3.68) based on HADs score. They also had tendency to doze off while driving and to be involved in road traffic accidents. Conclusions: A third of primary care attendees have insomnia symptoms and chronic insomnia, associated with significant daytime dysfunction and psychological morbidity. By identifying those at risk of having chronic insomnia, appropriate interventions can be commenced. Keywords: Insomnia, Psychological morbidity, Prevalence, Primary care, Malaysia Background chronic insomnia have more severe sleep complaints Insomnia is a common public health problem with an and poorer daytime functioning, and consulted more estimated prevalence in both Western and Asian general often [9]. Patients with insomnia have been reported to populations in the range of 11-50% [1-7]. The wide vari- have twice as many admissions to hospital, more visits ation of prevalence is due to differences in definitions of to GPs (increased 14%) and undergo more laboratory insomnia used, populations studied and research meth- testing (increased 9%). They were also noted to have odology. Studies conducted in Western settings have clinical consultations an average 12.87 times per year reported that primary care populations have a higher compared to 5.25 per year for the non insomnia patients prevalence of insomnia (64-69%) than the general popu- [8]. The strong association between insomnia and health lation [8-10]. Patients in primary care clinics with care utilisation persists even after adjustments for age, gender and chronic disease [10]. Insomnia has a significant impact on individual health * Correspondence: drzailina@yahoo.com particularly those with co-morbid conditions, it has been Department of Family Medicine, International Medical University, Jalan Rasah, Seremban, Negeri Sembilan 70300, Malaysia reported to be associated with chronic diseases such as Full list of author information is available at the end of the article © 2012 Zailinawati et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Zailinawati et al. Asia Pacific Family Medicine 2012, 11:9 Page 2 of 8 http://www.apfmj.com/content/11/1/9 ischemic heart disease and hypertension, morning head- study in the public clinics and consecutive patients were aches and depression [11-13]. Epidemiological studies recruited by the doctors in the private clinics. We col- have demonstrated that lack of sleep is associated with day- lected an equal number of patients from each setting. time consequences such as poor performance at work [14], Participants in the study were aged 18 years and above impaired memory and concentration [3,10]. Insomnia has attending the primary care clinics for any reason. Exclu- also been shown to be related to higher rates of work sion criteria were serious illness, impaired memory, those absenteeism and increased rates of motor vehicle and with mental illness, women who were either pregnant or workplace accidents [15]. All these have significant direct up to 6 weeks postpartum and illiterate patients, as they and indirect economic implications [8,10,14-16]. Simon may not be able to provide accurate responses which may et al. reported that those with insomnia used average 60% introduce bias to the study. higher of total health services compared those without insomnia. Despite the high reported prevalence and public Questionnaires health burden of insomnia worldwide, it remains a problem The self-administered questionnaire sought data on socio- that is widely under-recognized and under-treated [2,17]. demographic factors, sleep, lifestyle issues (cigarette use, In view of the significant impact on individuals and caffeine and alcohol consumption) and utilized the Epworth society, and primary care being the first patients’ en- Sleepiness Scale (ESS) [19] to measure daytime dysfunction counter, there is a need to explore this issue in primary (sleepiness) and the Hospital Anxiety and Depression Scale care settings further. To date, there have been no studies (HADs scale) to measure psychological symptoms [20]. on insomnia in Malaysian or any other Asian primary The study was conducted in English and Malay as most care settings. This study was conducted in seven primary Malaysians understand either of these languages. care clinics in Peninsular Malaysia. We aimed to docu- To evaluate their sleep pattern, respondents were asked ment the prevalence of self-reported insomnia symp- about difficulty in falling asleep (> 30 min to fall asleep), toms and sleep patterns amongst adult primary care maintaining sleep (> 3 night-time awakenings), early morn- attendees in Malaysia, to see if this was associated with ing awakening (waking between 2 to 5am) and complaints socio-demographic and clinical characteristics, to ascer- of un-refreshing sleep (waking non refreshed in the morn- tain the impact of insomnia on daily functioning and ing) and the frequency and duration of these events. to describe the psychological profile of patients with The presence of any of the above symptoms on at least insomnia. 3 days in a week was considered to be insomnia, based on the International Classification of Sleep Disorders Methods (ICSD 2001) [21] and DSM IV criteria [22]. Study design Daytime impairment was said to occur when the re- The study was a cross-sectional, self-administered ques- spondent answered positively to any of the following [23]: tionnaire survey, conducted in five private primary care trouble functioning during the day due to sleepiness, feel- clinics and two public primary care clinics in Malaysia. ing irritable, feeling anxious, feeling depressed, loss of It was conducted between January to November 2007. concentration, exhaustion, decreased work productivity, Primary care providers in Malaysia can be broadly classi- poor memory, Epworth Sleepiness Scale [19] is ≥ 11. fied into private and government sectors. Since there is The respondents with insomnia were classified into 3 no complete sampling frame for the private care provi- categories based on the Italian sleep study [8]: ders in Malaysia convenience sampling was employed. Purposive selection of the clinics was based on their 1) Level 1 - Insomnia (any of the insomnia symptoms varied geographical locations in the northern, central on at least 3 days of the week) with absence of and southern part of Peninsular Malaysia and to ensure daytime dysfunction representation of the different ethnic groups that make 2) Level 2 - Chronic insomnia (Level 1 insomnia) with up Malaysia’s multiethnic population. A pilot study was symptoms persisting for > than 4 weeks duration conducted to refine the questionnaire and study protocol 3) Level 3 - Chronic insomnia (Level 2 insomnia) with [18]. Ethical approval for the study was obtained from daytime impairment. the Human Ethics Committees of Monash University, Australia and International Medical University, Malaysia. Psychological symptoms were considered as absent if the HADs score was 0–7, mild if subjects scored 8–10, Sampling and enrollment criteria moderate if 11–14 and severe if 15–21. The scales used Due to the large difference in daily number of patients in this study have acceptable validity, reliability and test- seen in public primary care clinics (200–400 patients per retest reliability [20,24]. Several studies have shown that day) and private primary care clinics (20–30 patients per HADS is dependable, stable, and consistent in producing day), one in five patients was invited to participate in the the result and has been validated in Malaysia [24-26]. Zailinawati et al. Asia Pacific Family Medicine 2012, 11:9 Page 3 of 8 http://www.apfmj.com/content/11/1/9 Table 1 Socio-demographic data of participants Statistical analysis Data were analyzed using the Statistical Package for Variable n Percentage (%) Social Sciences (SPSS) version 11.0. Statistical compari- Gender son of categorical variables and continuous data was Male 908 44.3 undertaken using χ test and t-test respectively. For or- Female 1141 55.7 dinal variable where linear trend is expected, chi-square Age group test for linear-to-linear association (equivalent to chi- 18-29 694 34.0 square test for trend) was applied. Statistical significance was set at p< 0.05. In the univariate analysis, insomnia is 30-39 467 22.9 the dependent variable (this is classified at several levels: 40-49 369 18.1 insomnia, chronic insomnia, chronic insomnia with day- 50-59 301 14.7 time consequences). The independent variables are fac- > 60 212 10.4 tors such as sex, age group, employment status and Ethnic group lifestyle habits. Malay 1242 60.6 Result Chinese 401 19.6 Demographics and prevalence of insomnia in primary Indian 375 18.3 care patients Others 31 1.5 Of the 2400 questionnaires distributed, 2075 patients Marital status returned the survey but 26 incomplete questionnaires Single 548 29.3 were excluded. The response rate varied in different cen- Married 1306 65.6 ters from 50.2% to 100%, with an average of 86.2%. The mean age of the respondents was 39 years (SD ± 14.46), Separated/divorced/widow 102 5.1 and the majority were employed (70.2%) (Table 1). Employment status Sixty percent of the study population had at least one Employed 1436 70.2 of the insomnia symptoms, with 38.9% classified as level Unemployed 429 21.0 1 insomnia, 30.7% as level 2 insomnia and 28.6% as level Pensioner 130 6.4 3 insomnia. Chronic (or level 2) insomnia was more Others 50 2.4 prevalent among those aged ≥ 60 years, of Indian ethni- city, those who were separated, divorced or widowed, Household income* who earned less than RM 500 per month, who were un- <500 121 6.0 employed or who had a low educational level. There was 501-1000 479 23.7 no significant gender difference in any level of insomnia 1001-2000 720 35.7 (Table 2). Amongst all respondents only 6.3% (130) and 2001-3000 333 16.5 amongst those with insomnia only 14.2% (113) discussed 3001-4000 156 7.7 their sleep problems with their doctors. Private clinics attendees tended to have more insomnia 4001-5000 70 3.5 than patients attending public clinics (47.6% vs. 30.5%, >5000 140 6.9 p<0.001). However, there was significantly more chronic Educational Level insomnia in public compared to private clinics (61.9% Never attended school 46 2.3 vs. 47.9%, p<0.001) and more chronic insomnia with Primary school only 275 13.5 daytime dysfunction in public clinics (55.3% vs. 45.8%, Secondary school only 1076 52.7 p<0.001). Tertiary education 694 31.6 Pattern of insomnia in primary care patients * RM- Ringgit Malaysia, 1 USD = 3.4 RM. Among those who reported insomnia, difficulty initiating sleep and un-refreshed sleep were noted in 32.6% and respondents who were older than 60 years old with 36.4% respectively, while difficulty maintaining sleep chronic insomnia experienced more difficulty in initiat- (20.5%) and early morning awakening (14.8%) were less ing sleep, compared to those between 18 to 29 years old frequent. A total of 57.4% and 55.3% of those who had (47.2% vs. 71.7%, p<0.001). The younger age group chronic insomnia reported having difficulty initiating reported more of un-refreshed sleep compared to the sleep and un-refreshed sleep respectively. While 32.5% elderly (68.5% vs. 44.1%, p<0.001). of those with chronic insomnia had difficulty maintain- Those who had insomnia and chronic insomnia took ing sleep and 24.5% had early morning awakening. The an average of 45 min (SD ± 41.5), and those who did not Zailinawati et al. Asia Pacific Family Medicine 2012, 11:9 Page 4 of 8 http://www.apfmj.com/content/11/1/9 Table 2 Demographic characteristics of patients with different level of insomnia Level 1 Insomnia n = 798 n (%) Level 2 Insomnia n = 630 n (%) Level 3 Insomnia n = 587 n (%) Gender Male 353 (39.2) 262 (51.2) 243 (47.3) Female 445 (39.3) 368 (54.9) 344 (51.0) Chi-square test χ =1.17, df=1, p>0.05 Ethnic Group Indian 158 (42.8)* 143 (67.5)* 135 (63.1)* Non-Indian (46.4) Chi-square test χ =19.5, df=1, p<0.001 Age Group 18-29 260 (37.7) 189 (45.5) 178 (42.6) 30-39 186 (40.3) 137 (47.1) 128 (43.8) 40-49 144 (39.2) 117 (54.9) 108 (50.2) 50-59 124 (41.5) 116 (69.0) 109 (64.9) >60 80 (38.1) 67 (73.6)* 60 (65.9)* Chi-square for trend χ =33.0, df=1, p<0.001 Marital Status Single 218 (37.7) 158 (44.3) 151 (42.2) Married 499 (38.6) 406 (55.9) 375 (51.4) Separated/Divorced/Widow 54 (52.9)* 49 (74.2)* 44 (66.7)* Chi-square for trend χ =15.9, df=1, p<0.001 Household Income <500 62 (52.5) 54 (65.9)* 53 (63.9)* 501-1000 181 (38.1) 145 (57.1) 136 (52.9) 1001-2000 266 (37.2) 212 (52.9) 194 (48.3) 2001-3000 131 (39.8) 102 (51.5) 93 (47.0) 3001-4000 59 (38.1) 45 (46.9) 40 (41.7) 4001-5000 28 (40.0) 19 (44.2) 18 (40.9) >5000 52 (37.1) 38 (45.8) 38 (45.8) Chi-square for trend χ =8.2, df=1, p=0.004 Employment Status Employed 582 (39.5) 421 (48.3) 390 (44.6) Unemployed 168 (39.6) 153 (69.9) 146 (66.1)* Pensioner 44 (33.8) 39 (72.2)* 34 (63.0) Chi-square test χ =36.7, df=2, p<0.001 Educational Level Never attended school 28 (60.9)* 24 (77.4)* 23 (74.2)* Primary school 125 (46.1) 114 (67.9) 107 (62.6) Secondary school 386 (36.1) 309 (53.6) 286 (49.4) Tertiary education 250 (40.4) 182 (44.9) 170 (41.9) Chi-square for trend χ =27.7, df=1, p<0.001 * p< 0.05 is significant. Level 1 insomnia – any of the insomnia symptoms occurring more than 3 times per week. Level 2 insomnia – chronic insomnia (any of the insomnia symptoms occurring more than 3 times per week, persist more than 4 weeks). Level 3 insomnia – chronic insomnia with daytime consequences. Zailinawati et al. Asia Pacific Family Medicine 2012, 11:9 Page 5 of 8 http://www.apfmj.com/content/11/1/9 have insomnia took an average of 17.7 min, (SD ± 14.6) of them having an ESS score ≥11 (28.2% vs. 18.3%, to fall asleep. Chronic insomniacs range of sleep latency p<0.001). (duration of time from “lights out,” or bedtime, to the Those with insomnia were more likely to exhibit psy- onset of sleep) was from 1 min to 5 h. Those who had chological symptoms such as, easily irritable (50.8% vs. insomnia, slept significantly less (about 5.7 h per night) 35.4%, p<0.001), anxious (57.5% vs. 36.0%, p<0.001) and (SD ± 1.25), compared to those without insomnia about felt depressed (45.1% vs. 25.4%, p<0.001). They also 6.6 h per night (SD ± 1.00). About 14.5% of those with reported loss of concentration at work (37.9% vs. 21.8%, insomnia slept less than 4 h per night, and a total of p<0.001), they felt tired easily (72.1% vs. 60.7%, p<0.001 39.6% slept less than 5 h per night. and had poorer memory (43.8% vs. 29.8%, p<0.001). They perceived that they were less productive (37.4% vs. Lifestyle factors associated with insomnia pattern in 18.9%, p<0.001) and felt that they poorer health (8.1% primary care patients vs. 2.2%, p<0.001). Table 3 shows the association between lifestyle factors Those with chronic insomnia were more likely to report and the different levels of insomnia. Smokers were more driving while sleepy (42.5% vs. 35.5%, p=0.032, OR 1.12, likely to have un-refreshed sleep, (49.5% vs. 32.9%, 95%CI 1.01-1.25) and about one in five reported to dozing p<0.001). Those who drank more than 5 cups of caffein- off while driving (19.1% vs. 13.1%, p=0.016, OR 1.07, 95% ated drinks per day, tended to have more symptoms of CI 1.01-1.14). Four percent of those chronic insomniacs insomnia with more difficulty falling asleep, (68.6% vs. were involved in road traffic accidents due to sleepiness 31.4%, p<0.001) and more un-refreshed sleep (77.1% vs. (3.9% vs. 1.1%, p=0.007, OR 1.03, 95%CI 1.00-1.05). 22.9%, p<0.001). While only 3.9% of respondents consumed alcohol in this study there were no differences in sleep patterns The psychological profile of patients with insomnia between those who drank and those who did not. Of the 780 primary care attendees that had insomnia, a Respondents with insomnia take more sedatives (8.4% total of 47.8% (285) had anxiety symptoms based on HADS, vs. 1.2% p<0.001). The ‘sleep medication’ that they pre- with OR 2.01; 95%CI 1.57-2.59 (60.0% were categorised as sumed helped them included paracetamol, antihistamines, having mild symptoms, 29.1% moderate and 2.9% severe anti-depressants, anxiolytics and benzodiazepines (Table 3). anxiety symptoms). A total of 36.5% (285) were considered to have depression (OR 2.74; 95%CI 2.04-3.68), with 70.5% The impact of insomnia on daily function amongst of them categorised as mild, 27.4% moderate and 2.1% had primary care patients severe symptoms of depression. Further analysis in the The majority of those who had any level of insomnia different category of insomnia, either chronic insomnia or (83.3%) reported fair to poor quality of sleep. Those with those with daytime dysfunction showed that the percentage insomnia symptoms were more likely to report signifi- who were positive for both anxiety and depression were cant daytime sleepiness (66.2% vs. 52.2%, p<0.001) and almost the same. Interestingly, of those with anxiety, 74.4% this was supported by a significantly higher percentage experienced insomnia, as did 80.1% of those with depression. Table 3 Lifestyle of the respondents (non insomnia and the different level of insomnia) Non-insomniacs n=819 Level 1 insomnia n=798 Level 2 insomnia n=630 Level 3 insomnia n=587 n (%) n (%) n (%) n (%) Cigarette smoking 73 (17.6) 208 (26.1)* 153 (24.3)* 145 (24.7)* Consume caffeinated drinks 304 (73.3) 605 (76.0) 483 (76.9) 454 (77.5) Number of cups caffeinated drinks per day 1-2 248 (81.0) 428 (70.7) 343 (71.0) 318 (69.6) 3-5 56 (18.3) 143 (23.6) 112 (23.3) 110 (24.2) >5 2 (0.7) 34 (5.6)* 28 (5.8)* 27 (5.9)* Consume coffee 1 h before 28 (7.1) 93 (12.4)* 77 (13.0)* 74 (13.4)* Bedtime Alcohol 18 (4.4) 45 (5.7) 38 (6.1) 34 (5.8) Sedative use 5 (1.2) 67 (8.4)* 57 (9.1)* 56 (9.5)* * p<0.05 is significant. Level 1 insomnia – any of the insomnia symptoms occurring more than 3 times per week. Level 2 insomnia – chronic insomnia (any of the insomnia symptoms occurring more than 3 times per week, persist more than 4 weeks). Level 3 insomnia – chronic insomnia with daytime consequences. Zailinawati et al. Asia Pacific Family Medicine 2012, 11:9 Page 6 of 8 http://www.apfmj.com/content/11/1/9 Multivariate analyses the total burden of disease in Malaysia, which is the top Logistic regression analysis indicated that the likelihood of three, after ischaemic heart disease (9.8%) and cardiovas- someone having chronic insomnia with daytime conse- cular disease (6.4%) [30]. Malaysian government is addres- quences was independently associated with being Indian sing these issues actively to reduce road traffic accidents ethnicity, (OR 1.79; 95%CI 1.28-2.49), aged 50 or older, (OR [31]. However, there is a need to include widespread na- 1.82; 95%CI 1.10-3.01), having anxiety symptoms, (OR 1.65; tional campaigns to advocate enough sleep, create aware- 95%CI 1.21-2.22) and depression symptoms, (OR 1.65; 95% ness of the symptoms and effect of sleep deprivation and CI 1.21-2.26). promote help seeking in those suffering from insomnia. Besides insomnia and daytime sleepiness, reports of per- sonality change in subjects with insomnia and associated Discussion cognitive changes could also contribute to traffic accidents The study population was representative of the primary [32], however, there are many other causes of daytime care attendees in the selected primary care clinics in the sleepiness which were not explored in this study [23]. Peninsular Malaysia. In our study, almost half of the Chronic insomnia may be a symptom of a psychiatric patients attended the clinics of any reasons, experienced disorder or predispose or be a risk factor for these condi- at least one of the insomnia symptoms, and one third tions [12,33-35]. This study confirmed the association be- experienced chronic insomnia. This confirms that the tween chronic insomnia and symptoms of depression and prevalence of insomnia in primary care is higher com- anxiety. We also noted that there was no particular pattern pared to the general population in Malaysia [27,28] and of insomnia associated with depression supporting others other Asian [4-7] and Western countries [1-3,17] using who have noted that the classical ‘early morning wakening’ the same definition. In Malaysia, 33.8% of the general symptom is not necessarily linked to depression [12]. We population were reported to have insomnia symptoms believe therefore that where a patient is found to suffer and 12.2% had chronic insomnia [27]. The high preva- from any form of insomnia, be that difficulty falling asleep lence is probably due to the possible underlying physical or maintaining sleep, early wakening or waking up un- and mental health problem that brought them to the pri- refreshed further exploration of psychological symptoms mary care clinics. Primary care attendees presented with should be undertaken. Some authors even suggest that a variety of reasons for visits. Various studies suggest treatment of insomnia may reduce the risk of psychological that majority of those with insomnia seen in primary disorders [12,34]. care clinics have co-morbid conditions [12,13]. Hence Our findings related to the socio-demographic variables the new phrase of “comorbid insomnia’ emerged from associated with insomnia concur with the results of other the 2005 National Institutes of Health’s (NIH) confer- studies [1-7,17]. The high prevalence of chronic insomnia ence [13]. Comorbid insomnia refers to insomnia related amongst the elderly probably due to the progressive in- to certain medical conditions (psychiatric or medical dis- activity, dissatisfaction with social life and concurrent med- orders), medicines, and certain substances such caffeine. ical and psychiatric problems [2,10,17]. The lack of gender Unfortunately, the reason for visits and co-morbidities predilection for insomnia in Malaysian women further sub- for the sample population of this study is out of the stantiates the result of a meta-analysis [36] and confirms scope of this paper. result of the other local studies [27,28] which report that This study shows that chronic insomnia is highly Asian countries have less gender (female) predisposition to prevalent (30.7%) if compared to most studies in general insomnia than Western countries. In a sub-analysis (not population [2-7] which generally reported 9-15%. This shown) the Indian ethnicity were significantly unemployed, finding indicates that chronic insomnia is common had low educational status and reported more depressive among those seeking health care; perhaps because asso- symptoms based on HADs scoring; which may explain the association with the increase risk of having insomnia ciated co-morbidities such as medical or psychiatric dis- orders cause symptoms of insomnia. The importance of symptoms compared to other ethnic groups. chronic insomnia is the association with poor daytime Like other studies [1,9], not many of the patients with in- somnia consulted a physician for sleep problems. Despite functioning which may in turn affect work efficiency and productivity and may be detrimental if their working en- the high prevalence of symptoms, less than ten percent of vironment demands high cognitive skills and constant thosewithinsomniawereonany type of sedatives. Unfor- tunately, we did not know type of sedatives used by the alertness. Our finding that chronic insomnia is significantly asso- patients. This study is an important study in primary care ciated with daytime sleepiness and falling asleep whilst driv- population in both private and public clinics in Malaysia as it shows that insomnia is common, under-recognised and ing may lead to a higher risk of road traffic accidents, concurs with other studies [15,29] and is of serious public under-treated. We were however unable to establish a health concern. Road traffic accidents constitute 5.7% of causal link between insomnia and psychiatric disorders due Zailinawati et al. Asia Pacific Family Medicine 2012, 11:9 Page 7 of 8 http://www.apfmj.com/content/11/1/9 to the cross-sectional design and the lack of clinical inter- study on psychological problem in general health care. Eur Psychiatry 1996, 11(Supp 1):5S–10S. view for diagnosing disorders in this study. A longitudinal 2. 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Sleep 2007, to promote the awareness of sleep problems for under- 30(3):263–273. graduates, post graduates and practicing physicians. 17. Sateia MJ, Doghramji K, Hauri PJ, Morin CM: Evaluation of chronic insomnia. An american academy of sleep medicine review. Sleep 2001, 23:243–308. Competing interests 18. Zailinawati AH, Schattner P, Mazza D: Doing a pilot study: why is it The authors declare that they have no competing interests. essential? Mal Fam Physician 2006, 1(2&3):70–73. 19. John MA: A new method of measuring daytime sleepiness: the Epworth Authors’ contributions Sleepiness Scale. Sleep 1991, 14:54–55. ZAH participated in the proposal, design, coordinating, carried out of the 20. Zigmond AS, Snaith RP: The hospital anxiety and depression scale. study and drafted the manuscript. DM participated in the proposal, design, Acta Psychiatr Scand 1983, 67:361–370. coordinating the study, and drafted the manuscript. CLT participated in the 21. International Classification of Sleep Disorders, Revised: Diagnostic and Coding proposal, design, coordinating the study, performed the statistical analysis Manual. American Sleep Disorders Association; 2001. and drafted the manuscript. All authors read and approved of the final 22. Diagnostic and Statistical Manual of Mental Disorders. 4th edition. American manuscript. Psychiatric Association; 1994. 23. Edinger JD, Bonnet MH, Bootzin RR, American Academy of Sleep Medicine Acknowledgements Work Group: Derivation of research diagnostic criteria for insomnia: We would like to thank all the doctors who have been involved in the report of an American Academy of Sleep Medicine Work Group. planning and data collection in this study. This work was supported by Sleep 2004, 27(8):1567–1596. International Medical University, Malaysia (IMU090/2005); and the Malaysian 24. 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Asia Pacific Family Medicine 2012 11:9. Submit your next manuscript to BioMed Central and take full advantage of: • Convenient online submission • Thorough peer review • No space constraints or color figure charges • Immediate publication on acceptance • Inclusion in PubMed, CAS, Scopus and Google Scholar • Research which is freely available for redistribution Submit your manuscript at www.biomedcentral.com/submit

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Asia Pacific Family MedicineSpringer Journals

Published: Nov 27, 2012

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