Asian Journal of Psychiatry 5 (2012) 231–235
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A comparison between acupuncture versus zolpidem in the treatment of primary insomnia Jung-Hung Tu a, Wei-Ching Chung c, Chun-Yuh Yang d, Dong-Sheng Tzeng a,b,* a
Department of Psychiatry, Chiayi Branch of Taichung Veterans General, Hospital, Chiayi, Taiwan Institute of Undersea and Hyperbaric Medicine, National Defense Medical Center, Taiwan c Department of Nursing, Fooyn General Hospital, Pingtung, Taiwan d Faculty of Public Health, College of Health Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 13 November 2010 Received in revised form 3 December 2011 Accepted 19 December 2011
Background: To determine the relative efficacy of acupuncture and zolpidem in the treatment of primary insomnia, we administered a sleep quality scale to thirty-three patients with primary insomnia randomly chosen to receive one of the two therapies at a psychosomatic clinic. Methods: A study in the psychosomatic clinic at a teaching hospital in southern Taiwan from November 2007 to November 2008. The 19 patients in acupuncture group underwent one acupuncture session a week. The 14 patients in the control group took zolpidem 1# (10 mg) every night. Members of both groups returned to our clinic once a week for four weeks. The main outcome measure was the Pittsburgh Sleep Quality Index (PSQI). Results: Both groups were found to have improved significantly. Using generalized estimating equation analysis to test the variance with group and time as factors, we found both groups improved over time at a similar rate (p = 0.79). In regression analysis, setting the fourth total PSQI score to zero, the baseline PSQI score was 4.13 (p < 0.001), the second score 1.32 (p = 0.005), and the third 1.49 (p = 0.03); men had a higher PSQI score 1.56 than women (p = 0.02); the increasing age of one year would have lower PSQI score 0.08 (p < 0.001) and increasing educational level of one year which would decrease PSQI score 0.25 (p = 0.007). Conclusions: Acupuncture might be used as an alternative strategy compared to zolpidem for the treatment of primary insomnia. ß 2011 Elsevier B.V. All rights reserved.
Keywords: Primary insomnia Acupuncture PSQI Zolpidem
1. Introduction The prevalence rate of primary insomnia in general population which applied the diagnostic criteria by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) classification with interview (Ohayon, 1997) is 1.3%. The incidence of sleepless symptoms of a population-based, longitudinal study showed 37% and the incidence of insomnia at 12 months was 15% (Morphy et al., 2007). The need and efficacy of treatment for primary insomnia are important topics in clinics. Insomnia has been traditionally treated with benzodiazepines and hypnotics, the most widely prescribed pharmaceuticals of insomnia (Baldessarini, 1996). Zolpidem, an imidazolopyrine, is a short-acting non-benzodiazepine hypnotic. This type I selective
* Corresponding author at: No. 2, Jung-Jeng 1st Rd., Kaohsiung City, Taiwan. Tel.: +886 7 7490782; fax: +886 7 7498706. E-mail addresses:
[email protected] (W.-C. Chung),
[email protected] (D.-S. Tzeng). 1876-2018/$ – see front matter ß 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.ajp.2011.12.003
gamma-aminobutyric acid receptor agent has fewer side-effects associated with its use and withdrawal than benzodiazepines (Langtry and Benfield, 1990; Nowell et al., 1997). In postmarketing surveillance, it has not been reported to result in increased risk of falls, driving impairment, rebound, respiratory depression, or exacerbation of sleep-disordered breathing (Phillips and Ancoli-Israel, 2001), though its use has been associated with sedation, psychomotor and cognitive impairment, and memory loss (Glass et al., 2005; Mort and Aparasu, 2002). Some non-pharmacological treatments for primary insomnia have been found to be effective (Petit et al., 2003). Acupuncture, which relies on the release of neurally active agents from endogenous stores, has been shown to have a superior side-effect profile compared to some psychoactive drugs for the treatment of insomnia (Han, 1986; Luo et al., 1998; Spence et al., 2004; Sarris and Byrne, 2011). While there have been several studies on the use of acupuncture to treat insomnia, two review studies report that the small number of randomized controlled trials, poor methodological quality and significant clinical heterogeneity has limited the value of their findings and, because of this, they cannot be used
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those positions for 30 min one regular day each week (Tuesday or Thursday each week at our outpatient clinic). The patients were interviewed using the PSQI before that 30 min period. The zolpidem group took one tablet (10 mg) every night at 09:00 pm and was not allowed to take any other antidepressants, sleeping medication or psychoactive drugs and did not receive acupuncture therapy during the study period. These patients came into the clinic every week and completed the PSQI. The pharmacological treatment group received the same standardized outpatient clinical therapy as the acupuncture group in registering, being interviewed, for mental status examination and outcome measurement.
to support the use of any form of acupuncture to treat insomnia (Cheuk et al., 2007; Sok et al., 2003). In a more comprehensive review study, Kalavapalli and Singareddy (2007), found that subjects enrolled in these studies had co-morbid psychiatric disorders such as depression or anxiety disorders and medical conditions such as end-stage renal disease (Tsay et al., 2004) or stroke (Kim et al., 2004). In spite of their limitations, however, Kalavapalli and Singareddy (2007), points out acupuncture can lead to significant improvement in insomnia. These reports had a significant limitation on the case definition in study design and neglected the different biological and psychosocial aspects between primary and secondary insomnia. In this study, we investigated whether acupuncture therapy would have as good a therapeutic effect as zolpidem in the treatment of primary insomnia. To find out, we administered the Pittsburgh Sleep Quality Index (PSQI) a well-accepted sleep quality index four times to thirty-three primary insomnia patients who did not receive any treatment before and were randomly selected to receive either daily treatment with zolpidem or weekly acupuncture treatment for their insomnia at the psychosomatic clinic from November 2007 to November 2008.
At the beginning of the study, we collected data regarding each patient’s gender, age, educational level, marital status, smoking history, history of alcohol use, non-sedative and non-hypnotic drug use, life events, snoring, medical disease history, family history of mental illness and primary insomnia and history of night shifts at work. We also administered the PSQI.
2. Materials and methods
3. Materials
2.1. Participants
3.1. PSQI
In November 2007, all potential participants were interviewed face-to-face by a senior psychiatrist in the psychosomatic clinic to confirm a diagnosis of primary insomnia in the psychosomatic clinic at Kaohaiung Armed Forces General Hospital. To be included, each participant had to meet the criteria for primary insomnia outlined in the ‘‘Instruction Manual for the Structured Clinical Interview’’ in the DSM-IV (American Psychiatric Association, 1994). The participant was diagnosed as having primary insomnia if (1) he or she had difficulty initiating or maintaining sleep for a minimum of one month, (2) his or her sleep disturbance produced significant distress, was associated with impaired social or occupational function, and (3) was independent of narcolepsy, other sleep and mental disorders, and was not directly related to medication side effects or to a medical condition. Any patient between eighteen and seventy five years old who met these criteria was referred to an assistant in this study who randomly assigned them to either the acupuncture or zolpidem therapy group if they agreed to participate in the study and gave informed consent. The process of randomization and blinded procedure was conducted by a research assistant who followed the rule of matching the gender balance between groups; the patients did not know which group they would be assigned to. Patients were excluded if they had comorbid medical disorders such as cancer, stroke, hypertension, cardiovascular disease, hepatic and renal function impairment, were undergoing chemotherapy or hormone therapy, had conditions of apparent severe mental disorders, psychoactive substanceuse disorders, received any treatment for insomnia, or were pregnant. All participants signed an IRB-approved consent form confirming that they understood the goals, risks, and potential benefits of the study and their right to withdraw from the study at any time. Acupuncture therapy was conducted in our outpatient clinic by a physician who graduated from medical school in Taiwan and had practiced Chinese medicine for more than fourteen years. Acupuncture therapy for insomnia was performed following previously reported standard procedures (Tsay et al., 2004; Kim et al., 2004). Briefly, the patient was seated in a relaxed position. Two needles were inserted 1.0 cm into the Shen-Men (He-7) and two 3.0 cm in Zusanli (St-36). These needles were turned right to make the patients having the feeling of ‘‘De-Qi’’. They were left in
Patient sleep quality was assessed using the PSQI (Buysse et al., 1989), which had been translated and back-translated (Wang et al., 2007). The PSQI is a 19-item questionnaire that collects data on sleep quality and disturbances during the past month. In this study, we asked our sample past one week to replace the past month due to the therapeutic and followed up plan. The 19 individual items were used to generate seven component scores: (1) subjective sleep quality, (2) sleep latency, (3) sleep duration, (4) habitual sleep efficiency, (5) sleep disturbances, (6) use of sleeping medication, and (7) daytime dysfunction. In all cases, a score of 0 indicates no difficulty, while a score of 3 indicates severe difficulty. The lower the overall score, the better the person sleeps (Buysse et al., 1989, 2000). In this study, because all sleeping medications were prohibited in the both groups, we did not include ‘‘use of sleeping medication’’ in the total score. PSQI scores ranged from 0 to 18. The same interviewer administered face-toface interviews before the acupuncture was performed and before medications were prescribed for a total of four times in four weekly visits and verified there was no missing data in the PSQI.
2.2. Instruments
3.2. Statistical analysis Chi-square test and Student’s t test were used to examine the differences in the demographic variables. Generalized estimating equation analysis (GEE) (Zeger and Liang, 1986) was used to assess the factors relative to outcome measures. The results of the PSQI were compared on a before and after basis for all subjects and were reported as mean scores. A p-value <0.05 was considered significant. All statistical operations were performed on SPSS 15.0 for Windows software package (SPSS, Chicago, IL). 4. Results As can be seen in Table 1, a summary of the characteristics of the participants, the acupuncture group consisted of 19 patients (7 men and 12 women) with a mean age of 53.68 years, and the zolpidem group consisted of 14 patients (8 men and 6 women) with a mean age of 53.43 years. There was no significant gender or age difference between the two groups (p = 0.26, 0.97 respectively). The mean systolic blood pressure was 118.3 mmHg in acupuncture therapy
J.-H. Tu et al. / Asian Journal of Psychiatry 5 (2012) 231–235 Table 1 Characteristics of patient with primary insomnia placed in either the acupuncture or zolpidem therapy groups.
Gender Male Female Age (year) Marriage Married Single Educational level (year) Blood pressure (mmHg) Systolic Diastolic Height (cm) Body weight (kg) Alcohol use No Yes Caffeine use No Yes Smoking use No Yes Snore No Yes *
Zolpidem (N = 14)
x2/t
p
Acupuncture group
7 (36.8%) 12 (63.2%) 53.68 16.66
8 (57.1%) 6 (42.9%) 53.43 17.04
14 (73.7%) 5 (20.3%) 7.74
12 (85.7%) 2 (14.3%) 7.07
0.39
0.71
118.3 8.1 71.0 5.2 161.2 7.7 58.5 11.5
120.6 8.2 77.1 7.9 164.1 7.3 66.9 10.0
0.79 2.19 1.11 2.19
0.44 0.01* 0.28 0.04*
17 (89.5%) 2 (10.5%)
13 (92.9%) 1 (7.1%)
0.33
0.75
16 (84.2%) 3 (15.8%)
10 (71.4%) 4 (28.6%)
0.81
0.39
0.85
0.40
0.24
0.81
17 (89.5%) 2 (10.5%) 13 (68.4%) 6 (31.6%)
Table 2 The case number and mean score of Pittsburg Sleep Quality Index before and after acupuncture and zolpidem therapy.
1.15
0.26
0.04 0.23
0.97 0.82
Week 1st 2nd 3rd 4th PSQI 1st 2nd 3rd 4th
Zolpidem group
19 19 18 17
x2/t
p
13.43
0.57
0.70 1.80 3.90 1.59
0.49 0.08 0.70 0.32
14 14 12 12
8.74 2.80 7.00 2.60 5.62 2.56 5.00 1.50
9.43 2.82 5.14 3.32 6.17 3.54 3.25 2.50
Pearson Chi-square test for PSQI and Time (week): value 62.13, p = 0.046.
mean total score of PSQI
Acupuncture (N = 19)
233
11 (78.6%) 3 (21.4%)
10 8 6 4 acupuncture
2
Zolpidem 0
1
2
3
4
week
9 (64.3%) 5 (35.7%)
Fig. 1. The comparison of PSQI between acupuncture and Zolpidem therapy groups.
Means p < 0.05.
group and 120.6 in the zolpidem therapy group (p = 0.44). The average diastolic pressure was 71.0 mmHg in acupuncture therapy group and 77.1 cases in the zolpidem therapy group (p = 0.01). The mean height was 161.2 cm in acupuncture therapy group and 164.1 cases in the zolpidem therapy group (p = 0.28). The mean body weight was 58.5 kg in acupuncture therapy group and 66.9 kg in the zolpidem therapy group (p = 0.04). There were no significant differences in educational level, marital status, systolic blood pressure, height, snoring, or use of alcohol, caffeine, tobacco, or non-sedative drugs between the two groups. In the first, second, third and fourth administrations of the survey, 19, 19, 18, and 17 acupuncture patients and 14, 14, 12, and 12 zolpidem patients answered the survey, respectively, (p = 0.57). In the acupuncture group, there was one drop out due to pain of acupuncture at 3rd week and one drop out due to lost to follow up at 4th week. In the zolpidem group, there was one drop out due to amnesia after awakening and the other one was due to oversleep. There were no severe adverse events in the study duration. We collected a total of 125 surveys. The mean PSQI scores were 8.74 2.8, 7.0 2.6, 5.62 2.56, and 5.0 1.5 for the acupuncture
group and 9.43 2.82, 5.14 3.32, 6.17 3.54, and 3.25 2.5 for the zolpidem group, respectively (p = 0.49, 0.08, 0.70, and 0.14) (Table 2). In between groups, results of Student’s t test showed no group differences in scores, but in the analysis within groups, the Pearson Chi-square test of PSQI for four time assessment values revealed 62.14 (p = 0.05). The mean score to PSQI between two therapeutic groups during the four assessments, is shown in Fig. 1. Using GEE analysis to test the variance with group and time as factors, we found no different therapeutic effectiveness between the two groups (95% C.I. 1.40 to 1.84, p = 0.79). When we set the fourth total score of PSQI to zero, the baseline score was 4.14 (95% C.I. 3.02–5.26, p < 0.001), the second score was 1.32 (95% C.I. 0.40– 2.24, p = 0.05), the third was 1.50 (95% C.I. 0.11–2.88, p = 0.03), higher than the fourth assessment. Both groups were found to benefit significantly from the therapies they received (Table 3). Using backward stepwise methods in GEE, we tested the relationship between various factors (gender, age, educational level, marital status, smoking history, social alcohol drinking history, non-addictive caffeine, non-sedative and non-hypnotic drug use, life events, snore phenomenon, night shift job and
Table 3 Generalized estimating equation analysis of total Pittsburg Sleep Quality Index score by time. 95% Wald confidence interval Parameter
B
Std. Error
(Intercept) [group = 1] [group = 2] [time = 1] [time = 2] [time = 3] [time = 4] (Scale)
4.76 0.22 0a 4.14 1.32 1.49 0a 7.92
0.78 0.82 – 0.57 0.46 0.70 –
Dependent variable: total score of PSQI. Model: (intercept), group, time. group 1: acupuncture group; group 2: zolpidem group. a Set to zero because this parameter is redundant.
Lower 3.23 1.39 – 3.02 0.40 0.11 –
Hypothesis test Upper
x2
df
Sig.
6.29 1.84 – 5.25 2.24 2.87 –
37.14 0.07 – 52.53 7.91 4.49 –
1 – 1 1 1 1 –
<0.001 0.79 – <0.001 0.005 0.03 –
J.-H. Tu et al. / Asian Journal of Psychiatry 5 (2012) 231–235
234
Table 4 Generalized estimating equation analysis of total Pittsburg Sleep Quality Index score analyzed by patient characteristics. Parameter
(Intercept) [group = 1] [group = 2] [sex = 1] [sex = 2] age educational level (Scale)
B
14.33 0.18 0a 1.56 0a 0.08 0.25 5.50
Std. error
1.16 0.72 – 0.68 – 0.02 0.09
95% Wald confidence interval
Hypothesis test
Lower
Upper
x2
df
Sig.
12.04 1.61 – 0.22 – 0.12 0.43
16.61 1.24 – 2.90 – 0.03 0.06
151.01 0.06 – 5.22 – 13.43 7.16
1 1 – 1 – 1 1
<0.001 0.80 – 0.02 – <0.001 0.007
Model: (intercept), group, sex, age, educational level, time. Dependent variable: total score of PSQI. The sex 1 is male, sex 2 is female. a Set to zero because this parameter is redundant.
medical disease history) and total score of PSQI (Table 4). We found a relationship between gender, age and educational level on PSQI. Men scored 1.57 points higher on PSQI than women (95% C.I. 0.22– 2.90, p = 0.02), one year’s increase in age was associated with a 0.08 point decrease in PSQI score (95% C.I. 0.12 to 0.04, p < 0.001), and one year’s increase in educational level was associated with a 0.25 point decrease PSQI score (95% C.I. 0.44 to 0.07, p = 0.007). 5. Discussion In this study of thirty-three patients with primary insomnia, we found that acupuncture might improve PSQI scores as effectively as zolpidem at a similar rate. This finding suggests that acupuncture could be used to treat primary insomnia. A better therapeutic outcome was found in older, female, or more highly educated patients. Acupuncture, which has a long history in Chinese medicine, has been frequently used for insomnia. Recent studies report that the insertion of acupuncture needle into the Zusanli (St-36) controls the autonomic nervous system (Hsieh et al., 1999) and insertion of the needle into the Shen-Men (He-7) reduces sympathetic activity (Abad-Alegria et al., 2001). Acupuncture may increase nocturnal melantonin secretion (Spence et al., 2004). Its effect may also be related to the GABAergic and striatal dopaminergic transmission possibly allowing it to play a key role in primary insomnia. In the argument of insufficient treatment condition, the dosage of zolpidem is 10 mg due to the absence of 6.25 mg tablets in Taiwan. The average dosage of zolpidem for initiating treatment of insomnia is around 6.25 mg (Nowell et al., 1997) which is lower than our study design. This study found no difference in the therapeutic effect of zolpidem and acupuncture in the treatment of primary insomnia which might not be due to insufficient treatment but the lack of power or a true equivalence of treatment effects. In a review of thirty years of research, Sok (Sok et al., 2003) found most experimental studies designed to study the effects of acupuncture on insomnia that it had a significant positive effect on insomnia, though sample sizes were small (<50 subjects, short duration). Still, reports on the efficacy of acupuncture have been inconsistent between studies for many sleep parameters, including sleep onset latency, total sleep duration and wake after sleep onset (Cheuk et al., 2007). These differences may result from different populations and methods used by these studies. Like Suen et al. (2003) and Sok et al. (2003), our randomized controlled trial found the older people and women had better outcomes. We also found improvements in outcomes in patients with higher educations. We used backward stepwise and controlled the patient’s characteristics that the gender, age, and educational level might have mediating or moderating for effects between PSQI and
interventions. We tried the analysis by six domains of PSQI and total score of PSQI independently to look for the associated factors. The reasons why these factors influenced the sleep quality might be due to the help-seeking behaviors for insomnia. According to Shochat et al. (1999), the four predictors of discussing insomnia with a physician were how patients felt physically, number of years of insomnia, age, and income. The selection bias could not be ruled out due to these psychosocial factors. But these mediating or moderating factors explored by GEE, demonstrated that a 125 longitudinal data set of primary insomnia would increase the effect size. The cases lost to 3rd or 4th follow up would include the 2nd and 3rd outcome variables in data analysis in GEE which would enhance the statistic power. Repeated measurement by GEE could enhance parameter estimation by Z robust (Zeger and Liang, 1986; Tzeng et al., 1995); it would be helpful to clarify the causal relationship between outcome variable and intervention, even with small sample size. It needs a cohort study and larger sample size in stratifying groups by the psychosocial factors to find out the causal relationship between the interventions with the treatment outcome. In all measurements, we found no group differences in total PSQI or in all six subscales of PSQI, which we analyzed by GEE (data not shown of six subscales). Buysse et al. (2000) has suggested that PSQI cannot be used to diagnose sleep disorders. Although its questions are heavily based on the memory over the past month, the tool has an adequate internal reliability, validity and consistency for clinical and community population (Petit et al., 2003). In our study, the PSQI was administered by only one senior psychiatrist even with and was based on the patient’s memory over the past week, not collected by self report, which might decrease the report bias arising from the interpretation of items by subjects with various educational levels and may decrease the inconsistent result for sleep parameters (Cheuk et al., 2007; Buysse et al., 1989); it would increase the sensitivity to change from the past month to a 4-week trial by interview. We did not include ‘‘use of sleeping medication’’ in total PSQI score because our control group was treated pharmacologically. Though the questionnaire was not complete, the PSQI remained a valid and reliable instrument for sleep quality measurement. While both groups show statistically significant improvement over the course of treatment, the patients in the acupuncture group have a mean PSQI of 5.00 1.5 at last assessment whereas patients in the zolpidem group have a mean of 3.25 2.5, which is in better response range; it needs further investigation in response or remission rate and follow up design to prove a true equivalence in treatment effects. Primary insomnia defined by DSM-IV excludes the secondary reasons such as mental and organic factors known to induce sleeplessness. Prevalence estimates reported in published studies
J.-H. Tu et al. / Asian Journal of Psychiatry 5 (2012) 231–235
for chronic insomnia range from 10% to 37% (Morphy et al., 2007; Katz and McHorney, 1998; Walsh, 2004). The reason of overestimation of prevalence is measured by questionnaires in insomnia. In our review of published scientific papers, the usual weaknesses were in subjects with comorbidity and having sleepless periods less than a month (Spence et al., 2004; Tsay et al., 2004; Kim et al., 2004;Suen et al., 2003). Primary insomnia is rare; people with sleepless symptoms and this disorder often do not seek the medical treatment in sleep clinics but rather primary care clinics (Ohayon, 1997). Secondary insomnia might be induced by biological, psychological and social factors and receive many drugs or therapies which may confound the therapeutic outcome in the research population (Morphy et al., 2007; Baldessarini, 1996). The subjects of this study were not induced by secondary reasons and did not receive any treatment before recruited to our randomized controlled trial which would decrease the information bias. 6. Conclusions Acupuncture might be as effective as zolpidem at a similar rate in the short-term treatment of primary insomnia and could be considered an alternative treatment for this disorder. Older patients, women, and more highly educated patients were found to have better treatment outcomes. Conflict of interest statement All authors declare no competing financial interests exists. References Abad-Alegria, F., Pormaron, C., Aznar, C., 2001. Objective assessment of the sympatholytic action of the Nei-Kuan acupoint. Am. J. Chin. Med. 29, 201–210. American Psychiatric Association, 1994. Diagnostic and Statistical Manual of Mental Disorders, fourth ed. American Psychiatric Association, Washington, DC. Baldessarini, 1996. Drugs and the treatment of psychiatric disorders; psychosis and anxiety. In: Hardman, J.G., Limbird, L.E., Molinoff, P.B., Ruddon, R.W., Goodman, G.A. (Eds.), The Pharmacological Basis of Therapeutics. ninth ed. McGrawHill, New York (Chapter 18). Buysse, D.J., Reynolds III, C.F., Monk, T.H., Berman, S.R., Kupfer, D.J., Rush, J., 2000. Modified From: Handbook of Psychiatric Measures. American Psychiatric Association, Washington, DC. Buysse, D.J., Reynolds, C.F., Monk, T.H., 1989. The Pittsburgh Sleep Quality Index (PSQI): a new instrument for psychiatric research and practice. Psychiatry Res. 28, 193–213. Cheuk, D.K., Yeung, W.F., Chung, K.F., Wong, V., 2007. Acupuncture for insomnia. Cochrane Database Syst. Rev. 18, CD005472. Glass, J., Lanctot, K.L., Herrmann, N., 2005. Sedative hypnotics in older people with insomnia: meta-analysis of risks and benefits. Br. Med. J. 331, 1169.
235
Han, J.S., 1986. Electroacupuncture: an alternative to antidepressants for treating affective diseases. Int. J. Neurosci. 29, 79–92. Hsieh, C.L., Lin, J.G., Chang, Q.Y., 1999. Changes of pulse rate and skin temperature evoked by electoacupuncture stimulation with different frequency on both Zusanli acupoints in humans. Am. J. Chin. Med. 27, 11–18. Kalavapalli, R., Singareddy, R., 2007. Role of acupuncture in the treatment of insomnia: a comprehensive review. Complement. Ther. Clin. Pract. 13, 184– 193. Katz, D.A., McHorney, C.A., 1998. Clinical correlates of insomnia in patients with chronic illness. Arch. Intern. Med. 158, 1099–1107. Kim, Y.S., Lee, S.H., Jung, W.S., 2004. Intradermal acupuncture on shen-men and neikuan acupoints in patients with insomnia after stroke. Am. J. Chin. Med. 32, 771–778. Langtry, H.D., Benfield, P., 1990. Zolpidem: a review of its pharmacodynamic and pharmacokinetic properties and therapeutic potential. Drugs 40, 291–313. Luo, H., Meng, F., Jia, Y., 1998. Clinical research on the therapeutic effect of the electro-acupuncture treatment in patients with depression. Psychiatry Clin. Neurosci. 52 (Suppl.), S338–S340. Morphy, H., Dunn, K.M., Lewis, M., Boardman, H.F., Croft, P.R., 2007. Epidemiology of insomnia: a longitudinal study in a UK population. Sleep 30 (3), 274–280. Mort, J.R., Aparasu, R.R., 2002. Prescribing of psychotropics in the elderly: why is it so often inappropriate. CNS Drugs 16, 99–109. Nowell, P.M., Mazumdar, S., Buysse, D.J., 1997. Benzodiazepines and zolpidem for chronic insomnia: a meta-analysis of treatment efficacy. J. Am. Med. Assoc. 278, 2170–2177. Ohayon, M.M., 1997. Prevalence of DSM-IV diagnostic criteria of insomnia: distinguishing insomnia related to mental disorders from sleep disorders. J. Psychiatr Res. 31, 333–346. Petit, L., Azad, N., Byszewski, A., 2003. Non-pharmacological management of primary and secondary insomnia among older people: review of assessment tools and treatments. Age Ageing 32, 19–25. Phillips, B., Ancoli-Israel, S., 2001. Sleep disorders in the elderly: a review. Sleep Med. 2, 99–114. Sarris, J., Byrne, G.J., 2011. A systematic review of insomnia and complementary medicine. Sleep Med. Rev. 15 (2), 99–106. Shochat, T., Umphress, J., Israel, A.G., Ancoli-Israel, S., 1999. Insomnia in primary care patients. Sleep 22 (Suppl. 2), S359–S365. Sok, S.R., Erlen, J.A., Kim, K.B., 2003. Effects of acupuncture therapy on insomnia. J. Adv. Nurs. 44, 375–384. Spence, D.W., Kayumov, L., Chen, A., 2004. Acupuncture increases nocturnal melatonin secretion and reduces insomnia and anxiety: a preliminary report. J. Neuropsychiatry Clin. Neurosci. 16, 19–28. Suen, L.K., Wong, T.K., Leung, A.W., Ip, W.C., 2003. The long-term effects of auricular therapy using magnetic pearls on elderly with insomnia. Complement. Ther. Med. 11, 85–92. Tsay, S.L., Cho, Y.C., Chen, M.L., 2004. Acupressure and transcutaneous electrical acupoint stimulation in improving fatigue, sleep quality and depression in hemodialysis patients. Am. J. Chin. Med. 32, 407–416. Tzeng, D.S., Lung, F.W., Lieu, K.L., 1995. A statistical application of repeated measurement on clinical trial: the effects of Carbamazepine and Haloperidol in acute mania. Taiwanese J. Psychiatry 9, 324–330. Walsh, J.K., 2004. Clinical and socioeconomic correlates of insomnia. J. Clin. Psychiatry 65 (Suppl. 8), 13–19. Wang, R.C., Wang, S.J., Chang, Y.C., Lin, C.C., 2007. Mood state and quality of sleep in cancer pain patients: a comparison to chronic daily headache. J. Pain Symptom Manage. 3, 32–39. Zeger, S.L., Liang, K.Y., 1986. Longitudinal data analysis for discrete and continuous outcomes. Biometrics 42, 121–130.