User:CarsWiski/sandbox

My main goal is to add an Epidemiology section to the Sleep Disorders article. 

I am also adding to the already existing Risks section.  Its current text is in italics.  The original does have references; they just didn't carry over when I used copy-paste

Risks[edit]

A systematic review found that traumatic childhood experiences (such as family conflict or sexual trauma) significantly increases the risk for a number of sleep disorders in adulthood, including sleep apnea, narcolepsy, and insomnia. It is currently unclear whether or not moderate alcohol consumption increases the risk of obstructive sleep apnea.

In addition, an evidence-based synopses suggests that the sleep disorder, idiopathic REM sleep behavior disorder (iRBD), may have a hereditary component to it. A total of 632 participants, half with iRBD and half without, completed self-report questionnaires. The results of the study suggest that people with iRBD are more likely to report having a first-degree relative with the same sleep disorder than people of the same age and sex that do not have the disorder. More research needs to be conducted to gain further information about the hereditary nature of sleep disorders.

A population susceptible to the development of sleep disorders is those who have experienced a traumatic brain injury (TBI). Because many researchers have focused on this issue, a systematic review was conducted to synthesize their findings. According to their results, TBI individuals are most disproportionately at risk for developing narcolepsy, obstructive sleep apnea, excessive daytime sleepiness, and insomnia. The study's complete findings can be found in the table below:

Source of data	Sleep variable	Community	TBI	Community	TBI
Sleep category		Nparticipants	Nparticipants	P	P	Z	prob
Healthy controls
Sleep disturbance	Overall	66	85	.32	.56	3.02	.003
Sleep problem	Sleep initiation	77	77	.05	.41	5.33	<.001
	Excessive daytime sleepiness	85	99	.10	.24	2.65	.008
Community samples
Sleep disturbance	Overall	2187	1706	.41	.50	5.59	<.001
Sleep disorders	Insomnia	1007	581	.10	.29	9.94	<.001
	Hypersomnia	7954	212	.10	.28	8.38	<.001
	Obstructive sleep apnoea	1741	283	.02	.25	15.51	<.001
	Periodic limb movements	18,980	212	.04	.08	2.95	.003
	Narcolepsy	18,980	152	.00b	.04	17.11	<.001
Sleep problem	Snoring	2629	65	.42	.60	3.56	<.001
	Insomnia	6340	1001	.31	.50	11.8	<.001
	Sleep maintenance	24,600	309	.27	.50	8.96	<.001
	Sleep efficiency	1007	119	.27	.49	4.93	<.001
	Sleep initiation	24,600	368	.27	.36	3.80	<.001
	Nightmares	2187	133	.08	.27	7.43	<.001
	Excessive daytime sleepiness	16,583	651	.09	.27	15.27	<.001
	Early morning awakening	24,600	364	.18	.38	9.76	<.001
	Sleep walking	4972	99	.02	.09	4.85	<.001

Epidemiology of Sleep Disorders

Children and Young Adults

According to one meta-analysis, the two most prevalent sleep disorders among children are confusional arousals and sleep walking. An estimated 17.3% of kids between 3 and 13 years old experience confusional arousals. About 17% of children sleep walk, with the disorder being more common among boys than girls. The peak ages of sleep walking are from 8 to 12 years old. A different systematic review offers a high range of prevalence rates of sleep bruxism for children. Between 15.29 and 38.6% of preschoolers grind their teeth at least one night a week. All but one of the included studies reports decreasing bruxist prevalence as age increased as well as a higher prevalence among boys than girls.

Another systematic review noted 7-16% of young adults suffer from delayed sleep phase disorder. This disorder reaches peak prevalence when people are in their 20's. Between 20 and 26% of adolescents report a sleep onset latency of >30 minutes. Also, 7-36% have difficulty initiating sleep. Asian teens tend to have a higher prevalence of all of these adverse sleep outcomes than their North American and European counterparts.

Insomnia

Combining results from 17 studies on insomnia in China, a pooled prevalence of 15.0% is reported for the country. This is considerably lower than a series of Western countries (50.5% in Poland, 37.2% in France and Italy, 27.1% in USA). However, the result is consistent among other East Asian countries. Men and women residing in China experience insomnia at similar rates. A separate meta-analysis focusing on this sleeping disorder in the elderly mentions that those with more than one physical or psychiatric malady experience it at a 60% higher rate than those with one condition or less. It also notes a higher prevalence of insomnia in women over the age of 50 than their male counterparts.

Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) affects around 4% of men and 2% of women in the United States. In general, this disorder is more prevalent among men. However, this difference tends to diminish with age. Women experience the highest risk for OSA during pregnancy. Also, they tend to report experiencing depression and insomnia in conjunction with obstructive sleep apnea. In a meta-analysis of the various Asian countries, India and China present the highest prevalence of the disorder. Specifically, about 13.7% of the Indian population and 7% of Hong-Kong's population is estimated to have OSA. The two groups experience daytime OSA symptoms such as difficulties concentrating, mood swings, or high blood pressure, at similar rates (prevalence of 3.5% and 3.57%, respectively).

Sleep Paralysis

A systematic review states 7.6% of the general population experiences sleep paralysis at least once in their lifetime. Its prevalence among men is 15.9% while 18.9% of women experience it. When considering specific populations, 28.3% of students and 31.9% of psychiatric patients have experienced this phenomenon at least once in their lifetime. Of those psychiatric patients, 34.6% have panic disorder. Sleep paralysis in students is slightly more prevalent for those of Asian descent (39.9%) than other ethnicities (Hispanic: 34.5%, African descent: 31.4%, Caucasian 30.8%).

Restless Leg Syndrome

According to one meta-analysis, the mean prevalence rate for North America and Western Europe is estimated to be 14.5±8.0%. Specifically in the United States, the prevalence of restless leg syndrome is estimated to be between 5 and 15.7% when using strict diagnostic criteria. RLS is over 35% more prevalent in American women than their male counterparts.