Running head: EVALUATION OF TWO DIAGNOSTIC SYSTEMS
Evaluation of Two Diagnostic Systems
Measuring Sleep Deprivation
Matthew Danskey
Anderson University
Evaluation of Two Diagnostic Systems Measuring Sleep Deprivation
Sleep deprivation is the concept of getting less sleep than one needs. It doesn’t take asking many people how they are before one of them admits their tiredness. Not getting enough sleep can result in decreased mood as well as increased errors in simple cognitive tasks (Barnett, 2008). It is a rare college student that hasn’t stayed up late to finish (or start) an assignment or study for a test. Where do we first steal time from when we are running short on it? Sleep. “Unfortunately, such cheating can ultimately make us clumsy, stupid, unhappy, and dead” (Coren, 1996, p. 11).
With sleep deprivation being a contributing cause to accidents such as in nuclear power plants in Chernobyl and Manhattan, paying more attention to this issue is called for (Coren, 1996). Both my system measuring average amount of sleep per night and my system measuring symptoms of sleep deprivation share the common purpose of diagnosing sleep deprivation.
Method
Instruments
I created and tested two separate diagnostic systems that measured sleep deprivation for this study. One looks at the average amount of sleep an individual gets while the other is based around symptoms of sleep deprivation.
Dx System One: Amount
of Sleep
The first system was based solely on the average amount of sleep the individual gets per night. The amounts were based on the needs of a young adult of college age, where typical sleep needs tend to be around nine hours a night. As each night of sleep is often of variable duration, the system uses an average estimation to gain a more accurate long-term picture of an individual’s sleep deprivation.
|
Dx System 1 |
Sleep Length |
|
Mild |
6-8 hours of sleep per night on average |
|
Moderate |
4-6 hours of sleep per night on average |
|
Severe |
0-4 hours of sleep per night on average. |
Amount of sleep is a straightforward and relatively objective criterion to use for diagnosis.
Dx System Two:
Symptoms of Sleep Deprivation
The second system focused on a symptomatic approach to diagnosis as opposed to a causal one. The four categories of symptoms I focused on were daytime sleepiness, mood, impairments related to accomplishing tasks, and hallucinations. Individuals vary and some symptoms will be more apparent than others in a given situation, so the most intense symptom is the one used to select the diagnosis.
|
Dx System 2 |
Sleepiness, Mood, Impairments, and Hallucinations Diagnose based on most intense symptom |
|
Mild Sleep Deprivation |
Some daytime sleepiness. Minimal impact on mood and accomplishing tasks. No hallucinations. |
|
Moderate Sleep Deprivation |
Desire for sleep during the day. Some impact on mood. Some impact on ability to accomplish tasks. Misperceptions of stimuli. |
|
Severe Sleep Deprivation |
Intense desire for sleep. Large impact on ability to accomplish tasks. Large impact on mood. Full-blown hallucinations. |
Procedure
To obtain reliability, I collected three case studies from published literature and wrote them up in a condensed format. I then created ten packets of three pages each, with one case study and a copy of the two diagnostic systems on each page. These packets were then distributed to ten aspiring diagnosticians in my Abnormal Psychology class and returned to me upon completion. I compiled the results and evaluated the consistency of diagnosis of the case studies using the systems.
Validity came from Hélène Danskey, a Registered Nurse. I sent her an electronic copy of the diagnostic packet and then compared the ten diagnosticians’ choices to her diagnoses. The overlapping choices determined the validity of each system.
Results
|
Case 1 |
D1
System 1: Sleep per night |
|
D1
System 2: Symptoms |
||||
|
Respondent: |
Mild |
Mod |
Severe |
Mild |
Mod |
Severe |
|
|
1 |
|
|
1 |
|
|
1 |
|
|
2 |
|
|
1 |
|
1 |
|
|
|
3 |
|
|
1 |
|
1 |
|
|
|
4 |
|
|
1 |
|
|
1 |
|
|
5 |
|
|
1 |
|
|
1 |
|
|
6 |
|
|
1 |
|
|
1 |
|
|
7 |
|
|
|
|
|
1 |
|
|
8 |
|
|
1 |
|
|
1 |
|
|
9 |
|
|
1 |
|
|
1 |
|
|
10 |
|
|
1 |
|
|
|
1 |
|
Case 2 |
D1
System 1: Sleep per night |
|
D1
System 2: Symptoms |
||||
|
Respondent: |
Mild |
Mod |
Severe |
Mild |
Mod |
Severe |
|
|
1 |
|
1 |
|
|
1 |
|
|
|
2 |
|
1 |
|
|
|
1 |
|
|
3 |
1 |
|
|
1 |
|
|
|
|
4 |
|
1 |
|
|
1 |
|
|
|
5 |
|
1 |
|
|
1 |
|
|
|
6 |
|
1 |
|
|
1 |
|
|
|
7 |
|
|
|
|
1 |
|
|
|
8 |
1 |
|
|
|
1 |
|
|
|
9 |
1 |
|
|
|
1 |
|
|
|
10 |
1 |
|
|
|
|
1 |
|
|
Case 3 |
D1
System 1: Sleep per night |
|
D1
System 2: Symptoms |
||||
|
Respondent: |
Mild |
Mod |
Severe |
Mild |
Mod |
Severe |
|
|
1 |
|
1 |
|
|
|
1 |
|
|
2 |
|
|
1 |
|
1 |
|
|
|
3 |
|
1 |
|
1 |
|
|
|
|
4 |
|
1 |
|
|
1 |
|
|
|
5 |
|
|
1 |
|
1 |
|
|
|
6 |
|
1 |
|
1 |
|
|
|
|
7 |
|
1 |
|
|
1 |
|
|
|
8 |
|
|
1 |
|
1 |
|
|
|
9 |
|
1 |
|
|
1 |
|
|
|
10 |
|
1 |
|
|
1 |
|
|
|
|
|
Case 1 |
Case 2 |
Case 3 |
R.
& V. Of Systems |
|
|
Dx 1 |
Mild |
0 |
4 |
0 |
Reliability |
21/30 |
|
Amount |
Moderate |
0 |
5 |
7 |
Validity |
17/30 |
|
|
Severe |
9 |
0 |
3 |
|
|
|
|
|
|
||||
|
Dx 2 |
Mild |
0 |
3 |
1 |
Reliability |
22/30 |
|
Symptoms |
Moderate |
2 |
6 |
8 |
Validity |
15/30 |
|
|
Severe |
8 |
1 |
1 |
|
|
|
Reliability |
17/20 |
11/20. |
15/20 |
|||
|
Validity |
17/20 |
11/20. |
4/20. |
|||
|
Key: |
Highest
Frequency |
Expert's
Choice |
||||
Discussion
The first system only looks at the raw, average amount of sleep that one gets. This approach ignores individual variances in sleep needs, variances in needs based on age, the regularity of the sleep schedule, and the quality of sleep. For example, those with sleep apnea may get ‘enough’ sleep from a temporal perspective, but awakening every two minutes and having dangerously low oxygen levels in the blood half the time is poor quality sleep. This system also overlooks the symptoms and signs of sleep deprivation and how much impairment it may be causing. One odd curiosity that it overlooks is that of alternative sleep schedules such as the Uberman Sleep Schedule. With this particular sleep schedule, only two hours of the day are spent sleeping yet, after an adjustment period of a week or two, one feels quite rested (PureDoxyk, 2000).
The second system looks at symptoms without taking heed of their causes. Any of the criteria I chose for the system could have underlying causes stemming from medical problems or psychological disturbances not related to sleep issues. It also ignores the amount of sleep one gets.
The critical piece of information that both systems ignore is sleep debt. Sleep debt is a concept that is viewed as the central mechanism for sleep deprivation: one loses sleep steadily and that lost sleep accumulates and becomes a heavier burden to bear as it gets bigger. The trick with sleep debt is that to get 7 hours of sleep debt, if a person needs 7 hours of sleep a night, then going to bed an hour later all week is equivalent to staying up an entire night (Coren, 1996, pp. 70-71).
Overall, reliability was decently high, being 70% or above for both systems. Validity was lower, at 56% for system one and 50% for system two. I suspect that system two had slightly less validity due to the differing perceptions of the diagnostician students and the expert on what constituted mild, moderate, or severe impairments. Reliability happened to be nearly identical, possibly due to the demographics of the diagnosticians. One would expect that the Amount of Sleep system would be more reliable due to its objective criteria. Diagnostician 7 did not answer for this diagnostic system on two of the cases and I decided to keep reliability out of 30 because if it wasn’t clear enough to answer, then it appears this system would not be a reliable way to diagnose, so giving a ‘benefit of the doubt’ and taking reliability out of 28 would be inflating my results.
The main lesson that I learned from this exercise is that wording is influential to the diagnoses that people will give. Two wordings in particular stand out: a diagnostic criterion and a piece of a case study.
One of the criteria in the Symptoms diagnostic system for the severe diagnosis was, “Full-blown hallucinations.” I believe this is what kept two of the ten diagnosticians from diagnosing the first case study as severe sleep deprivation under system two. The case study tells of a woman who stayed up for seven days and then heard voices coming from the fridge. This is clearly an auditory hallucination. I think the problem arises in that when one thinks of full-blown hallucinations, one tends to think of seeing unicorns in the sky and the grass slithering and trumpets from heaven blaring, not just voices from a fridge.
The second case of unfortunate wording was in the case study where I had summarized, “He has difficulty focusing his eyes to read things,” which should have read as, “He couldn’t focus his eyes to read anything.” One says that reading is harder than it should be, and the other says it’s impossible. This is the kind of difference that can make the difference between a diagnosis of moderate and severe sleep deprivation. I think this less-than-optimally worded phrase contributed to the 4/20 validity for Case Study 3 when both other case studies had equal validity and reliability.
I also learned how difficult it is to get a proper handle on a syndrome. I attacked the challenge of sleep deprivation from two different angles and still didn’t get at the heart of the issue: sleep debt. That illustrates the difficulty of diagnosis: how does one measure what we really intend to measure?—and how does one know what measurement is important in the first place? Diagnoses seem at best to be what happens when one puts working theories into practice, and are thus inherently biased, even if only slightly.
Conclusion
The systems that I created both can test the waters of one’s sleep deprivation. Neither one is definitive, however. A fair amount of people would be fine on 6 to 8 hours of sleep on average and many of the effects of sleep deprivation can be caused by other factors. My validities are simply not high enough above chance to convince me that either system is a great tool. System one is based on arbitrary distinctions in amount of sleep and system two relies on subjective interpretations of severity of symptoms. Given these, and given the specific scope of the diagnostic criteria, it is a pleasant surprise to have two not-entirely-useless systems, and they served as magnificent learning examples.
References
Barnett, K. (2008). The effects of a poor night sleep on mood, cognitive, autonomic and electrophysiological measures. Journal of Integrative Neuroscience, 7(3), 405-420.
Buysse, D. (2008). Chronic insomnia. The American Journal of Psychiatry, 165(6), 678-686.
Coren, S. (1996). Sleep thieves: An eye-opening exploration into the science and mysteries of sleep. New York, NY: The Free Press.
Fernando, A., & Chew, G. (2005). Acute sleep onset insomnia in the elderly: Damage to the ventrolateral preoptic nucleus?. Australasian Psychiatry: Bulletin Of Royal Australian And New Zealand College Of Psychiatrists, 13(3), 313-314.
PureDoxyk. (2000, December 29). Uberman’s Sleep Schedule. Everything2. Retrieved November 17, 2010, from http://www.everything2.com/index.pl?node_id=892542
Appendix A: Diagnostic Packet, Including Case Studies
CASE # 1
The first
case is of a 62-year old European Woman. After a surgery, she was awake
continuously for seven days. Hallucinations of hearing voices from the fridge
came on the seventh day. Also, she heard a high-pitched buzzing sound that
later sounded like music.
|
Dx
System 1 |
Sleep
Length |
Dx chosen: |
|
Mild Sleep Deprivation |
6-8 hours of sleep per night on average |
|
|
Moderate Sleep Deprivation |
4-6 hours of sleep per night on average |
|
|
Severe Sleep Deprivation |
0-4 hours of sleep per night on average. |
|
|
Dx
System 2 |
Sleepiness, Mood, Impairments, and Hallucinations Diagnose based on most intense symptom |
Dx
chosen: |
|
Mild Sleep Deprivation |
Some daytime sleepiness. Minimal impact on mood and accomplishing
tasks. No hallucinations. |
|
|
Moderate Sleep Deprivation |
Desire for sleep during the day. Some impact on mood. Some impact on ability to accomplish tasks. Misperceptions of stimuli. |
|
|
Severe Sleep Deprivation |
Intense desire for sleep. Large impact on ability to accomplish
tasks. Large impact on mood. Full-blown hallucinations. |
|
CASE # 2
The next
case is of Ms. F, a 42-year old divorced woman with difficulty falling asleep
(30+ minutes) and staying asleep (frequent awakenings of 30 minutes or longer).
She goes to bed at 10:00 p.m. and gets up at 7:00 a.m. on weekdays and 9:00
a.m. on weekends. She is irritable during the day and has difficulty focusing
and organizing her thoughts. She sees these as impairing her work performance.
She says she has “No energy for anything extra,” that she often declines
invitations to social and family activities, and that her house is a mess. She
is frustrated with not being able to function more effectively, and she
attributes this to her insomnia. She sees a connection between quality of sleep
of a given night and her amount of irritability and cognitive impairment the
next day.
|
Dx
System 1 |
Sleep
Length |
Dx chosen: |
|
Mild Sleep Deprivation |
6-8 hours of sleep per night on average |
|
|
Moderate Sleep Deprivation |
4-6 hours of sleep per night on average |
|
|
Severe Sleep Deprivation |
0-4 hours of sleep per night on average. |
|
|
Dx
System 2 |
Sleepiness, Mood, Impairments, and Hallucinations Diagnose based on most intense symptom |
Dx
chosen: |
|
Mild Sleep Deprivation |
Some daytime sleepiness. Minimal impact on mood and accomplishing
tasks. No hallucinations. |
|
|
Moderate Sleep Deprivation |
Desire for sleep during the day. Some impact on mood. Some impact on ability to accomplish tasks. Misperceptions of stimuli. |
|
|
Severe Sleep Deprivation |
Intense desire for sleep. Large impact on ability to accomplish
tasks. Large impact on mood. Full-blown hallucinations. |
|
CASE # 3
The third
case is of a male resident physician at a hospital. He averages an 80-hour work
week, which results in his sleep time being under five hours a day. He
currently is at the end of 36 hours of either being on duty or on call. He
tries to grab naps whenever he is able, especially when on call. He has been
able to catch an hour’s worth of naps during this time. He has difficulty
focusing his eyes to read things and occasionally stops mid-sentence and
forgets what was being asked about. He reports sometimes feeling strong
feelings of depression, and admits he’d rather sleep than develop rapport with
patients, even though developing those relationships is something he desires to
do in the future—when he gets adequate rest. He says he’s developed “survival
techniques” such as keeping his paperwork briefer than it otherwise would be.
|
Dx
System 1 |
Sleep
Length |
Dx chosen: |
|
Mild Sleep Deprivation |
6-8 hours of sleep per night on average |
|
|
Moderate Sleep Deprivation |
4-6 hours of sleep per night on average |
|
|
Severe Sleep Deprivation |
0-4 hours of sleep per night on average. |
|
|
Dx
System 2 |
Sleepiness, Mood, Impairments, and Hallucinations Diagnose based on most intense symptom |
Dx
chosen: |
|
Mild Sleep Deprivation |
Some daytime sleepiness. Minimal impact on mood and accomplishing
tasks. No hallucinations. |
|
|
Moderate Sleep Deprivation |
Desire for sleep during the day. Some impact on mood. Some impact on ability to accomplish tasks. Misperceptions of stimuli. |
|
|
Severe Sleep Deprivation |
Intense desire for sleep. Large impact on ability to accomplish
tasks. Large impact on mood. Full-blown hallucinations. |
|