SHORT COMMUNICATON
Nagoya J. Med. Sci. 83. 851–860, 2021
doi:10.18999/nagjms.83.4.851

Relationship between use of sleep medication and accidental
falls during hospitalization
Kazuyoshi Kobayashi1, Kei Ando1, Hiroaki Nakashima1, Yusuke Suzuki2,
Yoshimasa Nagao3 and Shiro Imagama1
1
Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
Center for Community Liaison and Patient Consultations, Nagoya University Hospital, Nagoya, Japan3
Department of Patient Safety, Nagoya University Hospital, Nagoya, Japan

2

ABSTRACT
Falls are common in elderly patients, and prevention of fall is important for safety and for reduction ofhealth care costs. Sleep medications are among many potential causes of fall. In this study, we examined
relationship of sleep medication with fall from January 2017 to December 2017. 726 falls occurred in 442
patients, and the average age at the time of fall was 60.7 ± 23.8 years. Fall was most common in patientswith neurological disease, followed by gastroenterological, ophthalmological, respiratory, and orthopedicconditions. Sleep medication was used in 223 falls (31%). Fall occurred at all times of day, but with adifferent distribution in patients with and without use of sleep medication. Thus, the rate of falls from22:00 to 6:00 was significantly higher in patients using sleep medication (62% vs. 18%, p<0.01). There
was also a significantly higher rate of multiple falls in patient using sleep medication (p<0.01). Zolpidem(25%, n=63), a non-benzodiazepine, was the most frequently used sleep medication, followed by brotizolam(16%, n=41) and etizolam (13%, n=32), which are both benzodiazepines. Multiple falls from 22:00 to6:00 occurred significantly more frequently in patients using ≥2 types of sleep medications compared toone (53% vs. 17%, p<0.01). Taking multiple sleeping pills makes it easier to fall, and even drugs with ashort half-life, which are considered to be safe, can cause falls at night in elderly patients. The results ofthis study show that careful selection of sleep medications is required to prevent fall in elderly patients.
Keywords: sleep medication, fall, elderly patients, hospitalization, risk management
This is an Open Access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
License. To view the details of this license, please visit (http://creativecommons.org/licenses/by-nc-nd/4.0/).

INTRODUCTION
Falls are common adverse events in elderly patients, and fall can cause fracture that leads
to a decrease in activities of daily living (ADL).1-3 Therefore, prevention of fall is importantfor medical safety and for reduction of costs for nursing care.4,5 Identification of causes of falls
and initiation of appropriate intervention for these factors are important to prevent future falls.
These causes are classified into external factors such as the presence or absence of steps andhandrails, and type of footwear; and internal factors such as age-related deterioration of muscle
Received: July 29, 2020; accepted: April 8, 2021
Corresponding Author: Kazuyoshi Kobayashi, MD
Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho,Showa-ku, Nagoya 466-8550, Japan
TEL: +81-52-744-1908, Fax: +81-52-744-2260, E-mail: kobakazu@med.nagoya-u.ac.jp
851

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strength, visual acuity and hearing, and drug resistance.
The number of medications taken and use of sleep medication are also associated with falls.6,7
The rate of use of sleep medications is high in elderly people due to an increase in sleep
disorders with aging.8 These include sleep onset disorder, mid-wake awakening, early awakening,and deep sleep disorder; thus, sleep medications are used for a wide variety of indications. Itis clear that fall occurs due to complex involvement of many factors. Sleep medication for
outpatients is important, but data from inpatients with a constant environment may be more
useful for defining the relationship between fall and sleep medication. Thus, the purpose of thestudy was to examine the relationship of sleep medication with accidental fall in inpatients using
data from fall incident reports.

MATERIALS AND METHODS
A total of 726 fall cases among admitted patients at our hospital from January 2017 toDecember 2017 were included in the analysis. The 726 falls (455 males, 271 females) occurredin 442 patients, and the average age at the time of a fall was 60.7 ± 23.8 years. The incidents
of fall were examined retrospectively using a database in the hospital event reporting system.
At our hospital, a clinical error or event is submitted as an incident or event report, regardlessof whether it results in harm to a patient. A web-based reporting system is used to maintainanonymity and produce a blame-free system. This approach facilitates easy access for reporting,a shorter data entry time, better legibility of reports, and immediate information sharing amonghospital staff. All reports are submitted to the patient safety management office for analysis, andthese reports are used to develop measures for future improvements.
A fall was defined as an involuntary change of posture whereby a patient ended up lying on
the floor. All patients with a fall were subsequently followed up until discharge. Demographic
data (incidence of fall, sex, and age), time of occurrence, location of occurrence, and type ofsleep medications were obtained from the database. The protocol of the study was approved by
the Ethics Committee of Nagoya University Graduate School of Medicine.
For assessment of fall risk, we used a fall risk score that was originally developed by our fallworking group. This score was evaluated routinely on admission, in each week of hospitalization,at the time of a fall, and as the medical condition changed. The risk was determined using a fall
assessment score sheet comprising 33 items, including age, history of fall, ADL, and cognition(Table 1). The sum of the scores for these items served as the risk score. Patients were classified
as grade 1 (low risk), grade 2 (moderate risk), and grade 3 (high risk) based on scores of 0–5,6–15, and ≥16 and including at least one of all the major items, respectively.

Table 1Assessment

Risk assessment score sheet aYesNo

Past history
History of fall10

History of syncope

10

History of convulsions

10

10

Impairment
Visual impairment

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Sleep medication and fall

Hearing impairment

10

Vertigo10

Wheelchair

10Cane10

Mobility

Walker10

Need assistance10

Disturbance of consciousness

10Restlessness

10Cognition

Memory disturbance

10Decreased judgment

10

Dysuria
Incontinence

10

Frequent urination

10

Need helper

10

Go to bathroom often at night10

Difficult to reach the toilet

10Sleeping pills

10

Psychotropic drugs

10Drug use

Morphine

10

Painkiller

10

Antiparkinson drug

10

Antihypertensive medication

10

Anticancer agents

10

Laxatives

10

10

Dysfunction
Muscle weakness
Paralysis, numbness

10

Dizziness

10

10

Bone malformation
Rigidity

10

Brachybasia

10aPatients were classified into three groups: Grade 1 (low risk), Grade 2 (moderate risk), and Grade3 (high risk) based on total scores of 0–5, 6–15, and ≥16 and including at least one item in eachcategory, respectively.

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Differences between two groups were analyzed by Mann-Whitney U test or Student t-test. Allanalyses were conducted using SPSS ver.25 for Window (IBM Inc., Chicago, IL), with p<0.05
considered to be significant.

RESULTS
The demographics of the patients with the 726 falls are shown in Table 2. Fall was mostcommon in patients with neurological disease as the main primary disease, followed by gastroenterological, ophthalmological, respiratory, and orthopedic conditions. The fall risk scores
placed 12%, 45%, and 43% of the patients in grades 1, 2 and 3, respectively; the location ofmost falls was in the hospital room (66%); and 51%, 38%, and 11% of patients had 1, 2 and≥3 falls, respectively.

Table 2

Demographics and characteristics of cases of fall

VariableCases

DemographicFalls (n)726

Age (years)

60.7±23.8

Sex (male/ female)455/271

Over 80 years of age

19% (138)

Over 60 years of age

68% (493)

Primary disease
Neurological

27% (196)

Gastroenterological

19% (138)

Ophthalmology

12% (87)

Respiratory

8% (58)

Orthopedics

6% (44)

Cardiac5% (37)

Pediatrics

5% (35)

Otolaryngology

5% (34)

Genecology

4% (29)Others9% (68)

Fall risk score
Grade 112% (87)

Grade 2

45% (327)

Grade 343% (312)

Location
Hospital room

66% (479)

Corridor

13% (94)

Restroom

8% (58)

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Sleep medication and fall

Bathroom

4% (29)Rehabilitation ward

2% (15)

Others7% (51)

Number of falls (per patient)Once

51% (225)

Twice

38% (170)

Three or more times

11% (47)

Falls with sleep medication

31% (223)

Sleep medication was used in 223 falls (31%) (Table 2). The distribution of patients by age
category is shown in Figure 1. Most falls involved patients in their 70s, followed by patients intheir 80s and 60s (Figure 1). Fall occurred at all times, but with a different distribution in patientswith and without use of sleep medication (Figure 2). The 228 falls from 22:00 to 6:00 included
139 falls with sleep medication (61%) (Figure 3A), and the rate of falls from 22:00 to 6:00
was significantly higher in patient using sleep medication (62% vs. 18%, p<0.01) (Figure 3B).

Fig. 1
Distribution of falls by age category.

Distribution of falls

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Fig. 2 Trends of falls
Distribution of falls by time, including in patients with and without sleep medication.

Fig. 3 Details of falls
Relationship between “fall from 22:00 to 6:00” and “sleep medication”.
Fig. 3A: Rate of falls from 22:00 to 6:00 in patients with sleep medication.
Fig. 3B:	Percentage of falls from 22:00 to 6:00 in patients with and without sleep medication (62% vs. 18%,p<0.01).

Use of sleep medication was significantly more frequent in patients over 60 and over 80 years
old (p<0.01) (Table 3). There was a significantly higher rate of multiple falls in patients using
sleep medication (p<0.01) (Table 4). The details of the sleep medication are shown in Table 5.
Zolpidem (25%, n=63) was the most frequently used sleep medication, followed by brotizolam(16%, n=41) and etizolam (13%, n=32), including use of multiple medications. Multiple falls
from 22:00 to 6:00 occurred significantly more frequently in patients using ≥2 types of sleep
medications compared to those using one sleep medication (53% vs. 17%, p<0.01) (Figure 4).

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Sleep medication and fall

Table 3Comparison of falls with and without use of sleep medication

Variable

Falls withsleep medication(n=223)

Falls without
sleep medication(n=503)

P value

DemographicAge (years)

64.1±22.4

59.2±23.7<0.05Female

36% (80)

38% (191)n.s.

Over 80 years of age30% (68)

18% (93)<0.01

Over 60 years of age

82% (183)

62% (310)<0.01

Grade I

11% (26)

12% (61)n.s.

Grade II

46% (103)

45% (224)

n.s.

Grade III

42% (94)

43% (218)n.s.

Hospital room

63% (141)67% (338)n.s.

Corridor

16% (35)

12% (59)n.s.

Restroom

9% (19)8% (39)n.s.

Bathroom

4% (9)

4% (20)n.s.

Rehabilitation ward

2% (5)

2% (10)n.s.

Others6% (14)

7% (37)n.s.

Fall risk score

Location

Table 4Comparison of number of falls with and without use of sleep medication

Patients withsleep medication(n=127)

Patients without
sleep medication(n=315)

P valueOnce

37% (47)57% (178)

<0.01

Twice

39% (50)38% (120)n.s.

Three or more times

24% (30)

5% (17)<0.01

Variable

Number of falls (per patient)

Table 5

Details of use of sleep medications in patients with falls

Classification

Drug namen

Very short half-life

Zolpidem (Myslee®)

25% (63)

Zopiclone (Amoban®)

8% (21)

Eszopiclone (Lunesta®)
Short half-life

Brotizolam (Lendormin®)

8% (19)bEtizolam (Depas®) b
Rilmazafone (Rhythmy®)

16% (41)
13% (32)

b3% (7)

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Kazuyoshi Kobayashi et al

Intermediate half-life

Flunitrazepam (Silece®) b4% (9)Nitrazepam (Benzarin®)

2% (4)Long half-life

Quazepam (Doral®)

OthersRamelteon (Rozerem®)

12% (29)

Suvorexant (Belsomra®)

8% (19)bTotalabb2% (6)250 aOverlap in some cases
Benzodiazepine

Fig. 4 Details of falls from 22:00 to 6:00 with sleep medication
Percentage of ≥2 falls from 22:00 to 6:00 in patients with ≥2 and only 1 type of sleep medication (53% vs.
17%, p<0.01).

DISCUSSION
Falls are a common health problem in elderly people, and in the adult population the incidenceof fall increases with aging. We have previously shown a fall rate of 1.85% (3,925 / 212,617)
for inpatients in all wards in our hospital from April 2012 to March 2017.2 At admission toour hospital, nurses assess the potential for fall with patients and their families using a risk
assessment score sheet, and a history of fall has a significant relationship with this fall risk
score.1,3,4 In our series, 49% of the patients had multiple falls; thus, in assessment of a patient
who has previously fallen, it is important to examine the evaluation method from the perspectiveof preventing recurrence.
The most common sleep medication used in this study was zolpidem, which is in the
non-benzodiazepine class, followed by brotizolam and etizolam, which are benzodiazepines. In
previous reports, benzodiazepines have been found to increase the risk of falls and fractures,7,9and non-benzodiazepines are recommended for insomnia in elderly patients in the “Guidelinesfor proper use of sleep medication”.10 However, several previous studies have also found a fall

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Sleep medication and fallrisk with non-benzodiazepines.11,12 The results of the current study show that taking multiple
sleep medications increases the risk of fall, and especially, the number of falls late at night andin the early morning increased significantly in patients who used multiple sleep medications.
Thus, such patients should be especially careful about falls, and a combination of drugs should
be used carefully. Also, as most sleep medications are metabolized in the liver, the effects ofthese drugs may be stronger in elderly patients due to their reduced metabolic function. Forexample, the half-life of zopiclone is 3.7 h, but this may be extended to as long as 16 h inelderly patients.13 The risk of fall may be increased by this extended half-life, and this should beconsidered in selection of sleep medication, particularly in elderly patients with impaired physiological function. Therefore, it is important to be aware that even short-half-life sleep medications
such as zolpidem and zopiclone can cause falls at night, especially in elderly people. Even sleep
medications previously thought to be unlikely to be related to fall may not always be safe for
elderly people, and it is necessary to warn patients taking these drugs of the possibility of falls.
There are some limitations in this study. First, the sample size is small. Second, non-fallpatients were not examined, and the fall risk rate of each drug could not be determined withcertainty. For example, although zolpidem was taken most often by patients with falls, it has avery short half-life and a minor muscle relaxant action. Thus, it was not possible to conclude
whether zolpidem alone was significantly associated with falls. Third, drugs other than sleep
medication were not examined, and factors such as environment maintenance, which is anothercause of falls, and use of slippers as footwear, were not fully examined. Furthermore, it was
not possible to examine the percentage of people on prescribed sleep medication with fall or
the behavior of those with fall at night. However, our investigation of the relationship of sleepmedication with accidental fall indicated that use of sleep medications was associated with falllate at night and in the early morning, and that multiple medications also had a significant
relationship with multiple falls in the same period. Therefore, sleep medications appear to havea large impact on fall. Taking multiple sleeping pills makes fall more likely, and even drugs
with a short half-life, which are considered to be safe, can cause falls at night in elderly people.
Although the study focused on the hospital environment, sleep medications are also prescribed formany patients in outpatient settings. In this context, we believe that our results are not limited tohospitalization, but may also apply to patients at home. The findings indicate the importance ofselection of sleep medication to prevent fall in all patients. It is also necessary to warn elderly
patients of the possibility of falls, especially with use of sleep medications.

DISCLOSURE STATEMENT
Financial support was from institutional sources only. None of the authors have a conflict ofinterest to declare.

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