Prevalence
of Tardive Dyskinesia, Tardive Dystonia, and Respiratory Dyskinesia Chinese Psychiatric Patients in Hong Kong
Among Helen Joseph
Chiu, M.R.C.Psych., Lau, Ph.D., Linda
Objective: tients has
Only scanty been available.
dyskinesia, Hong Kong.
tardive Method:
admission
and
Scale, and In addition,
standard patients
for respiratory 91 7 patients
Patrick Shum, M.R.C.Psych., F.R.A.N.Z.C.P., Lam, M.R.C.Psych., and Sing Lee, M.R.C.Psych.
information This study
dystonia, and All inpatients
children’s
wards,
on the prevalence was undertaken
of tardive to examine
respiratory dyskinesia ofa mental hospital were
research criteria were screened
surveyed
were used for tardive
dyskinesia by physical surveyed, the prevalence
examination rates were
with
9.3%
in Chinese psychiatric in Hong Kong, except the
to establish dystonia,
dyskinesia in Chinese pathe prevalence of tardive
Abnormal
Involuntary
the diagnosis oftardive according to published
and laboratory for tardive
tests. Results: dyskinesia, 0.4%
patients in those in the Movement dyskinesia. criteria, and Among the for tardive
dystonia, and I .2 % for respiratory dyskinesia. With multivariate analysis, greater age and a lower current dose ofantipsychotic, but not the presence ofmood disorder, were factors found to be significantly associated with tardive dyskinesia. Conclusions: The prevalence rates were much lower than those found in Western studies. This may indicate that there is an ethnic difference
in the prevalence
ofthese
to explore this possibility. (Am J Psychiatry 1992;
conditions.
ardive dyskinesia is an involuntary movement disorder associated with prolonged use of neunoleptics. Kane and Smith (1) reviewed 56 studies involving 34,555 patients and found an average prevalence of 20%. In the same article, these investigators reviewed 19 studies on spontaneous dyskinesia and identified a prevalence of 5%. These were mostly American and European studies; information on Chinese patients is scanty. Eleven Asian studies on the prevalence of tardive dyskinesia, involving 8,647 patients, have so far been published (2-12). The average prevalence is 1 1 .6%, but the range is wide (2.S%-27.6%). This variability is multifactorial and may be due to differences in the methods of assessing dyskinesia, to sociodemographic and clinical characteristics, and/or to the fluctuating nature of tardive dyskinesia. In fact, earlier studies were fraught with methodological problems, such as use of variable
June
11,
1991;
revision
received
Dec.
10,
1991;
accepted
Dec. 20, 1991. From the Department of Psychiatry, Chinese University of Hong Kong. Address reprint requests to Dr. Chiu, Department ofPsychiatry, Chinese University ofHong Kong, 1 1fF, Prince of Wales Hospital,
Shatin,
Hong
The authors thank analysis. Copyright © 1992
Am
] Psychiatry
Kong.
Mr. Albert American
1 49:8,
Cheung
for help with
Psychiatric
Association.
August
1992
cross-culturalstudies
are necessary
149:1081-1085)
T
Received
Prospective
the statistical
diagnostic criteria, methods of case finding, and examination techniques. In the three studies that examined a homogeneous population of Chinese patients, the Taipei study (3) did not provide details on diagnosis and methodology, the Hong Kong study (6) did not use a standardized instrument to assess dyskinesia, and the Shanghai study (10) involved only chronic schizophrenic patients. Our first aim, therefore, was to examine the prevalence of tardive dyskinesia in various groups of Chinese psychiatric patients by using an improved method. In addition, we wished to examine the prevalence of tardive dystonia and respiratory dyskinesia. Tardive dystonia (13) is an underrecognized condition that is frequently more disabling than classical tardive dyskinesia. Although it may be a variant or subsyndrome of tardive dyskinesia, it is potentially useful to isolate it in epidemiological and treatment studies, since there is preliminary evidence that it differs from classical tardive dyskinesia in some significant ways (14). In this article, the term “tandive dyskinesia” is therefore confined to the bucco-linguo-masticatory syndrome and choreoathetoid movements of the limbs and trunk. Respiratory dyskinesia is characterized by irregularity in the rate, rhythm, and depth of breathing and usually occurs in patients with tardive dyskinesia (15).
1081
DYSKINESIA
TABLE
AND
DYSTONIA
1. Prevalence
AMONG
of Tardive
Dyskinesia
CHINESE
PATIENTS
and Data on Drug Treatment
of 917 Chinese
Patients With Tardive
Schizophrenia Manic-depressive Manic-depressive Dementia
(N=602) psychosis, psychosis,
(N=97)
Mental retardation Other (N=77) aRefers
circular type (N=22) depressed type (N=22)
to patients
SI 4 S
8.5 18.2 22.7
14
14.4
54
3.1 10.4
79 49
3 8
(N=97) currently
%
taking
antipsychotic
15 6
Taking Anticholinergic
of
chlorpromazine equivalents)
N 589
Patients Currently
of
%
Mean
97.8 68.2 27.3 55.7 81.4 63.6
Drug (N=s63)a SD
N
%
993.4
881.8
452
76.7
710.0 48.9 77.0
1044.3 121.1 222.6
529.9 255.9
12 3 10
80.0 50.0 18.5
617.1
57
72.2
385.2
29
59.2
drugs.
METHOD Our survey was conducted from October to November 1989 in one of the three mental hospitals in Hong Kong. At the outset of the study, 30 randomly chosen patients were examined independently by two of the investigators (H.C. and L.L.), both psychiatrists, with the Abnormal Involuntary Movement Scale (AIMS) (16) to test interrater reliability. Kappas for the seven items of the AIMS ranged from 0.8 to 1.0. All inpatients except those in the admission and children’s wards were examined by one or the other of the two investigators (H.C. and L.L.) with the AIMS after informed consent had been given. Patients in the admission wards were excluded because they were mentally unstable and their clinical diagnoses were frequently uncertain. Clinical diagnoses had been made previously according to ICD-9 by the psychiatrists in charge of the patients. The investigators were blind to these diagnoses. Schooler and Kane’s research diagnostic criteria (17) were used to establish the diagnosis of tardive dyskinesia. Prerequisites include 1 ) exposure to antipsychotics for at least 3 months, 2) at least “mild” involuntary movements in two or more body areas or at least “moderate” involuntary movements in one or more body aneas, and 3) absence of other conditions causing involuntary movement. All patients were also examined for the presence of tardive dystonia according to the criteria of Burke et al. ( 1 3 ): 1 ) the presence of chronic dystonia, 2) history of antipsychotic drug treatment preceding or concurrent with the onset of dystonia, 3) exclusion of known causes of secondary dystonia by appropriate clinical and laboratory evaluation, and 4) no family history of dystonia. To exclude secondary causes of dystonia, affected subjects underwent further examination, including CBC, tests of liver, renal, and thyroid function, determination of ceruloplasmin and copper levels, and slitlamp examination. In the examination for respiratory dyskinesia, patients were bared to the waist and respiration was observed for 3 minutes in both sitting and lying positions. Irregularity of breathing rate, rhythm, and depth was necessary for the diagnosis. Using such criteria, we
1082
Dose
Antipsychotic (mg/day
Drugs (N=792)
N
in Hong Kong
Current
Taking Antipsychotic
Dyskinesia (N=85) Diagnosis
Psychi atric Patients
Patients Currently
found that the presence or absence of respiratory dyskinesia was determined without difficulty. Affected patients were also examined for cardiac or lung disease and underwent a battery of tests, including ECG, chest
X-ray,
determination
function, condings
were performed All patients tion, case demographic ment histories.
Patients with
the
Those
of serum
and blood of thoracic
for
multivaniate identify
the dyskinesia
tardive
dyskinesia
3 months
continued
after
to meet
diagnosed
confidence
objectively.
factors
were
their
intervals
interviews.
for tardive
persistent
of prevalence
diagnostic test and
regression) associated
reexamined
initial
the criteria
as having
the different (Mann-Whitney
(logistic the
liver
subsequently interviewed. In addinotes and drug charts were reviewed for data and family, psychiatric, and treat-
were (17).
The 95% culated univaniate
to confirm
with
dyskinesia dyskinesia
levels,
were
AIMS
who
electrolyte
gases, and CBC. Polygraphic reand abdominal respiratory efforts
were
subgroups. chi-square
analyses with
tardive
tandive
were
cal-
Both test) and
used
to
dyskinesia.
RESULTS Nine hundred seventeen patients (503 male and 414 female) were surveyed, among whom 863 (94.1%) had histories ofexposure to antipsychotic medication. Their mean age was 46.5 years (SD=18.0, nange=16-103), and the mean duration of hospitalization was 3.1 years (SD=2.4). Seven hundred ninety-two (86.4%) ofthe patients were currently taking antipsychotic drugs (table 1 ). Their mean current dose of antipsychotic in chlor-
promazine equivalents 853.1, median=600,
(18) was 876.3 range=10-472S).
mg/day Patients
(SD= were
commonly prescribed one to three types of antipsychotic drugs; chlorpromazine was the most widely used, followed by trifluopenazine, halopenidol, and thionidazine (table 2). Of the 792 patients currently taking antipsychotics, 71.1% were given an anticholinergic drug (table 1 ). Trihexyphenidyl was the only anticholinergic drug used, and the mean daily dose was 6.29 mg (SD=3.02).
Am
]
Psychiatry
1 49:8,
August
1992
CHIU,
TABLE 2. Patients in Hong Kong
Currently
Taking the Four M ost Commonly
Prescribed
Patients Taking Chlorpromazine (N=336) Diagnosis
Mental Other
circular depressed
type type
retardation
Eighty-five
a prevalence 1 1.2%).
%
N
79.5 1.2 0.9 3.9
197
4 3 13
35 14
10.4 4.2
267 psychosis, psychosis,
patients
had
of 9.3%
(95%
tardive
dyskinesia
confidence
Drugs in a Survey of 917 Chinese
Patients Taking Trifluoperazine (N=221)
N
Schizophrenia Manic-depressive Manic-depressive Dementia
Antipsychotic
(table
1),
mean age of these patients was 61.7 years range=24-94). Seventy-two (84.7%) of these patients had persistent tardive dyskinesia. No patients without a history of exposure to antipsychotics had dyskinesia. The majority of the patients (N=602) were schizophrenic (table 1 ), among whom the prevalence of tardive dyskinesia was 8.5% (9.5% confidence interval= Four patients nia, a prevalence
0.1%-1.1%).
(two of each sex) had tardive dystoof 0.4% (95% confidence interval= Their mean age was 39.3 years (SD=1.1,
range=38-41 ). The duration of dystonia ranged from 2 to S years. Two of these patients had coexistent tardive dyskinesia. Eleven patients (three male and eight female) had respiratory dyskinesia, an overall prevalence of 1.2% (95% confidence interval=0.6%-2.2%) and a prevalence of 12.9% among those with tardive dyskinesia. Their mean age was 65.5 years (SD=16.0, range=3889). Clinical and polygraphic characteristics of these patients will be presented in a separate paper. Older age (Mann-Whitney test, z=-7.9, p
of Tardive Dyskinesia, Tardive Dystonia, and Respiratory Dyskinesia Chinese Psychiatric Patients in Hong Kong
Among Helen Joseph
Chiu, M.R.C.Psych., Lau, Ph.D., Linda
Objective: tients has
Only scanty been available.
dyskinesia, Hong Kong.
tardive Method:
admission
and
Scale, and In addition,
standard patients
for respiratory 91 7 patients
Patrick Shum, M.R.C.Psych., F.R.A.N.Z.C.P., Lam, M.R.C.Psych., and Sing Lee, M.R.C.Psych.
information This study
dystonia, and All inpatients
children’s
wards,
on the prevalence was undertaken
of tardive to examine
respiratory dyskinesia ofa mental hospital were
research criteria were screened
surveyed
were used for tardive
dyskinesia by physical surveyed, the prevalence
examination rates were
with
9.3%
in Chinese psychiatric in Hong Kong, except the
to establish dystonia,
dyskinesia in Chinese pathe prevalence of tardive
Abnormal
Involuntary
the diagnosis oftardive according to published
and laboratory for tardive
tests. Results: dyskinesia, 0.4%
patients in those in the Movement dyskinesia. criteria, and Among the for tardive
dystonia, and I .2 % for respiratory dyskinesia. With multivariate analysis, greater age and a lower current dose ofantipsychotic, but not the presence ofmood disorder, were factors found to be significantly associated with tardive dyskinesia. Conclusions: The prevalence rates were much lower than those found in Western studies. This may indicate that there is an ethnic difference
in the prevalence
ofthese
to explore this possibility. (Am J Psychiatry 1992;
conditions.
ardive dyskinesia is an involuntary movement disorder associated with prolonged use of neunoleptics. Kane and Smith (1) reviewed 56 studies involving 34,555 patients and found an average prevalence of 20%. In the same article, these investigators reviewed 19 studies on spontaneous dyskinesia and identified a prevalence of 5%. These were mostly American and European studies; information on Chinese patients is scanty. Eleven Asian studies on the prevalence of tardive dyskinesia, involving 8,647 patients, have so far been published (2-12). The average prevalence is 1 1 .6%, but the range is wide (2.S%-27.6%). This variability is multifactorial and may be due to differences in the methods of assessing dyskinesia, to sociodemographic and clinical characteristics, and/or to the fluctuating nature of tardive dyskinesia. In fact, earlier studies were fraught with methodological problems, such as use of variable
June
11,
1991;
revision
received
Dec.
10,
1991;
accepted
Dec. 20, 1991. From the Department of Psychiatry, Chinese University of Hong Kong. Address reprint requests to Dr. Chiu, Department ofPsychiatry, Chinese University ofHong Kong, 1 1fF, Prince of Wales Hospital,
Shatin,
Hong
The authors thank analysis. Copyright © 1992
Am
] Psychiatry
Kong.
Mr. Albert American
1 49:8,
Cheung
for help with
Psychiatric
Association.
August
1992
cross-culturalstudies
are necessary
149:1081-1085)
T
Received
Prospective
the statistical
diagnostic criteria, methods of case finding, and examination techniques. In the three studies that examined a homogeneous population of Chinese patients, the Taipei study (3) did not provide details on diagnosis and methodology, the Hong Kong study (6) did not use a standardized instrument to assess dyskinesia, and the Shanghai study (10) involved only chronic schizophrenic patients. Our first aim, therefore, was to examine the prevalence of tardive dyskinesia in various groups of Chinese psychiatric patients by using an improved method. In addition, we wished to examine the prevalence of tardive dystonia and respiratory dyskinesia. Tardive dystonia (13) is an underrecognized condition that is frequently more disabling than classical tardive dyskinesia. Although it may be a variant or subsyndrome of tardive dyskinesia, it is potentially useful to isolate it in epidemiological and treatment studies, since there is preliminary evidence that it differs from classical tardive dyskinesia in some significant ways (14). In this article, the term “tandive dyskinesia” is therefore confined to the bucco-linguo-masticatory syndrome and choreoathetoid movements of the limbs and trunk. Respiratory dyskinesia is characterized by irregularity in the rate, rhythm, and depth of breathing and usually occurs in patients with tardive dyskinesia (15).
1081
DYSKINESIA
TABLE
AND
DYSTONIA
1. Prevalence
AMONG
of Tardive
Dyskinesia
CHINESE
PATIENTS
and Data on Drug Treatment
of 917 Chinese
Patients With Tardive
Schizophrenia Manic-depressive Manic-depressive Dementia
(N=602) psychosis, psychosis,
(N=97)
Mental retardation Other (N=77) aRefers
circular type (N=22) depressed type (N=22)
to patients
SI 4 S
8.5 18.2 22.7
14
14.4
54
3.1 10.4
79 49
3 8
(N=97) currently
%
taking
antipsychotic
15 6
Taking Anticholinergic
of
chlorpromazine equivalents)
N 589
Patients Currently
of
%
Mean
97.8 68.2 27.3 55.7 81.4 63.6
Drug (N=s63)a SD
N
%
993.4
881.8
452
76.7
710.0 48.9 77.0
1044.3 121.1 222.6
529.9 255.9
12 3 10
80.0 50.0 18.5
617.1
57
72.2
385.2
29
59.2
drugs.
METHOD Our survey was conducted from October to November 1989 in one of the three mental hospitals in Hong Kong. At the outset of the study, 30 randomly chosen patients were examined independently by two of the investigators (H.C. and L.L.), both psychiatrists, with the Abnormal Involuntary Movement Scale (AIMS) (16) to test interrater reliability. Kappas for the seven items of the AIMS ranged from 0.8 to 1.0. All inpatients except those in the admission and children’s wards were examined by one or the other of the two investigators (H.C. and L.L.) with the AIMS after informed consent had been given. Patients in the admission wards were excluded because they were mentally unstable and their clinical diagnoses were frequently uncertain. Clinical diagnoses had been made previously according to ICD-9 by the psychiatrists in charge of the patients. The investigators were blind to these diagnoses. Schooler and Kane’s research diagnostic criteria (17) were used to establish the diagnosis of tardive dyskinesia. Prerequisites include 1 ) exposure to antipsychotics for at least 3 months, 2) at least “mild” involuntary movements in two or more body areas or at least “moderate” involuntary movements in one or more body aneas, and 3) absence of other conditions causing involuntary movement. All patients were also examined for the presence of tardive dystonia according to the criteria of Burke et al. ( 1 3 ): 1 ) the presence of chronic dystonia, 2) history of antipsychotic drug treatment preceding or concurrent with the onset of dystonia, 3) exclusion of known causes of secondary dystonia by appropriate clinical and laboratory evaluation, and 4) no family history of dystonia. To exclude secondary causes of dystonia, affected subjects underwent further examination, including CBC, tests of liver, renal, and thyroid function, determination of ceruloplasmin and copper levels, and slitlamp examination. In the examination for respiratory dyskinesia, patients were bared to the waist and respiration was observed for 3 minutes in both sitting and lying positions. Irregularity of breathing rate, rhythm, and depth was necessary for the diagnosis. Using such criteria, we
1082
Dose
Antipsychotic (mg/day
Drugs (N=792)
N
in Hong Kong
Current
Taking Antipsychotic
Dyskinesia (N=85) Diagnosis
Psychi atric Patients
Patients Currently
found that the presence or absence of respiratory dyskinesia was determined without difficulty. Affected patients were also examined for cardiac or lung disease and underwent a battery of tests, including ECG, chest
X-ray,
determination
function, condings
were performed All patients tion, case demographic ment histories.
Patients with
the
Those
of serum
and blood of thoracic
for
multivaniate identify
the dyskinesia
tardive
dyskinesia
3 months
continued
after
to meet
diagnosed
confidence
objectively.
factors
were
their
intervals
interviews.
for tardive
persistent
of prevalence
diagnostic test and
regression) associated
reexamined
initial
the criteria
as having
the different (Mann-Whitney
(logistic the
liver
subsequently interviewed. In addinotes and drug charts were reviewed for data and family, psychiatric, and treat-
were (17).
The 95% culated univaniate
to confirm
with
dyskinesia dyskinesia
levels,
were
AIMS
who
electrolyte
gases, and CBC. Polygraphic reand abdominal respiratory efforts
were
subgroups. chi-square
analyses with
tardive
tandive
were
cal-
Both test) and
used
to
dyskinesia.
RESULTS Nine hundred seventeen patients (503 male and 414 female) were surveyed, among whom 863 (94.1%) had histories ofexposure to antipsychotic medication. Their mean age was 46.5 years (SD=18.0, nange=16-103), and the mean duration of hospitalization was 3.1 years (SD=2.4). Seven hundred ninety-two (86.4%) ofthe patients were currently taking antipsychotic drugs (table 1 ). Their mean current dose of antipsychotic in chlor-
promazine equivalents 853.1, median=600,
(18) was 876.3 range=10-472S).
mg/day Patients
(SD= were
commonly prescribed one to three types of antipsychotic drugs; chlorpromazine was the most widely used, followed by trifluopenazine, halopenidol, and thionidazine (table 2). Of the 792 patients currently taking antipsychotics, 71.1% were given an anticholinergic drug (table 1 ). Trihexyphenidyl was the only anticholinergic drug used, and the mean daily dose was 6.29 mg (SD=3.02).
Am
]
Psychiatry
1 49:8,
August
1992
CHIU,
TABLE 2. Patients in Hong Kong
Currently
Taking the Four M ost Commonly
Prescribed
Patients Taking Chlorpromazine (N=336) Diagnosis
Mental Other
circular depressed
type type
retardation
Eighty-five
a prevalence 1 1.2%).
%
N
79.5 1.2 0.9 3.9
197
4 3 13
35 14
10.4 4.2
267 psychosis, psychosis,
patients
had
of 9.3%
(95%
tardive
dyskinesia
confidence
Drugs in a Survey of 917 Chinese
Patients Taking Trifluoperazine (N=221)
N
Schizophrenia Manic-depressive Manic-depressive Dementia
Antipsychotic
(table
1),
mean age of these patients was 61.7 years range=24-94). Seventy-two (84.7%) of these patients had persistent tardive dyskinesia. No patients without a history of exposure to antipsychotics had dyskinesia. The majority of the patients (N=602) were schizophrenic (table 1 ), among whom the prevalence of tardive dyskinesia was 8.5% (9.5% confidence interval= Four patients nia, a prevalence
0.1%-1.1%).
(two of each sex) had tardive dystoof 0.4% (95% confidence interval= Their mean age was 39.3 years (SD=1.1,
range=38-41 ). The duration of dystonia ranged from 2 to S years. Two of these patients had coexistent tardive dyskinesia. Eleven patients (three male and eight female) had respiratory dyskinesia, an overall prevalence of 1.2% (95% confidence interval=0.6%-2.2%) and a prevalence of 12.9% among those with tardive dyskinesia. Their mean age was 65.5 years (SD=16.0, range=3889). Clinical and polygraphic characteristics of these patients will be presented in a separate paper. Older age (Mann-Whitney test, z=-7.9, p
