Severe acute respiratory syndrome (SARS) was contained globally by widespread quarantine
measures, measures that had not been invoked to contain an infectious disease in North
America for >50 years (
1
–
6
). Although quarantine has periodically been used for centuries to contain and control
the spread of infectious diseases such as cholera and the plague with some success
(
1
–
4
,
6
–
8
), the history of invoking quarantine measures is tarnished by threats, generalized
fear, lack of understanding, discrimination, economic hardships, and rebellion (
1
,
3
,
4
,
6
–
8
).
Quarantine separates persons who have been potentially exposed to an infectious agent
(and thus at risk for disease) from the general community. For the greater public
good, quarantine may create heavy psychological, emotional, and financial problems
for some persons. To be effective, quarantine demands not only that at-risk persons
be isolated but also that they follow appropriate infection control measures within
their place of quarantine. Reporting on SARS quarantine has focused on ways in which
quarantine was implemented and compliance was achieved (
1
–
4
,
6
–
8
). Adverse effects on quarantined persons and the ways in which those quarantined
can best be supported have not been evaluated. Moreover, little is known about adherence
to infection-control measures by persons in quarantine.
Knowledge and understanding of the experiences of quarantined persons are critical
to maximize infectious disease containment and minimize the negative effects on those
quarantined, their families, and social networks. The objectives of our study were
to assess the level of knowledge about quarantine and infection control measures of
persons who were placed in quarantine, to explore ways by which these persons received
information to evaluate the level of adherence to public health recommendations, and
to understand the psychological effect on quarantined persons during the recent SARS
outbreaks in Toronto, Canada.
Methods
Description of Quarantine in Toronto
During the first and second SARS outbreaks in Toronto, >15,000 persons with an epidemiologic
exposure to SARS were instructed to remain in voluntary quarantine (Health Canada,
unpub. data). Data on the demographics of the quarantined population were collected,
but have not yet been analyzed (B. Henry, Toronto Public Health, pers. comm.). Quarantined
persons were instructed not to leave their homes or have visitors. They were told
to wash their hands frequently, to wear masks when in the same room as other household
members, not to share personal items (e.g., towels, drinking cups, or cutlery), and
to sleep in separate rooms. In addition, they were instructed to measure their temperature
twice daily. If any symptoms of SARS developed, they were to call Toronto Public Health
or Telehealth Ontario for instructions (
5
).
Study Population
All persons who were placed in quarantine during the SARS outbreaks in Toronto (at
least 15,000 persons) were eligible for participation in this study. The survey was
announced through media releases, including locally televised interviews with the
principal investigators. Information on the study and invitations to participate were
posted in local healthcare institutions, libraries, and supermarkets. Ethics approval
was obtained from the research ethics board of the University Health Network, a teaching
institution affiliated with the University of Toronto.
Survey Instrument
A Web-based survey composed of 152 multiple choice and short- answer questions was
to be completed after participants ended their period of quarantine. It took approximately
20 minutes to complete. Questions explored included the following: 1) knowledge and
understanding of the reasons for quarantine (
2
), knowledge of and adherence to infection control directives, and (
3
) source of this knowledge.
The psychological impact of quarantine was evaluated with validated scales, including
the Impact of Event Scale—Revised (IES-R) (
9
) and the Center for Epidemiologic Studies—Depression Scale (CES-D) (
10
). The IES-R is a self-report measure designed to assess current subjective distress
resulting from a traumatic life event and is composed of 22 items, each with a Likert
rating scale from 0 to 4. The maximum score is 88. In a study of journalists working
in war zones, the mean IES-R score of posttraumatic stress disorder (PTSD) was 20.
In these persons, the presence of PTSD symptoms, as measured by this scale, was correlated
with diagnostic psychiatric interviews (
11
). The CES-D is a measure of depressive symptoms composed of 20 self-report items,
each with a Likert rating scale from 0 to 3. The maximum score is 60 (
10
). A score of> 16 has been shown to identify persons with depressive symptoms similar
in severity to the levels observed among depressed patients (
10
,
12
,
13
). Open-ended questions provided respondents with the opportunity to relate the aspects
of quarantine that were most difficult for them and allowed them to provide additional
comments on their unique experiences.
Statistical Analysis
Means were calculated to summarize continuous variables. For categorical variables,
group proportions were calculated. Student t tests were used to examine relationships
between demographic variables and the psychological outcome variables, the scores
on the IES-R and CES-D. A score of >20 on the IES-R was used to estimate the prevalence
of PTSD symptoms (
11
). A score of >16 on the CES-D was used to estimate the prevalence of depressive symptoms
(
10
,
12
,
13
).
Analysis of variance (ANOVA), chi-square, and the Cochran-Armitage test for trend
were used to examine relations between the IES-R and CES-D scores and the following
independent variables: healthcare worker status, home or work quarantine, acquaintance
of or direct exposure to someone with a diagnosis of SARS, combined annual household
income, and the frequency with which persons placed in quarantine wore their masks.
Linear regression for the trends between income categories and both PTSD and depressive
symptoms was analyzed. The relationships between the IES-R and CES-D and whether persons
in quarantine wore their masks all of the time versus never were examined by the Duncan-Waller
K-ratio t tests. A p value of < 0.05 was considered to be significant for all analyses.
Qualitative data were coded and analyzed to show emerging themes. The development
and confirmation of the thematic coding structure is an iterative process involving
two researchers in individual, recursive reading of the textual data and group meetings
to discuss and test the emerging themes. Discrepancies were resolved by consulting
specific instances in the data, discussing their relationship to established themes,
and reaching consensus as a group (
14
).
Results
Demographics and Description of Quarantined Persons
The survey was completed by 129 of more than 15,000 eligible persons who were placed
in quarantine (Figure). All respondents completed the survey at the end of quarantine
with a minimum time from the end of quarantine to the completion of the survey of
2 days. The median time from the end of quarantine to completion of the survey was
36.0 days (interquartile range, 10–66 days). Sixty-eight percent of respondents were
healthcare workers, 64% were 26–45 years of age, 58% were married, 72% had a college
level of education or higher, and 48% had a combined household income of >$75,000
(Canadian dollars [CAD]).
Figure
Number of persons in quarantine, Toronto, Canada, February 23–June 30, 2003. Figure
courtesy of Toronto Public Health.
The 129 respondents described 143 periods of quarantine with 90% of respondents being
placed into quarantine only once; 66% of respondents were on home quarantine, while
34% were on work quarantine. The median duration of quarantine was 10 days (interquartile
range 8–10 days). Half of respondents knew someone who was hospitalized with SARS
of whom 77% were colleagues; 10% knew someone who had died of SARS (Table 1).
Table 1
Characteristics of quarantined persons who responded to the survey
Characteristic
No. (%) N=129
Age (y)
18–25
11 (8.6)
26–35
37 (28.9)
36–45
44 (34.4)
46–55
21 (16.4)
56–65
11 (8.7)
66+
4 (3.1)
Marital status
Married or common law
87 (68.0)
Single or divorced
41 (32.0)
Education
High school
11 (9.2)
College or university
109 (90.8)
Income (Canadian $)
<$20,000
6 (5.8)
$20,000–$39,999
8 (8.5)
$40,000–$74,999
35 (33.0)
$75,000–$99,999
20 (18.8)
>$100,000
36 (34.0)
Healthcare worker status
No
40 (31.8)
Yes
86 (68.3)
Type of quarantine
(N = 143 episodes)
Work
49 (34.3)
Home
94 (65.7)
Household members
No. adults
1
28 (21.9)
2
72 (56.4)
3
22 (17.2)
4
5 (3.9)
>5
1 (0.8)
No. children
0
72 (55.8)
1
24 (18.6)
2
25 (19.4)
3
8 (6.2)
Persons were notified of their need to go into quarantine from the following sources:
their workplace (58%), the media (27%), their healthcare provider (7%), and public
health officials (9%). Most (68%) understood that they were quarantined to prevent
them from transmitting infection to others; 8.5% of respondents believed they were
quarantined to protect themselves from infection; 15% did not believe they should
have been placed into quarantine at all; and 8.5% provided more than one of these
responses.
The source of notification for quarantine influenced understanding of the reason for
quarantine. Those who were notified by the media or their workplace were more likely
to understand the reason for quarantine than those who were notified by their healthcare
provider or public health unit (p = 0.04). Healthcare workers were also more likely
to understand the reason for quarantine compared with non–healthcare workers, 76.5%
versus 52.5% (p = 0.007). Combined household income and level of education did not
influence understanding of the reason for quarantine.
Information on Infection Control Measures
Persons received their information regarding infection control measures to be adhered
to during their quarantine from the following sources: the media (54%), public health
authorities (52%), occupational health department (33%), healthcare providers (29%),
word-of-mouth (23%), hospital Web sites (21%), and other Web sites (40%).
Those who did not think they had been well-informed were angry that information on
infection control measures and quarantine was inconsistent and incomplete, frustrated
that employers (healthcare institutions) and public health officials were difficult
to contact, disappointed that they did not receive the support they expected, and
anxious about the lack of information on the modes of transmission and prognosis of
SARS (Appendix).
During the outbreaks, nearly 30% of respondents thought that they had received inadequate
information about SARS. With respect to information regarding home infection control
measures, 20% were not told with whom they could have contact; 29% did not receive
specific instructions on when to change their masks; and 40%–50% did not receive instructions
on the use and disinfection of personal items, including toothbrushes and cutlery;
77% were not given instructions regarding use and disinfection of the telephone. Healthcare
worker status did not influence whether respondents thought they had received adequate
information regarding any of the listed home infection control measures, except regarding
the frequency of mask changing: healthcare workers more frequently reported that they
had received adequate information, 78.8% versus 60.5% (p = 0.03).
Adherence to Infection Control Measures
Eighty-five percent of quarantined persons wore a mask in the presence of household
members; 58% remained inside their residence for the duration of their quarantine.
Thirty-three percent of those quarantined did not monitor their temperatures as recommended:
26% self-monitored their temperatures less frequently than recommended, and 7% did
not measure their temperatures at all. No differences between healthcare workers and
nonhealthcare workers were found with respect to adherence to recommended infection
control measures.
Psychological Impact of Quarantine
The mean IES-R score was 15.2±17.8, and the mean CES-D was 13.0±11.6. The IES-R score
was >20 for 28.9%; the CES-D score was >16 in 31.2% of quarantined persons (Table
2). The mean IES-R scores were not different for persons on home or work quarantine,
14.1±18.8 versus 17.6±16.6 (p = 0.33); the mean CES-D scores were also not different
between the groups, 12.0±12.0 versus 15.2±10.7 (p = 0.16).
Table 2
Prevalence of posttraumatic stress disorder and depressive symptoms according to patient
demographicsa
Characteristic
No. (%) N=129
Prevalence
CES-D
<16
84 (68.8)
>16
38 (31.2)
IES-R
<20
86 (71.1)
>20
35 (28.9)
Marital status
Mean
SD
p value
CES-D
Single or divorced (n = 40)
12.9
10.7
0.85
Married (n = 79)
12.5
11.4
IES-R
Single or divorced (n = 39)
14.5
16.6
0.82
Married (n = 79)
13.8
14.6
Income (Canadian $)
CES-D
<$40,000
18.3
15.4
0.05b
$40,000–$75,000
15.5
13.2
>$75,000
10.9
9.2
IES-R
<$40,000
24.2
20.6
0.03b
$40,000–$75,000
19.9
24.4
>$75,000
11.8
11.6
Duration of quarantine (d)
CES-D
<10
11.2
10.1
0.07
>10
17.0
14.2
IES-R
<10
11.7
10.7
0.05
>10
23.7
27.2
aCES-D, Center for Epidemiologic Studies—Depression Scale (
10
); IES-R,Impact of Event Scale—Revised (
9
).
bBy analysis of variance.
The presence of PTSD symptoms was correlated with the presence of depressive symptoms
(p < 0.0001, r = 0.78). Marital status did not offset the presence of PTSD symptoms,
mean IES-R score of 14.5±16.6 for those who were unmarried versus 13.8±14.6 for those
who were married (p = 0.82). Similarly, marital status did not influence the presence
of depressive symptoms, with a mean CES-D score of 12.9±10.7 for those who were unmarried
versus 12.5±11.4 for those who were married (p = 0.85)
A combined annual household income of CAD <$40,000 versus CAD $40,000 to CAD $75,000
versus CAD >$75,000 was associated with increased PTSD symptoms (mean IES-R score
of 24.2±20.6 versus 20.0±24.4 versus 11.8±11.6, respectively) (p = 0.03 for the three-way
comparison). Linear regression testing for trend over income categories was also significant
(p = 0.01). A combined annual household income of CAD <$40,000 versus CAD $40,000
to CAD $75,000 versus CAD >$75,000 was also associated with increased depressive symptoms
(mean CES-D score of 18.3±15.4 versus 15.5±13.2 versus 10.9±9.2, respectively) (p
= 0.05 for the three-way comparison) (Table 2). Results of linear regression testing
for trend over income categories were also significant (p = 0.01).
Neither age, level of education, healthcare worker status, living with other adult
household members, nor having children was correlated with PTSD and depressive symptoms.
The duration of quarantine was significantly related to increased PTSD symptoms, mean
IES-R score of 23.7±27.2 for those in quarantine >10 days compared with 11.7±10.7
for those in quarantine <10 days (p < 0.05). Persons who were in quarantine for a
longer duration showed a trend toward higher CES-D scores; however, this difference
did not reach statistical significance (mean CES-D of 17.0±14.2 for those in quarantine
>10 days versus 11.2±10.1 for those in quarantine <10 days [p = 0.07]). Acquaintance
with or exposure to someone who was hospitalized with SARS was associated with a higher
mean IES-R score, 18.6±20.2 versus 11.8±14.3 (p = 0.03) and a higher mean CES-D score,
15.5±12.1 versus 10.2±10.5 (p = 0.01). Overall, acquaintance with or exposure to someone
who died of SARS was not correlated with PTSD or depressive symptoms (data not shown).
Persons were categorized as having worn their masks all of the time, including times
when it was not recommended, having worn their masks according to recommendations,
or not having worn their masks at all. Those who wore their masks all of the time
had higher mean IES-R scores (29.7±18.6 versus 14.1±17.9 versus 12.3±15.1, p = 0.003
for the three-way comparison) and higher mean CES-D scores (25.6±12.7 versus 12.2±11.1
versus 11.5±11.6, p = 0.002 for the three-way comparison). Those who wore their masks
all of the time also had higher mean IES-R scores (p = 0.03) and higher mean CES-D
scores (p = 0.002) than those who never wore their masks.
All respondents described a sense of isolation. The mandated lack of social and, especially,
the lack of any physical contact with family members were identified as particularly
difficult. Confinement within the home or between work and home, not being able to
see friends, not being able to shop for basic necessities of everyday life, and not
being able to purchase thermometers and prescribed medications enhanced their feeling
of distance from the outside world. Infection control measures imposed not only the
physical discomfort of having to wear a mask but also significantly contributed to
the sense of isolation. In some, self-monitoring of temperature provoked considerable
anxiety: "taking temperatures was mentally difficult" (respondent #27) and "taking
my temperature made my heart feel like it was going to pound out of my chest each
time" (respondent #62).
While most quarantined persons (60%) did not believe that they would contract SARS,
59% were worried that they would infect their family members. In contrast, only 28%
were concerned that a quarantined family member would infect someone else in the home.
Following quarantine, 51% of respondents had experiences that made them feel that
people were reacting differently to them: avoiding them, 29%; not calling them, 7%;
not inviting them to events, 8%; and not inviting their families to events, 7%.
Discussion
Persons placed in quarantine have their freedom restricted to contain transmissible
diseases. This takes a considerable toll on the person. In relation to the recent
global outbreak of SARS, considerable time has been spent discussing the specifics
of quarantine and how to promote adherence to infection control measures. Little,
if any, analysis has focused on the effect of quarantine on the well-being of the
quarantined person. The objective of the study survey was to capture a range of experiences
of quarantined persons to better understand their needs and concerns. This knowledge
is critical if modern quarantine is to be an effective disease-containment strategy.
To our knowledge, a consideration of the adverse effects of quarantine, including
psychological effects, has not previously been systematically attempted.
Our results show that a substantial proportion of quarantined persons are distressed,
as evidenced by the proportion that display symptoms of PTSD and depression as measured
by validated scales. Although quarantined persons experienced symptoms suggestive
of both PTSD and depression, the scales that were used to measure these symptoms are
not sufficient to confirm these diagnoses. To confirm the diagnoses of PTSD and depression,
structured diagnostic interviews are required. Because the survey was anonymous, this
was not possible.
A score of >20 on the IES-R was used to estimate the prevalence of PTSD symptoms in
our study population. This corresponds to the mean score measured on the IES-R in
a study of journalists working in war zones that used diagnostic psychiatric interviews
to confirm the presence of this disorder (
11
). Since most respondents to our survey were healthcare workers, we chose a work-related
traumatic event for the comparison group. While other cutoff points may have been
used to estimate the prevalence of PTSD symptoms in our population, the risk factors
that we identified for increased PTSD symptoms, rather than the absolute prevalence
of PTSD in our study participants, are the important findings of this study. This
also applies to the risk factors that we identified for increased depressive symptoms
in the respondents. Quarantined persons with risk factors for either PTSD or depressive
symptoms may benefit from increased support from public health officials.
In this population, the presence of PTSD symptoms was highly correlated with the presence
of depressive symptoms even though different clinical symptoms characterize the two
disorders. Kessler's National Comorbidity Study indicated a 48.2% occurrence of depression
in patients with PTSD (
15
).
PTSD is an anxiety disorder characterized by avoiding stimuli associated with a traumatic
event, reexperiencing the trauma, and hyperarousal, such as increased vigilance (
16
). This disorder may develop after exposure to traumatic events that involve a life-threatening
component, and a person's vulnerability to the development of PTSD can be increased
if the trauma is perceived to be a personal assault (
17
). Increased length of time spent in quarantine was associated with increased symptoms
of PTSD. This finding might suggest that quarantine itself, independent of acquaintance
with or exposure to someone with SARS, may be perceived as a personalized trauma.
The presence of more PTSD symptoms in persons with an acquaintance or exposure to
someone with a diagnosis of SARS compared to persons who did not have this personal
connection may indicate a greater perceived self-risk. The small number of respondents
who were acquainted with or exposed to someone who died of SARS may explain the lack
of correlation between this group and greater PTSD and depressive symptoms (44 persons
died of SARS in the greater Toronto area).
This study also notes the trend toward increasing symptoms of both PTSD and depression
as the combined annual income of the respondent household fell from CAD >$75,000 to
CAD <$40,000. Quarantined persons with a lower combined annual household income may
require additional levels of support. Since the survey was Web-based and required
that respondents have access to a computer, the survey was likely answered by a more
affluent and educated subgroup of persons. Since respondents with a lower combined
annual household income experienced increased symptoms of PTSD and depression, and
since those with lower combined annual household incomes were not as likely to have
access to a computer, the results of this survey may underestimate the prevalence
of psychological distress in the overall group of quarantined persons. Overall, most
respondents did not report financial hardship as a result of quarantine. This finding
is likely explained by the fact that >50% of the respondents reported a combined annual
household income of CAD >$75,000.
As many as 50% of respondents felt that they had not received adequate information
regarding at least one aspect of home infection control, and not all of the respondents
adhered to recommendations. Why some infection control measures were adhered to while
others were not is unclear. A combination of lack of knowledge, an incomplete understanding
of the rationale for these measures, and a lack of reinforcement from an overwhelmed
public health system were likely contributors to this problem. Of particular interest,
strictly adhering to infection control measures, including wearing masks more frequently
than recommended, was associated with increased levels of distress. Whether persons
with higher baseline levels of distress were more likely to strictly adhere to infection-control
measures or whether adherence to recommended infection-control strategies resulted
in developing higher levels of distress cannot be clarified without interviewing the
respondents. Regardless of the cause, this distress may have been lessened with enhanced
education and continued reinforcement of the rationale for these measures and outreach
efforts to optimize coping with the stressful event.
This study has several limitations. The actual number of respondents is low compared
to the total number of persons who were placed into quarantine and therefore may not
be representative of the entire group of quarantined persons. However, lack of funding,
confidentiality of public health records, and an overloaded public health response
system limited sampling in this study. Furthermore, a self-selection effect may have
occurred with those persons who were experiencing the greatest or least levels of
distress responding to the survey. In addition, respondents required access to a computer
to respond, which suggests that they may be more educated and have higher socioeconomic
status than the overall group who were quarantined. They also had to be English speaking.
Recognizing these limitations, however, an anonymous Web-based method was chosen because
concerns about persons' confidentiality precluded us from access to their public health
records.
A Web-based format was chosen over random-digit dialing for both cost considerations
and time constraints. The project was initiated and completed without a funding source
soon after the outbreak period at a time when concerns about SARS were still a part
of daily life in Toronto. Obtaining as much information about the adverse effects
of quarantine as close to the event as possible was important because a study conducted
several months later would have been subject to the limitations of substantial recall
bias. If this study were to be repeated, a study design ensuring a more representative
selection of the population that used a combination of quantitative and qualitative
methods, including structured diagnostic interviews, would be recommended to overcome
these concerns. In the event of future outbreaks, a matched control group of persons
who were not quarantined should be considered because it would allow an assessment
of the distress experienced by the community at large.
Finally, we determined only the prevalence of symptoms of PTSD and depression in our
study population because these were the predominant psychological distresses that
were observed to be emerging in our SARS patient population (W.L.G., pers. comm.).
We also focused on symptoms of PTSD and depression because we believed that they would
be the most likely to cause illness and interfere with long-term functioning. Future
studies should assess persons for other psychological responses, including fear, anger,
guilt, and stigmatization. A standardized survey instrument that considers the full
spectrum of psychological responses to quarantine should be developed. In the event
of future outbreaks in which quarantine measures are implemented, a standardized instrument
would enable a comparison between the psychological responses to outbreaks of different
infectious causes and could be used to monitor symptoms over time.
Despite these limitations, the results of this survey allow for the generation of
hypotheses that require further exploration. Our data show that quarantine can result
in considerable psychological distress in the forms of PTSD and depressive symptoms.
Public health officials, infectious diseases physicians, and psychiatrists and psychologists
need to be made aware of this issue. They must work to define the factors that influence
the success of quarantine and infection control practices for both disease containment
and community recovery and must be prepared to offer additional support to persons
who are at increased risk for the adverse psychological and social consequences of
quarantine.
Appendix
Comments from survey respondents
Unmet informational needs:
1. Public health /employers:
a. Difficulty in access: "Called Public Health for 2 days. Got through 3 times; waited
on hold for hours, then got hung up on." (respondent # 131)
b. Failed expectations: "I was expecting someone from Public Health to check up on
me but never got a call except on my last day of quarantine." (respondent #126); "Nobody
told me anything. I was not contacted by health officials at all." (respondent# 99);
"My employer should have been more forthcoming." (respondent #7); "I was not called
by the hospital I worked at. I saw the quarantine on the news and spent a whole day
trying to get through to my unit." (respondent #40)
c. Lack of support: "I was looking for more support from the health care professionals.
They left me in the dark to deal with this." (respondent #22)
2. Nature of information:
a. Details re: infection control: "I have since learned that there are a lot of precautions
that no one ever told me about." (respondent #81)
b. Inconsistencies: "Information was not always the same. Many inconsistencies." (respondent
#66)
c. Timing: "Information was given too late, as I started 1 week after exposure. Unacceptable!"
(respondent #27)
d. Specific issues:
i. Children: "Nobody can tell me exactly where my children would be arranged to go
in case I got SARS myself. I was very panicked at that time and my husband was admitted
that time because of the SARS." (respondent # 78)
ii. Onset of symptoms: "What symptoms were considered serious and what to do when
I experienced those symptoms." (respondent # 21); "I was mildly alarmed to realize
that I didn't know what to do if I actually did develop symptoms of SARS." (respondent
# 111)
iii. Prognosis of SARS: "Most of the really important info is largely unknown" (respondent
#53); "Prognosis for SARS, how many have recovered, what health problems recovered
patients still have." (respondent #8I)
iv. Mode of transmission: "If airborne what were the chances of contracting the disease…
MD unable to answer." (respondent #90)