Probable Post-Traumatic Stress Disorder and Its Predictors in Disaster-Bereaved Survivors: A Longitudinal Study After the Sichuan Earthquake

Archives of Psychiatric Nursing xxx (2015) xxx–xxx

Contents lists available at ScienceDirect

Archives of Psychiatric Nursing journal homepage: www.elsevier.com/locate/apnu

Probable Post-traumatic Stress Disorder and Its Predictors in Disaster-Bereaved Survivors: A Longitudinal Study After the Sichuan Earthquake Xiuying Hu a,⁎,1, Xiaoyi Cao b,1, Heng Wang a, Qian Chen a, Maoqiong Liu c, Aiko Yamamoto d a

Department of Nursing, West China Hospital/West China School of Medicine, Sichuan University, Chengdu, Sichuan Province, China Hemodialysis Center, Department of Nephrology, West China Hospital/West China School of Medicine, Sichuan University, Chengdu, Sichuan Province, China c Department of Nursing, Dujiangyan Second People's Hospital, Dujiangyan, Sichuan Province, China d Research Institute of Nursing Care for People & Community, University of Hyogo, Japan b

a b s t r a c t This study examined the trajectory of probable PTSD prevalence and severity, and analyzed the predictors for PTSD severity in bereaved survivors at 6 months and 18 months after the 2008 Sichuan earthquake. This was a longitudinal study with 226 bereaved survivors sampled at 6 months and 18 months post-earthquake. The instrument used in the study was the revised version of the Impact of Event Scale. The results showed that the prevalence of probable PTSD in bereaved survivors decreased significantly from 38.9% at 6 months to 16.8% at 18 months post-earthquake. Loss of a child, being directly exposed to the death of family members and property loss during the earthquake, and mental health services utilization after the earthquake were significant predictors for PTSD severity at both assessments. These findings can contribute to post-disaster psychological rescue work. The bereaved survivors at high risk for more severe PTSD should be particularly targeted. © 2015 Elsevier Inc. All rights reserved.

Natural disasters such as earthquakes, hurricanes and floods can lead to short-term and long-term physical and mental disorders such as somatic symptoms, insomnia, anxiety, depression and posttraumatic stress disorder (PTSD) in disaster survivors (Heo et al., 2008; Mason, Andrews, & Upton, 2010; Papanikolaou, Adamis, Mellon, & Prodromitis, 2011; Zhang, Shi, Wang, & Liu, 2011). Among these, PTSD is regarded as one of the most common and severe psychological symptoms and can result in a range of psychiatric and behavioral problems such as suicidal ideation, sleep problems, aggressive and addictive behaviors, and poor health-related quality of life (Beaudoin, 2011; Scott, Lapré, Marsee, & Weems, 2014; Wen, Shi, Li, Yuan, & Wang, 2012; Ying et al., 2015; Zhou, Wu, An, & Fu, 2014). PTSD is defined as a series of symptoms that is composed of disturbing recurring flashbacks, avoidance or numbing of memories of the event, and hyperarousal that continue for more than a month after the occurrence of a traumatic event (American Psychiatric Association, 2013). Current evidences showed that PTSD symptoms are common in disaster survivors (Altindag, Ozen, & Sir, 2005; Wu et al., 2006; Xu & Song, 2011). Moreover, the findings from previous longitudinal studies have demonstrated the great variability in the prevalence of PTSD symptoms among disaster survivors as time passed. For instance,

⁎ Corresponding Author: Xiuying Hu. Department of Nursing, West China Hospital/ West China School of Medicine, Sichuan University, No 37 Guoxue Road, Chengdu, Sichuan Province, China. E-mail addresses: [email protected] (X. Hu), [email protected] (X. Cao). 1 Xiuying Hu and Xiaoyi Cao contributed to this paper equally.

Altindag et al. (2005) showed that the prevalence of PTSD at 1 month after the Turkey earthquake was twice as much as that at 13 months (Altindag et al., 2005). Jia et al. (2013) reported that no significant change was found on the prevalence of PTSD (ranging from 12.4% to 10.7%) in child survivors at 15 months and 36 months after the Sichuan earthquake (Jia et al., 2013). Similarly, the prevalence of PTSD in secondary school students was the highest (36.5%) at 3 months after the 2008 Sichuan earthquake, then, declined gradually from 24.8% to 22.2% at 9 months and 12 months after the earthquake (Hou et al., 2011). In addition, it was reported that, as compared to the PTSD prevalence at 3 months after the Sichuan earthquake (16.9%), the estimated rate of PTSD in adolescents declined significantly at 17 months postearthquake (12.1%) (Zhang, Liu, Jiang, Wu, & Tian, 2014). Bereavement related to natural disasters can result in a range of serious short-term and long-lasting psychiatric disorders in disasteraffected populations. Being bereaved during disasters has been demonstrated as a risk factor significantly related to the occurrence of PTSD in disaster survivors. For example, Cheng et al. (2015) reported that bereaved survivors were 5.51 times more likely to report PTSD than non-bereaved survivors at 1 year after the Sichuan earthquake (Cheng et al., 2015). The prevalence of PTSD in bereaved Norwegians at 2 years after the 2004 Tsunami was 34.4% (Kristensen, Weisaeth, & Heir, 2009). Similarly, Chan et al. (2012) found that the rate of PTSD in bereaved survivors (65.6%) at 1 year after the 2008 Sichuan earthquake was significantly higher than those in non-bereaved survivors (27.1%), and loss of a child was a significant predictor for psychopathological symptoms (Chan et al., 2012). Furthermore, the findings from previous

http://dx.doi.org/10.1016/j.apnu.2015.08.011 0883-9417/© 2015 Elsevier Inc. All rights reserved.

Please cite this article as: Hu, X., et al., Probable Post-traumatic Stress Disorder and Its Predictors in Disaster-Bereaved Survivors: A Longitudinal Study After the Sichuan ..., Archives of Psychiatric Nursing (2015), http://dx.doi.org/10.1016/j.apnu.2015.08.011

2

X. Hu et al. / Archives of Psychiatric Nursing xxx (2015) xxx–xxx

literatures indicated that known risk factors for PTSD in bereaved survivors included female gender, being directly exposed to the disaster, loss of a child, loss of a parent, loss of friends or neighbors, house damage or collapse, proximity to the epicenter, psychosocial stressors and initial feelings of guilt (Chan et al., 2011; Chan et al., 2012; Kristensen et al., 2009). On May 12, 2008, an 8.0-magnitude earthquake occurred in Sichuan province of China. As the second deadliest and strongest earthquake in China over the past 100 years, the Sichuan earthquake has resulted in 69,227 deaths, 374,643 individuals injured and 17,923 individuals missing in the disaster-exposed areas (Central People's Government of the People's Republic of China, 2008). Many disaster survivors lost their close family members, and bereavement is a devastating experience for bereaved survivors. Although previous studies have addressed the high prevalence of PTSD in bereaved survivors after disasters, limited longitudinal studies have examined the trajectories of PTSD symptoms and the longitudinal changes in predictors for PTSD symptoms in bereaved individuals after disasters. Such information is important for health care professionals for early intervention to prevent or reduce psychiatric disorders in bereaved survivors. Therefore, the aims of our study were to examine the longitudinal changes in probable PTSD prevalence and severity, and to explore the longitudinal changes in associated predictors for probable PTSD symptoms in bereaved survivors at 6 months and 18 months after the 2008 Sichuan earthquake. METHODS Ethical approval was obtained from the Human Subjects Ethics Subcommittee of Sichuan University prior to the study. Written informed consent was obtained from each participant who was assured of anonymity, confidentiality and their rights to withdraw from the study at any time. Participants A multi-stage stratified sampling method was used in our study. First, two cities were randomly selected from the 10 hardest-hit cities in the earthquake. Second, two villages were randomly chosen from each of the two selected cities. Third, two communities in each village were randomly selected. Finally, all the bereaved survivors were chosen in the selected communities. The randomization procedure was achieved by a computer random number generator according to the names of the selected cities, villages and communities which were arranged in alphabetical order independently. The inclusion criteria were as follows: (1) aged 18 and older; (2) personally experienced the earthquake; (3) lost biological family members during the earthquake such as spouse, children, parents, siblings, grandchildren and grandparents; (4) agreed to participate in the study. Participants who had visual or hearing impairment, or cognitive impairment were excluded. Cognitive impairment was evaluated by the Chinese Mini-Mental State Examination (MMSE). Three cut-off scores were used according to the different educational levels of the participants with a score b 17 (illiteracy), b20 (primary school), and b 24 (junior high school or above) suggesting cognitive impairment (Zhang et al., 1990). In conclusion, 18 potential participants were excluded due to their visual or hearing impairment, and 24 potential participants were excluded according to their MMSE scores. Of 308 potential participants who were eligible to take part in the study, 266 participants volunteered to complete the survey (86.4%).

score the severity of each symptom over the past 7 days on a 5-point Likert scale ranging from 0 (“not at all”) to 4 (“extremely”) with higher scores indicating more severe post-traumatic stress symptoms. Previous studies show a high degree of inter-correlation of the 3 subscales (r ranges from 0.52 to 0.87) (Creamer, Bell, & Failla, 2003). Cronbach's alpha of each subscale ranges from 0.79 to 0.94, and the test–retest reliability ranges from 0.89 to 0.94 (Weiss & Marmar, 1997). Participant with a mean IES-R score greater than 1.5 or a total IES-R score over 33 is classified as a probable PTSD case (Creamer et al., 2003). The Chinese version has been demonstrated as a reliable and valid measure (Guo, Xin, & Geng, 2007). In the present study, Cronbach's alpha for each subscale ranged from 0.87 to 0.92. In addition, demographic variables in the study included gender, age, marital status and educational level. Earthquake-exposed variables included property loss, personal physical injury, being directly exposed to the death of family members or not, and types of dead family members during the earthquake (spouse, children, parents, siblings, grandchildren and grandparents). Post-earthquake variables included house conditions, self-reported health status and mental health services utilization (group intervention, family therapy, individual counseling or psychopharmacology treatments from health care professionals) after the earthquake. Data Collection Prior to the study, two research assistants each with a master's degree in medical science were selected and trained for the data collection procedure. Participants were told the importance and purposes of the study, and were requested to complete the questionnaires independently and anonymously according to their actual feelings after each written inform consent was obtained. As for the illiterate participants, the research assistants read the questions and answers and recorded their responses. With regard to those participants who could not complete the questionnaires due to physical injuries, the research assistants recorded their answers. These questionnaires were collected immediately after completion and checked for incomplete items. The data collection process was conducted at 6 months (November 2008) and 18 months (November 2009) after the earthquake, respectively. Data Analysis The statistical analysis software used in the study was SPSS 16.0 (SPSS Inc., Chicago, IL, USA). Continuous variables were described as means with standard deviations, and categorical variables were presented as frequencies with percentages. Chi-square tests (Fisher's exact tests) or two independent samples t-tests were used to evaluate differences in demographic data, and earthquake-exposed and postearthquake variables between the followed up participants and the missed participants. Chi-square tests were performed to identify difference in probable PTSD prevalence between two waves of survey. The multivariate linear regression analyses were used to detect significant predictive effects of demographic characteristics, earthquake-exposed variables and postearthquake variables on PTSD severity at both assessments. Among these independent variables, types of dead family members in the earthquake were included in the regression equation as dummy variables (reference group: other family members: grandparents, siblings and grandchildren). P value b 0.05 was considered statistically significant (two-tailed). RESULTS

Measures Characteristics of Participants The Revised Version of the Impact of Event Scale (IES-R) (Weiss & Marmar, 1997) The measure is generally used to evaluate the symptoms of probable post-traumatic stress disorder. It is composed of 22 items and 3 dimensions: intrusion (8 items), avoidance (8 items) and hyperarousal symptoms (6 items) (Weiss & Marmar, 1997). Participants are required to

During the first assessment, 266 subjects were investigated at 6 months after the earthquake. Then, 40 of 266 subjects (15.0%) dropped out during the second assessment. Dropouts can be ascribed to the poor compliance to remain in the study (14 subjects), to the relocation to another place (18 subjects), and to death of the participants (8

Please cite this article as: Hu, X., et al., Probable Post-traumatic Stress Disorder and Its Predictors in Disaster-Bereaved Survivors: A Longitudinal Study After the Sichuan ..., Archives of Psychiatric Nursing (2015), http://dx.doi.org/10.1016/j.apnu.2015.08.011

X. Hu et al. / Archives of Psychiatric Nursing xxx (2015) xxx–xxx

subjects). In conclusion, 226 subjects (85.0%) completed the two assessments. No statistically significant differences were found in demographic characteristics, earthquake-exposed variables and post-earthquake variables between the subjects who completed the both assessments and those who did not (P N .05) (Table 1). Of the 226 subjects in the present study, 42.5% were male, and 57.5% were female. The mean age was 46.83 years (SD = 15.58) ranging from 18 to 82. The majority of the respondents were married (64.6%), and most of the respondents have graduated from junior high school and below (83.2%). During the earthquake, 166 respondents experienced property loss (73.5%). Twelve respondents were physically injured (10.6%) in the earthquake. Moreover, as for the types of dead family members in the earthquake, 18 respondents lost their spouse (15.9%), 53 respondents lost their children (46.9%). In addition, 72.7% of the respondents lived in shelters or temporary houses after the earthquake, and 57.8% of the respondents reported poor health status. Approximately half of the respondents reported that they have obtained mental health service (42.5%) after the earthquake (Table 1).

Table 1 Demographic Characteristics, and Earthquake-Exposed and Post-Earthquake Variables in Bereaved Survivors.

Variables Demographic characteristics Age (years, M ± SD) Gender Male Female Marital status Single (unmarried/divorced/ widowed) Married Educational level Primary school and below Junior high school Senior high school and above Earthquake-exposed variables Property loss No Yes Personal physical injury No Yes Types of dead family members Spouse Children Parents Other (siblings, grandparent or grandchildren) Being directly exposed to the death of family members Yes No Post-earthquake variables House conditions Original house Shelter/Temporary house Self-evaluated health status Healthy Unhealthy Mental health service utilization Yes No ⁎ Fisher's exact tests.

Both assessing participants (N = 226)

Missing participants (N = 40)

N.

N.

Pert. (%)

t/χ2

Pert. (%)

46.83 15.58 44.93 17.84 0.604 0.677 96 42.5 20 50.0 130 57.5 20 50.0 0.110 80 35.4 13 32.5 146

64.6

27

P value

0.547 0.461

0.847

3.665 38.1 45.1 16.8

15 13 12

37.5 32.5 30.0

60 166

26.5 73.5

6 34

15.0 85.0

202 24

89.4 10.6

35 5

87.5 12.5

36 106 34 50

15.9 46.9 15.0 22.1

7 14 7 12

17.5 35.0 17.5 30.0

15 25

3.481

0.503

0.254

0.756

3.011

0.222

37.5 62.5

64 162

27.3 72.7

15 25

37.5 62.5

100 126

44.2 57.8

19 21

47.5 52.5

130 96

57.5 42.5

17 23

57.5 42.5

Predictors for PTSD Severity in Bereaved Survivors The results of multivariate linear regression analysis indicated that, with regard to earthquake-exposed variables, loss of a child during the disaster was the strongest significant predictor for PTSD severity in bereaved survivors at 6 months post-earthquake (β = .279, P b .05), followed by being directly exposed to the death of family members (β = .229, P b .05) and property loss (β = .198, P b .05). As for postearthquake variables, bereaved survivors who lived in shelters or temporary houses at 6 months post-earthquake reported significantly higher IES-R total scores as compared to those who lived in their original houses (β = .221, P b .05). Meanwhile, self-reported health status and mental health service utilization were significant predictors for PTSD severity among bereaved survivors at 6 months after the disaster (β = .225, P b .05; β = −.181, P b .05) (Table 3). The results also indicated that, at 18 months post-earthquake, mental health service utilization was the strongest significant protective factor for the severity of PTSD symptoms in bereaved survivors (β = −.281, P b .05). Meanwhile, the predictive effects of loss of a child during the disaster (β = .217, P b .05), being directly exposed to the death of family members (β = .196, P b .05) and property loss (β = .181, P b .05) on PTSD severity were still statistically significant (P b .05). However, the predictive effects of self-reported health status and house conditions post-earthquake were not statistically significant (β = .022, P N .05; β = .106, P N .05) (Table 3).

Longitudinal Changes in Probable PTSD Prevalence and Severity in Bereaved Survivors

0.106⁎ 0.772

34.5 65.5

The results indicated that scores for intrusion, avoidance and hyperarousal symptoms subscales, as well as the total IES-R score in bereaved survivors at 18 months post-earthquake were significantly lower compared to those at 6 months (t = 2.522, P b .05; t = 3.038, P b .05; t = 5.036, P b .001; t = 3.782, P b .001) (Table 2). Moreover, the findings showed that the rate of probable PTSD in bereaved survivors after the earthquake decreased significantly from 38.9% (6 months) to 16.8% (18 months) (χ 2 = 13.755, P b .001) (Table 2).

0.160

4.838⁎ 0.089

39 74

Longitudinal Changes in Probable PTSD Prevalence and Severity in Bereaved Survivors

DISCUSSION

67.5

88 102 38

3

0.126

0.854

0.000

1.000

Our study found that the prevalence of probable PTSD in bereaved survivors at 18 months after the 2008 Sichuan earthquake (16.8%) was significantly lower than those at 6 months (38.9%), which is similar to the findings of previous studies on disaster survivors presenting a positive tendency (Karamustafalioglu et al., 2006; Pietrzak et al., 2012; Zhang et al., 2012). Karamustafalioglu et al. (2006) reported that the prevalence of PTSD among adult survivors was 26.9% at 6 to 10 months and decreased significantly to 10.6% at 18 to 20 months following the Turkey earthquake (Karamustafalioglu et al., 2006). Pietrzak Table 2 Longitudinal Changes in the Prevalence and Severity of Probable PTSD Symptoms Among Bereaved Survivors (N = 226). 6-month

18-month

Variables

M

SD

M

SD

IES-R Intrusion Avoidance Hyperarousal symptoms Total score Probable PTSD Yes No

11.04 11.16 10.33 32.53 Freq. 44 69

5.84 5.94 5.74 16.79 Pert. (%) 38.9 61.1

9.47 9.14 7.07 25.68 Freq. 19 94

4.77 4.90 3.84 13.02 Pert. (%) 16.8 83.2

t value

P value

2.522 3.038 5.036 3.782 χ2 value 13.755

0.013 0.003 0.000 0.000 P value 0.000

Please cite this article as: Hu, X., et al., Probable Post-traumatic Stress Disorder and Its Predictors in Disaster-Bereaved Survivors: A Longitudinal Study After the Sichuan ..., Archives of Psychiatric Nursing (2015), http://dx.doi.org/10.1016/j.apnu.2015.08.011

4

X. Hu et al. / Archives of Psychiatric Nursing xxx (2015) xxx–xxx

Table 3 Predictors for PTSD Severity Among the Bereaved Survivors at 6 Months and 18 Months After the Earthquake (N = 226). 6-month β

18-month P value

β

Dependent variables

Independent variables

Total IES-R score

Demographic characteristics Gender 0.039 0.639 0.002 Age (years) 0.084 0.364 0.055 Marital status −0.093 0.299 −0.055 Educational level 0.060 0.523 0.065 Earthquake-exposed variables Property loss 0.198 0.046 0.181 Personal physical injury 0.049 0.579 0.059 Types of dead family members Spouse 0.192 0.051 0.092 Children 0.279 0.028 0.217 Parents 0.129 0.068 0.006 Other (reference group) Being directly exposed to the 0.229 0.021 0.196 death of family members Post-earthquake variables House 0.221 0.034 0.106 Self-evaluated health status 0.225 0.013 0.022 Mental health service −0.181 0.047 −0.281 utilization F 4.597 4.655 P value 0.000 0.000 0.473 0.376 R2 R2 change 0.343 0.295

P value 0.981 0.568 0.526 0.484 0.044 0.496 0.333 0.049 0.953

family structure and family dysfunction, and the presence of psychiatric distress (Cao, Jiang, Li, Hui, & Li, 2013; Cao et al., 2013). Cheng et al. (2015) demonstrated that bereaved survivors were 5.51 times more likely to report PTSD than non-bereaved survivors after the Sichuan earthquake (Cheng et al., 2015). Dell'OSso et al. (2011) found that there was a significant difference in PTSD prevalence between bereaved and non-bereaved subjects after the 2009 earthquake in Italy (Dell'OSso et al., 2011). These outcomes in our study confirm the facilitating effect of bereavement on psychiatric distress (Norris et al., 2002), and demonstrate that psychological disorders resulting from bereavement are more serious. These results also emphasize the necessity of establishing short-term and medium-term mental health recovery programs for alleviating PTSD severity among bereaved survivors after the 2008 Sichuan earthquake.

Predictors for PTSD Severity in Bereaved Survivors 0.038

0.349 0.806 0.005

NOTE. β: standardized regression coefficients derived from multiple hierarchical linear regression analysis. Variable code: gender (male = 0, female = 1), age (b40 = 0, ≥40 = 1), marital status (single = 0, married = 1), educational level (primary school and below = 0, junior high school = 1, senior high school and above =2), property loss (no = 0, yes = 1), personal physical injury (no = 0, yes =1), directly exposed to the death of family members (no = 0, yes = 1), post-earthquake house (original house = 0, shelter/temporary house = 1), self-evaluated health status (healthy = 0, unhealthy = 1), Mental health service utilization (no = 0, yes = 1).

et al. (2012) found that the prevalence of hurricane-related PTSD among the affected adults in the US were 6.9% and 2.5% at 5 to 9 months and 14 to 18 months after the Hurricane Ike, respectively (Pietrzak et al., 2012). Similarly, Zhang et al. (2012) demonstrated that the positive rate of PTSD symptoms in adolescents decreased significantly from 9.7% at the 6-month follow-up to 1.6% at the 18-month follow-up after the 2008 Sichuan earthquake (Zhang et al., 2012). The outcome in our study may be ascribed to the timely and effective mental health services and psychological relief programs implemented by the central and local governments and nongovernmental organizations in China (Chinese psychological Society, 2008). In addition, the possibility that psychiatric disorder can spontaneously improve as time passes is another explanation for our findings. However, because no previous study has examined the longitudinal changes in prevalence and severity of PTSD symptoms in bereaved survivors at short-term and mediumterm follow-ups after disasters, our findings cannot be compared with results from previous studies. Moreover, as compared to the PTSD prevalence among disaster survivors in previous studies, bereaved individuals' PTSD prevalence in our study at 6 months (38.9%) and 18 months (16.8%) after disasters were relatively higher, respectively (Piyasil et al., 2007; Zhang et al., 2012; Zhou et al., 2013). Zhang et al. (2012) reported that the prevalence of PTSD among adolescent survivors were 9.7% and 1.6% at 6 months and 18 months after the Sichuan earthquake (Zhang et al., 2012). Zhou et al. (2013) found that the prevalence of PTSD in adult survivors 6 months after the Sichuan earthquake was 15.6% (Zhou et al., 2013). Similarly, Piyasil et al. (2007) reported that, 18 months after the 2004 Hurricane Tsunami, the prevalence of PTSD among the affected children in Thailand was 10.4% (Piyasil et al., 2007). Natural disasters can lead to sudden and unpredictable damage to personal properties and human lives. Bereavement related to disasters can result in disequilibrium in

We found that loss of a child during the earthquake was the strongest significant predictor for PTSD severity among bereaved survivors at 6 months, and the predictive effect of loss of a child on the severity of PTSD was still significant at 18 months post-earthquake, which indicated that loss of a child had short-term and medium-term negative impacts on bereaved survivors' mental health. These outcomes in our study are similar to the findings of previous studies (Chan et al., 2011; Chan et al., 2012). Chan et al. (2012) found that loss of a child was a significant predictor for psychopathological symptoms in Chinese bereaved survivors at 8 months after the 2008 Sichuan earthquake (Chan et al., 2012). Kristensen et al. (2009) also reported that loss of a child significantly predicted PTSD severity in bereaved Norwegians at 2 years after the 2004 Tsunami disaster (Kristensen et al., 2009). Children are the major source of hope, joy, meaning and purpose in parents' lives in our modern society, and sudden loss of a child is devastating and heartbreaking (Hindmarch, 2009). Meanwhile, “one couple, one child” policy lasts for several years in China, and children play a key role in maintaining family linkage and generational continuity, and caring for their parents in their late years. Thus, sudden loss of a child can result in disrupted family structure and dysfunctional family functioning. Parents who lost their child may feel extremely hopeless, helpless and desperate. We also found that bereaved individuals who were directly exposed to the death of family members during the earthquake reported significantly higher PTSD scores than those who were not directly exposed at both assessments, which demonstrated the intensive and lasting negative impact of experiencing the death of family members on psychiatric disorders. The findings in our study are consistent with the outcomes of previous studies (Cao, Jiang, Li, Hui, et al., 2013; Chan et al., 2011; Chan et al., 2012). Bereaved survivors who directly witnessed the death of family members were exposed to the mutilated bodies and body parts, they often had feelings of guilt for their inability to save lives of their family members during the disaster and they should be responsible for the death of their family members. Moreover, consistent with the results of previous studies (Chan et al., 2011; Zhang et al., 2014), it was found that property loss during the earthquake was a significant risk factor for PTSD severity among bereaved survivors at 6 months and 18 months post-earthquake. The results of Chan et al. (2011) indicated that residential house damage or collapse were significant predictive factors for PTSD symptoms in Chinese adult survivors at 7 months after the Sichuan earthquake (Chan et al., 2011). It was found that property loss in adolescents at 17 months after the earthquake was a significant risk factor for PTSD severity (Zhang et al., 2014). Loss of personal property during disasters can lead to massive economic pressure in the family and has shortterm and medium-term negative effects on bereaved individuals' psychological well-being. Thus, long-lasting efforts to help survivors rebuilding and reinforcing their houses are needed.

Please cite this article as: Hu, X., et al., Probable Post-traumatic Stress Disorder and Its Predictors in Disaster-Bereaved Survivors: A Longitudinal Study After the Sichuan ..., Archives of Psychiatric Nursing (2015), http://dx.doi.org/10.1016/j.apnu.2015.08.011

X. Hu et al. / Archives of Psychiatric Nursing xxx (2015) xxx–xxx

In parallel with the previous studies (Boscarino, Adams, Stuber, & Galea, 2005; Xu & Deng, 2013), an important and interesting outcome in our study was that, mental health services utilization postearthquake was a significant predictor for PTSD severity among bereaved survivors at both assessments. Mental health services are public-funded or private therapy services organized within government departments of health or non-governmental organizations. Most are multidisciplinary teams including health care professionals who provide group intervention, family therapy, individual counseling or psychopharmacology treatments. Immediately after the 2008 Sichuan earthquake, central and local governments and nongovernmental organizations in China took a range of timely and effective measures to help disaster survivors deal with various physical and mental health problems, such as sending rescuers and medical care teams to the earthquake-affected areas, transferring the wounded to other provinces for medical treatment, establishing mental health services stations and psychological rescue training programs (Ministry of Civil Affairs of the People's Republic of China, 2008). These methods may be helpful to alleviate psychiatric disorders after disasters. In addition, we also found that mental health service utilization at the first evaluation had significant association with PTSD severity in bereaved survivors at 18 months post-earthquake, which demonstrated its lasting significant protective effect on PTSD symptoms. These results may be attributed to their basic psychological rescue and relief knowledge and skills learned from mental health professionals. Furthermore, it was found that female gender was not a significant contributor to PTSD severity, which is not in line with the results of previous studies (Chan et al., 2011; Kristensen et al., 2009). Possible explanation for the observed data in our study may be attributed to the smaller sample size. In addition, bereaved parents are permitted to have another baby after the earthquake under “one couple, one child” policy in China. The birth of another baby can bring hope and enhance emotional connection among family members, and reduce the occurrence of PTSD symptoms in female survivors. Limitations Several limitations were noted in the present study. First, the revised version of the impact of event scale is a self-reported measure, which may result in the over- or under-estimation of our results. Second, our study examined the short-term and medium-term effects of Sichuan earthquake on probable PTSD prevalence and severity; future studies are needed to explore the long-lasting impact. Third, although our study analyzed the associations between certain demographic data, earthquake-exposed variables and post-earthquake variables and PTSD symptoms at two different time point, other factors such as family functioning, perceived social support and coping strategies may also be predictors for PTSD symptoms in disaster-affected populations. Finally, participants of our study lived in a hardest-hit region, which may limit the representativeness of our samples. Further studies are needed to recruit diverse samples from various earthquake-exposed areas. CONCLUSIONS To our knowledge, this is the first study to examine the longitudinal course of probable PTSD prevalence and severity, and to analyze the longitudinal changes in predictors for PTSD severity in disaster-bereaved survivors at 6 months and 18 months after the 2008 Sichuan earthquake. The prevalence of probable PTSD at 18 months in bereaved individuals decreased significantly as compared to those at 6 months postearthquake. Earthquake-related factors such as loss of a child, being directly exposed to the death of family members and serious property loss during the earthquake were significantly related to more severe PTSD symptoms at both assessments among bereaved survivors. As for post-earthquake variables, living in shelters or temporary houses, poor self-reported health status and mental health services utilization were

5

significant predictors for PTSD severity at 6 months. The findings support focusing on post-earthquake efforts for psychiatric nurses to provide effective and sustainable mental health services such as group intervention, family therapy, individual counseling or psychopharmacology treatments for bereaved survivors, especially for those at high risk for PTSD symptoms. AUTHOR CONTRIBUTIONS Conceived and designed the experiments: XYH XYC HW QC MQL AY. Performed the experiments: XYH XYC HW QC. Analyzed the data: XYH XYC HW QC MQL AY. Wrote the paper: XYH XYC HW QC MQL AY. Interpretation of data: XYH XYC HW QC MQL AY. ETHICAL APPROVAL Ethical approval was obtained from the Human Subjects Ethics Subcommittee of Sichuan University. Written informed consent was obtained from each participant. COMPETING INTEREST The author(s) declare that they have no competing interests. Acknowledgment The authors thank for expert panelists and all participants. References Altindag, A., Ozen, S., & Sir, A. (2005). One-year follow-up study of posttraumatic stress disorder among earthquake survivors in Turkey. Comprehensive Psychiatry, 46, 328–333. American Psychiatric Association (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Publishing. Beaudoin, C. E. (2011). Hurricane Katrina: Addictive behavior trends and predictors. Public Health Reports, 126, 400–409. Boscarino, J. A., Adams, R. E., Stuber, J., & Galea, S. (2005). Disparities in mental health treatment following the World Trade Center Disaster: Implications for mental health care and health services research. Journal of Trauma Stress, 18, 287–297. Cao, X., Jiang, X., Li, X., Hui, L. M., & Li, R. (2013a). Family functioning and its predictors among disaster bereaved individuals in China: Eighteen months after the Wenchuan earthquake. PLoS One, 8, e60783. Cao, X., Jiang, X., Li, X., Hui, L. M., Li, R., & Dou, X. M. (2013b). Perceived family functioning and depression in bereaved parents in China after the 2008 Sichuan earthquake. Archives of Psychiatric Nursing, 27, 204–209. Central People’s Government of the People’s Republic of China (2008). Up to June 9, there were 69,142 individuals dead in Wenchuan earthquake. Available at: http://www. gov.cn/jrzg/2008-06/09/content_1010832.htm Chan, C. L., Wang, C. W., Ho, A. H., Qu, Z. Y., Wang, X. Y., Ran, M. S., ... Zhang, X. L. (2012). Symptoms of posttraumatic stress disorder and depression among bereaved and non-bereaved survivors following the 2008 Sichuan earthquake. Journal of Anxiety Disorders, 26, 673–679. Chan, C. L., Wang, C. W., Qu, Z., Lu, B. Q., Ran, M. S., Ho, A. H., et al. (2011). Posttraumatic stress disorder symptoms among adult survivors of the 2008 Sichuan earthquake in China. Journal of Trauma Stress, 24, 295–302. Cheng, Z., Ma, N., Yang, L., Agho, K., Stevens, G., Raphael, B., ... Yu, X. (2015). Depression and posttraumatic stress disorder in temporary settlement residents 1 year after the Sichuan earthquake. Asia Pacific Journal of Public Health, 27, 1962–1972. Chinese psychological Society (2008). Mental health services after the 2008 Wenchuan earthquake. Available at: http://www.cpsbeijing.org/cn/ztnews02.php?zhuantiid= 21&sortid=16&id=39 Creamer, M., Bell, R., & Failla, S. (2003). Psychometric properties of the impact of event scale – Revised. Behaviour Research and Therapy, 41, 1489–1496. Dell'OSso, L., Carmassi, C., Massimetti, G., Conversano, C., Daneluzzo, E., Riccardi, I., ... Rossi, A. (2011). Impact of traumatic loss on post-traumatic spectrum symptoms in high school students after the L'Aquila 2009 earthquake in Italy. Journal of Affective Disorders, 134, 59–64. Guo, S. R., Xin, Z. Q., & Geng, L. N. (2007). Reliability and validity of the Chinese version of the Impact of Event Scale – Revised. Chinese Clinical Psychology, 1, 15–17. Heo, J. H., Kim, M. H., Koh, S. B., Noh, S., Park, J. H., Ahn, J. S., ... Min, S. (2008). A prospective study on changes in health status following flood disaster. Psychiatry Investigation, 5, 186–192. Hindmarch, C. (2009). On the death of a child. New York: Radcliffe Publishing. Hou, F. S., Li, T., Li, J., Hu, X. Q., Liu, Z. Y., & Yuan, P. (2011). The effects of demographic features on differences in sensitivity between PCL-C and SCL-90 scores in a follow-up study in secondary school students in the Wenchuan earthquake region. Biomedical and Environmental Sciences, 24, 642–648.

Please cite this article as: Hu, X., et al., Probable Post-traumatic Stress Disorder and Its Predictors in Disaster-Bereaved Survivors: A Longitudinal Study After the Sichuan ..., Archives of Psychiatric Nursing (2015), http://dx.doi.org/10.1016/j.apnu.2015.08.011

6

X. Hu et al. / Archives of Psychiatric Nursing xxx (2015) xxx–xxx

Jia, Z., Shi, L., Duan, G., Liu, W., Pan, X., Chen, Y., ... Tian, W. (2013). Traumatic experiences and mental health consequences among child survivors of the 2008 Sichuan earthquake: A community-based follow-up study. BMC Public Health, 13, 104. Karamustafalioglu, O. K., Zohar, J., Güveli, M., Ga, l. G, Bakim, B., Fostick, L., ... Sasson, Y. (2006). Natural course of posttraumatic stress disorder: A 20-month prospective study of Turkish earthquake survivors. Journal of Clinical Psychiatry, 67, 882–889. Kristensen, P., Weisaeth, L., & Heir, T. (2009). Psychiatric disorders among disaster bereaved: An interview study of individuals directly or not directly exposed to the 2004 tsunami. Depression and Anxiety, 26, 1127–1133. Mason, V., Andrews, H., & Upton, D. (2010). The psychological impact of exposure to floods. Psychology Health Medicine, 15, 61–73. Ministry of Civil Affairs of the People’s Republic of China (2008). Emergency assistance was provided by central and local governments immediately after the Wenchuan earthquake. Available at: http://www.mca.gov.cn/article/zwgk/mzyw/200805/ 20080500014264.shtml Norris, F. H., Friedman, M. J., Watson, P. J., Byrne, C. M., Diaz, E., & Kaniasty, K. (2002). 60. 000 disaster victims speak: Part 1. An empirical review of the empirical literature, 1981–2001. Psychiatry, 65, 207–239. Papanikolaou, V., Adamis, D., Mellon, R. C., & Prodromitis, G. (2011). Psychological distress following wildfires disaster in a rural part of Greece: A case-control population-based study. International Journal of Emergency Mental Health, 13, 11–26. Pietrzak, R. H., Tracy, M., Galea, S., Kilpatrick, D. G., Ruggiero, K. J., Hamblen, J. L., ... Norris, F. H. (2012). Resilience in the face of disaster: Prevalence and longitudinal course of mental disorders following hurricane Ike. PLoS One, 7, e38964. Piyasil, V., Ketuman, P., Plubrukarn, R., Jotipanut, V., Tanprasert, S., Aowjinda, ... Thaeeromanophap, S. (2007). Post traumatic stress disorder in children after tsunami disaster in Thailand: 2 years follow-up. Journal of The Medical Association of Thailand, 90, 2370–2376. Scott, B. G., Lapré, G. E., Marsee, M. A., & Weems, C. F. (2014). Aggressive behavior and its associations with posttraumatic stress and academic achievement following a natural disaster. Journal of Clinical Child Adolescent Psychology, 43, 43–50. Weiss, D. S., & Marmar, C. R. (1997). The impact of Event Scale-Revised. In J. P. Wilson, & T. M. Keane (Eds.), Assessing psychological trauma and PTSD. New York: Guilford Press.

Wen, J., Shi, Y. K., Li, Y. P., Yuan, P., & Wang, F. (2012). Quality of life, physical diseases, and psychological impairment among survivors 3 years after Wenchuan earthquake: A population based survey. PLoS One, 7, e43081 (13). Wu, H. C., Chou, P., Chou, F. H., Su, C. Y., Tsai, K. Y., Ou-Yang, W. C., ... Chen, M. C. (2006). Survey of quality of life and related risk factors for a Taiwanese village population 3 years post-earthquake. The Australian and New Zealand Journal of Psychiatry, 40, 355–361. Xu, J., & Deng, Y. (2013). Mental health service use one year after China 5.12 earthquake: Relationship with post-traumatic stress disorder among survivors. Journal of Mental Health, 22, 509–518. Xu, J., & Song, X. (2011). Posttraumatic stress disorder among survivors of the Wenchuan earthquake 1 year after: Prevalence and risk factors. Comprehensive Psychiatry, 52, 431–437. Ying, L., Chen, C., Lin, C., Greenberger, E., Wu, X., & Jiang, L. (2015). The relationship between posttraumatic stress symptoms and suicide ideation among child survivors following the Wenchuan earthquake. Suicide Life Threat Behavior, 45, 230–242. Zhang, M. Y., Katzman, R., Salmon, D., Jin, H., Cai, G. J., Wang, Z. Y., ... Levy, P. (1990). The prevalence of dementia and Alzheimer's disease in Shanghai, China: Impact of age, gender, and education. Annals of Neurology, 27, 428–437. Zhang, W., Liu, H., Jiang, X., Wu, D., & Tian, Y. (2014). A longitudinal study of posttraumatic stress disorder symptoms and its relationship with coping skill and locus of control in adolescents after an earthquake in China. PLoS One, 9, e88263. Zhang, Z., Shi, Z., Wang, L., & Liu, M. (2011). One year later: Mental health problems among survivors in hard-hit areas of the Wenchuan earthquake. Public Health, 125, 293–300. Zhang, Z., Ran, M. S., Li, Y. H., Ou, G. J., Gong, R. R., Li, R. H., ... Fang, D. Z. (2012). Prevalence of post-traumatic stress disorder among adolescents after the Wenchuan earthquake in China. Psychology Medicine, 42, 1687–1693. Zhou, X., Kang, L., Sun, X., Song, H., Mao, W., Huang, X., et al. (2013). Prevalence and risk factors of post-traumatic stress disorder among adult survivors six months after the Wenchuan earthquake. Comprehensive Psychiatry, 54, 493–499. Zhou, X., Wu, X., An, Y., & Fu, F. (2014). Longitudinal relationships between posttraumatic stress symptoms and sleep problems in adolescent survivors following the Wenchuan earthquake in China. PLoS One, 9, e104470.

Please cite this article as: Hu, X., et al., Probable Post-traumatic Stress Disorder and Its Predictors in Disaster-Bereaved Survivors: A Longitudinal Study After the Sichuan ..., Archives of Psychiatric Nursing (2015), http://dx.doi.org/10.1016/j.apnu.2015.08.011