Transcultural Psychiatry 2015, Vol. 52(5) 594–615 ! The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1363461515569756 tps.sagepub.com

Article

A community-based study of the relationship between somatic and psychological distress in Hong Kong Sing Lee The Chinese University of Hong Kong

Candi MC Leung The Chinese University of Hong Kong

Kathleen PS Kwok The Chinese University of Hong Kong

King Lam Ng The University of Hong Kong

Abstract Although the predominantly somatic presentation of distress has been used to explain low rates of emotional illnesses and health service use in Chinese communities, this concept of somatization has not been examined by concurrently studying the profile of somatically and psychologically distressed Chinese individuals. A random populationbased sample of 3014 adults underwent a structured telephone interview that examined their sociodemographic characteristics, somatic distress (Patient Health Questionnaire15, PHQ-15), non-specific psychological distress (Kessler Scale-6, K6), health service use, and functional impairment. Four groups of individuals identified by PHQ-15 and K6 cut-off scores were compared. Results showed that PHQ-15 and K6 scores were positively correlated. The large majority of respondents (85.9%) reported both somatic and psychological distress. The proportions of Low Distress Group, Somatically Distressed Group, Psychologically Distressed Group, and Mixed Distress Group were 69.2%, 5.0%, 15.8%, and 10.0%, respectively. Specific age range, male gender, greater family income, higher education level, and retirement were associated with decreased odds of somatic and/or psychological distress. Although psychological distress best predicted impairment, somatic distress best predicted health service use. Mixed distress predicted most impairment and health service use. Thus, psychological distress and

Corresponding author: Sing Lee, Director, Hong Kong Mood Disorders Center, 7A, Block E, Staff Quarters, Prince of Wales Hospital, Shatin, N.T., Hong Kong. Email: [email protected]

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somatic distress commonly coexist across Chinese sociodemographic groups. This speaks against the conventional notion of somatization and is consistent with recent findings of a higher prevalence of emotional illnesses in Chinese people. That psychologically distressed individuals are more impaired but less inclined to seek help than somatically distressed individuals may partly explain low levels of help-seeking for mental disorders found in epidemiological studies. Keywords Chinese, help-seeking, impairment, psychological distress, somatic symptoms, somatization

Introduction Somatization is a multi-faceted construct (Kirmayer & Young, 1998) that can be studied across as well as within cultural groups. Recent cross-national studies of group differences in somatic and psychological symptoms reporting indicated that the somatization effect can be understood as a relative difference between cultural groups (Parker, Cheah, & Roy, 2001; Ryder et al., 2008; Yen, Robins, & Lin, 2000). Thus, Ryder and Chentsova-Dutton (2012) noted that Chinese somatization was a matter of symptom emphasis, in that Chinese people were more likely to acknowledge somatic symptoms than their Western counterparts for various cultural reasons. Within the Chinese cultural group, somatization has also been understood as the predominantly or exclusively somatic presentation of distress at the level of individuals (Kirmayer & Robbins, 1991). With respect to this approach, there has been an enduring belief that Chinese people are particularly prone to exhibiting somatic distress and denying psychological distress (Hsu & Folstein, 1997; Kleinman, 1982). This notion of somatization has been routinely used to explain the community and clinical epidemiological findings of low rates of common emotional illnesses, such as depression, in Chinese people (Guo, Tsang, Li, & Lee, 2011; Hsu & Folstein, 1997). However, the empirical support for this explanation is mixed. Various studies across the decades have shown that somatic symptoms were common among Chinese patients with mental health problems in primary and tertiary care settings in Chinese communities. For example, 70%–88% of psychiatric outpatients initially presented with somatic complaints in the absence of dysphoric affect (Kleinman, 1977; Tseng, 1975). High rates of a reportedly culturespecific somatic syndrome of neurasthenia were also found in clinical (Lee et al., 2000) and community studies (Zhang, 1989). These findings suggest that the somatic expression of distress is dominant in Chinese societies. This somatic emphasis is believed to contribute to very low rates of help-seeking for emotional illnesses (Lee et al., 2010). Nonetheless, there is evidence against this notion of Chinese somatization. The somatic presentation of distress has repeatedly been found to be common in a

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variety of both Western and non-Western communities (Kirmayer & Young, 1998; Simon, VonKorff, Piccinelli, Fullerton, & Ormel, 1999; Zhou et al., 2011). Although the use of restrictive samples and dissimilar measurement tools has made it difficult to compare somatization cross-nationally, a recent populationbased study (Lee, Ma, & Tsang, 2011) suggested that the prevalence and profile of 15 kinds of commonly experienced somatic distress in the general population of Hong Kong were mostly similar to those of their Western counterparts (Kroenke, Spitzer, & Williams, 2002). Moreover, recent studies have found, by and large, comparable rates of depression and anxiety disorders in Chinese and Western communities (Hu et al., 2009; Lee, Tsang, & Kwok, 2007; Phillips et al., 2009). This suggests that psychological distress may be more common in Chinese groups than previously thought. One major methodological limitation of the previous studies on Chinese somatization is that they did not concurrently measure somatic and psychological distress at the level of individuals. These studies therefore did not directly demonstrate that the presence of somatic distress was accompanied by a relative absence of psychological distress (Isaac et al., 1995; Zhang, 1989). Likewise, recent studies on psychological distress did not examine how emotionally distressed Chinese people might experience somatic distress (Lee et al., 2007; Phillips et al., 2009). This is undesirable because somatic distress may only be the initial mode of expressing distress among Chinese people. Moreover, psychological distress in Chinese people might be readily reported when facilitative methods of symptom elicitation are used (Guo et al., 2011; Kleinman, 1982; Yeung, Chang, Gresham, Nierenberg, & Fava, 2004). At this stage, the relationship between mode of distress expression and low rates of help-seeking for emotional illnesses in Chinese people remains unclear. The evidence briefly reviewed above argues against a simple picture of either somatization or psychologization in Chinese people. It suggests a more complex picture in which somatic and psychological distress may lie on a continuum and coexist in different degrees across groups of individuals. Although previous cross-national primary care studies suggested that a mixed presentation of somatic and psychological symptoms was common (Simon, Gater, Kisely, & Piccinelli, 1996; Simon et al., 1999), the extent to which Chinese people in Chinese community settings somatize distress is unknown. Those studies typically oversampled somatically distressed individuals by using outpatients from primary and tertiary psychiatric settings. Such clinical samples were often biased by help-seeking behavior. For example, higher-income, educated and younger people were more likely to seek psychiatric treatment (Wang et al., 2005). There was one community study on somatization in which Mak and Zane (2004) found that the reporting of somatic symptoms by Chinese Americans was comparable to that of Russian immigrants in Israel. Nonetheless, since people’s tendency for somatization could be modified by their having lived in a Western community (Parker, Chan, Tully, & Eisenbruch, 2005), the findings of this community-based study of Chinese

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people living in the United States may not be generalizable to Chinese people living in Chinese communities. The present study aims to examine both somatic and non-specific psychological distress in a Chinese community sample. We delineated four admittedly arbitrary groups of Chinese individuals with regard to distress expression as follows: 1) somatically distressed, 2) psychologically distressed, 3) both somatically and psychologically distressed, and 4) healthy persons with low somatic and psychological distress. Using tools specific for measuring somatic and psychological distress respectively, we aimed to examine the relative prevalence and correlates of these four hypothesized groups including their relationships with impairment and health service use.

Method Sampling This study was approved by the research ethics committee of The Chinese University of Hong Kong. A random telephone survey of the general population aged 15–65 years was conducted between September 2 and 22, 2009. A total of 11,120 calls had successfully established contact with the household, with 1625 calls having no interviewee aged between 15 and 65 years, 4004 calls being hung up immediately by receivers, and 2477 calls being rejected for an interview. Thus, 3014 telephone interviews were successfully completed with informed verbal consent. Of the households that were successfully contacted and had interviewees within the age range, the participation rate was 54.9% (3014/[3014 + 2477]  100%) in accordance with the recommendation for reporting response rate in telephone surveys (Johnson & Owens, 2003). Informed verbal consent was obtained prior to each interview. The sample was weighted according to the gender distribution of different age groups in Hong Kong as reported by the Census and Statistics Department of the Hong Kong Government. With a 95% confidence level, the maximum sampling error was 1.76%.

Instruments An independent survey research organization, the Hong Kong Institute of AsiaPacific Studies of The Chinese University of Hong Kong, was commissioned to conduct the survey. The interviewers were university students with experience in administering telephone survey interviews, including those on mental health issues. The interview was conducted in Cantonese Chinese, the predominant dialect used in Hong Kong. Besides sociodemographic information, the questionnaire included Chinese versions of the Patient Health Questionnaire-15, the Kessler Scale-6, Sheehan Disability Scale, and items probing the frequency of health service use.

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Patient Health Questionnaire-15 (PHQ-15). This questionnaire (Cantonese Chinese version) was used to measure the somatic distress of respondents. The respondents were asked to rate how much they have been bothered by each of the 15 somatic symptoms in the past month on a “0” (not bothered at all) to “2” (bothered a lot) scale, yielding a total score of 0 to 30 for females and 0 to 28 for males (Kroenke, 2007). While the PHQ-15 is a continuous measure of somatic distress, respondents can also be categorized into four grades of severity: minimal (score ¼ 0–4), mild (score ¼ 5–9), moderate (score ¼ 10–14), and severe (score ¼ 15–30) (Kroenke et al., 2002). Using the same cut-offs, a study that used the same sample of respondents as the present study reported that the level of impairment and health service use increased with each increasing level of somatic distress. That study supported the reliability and validity of the Chinese PHQ-15 in our sample (Lee et al., 2011). The Cronbach’s alpha of the PHQ-15 was .79 in this study. Kessler Scale-6 (K6). The K6 has been widely used for measuring non-specific psychological distress. It is sensitive to both mood and anxiety disorders as stipulated in the Diagnostic and Statistical Manual of Mental Disorders, Fourth edition, Text Revision (DSM-IV-TR; American Psychiatric Association [APA], 2000) (Kessler et al., 2002). The Cantonese Chinese version (Lee et al., 2012) was used in this study. It consists of six questions that inquire how often the respondents feel (i) nervous, (ii) hopeless, (iii) restless or fidgety, (iv) so depressed that nothing could cheer you up, (v) that everything was an effort, and (vi) worthless in the past month. Response options included the whole 30 days (4), most of the time (3), some of the time (2), a little of the time (1), and none of the time (0), yielding a score range of 0–24. A score of 13 or higher indicates high psychological distress, a score of 8 to 12 indicates moderate psychological distress, and a score of 0 to 7 indicates low psychological distress (Wang et al., 2007). The internal consistency, reliability, and validity of this Cantonese Chinese version of K6 have been established in the same sample of respondents who participated in the present study (Lee et al., 2012). The Cronbach’s alpha of the K6 was .76 in this study. Sheehan Disability Scale (SDS). Impairment in four domains of life in the previous four weeks was assessed using the SDS. The four domains include household responsibilities (“doing housework, such as cleaning and grocery shopping”), work/school (“the ability to work, such as working, studying, or taking exams”), close relationships (“the ability to form and maintain close relationships with other people, such as romantic partner, family members, or close friends”), and social life (“the ability to form social relationship”). Severity was rated on a scale of 0–10 (none [0], mild [1–3], moderate [4–6], severe [7–9] and very severe [10]) (Leon, Olfson, Portera, Farber, & Sheehan, 1997). The SDS has been widely used in both Western and Chinese community psychiatric surveys (Lee et al., 2011). The Cronbach’s alpha of the SDS was .86 in this study.

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Frequency of health service use. The question “in the previous year, how often on average did you seek help from health professionals?” was asked to assess frequency of health service use. Respondents were given a choice of seven response categories ranging from “nil in the previous year” to “once a week or more”, with a higher score representing more frequent health service use.

Statistical analyses The PHQ-15 and K6 were used as dimensional measures of somatic distress and psychological distress respectively. Pearson correlation was computed to examine the linear relationship between somatic distress and psychological distress. Respondents were divided into four groups according to their scores on PHQ-15 (cut-off: 9/10) (Kroenke et al., 2002) and K6 (cut-off: 7/8) (Wang et al., 2007): 1) Somatically Distressed Group who had high level of somatic distress and low level of psychological distress (PHQ-15 score > ¼ 10 and K6 score < ¼ 7); 2) Psychologically Distressed Group who had low level of somatic distress and high level of psychological distress (PHQ-15 score < ¼ 9 and K6 score > ¼ 8); 3) Mixed Distress Group who were high on both somatic and psychological distress (PHQ15 score > ¼ 10 and K6 score > ¼ 8); 4) Low Distress Group who were low in both somatic and psychological distress (PHQ-15 score < ¼ 9 and K6 score < ¼ 7). Cross-tabulations and Chi-square tests were conducted to estimate the distributions of sociodemographic variables across the four subgroups. Multi-nominal logistic regression analysis was used to compare demographic differences in the Somatically Distressed Group, Psychologically Distressed Group, and Mixed Distress Group against the Low Distress Group. Additional ordinal logistic regression analysis was conducted to test if rates of somatic symptoms were higher in males. To examine the differences in impairment and health service use across these four subgroups, Chi-square test, Welch test, Kruskal-Wallis test, Mann-Whitney U Test (as non-parametric post hoc test), and regression analyses were used. For dimensional analyses, Pearson and Spearman correlations were conducted for examining linear relationships between somatic and psychological distress with impairment and health service use. Linear regression and ordinal regression analyses were used to determine the association of somatic and psychological distress with impairment and health service use while adjusting for sociodemographic variables. Receiver operating characteristics (ROC) curve and area under curve (AUC) analyses were also conducted to examine whether severe impairment (dichotomously defined as a score of 7 or higher on at least one domain of SDS) and frequent health service use (dichotomously defined as having sought professional help once a month or more in the previous year) were attributable to somatic distress or psychological distress. 95% confidence intervals were reported. The results were evaluated based on an alpha level of .05 of a two-tailed test.

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Results PHQ-15 and K6 profiles Of the respondents, 48.7%, 36.8%, 11.1%, and 3.5% were classified as having minimal, mild, moderate, and severe somatic distress, respectively. The mean PHQ-15 score for the whole sample is 5.43 (SD ¼ 4.10). As for the K6, 74.2%, 19.7%, and 6.1% of the respondents had low, moderate, and high psychological distress respectively. The mean K6 score for the whole sample is 5.24 (SD ¼ 12.58). Both PHQ-15 and K6 scores showed a positively skewed distribution. Figure 1 illustrates the number of respondents scoring different levels on the K6 and PHQ-15. Only 3.3% of the respondents did not report any somatic and psychological distress (PHQ-15 score ¼ 0 and K6 score ¼ 0). While 6.3% of the respondents reported any somatic distress (PHQ-15 score > 0) without psychological distress (K6 score ¼ 0), 4.5% of the respondents presented with any psychological distress (K6 score > 0) without somatic distress (PHQ-15 score ¼ 0). Thus, the overwhelming majority of respondents (85.9%) reported a varying mix of somatic and psychological distress. Correlation between PHQ-15 and K6 total scores was positive and high (r ¼ .60, p < .001).

Prevalence and sociodemographic profile The majority of respondents were classified as Low Distress Group (69.2%), while the proportions of those classified as Somatically Distressed Group, Psychologically Distressed Group, and Mixed Distress Group were 5.0%, 15.8%, 10.0%, respectively. These four groups differed significantly in the distributions of gender, age, marital status, educational attainment, occupational status, and family monthly income (p < .05) (Table 1). When compared with Low Distress Group, males and those with university-level education were less likely to be in the Somatically Distressed Group. Male gender, age 55–65, and family income of HKD30,000 or above were significantly associated with decreased odds of being in the Psychologically Distressed Group. Finally, individuals with male gender, aged 55–65, retired from work, with educational attainment higher than primary education, with family income of HKD10,000 or above were less likely to be in the Mixed Distress Group (Table 2). Additional analysis revealed that females were more likely than males to report somatic distress after controlling for demographic variables and psychological distress (OR ¼ 2.49, Wald ¼ 117.52, p < .001).

Impairment Of the respondents, 17.2% were found to be severely impaired in at least one of the four SDS domains; 8.2% of the Low Distress Group, 16.7% of the Somatically

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400 350

No. of respondents

300 250 200 150 100 50 0 0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Kessler Scale-6 (K6)

350

300

No. of respondents

250

200

150

100

50

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Patient Health Questionnaire-15 (PHQ-15)

Figure 1. Number of respondents scoring different levels on the Kessler Scale-6 and Patient Health Questionnaire-15.

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Gender Male Female Agea 15–24 25–34 35–44 45–54 55–65 Educational Statusa Primary (Grade 1–6) Secondary (Grade 7–11) Post-secondary University or above Marital Statusa Single Married/Cohabited Divorced/Widowed

46.6 53.4

20.2 13.5 20.5 26.2 19.7

12.4 45.9 12.0 29.6

35.6 60.0 4.5

608 405 616 787 592

373 1377 361 887

1065 1796 134

%

1404 1610

n

Whole sample (N ¼ 3014, 100%)

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701 1293 78

244 939 261 631

400 258 424 560 442

947 1140

n

65.8 72.0 58.2

65.4 68.2 72.3 71.1

65.8 63.7 68.8 71.2 74.7

75.2 65.0

%

Low Distress Groupc (n ¼ 2087, 69.2%)

47 97 6

23 85 13 29

27 18 32 43 29

36 114

n

4.4 5.4 4.5

6.2 6.2 3.6 3.3

4.4 4.4 5.2 5.5 4.9

2.9 6.5

%

Somatically Distressed Groupd (n ¼ 150, 5.0%)

218 231 27

45 203 62 167

124 85 92 111 65

203 274

n

20.5 12.9 20.1

12.1 14.7 17.2 18.8

20.4 21.0 14.9 14.1 11.0

16.1 15.6

%

Psychologically Distressed Groupe (n ¼ 477, 15.8%)

Table 1. Sociodemographic characteristics of the whole sample and the four subgroups.

99 175 23

61 150 25 60

57 44 68 73 56

73 227

n

9.3 9.7 17.2

16.4 10.9 6.9 6.8

9.4 10.9 11.0 9.3 9.5

5.8 12.9

%

Mixed Distress Groupf (n ¼ 300, 10.0%)

41.01

52.41

33.94

68.25

A community-based study of the relationship between somatic and psychological distress in Hong Kong.

Although the predominantly somatic presentation of distress has been used to explain low rates of emotional illnesses and health service use in Chines...
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