Int.J. Behav. Med. DOI 10.1007/s12529-014-9391-9
The Development and Validation of a Chinese Version of the Illness Attitude Scales: an Investigation of University Students Danyan Luo & Yinxi Zhang & Enyan Yu & Yunfei Tan & Zhou Tong & You Zhou & Wanzhen Chen & Hao Chai & Wei Wang
# International Society of Behavioral Medicine 2014
Abstract Background The Illness Attitude Scales (IAS) are considered as one of the most suitable instruments to screen hypochondriasis. Purpose Whether it has cross-cultural validity in China remains to be determined. Methods In Chinese university students (141 women and 141 men), we have administered the IAS, the Zuckerman– Kuhlman Personality Questionnaire (ZKPQ), and the Plutchik–van Praag Depression Inventory (PVP). Results For the first time in Chinese culture, we have identified a four-factor structure of the IAS: patho-thanatophobia, symptom effect, treatment seeking, and hypochondriacal belief. Women scored significantly higher on IAS pathothanatophobia and treatment seeking, on ZKPQ neuroticismanxiety and activity, and on PVP than men did. The neuroticism-anxiety was significantly correlated with pathothanatophobia and symptom effect, and PVP was positively correlated with symptom effect in women. Neuroticismanxiety was significantly correlated with pathothanatophobia, and impulsive sensation seeking and activity were significantly correlated with symptom effect in men.
D. Luo : Y. Zhang : Z. Tong : Y. Zhou : W. Chen : H. Chai : W. Wang (*) Department of Clinical Psychology and Psychiatry/School of Public Health, Zhejiang University College of Medicine, Yuhangtang Road 866, Hangzhou, Zhejiang 310058, China e-mail: [email protected] W. Wang e-mail: [email protected] E. Yu : Y. Tan : W. Wang Department of Psychiatry, Zhejiang Provincial People’s Hospital, Hangzhou, China
Conclusion In Chinese students, we have found a stable fourfactor IAS structure. Keywords Chinese university student . Gender effect . Hypochondriasis . Personality trait . Illness Attitude Scales (IAS)
Introduction Hypochondriasis is a preoccupation with fears of having, or the belief that one has, serious disease based on the misinterpretation of bodily symptoms [1]. It has a prevalence of about 0.26 to 8.5 % in primary care, and it considerably reduces the quality of life of people and increases their medical consultation and seeking for psychotherapeutic or psychiatric treatment [2]. There are some inventories to screen the disorder both in clinical samples and in the general population, for instance the Whiteley Index [3], the Somatosensory Amplification Scale [4], the Illness Worry Scale [5], the Multidimensional Inventory of Hypochondriacal Traits [6], and the Illness Attitude Scales (IAS) [7]. Moreover, there are other inventories to assess somatic symptoms such as the clinical hypochondriasis scale of the Minnesota Multiphasic Personality Inventory [8]. The IAS in particular has been tested in students [9–11] and nonclinical [12–14] and clinical participants [15–19]. Due to its ability to discriminate the hypochondriacal patients from healthy volunteers, it is considered as one of the most suitable instruments to screen hypochondriasis [20]. Although initially designed as a clinimetric instrument with nine scales containing 27 items [7], it was later tested by factorial analyses to be a two- [15, 17, 18], three- [16, 19], four- [9, 11, 13], or fivefactor structured one [10, 12]. Specifically, for testing its factor structures in different cultures, the 27-item IAS has been proven to be valid in England [9], Canada [10, 12], and
Int.J. Behav. Med.
America [17]; while its simplified (item reduced) versions have proven to be valid in the Netherlands [15], Norway [16], and Germany [11, 18, 19]. One might therefore wonder what the structure of the IAS would be or whether it could help to measure hypochondriasis in an eastern country, such as China. When referring to the etiopathology of hypochondriasis, some scholars have found that young age [21], unemployment, and low socioeconomic status [22] were related factors. Educational level might contribute to the health concern, but findings are inconclusive, since both high [21] and low [22] educational levels were reported to be related. Cognitive factors such as dysfunctions of health-related beliefs or selective memory might also play a role in the development of hypochondriasis [23]. Gender might be an additional factor that influences hypochondriasis. Some scholars reported that women presented more hypochondriacal concerns than men did [4, 15, 24, 25], which might be due to the fact that women have higher levels of expressiveness [26] or amplification of the somatic symptoms [27], but lower levels of healthcare seeking [28]. However, others failed to find substantial gender differences regarding the hypochondriacal concerns or attitudes toward illness [2, 29]. One might therefore question whether the inconclusive results were due to different hypochondriasis measures used across the studies. An extra curiosity one might have is whether there are some gender differences regarding hypochondriasis in Chinese culture. Furthermore, personality variables might contribute to hypochondriasis. For instance, personality disorders, particularly the obsessive-compulsive type, were highly prevalent in patients with hypochondriasis [30, 31]. The hypochondriacal concerns were positively correlated with neuroticism [10, 16, 32–38] and anxiety [16, 39–42], but negatively with extraversion [10, 32–34]. Consciousness was reported to be highly correlated [10], weakly correlated [34], or not correlated [38] with hypochondriasis. The unclear relationships or controversies might be partly due to the different personality measures used in different studies. For example, in different studies, the adjective- [34, 38] or statement-based (e.g., [32, 35]) personality instruments were employed. In light of this, we believed that the relationship between hypochondriasis and personality traits could be further delineated by using the IAS and the Zuckerman–Kuhlman Personality Questionnaire (ZKPQ) [43], at least in young university students in China. Since the hypochondriacal concerns were related to sensation seeking [35] and activity [44], and ZKPQ covers both the impulsive sensation seeking and activity traits [43], it might help to display a clear and stable relationship between personality and hypochondriasis and might also help to depict the convergent validity of the IAS. The main purpose of our study was to test the cross-cultural stability of the IAS in Chinese culture, by using both
exploratory and confirmatory factor analyses. Besides the observed IAS factor constructs, we would like to compare the IAS scale scores between men and women for assessing differences between genders and to correlate the IAS scales with the ZKPQ personality traits for assessing the relationship with personality traits. Therefore, we hypothesized that (1) women score higher on some IAS dimensions regarding illness anxiety, and illness behavior, on ZKPQ neuroticismanxiety and on the Plutchik–van Praag Depression Inventory (PVP), and (2) in both women and men, the ZKPQ neuroticism-anxiety is particularly correlated with (or predicts) the IAS dimension regarding illness anxiety. Considering balances of both age and education, we utilized Chinese university students in the current study. In addition, as depression was found to be frequently comorbid with hypochondriasis [24, 35, 41, 45, 46], we used the PVP [47] to control the depressive mood in participants of our study.
Methods Participants Three hundred and sixty-nine healthy Chinese undergraduate students (aged from 17 to 26 years) participated in the current study. Seventy-eight participants scored more than 3 on the ZKPQ lie scale, and nine scored more than 25 on PVP (i.e., considered depressed, see below for the criteria). Data obtained from these participants were removed from further analyses. Finally, 141 men (mean age 20.67 years with 1.68 SD, range 17–26 years) and 141 women (mean age 20.71 years with 1.36 SD, range 18–25) were retained. There was no significant age difference between two gender groups (t= 0.23; 95 % confidence interval (CI), −0.40∼0.32; p=0.82). The history of psychiatric (including depression mentioned above) or neurological disorders among the students was evaluated by two experienced clinicians (who were also coauthors, EY and WW). All participants were confirmed to have no history of psychiatric or neurological abnormalities and had to be drug or alcohol free for at least 72 h prior to the test. The protocol was approved by a local ethics committee and all participants had given their written informed consent. Instruments The participants were asked to fill in the following three questionnaires (Chinese versions) in a quiet room: 1. The IAS [7]: The scales consist of 27 items which are the core features of hypochondriasis, to be rated on a fivepoint scale (0—no, 1—rarely, 2—sometimes, 3—often, 4—most of the time) (see left column of Table 1). The other two open question items are about specifying
Int.J. Behav. Med. Table 1 Loadings of the original 27 items of Illness Attitude Scales on four factors in 282 participants Factor 1 Factor 1, patho-thanatophobia 3. Does the thought of a serious illness scare you? 18. Are you afraid that you may have another serious illness? 16. Are you afraid that you may have cancer? 2. Are you worried that you might get a serious illness in the future? 14. Does the thought of death scare you? 4. If you have a pain, do you worry that it may be caused by a serious illness? 13. Are you afraid of news that reminds you of death? 15. Are you afraid that you may die soon? 1. Do you worry about your health? 17. Are you afraid that you may have heart disease? 6. If a pain lasts a week or more, do you believe that you have a serious illness? 21. When you feel a sensation in your body, do you worry about it? Factor 2, symptom effect 26. Do your bodily symptoms stop you from concentrating on what you are doing? 25. Do your bodily symptoms stop you from working? 27. Do your bodily symptoms stop you from enjoying yourself? 20. When you notice a sensation in your body, do you find it difficult to think of something else? Factor 3, treatment seeking 23. How many different doctors, chiropractors, or other healers have you seen in the past year? 24. How often have you been treated during the past year (e.g., drugs, surgery)? 22. How often do you see a doctor? 5. If a pain lasts for a week or more, do you see a physician? 9. Do you examine your body to find whether there is something wrong? 8. Do you avoid foods which may not be healthy? Factor 4, hypochondriacal belief 10. Do you believe that you have a physical disease but the doctors have not diagnosed it correctly? 11. When your doctor tells you that you have no physical disease, do you refuse to believe him? 12. When you have been told by a doctor what he found, do you soon begin to believe that you may have developed a new illness? 19. When you read or hear about an illness, do you get symptoms similar to those of the illness? 7. Do you avoid habits which may be harmful to you such as smoking?
2
3
4
0.72 0.70 0.69 0.62 0.50 0.47 0.45 0.44 0.41 0.41 0.37 0.33
0.01 0.10 0.06 0.03 0.01 0.22 0.07 0.11 0.12 0.12 0.06 0.21
0.07 0.13 0.08 0.15 0.05 0.10 0.12 −0.03 0.16 0.01 0.17 0.27
0.00 0.11 0.13 0.18 −0.12 0.22 −0.01 0.05 0.11 0.31 0.16 0.08
0.11 0.01 0.25
0.91 0.79 0.73
0.11 0.04 0.02
−0.01 0.17 −0.03
0.17
0.48
0.22
0.09
0.03 0.09 0.07 0.12 0.07 0.09
0.13 0.17 0.12 0.11 −0.06 −0.05
0.83 0.71 0.55 0.43 0.27 0.18
0.08 0.14 0.10 −0.12 0.09 −0.11
0.16 0.14 0.29
0.10 0.06 0.04
0.14 0.06 0.10
0.70 0.56 0.40
0.30 0.09
0.21 0.07
0.10 0.12
0.32 −0.20
Loadings higher than 0.40 are presented in bold for clarity
illnesses and treatment. All the items were translated into Chinese by the first author (D. L.) and blindly back-translated into English by two of the co-authors (Y. Z. and Z. T.). Disagreements and subsequent amendments were independently translated into Chinese by the last author (W. W.). This process was continued until the translation and back-translation agreed. 2. The ZKPQ [43]: The test includes five dimensions: (a) impulsive sensation seeking (19 items); (b) neuroticismanxiety (19 items); (c) aggression-hostility (17 items); (d) activity (17 items); and (e) sociability (17 items). One point is given to each chosen item corresponding to personality traits. In this questionnaire, ten items of another scale of dissimulation (infrequency or lie) were randomly
inserted into the test body. Any score above 3 on the infrequency scale suggests either inattention to the content of the items and acquiescence or a very strong social desirability set; therefore, the infrequency scale was used as a test validity indicator for individuals [43]. The infrequency scale also helps to present clear relationships between ZKPQ and IAS scales; thus, it might help to display reliable indications for the IAS convergent validity in the current study. The ZKPQ has proven to be reliable in Chinese culture [48]. 3. The PVP [47]: Each of the 34 items of PVP has three scale points (0, 1, 2) corresponding with increasing depressive tendencies. Participants have “possible depression” if they score between 20 and 25 or “depression” if they score above 25.
Int.J. Behav. Med.
Statistical Analyses Answers to the 27 items of the IAS were subjected to a principal axis analysis first, using a computer program SPSS, factor analysis. The factor loadings were rotated orthogonally using the varimax normalized method. Items which were loaded less heavily (below 0.40) on a target factor, or crossloaded heavily (higher than 0.30) on other factor(s), were removed from subsequent analyses one-by-one. After each removal, the remaining items were subjected to a new round of principal axis analysis. The procedure continued until no further item was needed to be removed. The number of extracted factors was determined using the Velicer minimum average partial test [49] and the parallel analysis according to a script developed by O’Connor [50]. The percentile value was set to 95 and the number of data sets was set to 1,000 for the parallel analysis. Afterwards, the fit of the remaining data (i.e., components extracted as latent factors) was evaluated by the confirmatory factor analysis (CFA) for the structural equation modeling using AMOS [51]. Once factors and the related items were identified, the internal reliabilities (Cronbach’s alphas) were calculated for each factor by another SPSS program—reliability and item analysis. Two-way ANOVA was applied to the mean scores of ZKPQ or IAS scales in two gender groups. Whenever a significant main effect was found, post hoc analysis by the Dunnett test was employed to evaluate between-group differences. The mean PVP scores in two groups were submitted to the independent Student’s t test, and their relationships with the IAS scales were evaluated by the Pearson linear correlation test. The possible intercorrelations between the IAS scales themselves were also evaluated by the Pearson test. When searching the ZKPQ scale prediction of the IAS scales, we employed the stepwise multiple linear regression. A p value ≤0.05 was considered to be significant.
Results We explored the eigenvalues of the latent IAS factors and their fitting model, and the inter-factor (scale) relationships, in order to depict the factorial structure of the IAS. Meanwhile, we calculated the internal consistencies (the Cronbach’s alphas) of the latent factors, and their relationships with the ZKPQ scales, which might help to depict the convergent validity of the IAS. We also computed the IAS factor scores and their relationships with ZKPQ scales for the male and female samples, to look for possible gender differences. Factor Analyses on the IAS After the principal axis analysis, eight factors emerged with eigenvalues larger than 1.0, which were 5.82, 2.42, 1.98, 1.73,
1.49, 1.37, 1.15, and 1.10, respectively. The minimum average partial test suggested a four-factor solution, while the parallel analysis suggested a six-factor one. As the parallel analysis tends to err in the direction of overextraction [50], we decided to choose a four-factor solution for subsequent analyses. The four factors accounted for 44.23 % of total variance. After the varimax normalized rotation, the loadings of the original 27 items on the four factors were calculated (Table 1). Seven IAS items (originally numbered 6, 7, 8, 9, 17, 19, and 21) with loadings lower than 0.40 or with significant cross-loadings higher than 0.30 on other nontarget factors were deleted. The remaining 20 items were retained for further CFA testing. The parameters for the model fit were satisfactory: χ2/df was 2.31, goodness of fit index 0.88, adjusted goodness of fit index 0.85, comparative fit index 0.88, Tucker–Lewis index 0.87, and the root mean square error of approximation 0.07. The IAS factor 1, with items originally numbered 1, 2, 3 (which belong to the original IAS category of “worry about illness” ), 4 (“con cern ab out pain” ), 13, 14 , 15 (“thanatophobia”), 16, and 18 (“disease phobia”), reflected the fears of having serious illnesses or death, thus was named as “patho-thanatophobia”; factor 2, with items 20 (which belongs to the original IAS category of “bodily preoccupation”), 25, 26, and 27 (“effect of symptoms”), described the effects of illness symptoms on everyday life and work, as “symptom effect”; factor 3, with items 5 (which belongs to the original IAS category of “concern about pain”), 22, 23, and 24 (“treatment experience”), reflected the actions of disease prevention and treatment, as “treatment seeking”; and factor 4, with items 10, 11, and 12 (which belong to the original IAS category of “hypochondriacal beliefs”), represented the doubting of being healthy despite medical reassurance, thus as “hypochondriacal belief”. The intercorrelations of the four IAS structure were significant but remained in a low or medium level (Table 2). The internal consistencies (Cronbach’s alphas) of the four factors were, however, satisfactory (Table 3). Gender Differences on Scales Afterwards, the mean scores of each IAS factor in the two gender groups were calculated (Table 3). Women scored significantly different on the four IAS scales (F (1, 280)=6.34, mean squared effect (MSE)=114.89, p
The Development and Validation of a Chinese Version of the Illness Attitude Scales: an Investigation of University Students Danyan Luo & Yinxi Zhang & Enyan Yu & Yunfei Tan & Zhou Tong & You Zhou & Wanzhen Chen & Hao Chai & Wei Wang
# International Society of Behavioral Medicine 2014
Abstract Background The Illness Attitude Scales (IAS) are considered as one of the most suitable instruments to screen hypochondriasis. Purpose Whether it has cross-cultural validity in China remains to be determined. Methods In Chinese university students (141 women and 141 men), we have administered the IAS, the Zuckerman– Kuhlman Personality Questionnaire (ZKPQ), and the Plutchik–van Praag Depression Inventory (PVP). Results For the first time in Chinese culture, we have identified a four-factor structure of the IAS: patho-thanatophobia, symptom effect, treatment seeking, and hypochondriacal belief. Women scored significantly higher on IAS pathothanatophobia and treatment seeking, on ZKPQ neuroticismanxiety and activity, and on PVP than men did. The neuroticism-anxiety was significantly correlated with pathothanatophobia and symptom effect, and PVP was positively correlated with symptom effect in women. Neuroticismanxiety was significantly correlated with pathothanatophobia, and impulsive sensation seeking and activity were significantly correlated with symptom effect in men.
D. Luo : Y. Zhang : Z. Tong : Y. Zhou : W. Chen : H. Chai : W. Wang (*) Department of Clinical Psychology and Psychiatry/School of Public Health, Zhejiang University College of Medicine, Yuhangtang Road 866, Hangzhou, Zhejiang 310058, China e-mail: [email protected] W. Wang e-mail: [email protected] E. Yu : Y. Tan : W. Wang Department of Psychiatry, Zhejiang Provincial People’s Hospital, Hangzhou, China
Conclusion In Chinese students, we have found a stable fourfactor IAS structure. Keywords Chinese university student . Gender effect . Hypochondriasis . Personality trait . Illness Attitude Scales (IAS)
Introduction Hypochondriasis is a preoccupation with fears of having, or the belief that one has, serious disease based on the misinterpretation of bodily symptoms [1]. It has a prevalence of about 0.26 to 8.5 % in primary care, and it considerably reduces the quality of life of people and increases their medical consultation and seeking for psychotherapeutic or psychiatric treatment [2]. There are some inventories to screen the disorder both in clinical samples and in the general population, for instance the Whiteley Index [3], the Somatosensory Amplification Scale [4], the Illness Worry Scale [5], the Multidimensional Inventory of Hypochondriacal Traits [6], and the Illness Attitude Scales (IAS) [7]. Moreover, there are other inventories to assess somatic symptoms such as the clinical hypochondriasis scale of the Minnesota Multiphasic Personality Inventory [8]. The IAS in particular has been tested in students [9–11] and nonclinical [12–14] and clinical participants [15–19]. Due to its ability to discriminate the hypochondriacal patients from healthy volunteers, it is considered as one of the most suitable instruments to screen hypochondriasis [20]. Although initially designed as a clinimetric instrument with nine scales containing 27 items [7], it was later tested by factorial analyses to be a two- [15, 17, 18], three- [16, 19], four- [9, 11, 13], or fivefactor structured one [10, 12]. Specifically, for testing its factor structures in different cultures, the 27-item IAS has been proven to be valid in England [9], Canada [10, 12], and
Int.J. Behav. Med.
America [17]; while its simplified (item reduced) versions have proven to be valid in the Netherlands [15], Norway [16], and Germany [11, 18, 19]. One might therefore wonder what the structure of the IAS would be or whether it could help to measure hypochondriasis in an eastern country, such as China. When referring to the etiopathology of hypochondriasis, some scholars have found that young age [21], unemployment, and low socioeconomic status [22] were related factors. Educational level might contribute to the health concern, but findings are inconclusive, since both high [21] and low [22] educational levels were reported to be related. Cognitive factors such as dysfunctions of health-related beliefs or selective memory might also play a role in the development of hypochondriasis [23]. Gender might be an additional factor that influences hypochondriasis. Some scholars reported that women presented more hypochondriacal concerns than men did [4, 15, 24, 25], which might be due to the fact that women have higher levels of expressiveness [26] or amplification of the somatic symptoms [27], but lower levels of healthcare seeking [28]. However, others failed to find substantial gender differences regarding the hypochondriacal concerns or attitudes toward illness [2, 29]. One might therefore question whether the inconclusive results were due to different hypochondriasis measures used across the studies. An extra curiosity one might have is whether there are some gender differences regarding hypochondriasis in Chinese culture. Furthermore, personality variables might contribute to hypochondriasis. For instance, personality disorders, particularly the obsessive-compulsive type, were highly prevalent in patients with hypochondriasis [30, 31]. The hypochondriacal concerns were positively correlated with neuroticism [10, 16, 32–38] and anxiety [16, 39–42], but negatively with extraversion [10, 32–34]. Consciousness was reported to be highly correlated [10], weakly correlated [34], or not correlated [38] with hypochondriasis. The unclear relationships or controversies might be partly due to the different personality measures used in different studies. For example, in different studies, the adjective- [34, 38] or statement-based (e.g., [32, 35]) personality instruments were employed. In light of this, we believed that the relationship between hypochondriasis and personality traits could be further delineated by using the IAS and the Zuckerman–Kuhlman Personality Questionnaire (ZKPQ) [43], at least in young university students in China. Since the hypochondriacal concerns were related to sensation seeking [35] and activity [44], and ZKPQ covers both the impulsive sensation seeking and activity traits [43], it might help to display a clear and stable relationship between personality and hypochondriasis and might also help to depict the convergent validity of the IAS. The main purpose of our study was to test the cross-cultural stability of the IAS in Chinese culture, by using both
exploratory and confirmatory factor analyses. Besides the observed IAS factor constructs, we would like to compare the IAS scale scores between men and women for assessing differences between genders and to correlate the IAS scales with the ZKPQ personality traits for assessing the relationship with personality traits. Therefore, we hypothesized that (1) women score higher on some IAS dimensions regarding illness anxiety, and illness behavior, on ZKPQ neuroticismanxiety and on the Plutchik–van Praag Depression Inventory (PVP), and (2) in both women and men, the ZKPQ neuroticism-anxiety is particularly correlated with (or predicts) the IAS dimension regarding illness anxiety. Considering balances of both age and education, we utilized Chinese university students in the current study. In addition, as depression was found to be frequently comorbid with hypochondriasis [24, 35, 41, 45, 46], we used the PVP [47] to control the depressive mood in participants of our study.
Methods Participants Three hundred and sixty-nine healthy Chinese undergraduate students (aged from 17 to 26 years) participated in the current study. Seventy-eight participants scored more than 3 on the ZKPQ lie scale, and nine scored more than 25 on PVP (i.e., considered depressed, see below for the criteria). Data obtained from these participants were removed from further analyses. Finally, 141 men (mean age 20.67 years with 1.68 SD, range 17–26 years) and 141 women (mean age 20.71 years with 1.36 SD, range 18–25) were retained. There was no significant age difference between two gender groups (t= 0.23; 95 % confidence interval (CI), −0.40∼0.32; p=0.82). The history of psychiatric (including depression mentioned above) or neurological disorders among the students was evaluated by two experienced clinicians (who were also coauthors, EY and WW). All participants were confirmed to have no history of psychiatric or neurological abnormalities and had to be drug or alcohol free for at least 72 h prior to the test. The protocol was approved by a local ethics committee and all participants had given their written informed consent. Instruments The participants were asked to fill in the following three questionnaires (Chinese versions) in a quiet room: 1. The IAS [7]: The scales consist of 27 items which are the core features of hypochondriasis, to be rated on a fivepoint scale (0—no, 1—rarely, 2—sometimes, 3—often, 4—most of the time) (see left column of Table 1). The other two open question items are about specifying
Int.J. Behav. Med. Table 1 Loadings of the original 27 items of Illness Attitude Scales on four factors in 282 participants Factor 1 Factor 1, patho-thanatophobia 3. Does the thought of a serious illness scare you? 18. Are you afraid that you may have another serious illness? 16. Are you afraid that you may have cancer? 2. Are you worried that you might get a serious illness in the future? 14. Does the thought of death scare you? 4. If you have a pain, do you worry that it may be caused by a serious illness? 13. Are you afraid of news that reminds you of death? 15. Are you afraid that you may die soon? 1. Do you worry about your health? 17. Are you afraid that you may have heart disease? 6. If a pain lasts a week or more, do you believe that you have a serious illness? 21. When you feel a sensation in your body, do you worry about it? Factor 2, symptom effect 26. Do your bodily symptoms stop you from concentrating on what you are doing? 25. Do your bodily symptoms stop you from working? 27. Do your bodily symptoms stop you from enjoying yourself? 20. When you notice a sensation in your body, do you find it difficult to think of something else? Factor 3, treatment seeking 23. How many different doctors, chiropractors, or other healers have you seen in the past year? 24. How often have you been treated during the past year (e.g., drugs, surgery)? 22. How often do you see a doctor? 5. If a pain lasts for a week or more, do you see a physician? 9. Do you examine your body to find whether there is something wrong? 8. Do you avoid foods which may not be healthy? Factor 4, hypochondriacal belief 10. Do you believe that you have a physical disease but the doctors have not diagnosed it correctly? 11. When your doctor tells you that you have no physical disease, do you refuse to believe him? 12. When you have been told by a doctor what he found, do you soon begin to believe that you may have developed a new illness? 19. When you read or hear about an illness, do you get symptoms similar to those of the illness? 7. Do you avoid habits which may be harmful to you such as smoking?
2
3
4
0.72 0.70 0.69 0.62 0.50 0.47 0.45 0.44 0.41 0.41 0.37 0.33
0.01 0.10 0.06 0.03 0.01 0.22 0.07 0.11 0.12 0.12 0.06 0.21
0.07 0.13 0.08 0.15 0.05 0.10 0.12 −0.03 0.16 0.01 0.17 0.27
0.00 0.11 0.13 0.18 −0.12 0.22 −0.01 0.05 0.11 0.31 0.16 0.08
0.11 0.01 0.25
0.91 0.79 0.73
0.11 0.04 0.02
−0.01 0.17 −0.03
0.17
0.48
0.22
0.09
0.03 0.09 0.07 0.12 0.07 0.09
0.13 0.17 0.12 0.11 −0.06 −0.05
0.83 0.71 0.55 0.43 0.27 0.18
0.08 0.14 0.10 −0.12 0.09 −0.11
0.16 0.14 0.29
0.10 0.06 0.04
0.14 0.06 0.10
0.70 0.56 0.40
0.30 0.09
0.21 0.07
0.10 0.12
0.32 −0.20
Loadings higher than 0.40 are presented in bold for clarity
illnesses and treatment. All the items were translated into Chinese by the first author (D. L.) and blindly back-translated into English by two of the co-authors (Y. Z. and Z. T.). Disagreements and subsequent amendments were independently translated into Chinese by the last author (W. W.). This process was continued until the translation and back-translation agreed. 2. The ZKPQ [43]: The test includes five dimensions: (a) impulsive sensation seeking (19 items); (b) neuroticismanxiety (19 items); (c) aggression-hostility (17 items); (d) activity (17 items); and (e) sociability (17 items). One point is given to each chosen item corresponding to personality traits. In this questionnaire, ten items of another scale of dissimulation (infrequency or lie) were randomly
inserted into the test body. Any score above 3 on the infrequency scale suggests either inattention to the content of the items and acquiescence or a very strong social desirability set; therefore, the infrequency scale was used as a test validity indicator for individuals [43]. The infrequency scale also helps to present clear relationships between ZKPQ and IAS scales; thus, it might help to display reliable indications for the IAS convergent validity in the current study. The ZKPQ has proven to be reliable in Chinese culture [48]. 3. The PVP [47]: Each of the 34 items of PVP has three scale points (0, 1, 2) corresponding with increasing depressive tendencies. Participants have “possible depression” if they score between 20 and 25 or “depression” if they score above 25.
Int.J. Behav. Med.
Statistical Analyses Answers to the 27 items of the IAS were subjected to a principal axis analysis first, using a computer program SPSS, factor analysis. The factor loadings were rotated orthogonally using the varimax normalized method. Items which were loaded less heavily (below 0.40) on a target factor, or crossloaded heavily (higher than 0.30) on other factor(s), were removed from subsequent analyses one-by-one. After each removal, the remaining items were subjected to a new round of principal axis analysis. The procedure continued until no further item was needed to be removed. The number of extracted factors was determined using the Velicer minimum average partial test [49] and the parallel analysis according to a script developed by O’Connor [50]. The percentile value was set to 95 and the number of data sets was set to 1,000 for the parallel analysis. Afterwards, the fit of the remaining data (i.e., components extracted as latent factors) was evaluated by the confirmatory factor analysis (CFA) for the structural equation modeling using AMOS [51]. Once factors and the related items were identified, the internal reliabilities (Cronbach’s alphas) were calculated for each factor by another SPSS program—reliability and item analysis. Two-way ANOVA was applied to the mean scores of ZKPQ or IAS scales in two gender groups. Whenever a significant main effect was found, post hoc analysis by the Dunnett test was employed to evaluate between-group differences. The mean PVP scores in two groups were submitted to the independent Student’s t test, and their relationships with the IAS scales were evaluated by the Pearson linear correlation test. The possible intercorrelations between the IAS scales themselves were also evaluated by the Pearson test. When searching the ZKPQ scale prediction of the IAS scales, we employed the stepwise multiple linear regression. A p value ≤0.05 was considered to be significant.
Results We explored the eigenvalues of the latent IAS factors and their fitting model, and the inter-factor (scale) relationships, in order to depict the factorial structure of the IAS. Meanwhile, we calculated the internal consistencies (the Cronbach’s alphas) of the latent factors, and their relationships with the ZKPQ scales, which might help to depict the convergent validity of the IAS. We also computed the IAS factor scores and their relationships with ZKPQ scales for the male and female samples, to look for possible gender differences. Factor Analyses on the IAS After the principal axis analysis, eight factors emerged with eigenvalues larger than 1.0, which were 5.82, 2.42, 1.98, 1.73,
1.49, 1.37, 1.15, and 1.10, respectively. The minimum average partial test suggested a four-factor solution, while the parallel analysis suggested a six-factor one. As the parallel analysis tends to err in the direction of overextraction [50], we decided to choose a four-factor solution for subsequent analyses. The four factors accounted for 44.23 % of total variance. After the varimax normalized rotation, the loadings of the original 27 items on the four factors were calculated (Table 1). Seven IAS items (originally numbered 6, 7, 8, 9, 17, 19, and 21) with loadings lower than 0.40 or with significant cross-loadings higher than 0.30 on other nontarget factors were deleted. The remaining 20 items were retained for further CFA testing. The parameters for the model fit were satisfactory: χ2/df was 2.31, goodness of fit index 0.88, adjusted goodness of fit index 0.85, comparative fit index 0.88, Tucker–Lewis index 0.87, and the root mean square error of approximation 0.07. The IAS factor 1, with items originally numbered 1, 2, 3 (which belong to the original IAS category of “worry about illness” ), 4 (“con cern ab out pain” ), 13, 14 , 15 (“thanatophobia”), 16, and 18 (“disease phobia”), reflected the fears of having serious illnesses or death, thus was named as “patho-thanatophobia”; factor 2, with items 20 (which belongs to the original IAS category of “bodily preoccupation”), 25, 26, and 27 (“effect of symptoms”), described the effects of illness symptoms on everyday life and work, as “symptom effect”; factor 3, with items 5 (which belongs to the original IAS category of “concern about pain”), 22, 23, and 24 (“treatment experience”), reflected the actions of disease prevention and treatment, as “treatment seeking”; and factor 4, with items 10, 11, and 12 (which belong to the original IAS category of “hypochondriacal beliefs”), represented the doubting of being healthy despite medical reassurance, thus as “hypochondriacal belief”. The intercorrelations of the four IAS structure were significant but remained in a low or medium level (Table 2). The internal consistencies (Cronbach’s alphas) of the four factors were, however, satisfactory (Table 3). Gender Differences on Scales Afterwards, the mean scores of each IAS factor in the two gender groups were calculated (Table 3). Women scored significantly different on the four IAS scales (F (1, 280)=6.34, mean squared effect (MSE)=114.89, p
