Development of a psychosomatic complaints scale for adolescents

Authors


Dr Yuriko Takata, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan. Email: takata@sakura.cc.tsukuba.ac.jp

Abstract

Abstract  There have been only a few questionnaires that can be used to comprehend the psychosomatic complaints of adolescents. Therefore, the objective of the present investigation was to develop a scale for high school students in order to comprehend psychosomatic complaints deriving from psychologic problems. The collection of scale items was performed referring to the health actual situation survey carried out on Japanese school children in the past, and 30 items with a high incidence of psychosomatic complaints were selected out of them and were set as scale items. A survey to assess reliability and validity of the 30 items of the psychosomatic complaint scale was then conducted on the subjects of 759 high school students in total over 3 years. At assessment of validity of the scale, one-factor structure was confirmed by factor analysis and both the eigenvalue and factor loading were found to be at acceptable levels. Further, at assessment of the reliability of the scale, both Cronbach's α coefficient indicating internal consistency and the correlation coefficient indicating reproducibility were found to be high. It was concluded that the psychosomatic complaint scale developed in the present investigation was excellent in validity and reliability and was highly practical, having a reduced number of items.

INTRODUCTION

In recent years, the health problems of adolescents have diversified in Japan.1 Growth and development at adolescence are extremely high. Physically, adolescents attain the secondary sex characters and grow greatly in height and bodyweight,2 and mental growth occurs after physical development. Because the mental growth is in the process of establishing identity,3 the process of mental growth is also changed much in this period. Concerning the diseases that are commonly found in the adolescence period, occurrence of anemia and mental diseases has been noted in the past.4 The issue that is more intensively indicated recently is the increase of students who come to the school infirmary and complain about physical symptoms caused by mental problems.5 Many children complain of headache or abdominal pain due to the problems of school work or human relations. In contrast, because lifestyles have changed to involve sitting up until late at night, some health problems have occurred because of the failure to perform such basic lifestyle habits such as sleeping and taking meals.

In order to comprehend the diversifying health problems of adolescents, a questionnaire that can be used ordinarily and easily in the school infirmary is convenient to understand problems. The standardized questionnaires such as Cornell Medical Index (CMI)6 and Minnesota Multiphasic Personality Inventory (MMPI)7 include many questions and are difficult to fill in by pupils within a short time such as the recess between the lesson periods at school. The objective of the present study is to develop a questionnaire relating to psychosomatic complaints of adolescents that pupils can fill in within a short time, and nurse teachers can evaluate immediately and use for health guidance then and there.

METHODS

Collection and preparation of scale items

To determine the scale items relating to psychosomatic complaints of adolescents, the following points were taken into account: (i) to include items relating to the psychologic symptoms that have been increasing recently; and (ii) to include items that reflect health problems borne by today's children. For high school students, because the mental growth is in the process of establishing identity, the process of mental growth is also changed much in this period. Children with psychologic problems often express their internal conflicts by physical symptoms such as headache and abdominal pain. Checking only the items relating to psychologic symptoms was not sufficient to comprehend the health status of today's children, therefore it was determined to include items that commonly occur in the body as a psychogenic response. The items were collected referring to a health actual-state survey carried out on school children in the past.8–10 This scale consists of 30 items constructed for assessment of adolescent pychosomatic complaints.

Assessment of each item was by choice of a reply such as ‘never’, ‘rarely’, ‘sometimes’ or ‘frequently’.

Instrument

The questionnaire consisted of: (i) 30 items of psychosomatic complaints; (ii) the General Health Questionnaire (GHQ) 28 items in Japanese;11 and (iii) sex and age as basic items. The GHQ was used as a concurrence scale. The GHQ-28 is simple; we can judge not only neurosis but also the degree of mental healthy by GHQ-28.

Conducting the survey

The survey was conducted to assess the constitution, reliability and validity of the scale, in order to verify if health problems complained of by today's children can be comprehended appropriately.

The survey was conducted on high school students at a high school in Tokyo. The present study was applied to students who are free from physical or mental diseases. The first sample consisted of 157 first-grade students (boys, 43 (27.4%); girls, 114 (72.6%)) enrolled in April 1997. The second sample consisted of 153 first-grade students (boys, 47 (30.8%); girls, 106 (69.2%)) enrolled in April 1998; and the third sample consisted of 459 first-, second- and third-grade students (boys, 127 (27.7%); girls, 332 (72.3%)) in 1999. The average age of the third sample was 16 years.

The reason for conducting the present study on first-grade students of the first and second sample was because it is necessary to begin health guidance and health education soon after students are enrolled from the viewpoint of primary prevention. In addition, Japanese first-grade high school students are reported to exhibit more psychosomatic complaints than second- or third-grade students.12

Selecting first-grade students of the high school as subjects, six surveys were carried out over 2 years. Based on those results, and selecting all school-grade students of the high school including the first-grade to third-grade students as subjects, the survey was performed in the 1999 school year, and the scale for the high school students were verified. The survey conducted in the form of the group surveys using questionnaires filled in by the students themselves with the cooperation of the homeroom teacher. For the first sample, the survey was conducted in June 1997, October 1997 and March 1998. For the second sample, the survey was conducted in June 1998, October 1998 and March 1999. For the third sample, the survey was conducted in June 1999. The response rate was all 100%.

The concurrence scale of GHQ-28 was conducted twice (in June 1998 and March 1999), which obtained agreement of the survey.

Data analysis

Assessment of psychosomatic complaints was scored from 0 to 3 points for replies consisting of ‘never’, ‘rarely’, ‘sometimes’ and ‘frequently’. In order to verify the construct validity, a principal factor analysis was employed, followed by a Varimax rotation. With respect to the concurrent validity, Pearson's product moment correlation was conducted in order to analyze the relations between 30 items regarding psychosomatic complaints and the GHQ-28. The GHQ28 was scored GHQ-mark.

In order to verify the reliability, Cronbach's α coefficient and product moment correlation coefficient were examined for consistency.

For analysis, the statistical package spss 9.05 for Windows was used (SPSS Japan, Tokyo, Japan).

RESULTS

Validity

Content validity was confirmed by specialists (one medical doctor and one psychologist).

As for the surface validity, five non-target high school students were asked to respond to the questions to obtain their opinions on the difficulty of expression of questions and the length of time for responding, and they did not indicate any problems.

The construct validity was studied using principal factor analysis with Varimax rotation.

As a result of the first sample in June, factors with an eigenvalue of 1.0 or higher were found in seven out of 30 items. However, regarding the eigenvalue, the eigenvalue of the first factor was extremely high by 10.24 and the difference of it from the eigenvalue of the second factor, 1.88, was large. For confirmation, factor analysis was performed, assigning factor numbers from 1 to 7. As a result, the best arrangement of factors was the one-factor structure. This was consistent with the one-factor structure estimated from eigenvalues. To examine the sex difference of the factor structure, the factor analyses were performed on the male and female answers separately. The result was that the eigenvalue of the first factor was extremely high and the difference of it from the eigenvalue of the second factor was large in both male and female answers. Therefore, it was judged that this scale was appropriate to be understood by one factor, ‘psychosomatic complaint’. Further, at application of the factor analysis, a factor with low factor loading is judged such that the loading on the factor is low, and removal of item and so on are performed. In this scale, factor loadings were 0.3 or more in all items (Table 1). Additionally, the coefficient of determination of the first factor was 34.1%.

Table 1.  Principal factor analysis of the psychosomatic complaints data
 First sampleThird sample
Eigenvalue10.249.32
Variance (%)34.1131.13
Factor loadings
 28. I feel gloomy.0.780.72
 26. I lack tenacity.0.750.71
 23. I get irritated without any reason.0.740.71
 27. I somehow feel sick.0.740.75
 11. I get tired easily.0.720.68
 25. I get distracted.0.710.72
  2. I feel heavy in the head.0.670.70
 20. I get in no mood to do anything.0.660.67
  5. I feel heavy in the stomach or I do have nausea.0.630.50
 19. I feel like lying.0.630.64
  9. I have a dizziness when I stand up.0.620.57
 21. I feel difficulty in putting my thoughts together.0.620.66
 22. I get tired of talking with other people.0.620.56
  3. I have a stomachache.0.600.41
 30. The relationship between myself and my friends gets bad.0.580.45
  1. I have a headache.0.540.56
 16. I have palpitation without any reasons.0.540.58
 17. I suddenly feel difficulty in breathing.0.540.54
  8. I have lumbago.0.530.45
  7. I have stiffness in the shoulder.0.510.45
 10. I catch a cold easily.0.510.36
 12. I have ear ringing.0.510.49
 24. I feel like shouting.0.510.56
  4. I have diarrhea.0.500.31
 14. I have eyestrain.0.460.54
  6. I have a poor appetite in the morning.0.430.36
 29. I feel I sleep badly.0.410.43
 18. I have numbness or trembling in the arms or legs.0.390.49
 13. I get eczema.0.350.30
 15. I have a tic.0.340.39

Next, in order to verify if this scale can be applied to understand the health of high school students of the first grade to third grade, a survey using this scale was carried out on three grades of students simultaneously in June 1999. As a result of principal factor analysis, the eigenvalue of the first factor was extremely high by 9.32 and the difference of it from the eigenvalue of the second factor, 2.04, was large. It was therefore found that this scale was appropriate to be understood by one factor. Similarly to the first sample, factor analysis was performed, assigning factor numbers from 1 to 6. As a result, the best arrangement of factors was the one-factor structure. In this scale too, factor loadings were 0.3 or more in all items (Table 1). Additionally, the coefficient of determination of the first factor was 31.1%.

With respect to the concurrent validity, the relationship between the 30 items on psychosomatic complaints and GHQ-28 conducted the second sample, was studied. Using Pearson's product moment correlation, the correlation coefficient between their psychosomatic complaints and the GHQ-28 was γ = 0.65 in June 1998 and γ = 0.64 in March 1999. We examined whether this scale can comprehend a body symptom of a mental cause. The psychosomatic complaints score of the students who frequently utilized the school infirmary was compared with the mean value of other students. The psychosomatic complaints score of two non-target students with eating disorder and the one student who was diagnosed with neurotic disorder who frequently utilized the school infirmary, was compared with the mean value of other students. The total mean of the psychosomatic complaints score was 35.38 ± 16.02; the scores of the two students with the eating disorder was 56 and 62, and the score of the one student with a neurotic disorder was 68.

Reliability

The Cronbach's α coefficient indicating internal consistency was high: 0.93 in 1997, 0.91 in 1998 and 0.92 in 1999.

The reproducibility was assessed using the first and the second samples. Using the results of the survey in June, the next survey after 4 months and the following survey after the next 8 months, correlations were examined among totals of 30 items of the scale. As a result, correlation between scales was γ = 0.5 or more.

DISCUSSION

Validity of scale

Factor analysis was employed in order to verify the construct validity. The best arrangement of factors was found to be the one-factor structure. The factor contribution rate was 34.1% in June 1997 and 31.1% in June 1999. Therefore, the construct validity of the scale was appropriate.

The items with the higher factor loading were the following: (i) items relating to attentiveness, concentrativeness, contemplative faculty and indefatigability; (ii) items indicating depressive state; (iii) items indicating impulsiveness and irritability; and (iv) items expressing pain or fatigue occurring in various parts of body. These results suggested that health problems borne by high school students included many symptoms caused by increase of psychologic stresses.

From results mentioned here, it was considered that the scale with 30 items in the present study was consistent with the working hypothesis at the time of settling of scale items, and included symptoms deriving from psychologic problems.

The concurrent validity was γ = 0.6 or more for all items between psychosomatic complaints and the GHQ-28. We can judge not only neurosis but also the degree of mental health by the GHQ-28 and the comparison of school infirmary frequent students and other students; therefore this is a simple and effective scale that comprehends the psychosomatic complaints of adolescents.

Reliability of scale

Cronbach's α coefficient is the most distinguished estimate of the reliability coefficient. It is well recognized that Cronbach's α coefficient must be ≥0.5 for a scale to be judged as reliable, and ≥0.8 for a scale used commonly.13,14 Cronbach's α coefficient of the scale with 30 items in the present investigation was high by 0.9 or more, and its reliability was judged to be sufficient.

The reproducibility was assessed using the first and the second samples. Using the results of the survey in June, the next survey after 4 months and the following survey 8 months later, correlations were examined among totals of 30 items of the scale.

The result of assessment on the reliability indicates a correlation coefficient of ≥0.5. Considering that the surveys including those after 4 months and 8 months were carried out after a long time, and that subjects were high school students who were unstable in their personality structures, the value can be said to be reasonable.

This scale, which includes a low number of items, can be used to comprehend psychosomatic complaints of adolescent children at an early stage and to prevent diseases, and is suggested to be a highly practical scale.

The present investigation was conducted on subjects of high school students over 3 years to develop a scale for adolescent psychosomatic complaints. Subjects consisted of students of one high school. As issues in the future, it is necessary to include students of other high schools to increase the sample number and to assess the cross validity.

Ancillary