The General Health Questionnaire (GHQ) measure is a self-reported questionnaire that assesses professionals’ general health. This scale is available in four versions: 60-item version (GHQ-60), 30-item version (GHQ-30), 28-item version (GHQ-28) and 12-item version (GHQ-12). In this study the General Health Questionnaire 30 was used (Goldberg 1972, 1979; Goldberg and William, 1988). GHQ-30 is a self-administered screening questionnaire designed to detect (screen) those with a diagnosable psychiatric disorder (Goldberg 1972). It is widely known and
is used as a screening measure to detect the status of mental well-being in the general population within a given community (i.e. non-psychiatric clinical settings or outpatient clinics). The measure evaluates the respondent’s present health status and asks if that differs from his or her usual state. This measure was chosen based on its ability to screen participants quickly and reliably. GHQ-30 is the only GHQ questionnaire that focuses solely on the factors corresponding to anxiety, feelings of incompetence, depression, difficulty in coping and social dysfunction, which are the essential factors that are highly associated with secondary traumatic stress (Figley 1995). As noted above, GHQ-30 is a widely used instrument by researchers in different fields, including those of occupational health, medicine and psychology, and clinicians who wish to screen individuals for psychiatric disorders.
3.5.1 Calculating GHQ-30 Scores
The four versions of the GHQ are connected to each other because they contain similar items, although diverse scoring techniques can be used for the questionnaire (including a modified Likert-type scoring technique) and a total score is produced. The total score indicates the intensity of psychological morbidity where higher scores show higher levels of morbidity and/or weaker general health. For each item the respondents have to indicate the occurrence of a particular symptom on a four-point scale: 1 – ‘less than usual’, 2 – ‘no more than usual’, 3 – ‘more than usual’, and 4 – ‘much more than usual’.
Goldberg (1979) explained that with positive questions such as ‘Been able to enjoy your normal day-to-day activities’, the response ‘same as usual’ evidently shows normal, healthy functioning and for this reason the absence of a symptom. For ‘negative’ questions the response ‘no more than usual’ shows what is normal for the person, but it also indicates the occurrence of a symptom, that is to say a chronic one. Since chronic circumstances can manipulate current
mental health, it can be said that they should considered when obtaining a score from the General Health Questionnaire. Even though there are a small number of accounted data on the reliability of the GHQ, at least six studies have focused on the validity of diverse versions of the GHQ, four in general practice consulting surroundings, and two in community assessments (Benjamin et al. 1982; Finlay-Jones and Murphy 1979; Goldberg and Blackwell 1970, Tarnopolsky et al. 1979; Tennant 1977). These six validity studies have recognized that the GHQ has a sensitivity of (A/ = 74%) and specificity of (M = 82%), and an adequate misclassification rate of (Af = 18%) as a screening tool in general practice and community surroundings. As such, this measure can be considered a valid tool for assessing participants’ general health and well-being.
3.5.2 Reliability and Validity of GHQ-30
A recent study tested the reliability and validity of GHQ-30 (Dale et al. 2012). The reliability of GHQ-30 was examined by assessing the internal consistency (homogeneity) with item-to-total correlations, calculated by Spearman’s rank correlations (rs) between each item and the total scale. Each item was excluded from the total scale score when that particular item was analysed (Streiner and Norman 2003). Internal consistency was also calculated with the Cronbach’s alpha 0.90. Construct validity of GHQ-30 was measured by comparing ‘known groups’ of people who were predicted to have high scores (i.e. those who perceived themselves to be in ill health and those who were perceived as having helplessness, loneliness, anxiety and depressive mood), with other ‘known groups’ of people with expected low scores (i.e. those who perceived themselves to be in good health and who did not perceive themselves as having helplessness, loneliness, anxiety and depressive mood). The purpose of these group characteristics relied on their expected relationships to mental health. Differences in median GHQ scores between these groups were calculated using the Mann–Whitney U-test for independent samples. Construct
validity of GHQ-30 was also measured by performing an explorative factor analysis; factor loadings greater than 0.40 were used as cut-off values for including the items in a factor. The chi-square test was used to observe sex differences, and the t-test for unrelated samples was used to test differences in age between the study participants and the dropouts.
The obtained Cronbach’s alpha reliability coefficient of 0.93 indicated a high level of homogeneity of the scale, and this outcome is in agreement with numerous former studies testing reliability and validity of GHQ-30. Homogeneity of the scale was also established in the item-to- total correlations, which presented that all items correlated significantly to the total scale (rs = 0.22). As suggested by Streiner and Norman (2003) the lowest value for item-to-total correlations should be r = 0.20. Furthermore, a general tendency was that the negatively worded items, reflecting mental distress or decline, had higher correlation values with the total scale than did the positively worded items which reflected coping abilities and social attachment. Construct validity was clearly supported by significant differences in the total GHQ-30 scores between groups with expected high and low scores. The outcomes specify that the apparatus could be suitable for screening mental conditions like depression and anxiety, perceived helplessness and loneliness, and perceived health in general. Corresponding outcomes were observed in the study by Dale et al. (2012) regarding scores for groups with good or poor health (P = 0.004); groups who perceived loneliness or not (P = 0001); groups who perceived anxiety or not (P = 0.035); and groups who felt depressed or not (P = 0.001). All these measurements are, to different extents and in different operationalized terms, included in the GHQ-30 (Goldberg, 1988; McDowell, 2006). Construct validity was also supported by a logical four factor solution that explained 50.0% of the variance.
0 Regarding the several versions of the GHQ that have been developed, the full 60-item
version is ideally recommended when possible (Streiner and Norman 2003). However, that version of the instrument is rather comprehensive and a lot of physical items are included. In the shortened versions the physical symptoms are removed, and among the several existing versions the 30-item GHQ has been used most. The 30-item version has been clearly recommended for use in general practice for screening mental health issues among helping professionals across many countries (McDowell 2006).