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Poster Session 1 Part IX Poster Session 1 99 SCALING DEPRESSION WITH PSYCHOPHYSICAL SCALING: A R COMPARISON BETWEEN THE BORG CR SCALE⃝ (CR100, R CENTIMAX⃝) AND PHQ-9 ON A NON-CLINICAL SAMPLE Elisabet Borg and Jessica Sundell Department of Psychology, Stockholm University, SE-10691 Stockholm, Sweden <[email protected]> Abstract A non-clinical sample (n =71) answered an online survey containing the Patient Health Questionnaire-9 (PHQ-9), that rates the frequency of symptoms of depression (DSM-IV). R R The questions were also adapted for the Borg CR Scale⃝ (CR100, centiMax⃝) (0–100), a general intensity scale with verbal anchors from a minimal to a maximal intensity placed in agreement with a numerical scale to give ratio data). The cut-off score of PHQ-9 10 was found to correspond to 29cM. Cronbach’s alpha for both scales was high (0.87)≥ and ≥ the correlation between the scales was r =0.78 (rs =0.69). Despite restriction of range, the cM- scale works well for scaling depression with added possibilities for valuable data analysis. According to the World Health Organisation (2016), depression is a growing health prob- lem around the globe. Since it is one of the most prevalent emotional disorders, can cause considerable impairment in an individual’s capacity to deal with his or her regular duties, and at its worst is a major risk factor for suicide attempt and suicide, correct and early diagnosis and treatment is very important (e.g., APA, 2013, Ferrari et al., 2013; Richards, 2011). Major depressive disorder (MDD) is characterized by distinct episodes of at least two weeks duration involving changes in affects, in cognition and neurovegetative func- tions, and described as being characterized by sadness, loss of pleasure or interest, fatigue, low self- esteem and self-blame, disturbed appetite and sleep, in addition to poor concen- tration (DSM- V, APA, 2013; WHO, 2016). In parallel to the Diagnostic and Statistical Manual of Mental Disorders (DSM-V, APA, 2013) several instruments have been developed for assessment of depression and its symptoms, for example: the Hospital Anxiety and Depression Scale (HAD, Zigmond & Snaith, 1983); the Beck Depression Inventory (BDI, Beck et al., 1961); the Montgomery— Asberg˚ Depression Rating Scale (Montgomery & Asberg,˚ 1979) and the Patient Health Questionnaire (PHQ-9, Kroenke, Spitzer & Williams, 2001). Weather constructed accord- ing to classical test theory or item response theory, the focus during construction of such psychological tests as these has been on the formulation and evaluation of test items, and not so much on the response scale used, commonly Likert scales of intensity, agree–not agree, or frequency. The test result for each individual is usually summed into a total score and compared to norms for the total population. Often, however, obtained data is of an ordinal character, more or less depression, and there is no saying how much more or less. Within the psychophysical tradition of scale development, the main interest has been scales to obtain response data that grow linearly with perception (and sensation) when studying psycho-physical relationships (of, for example, loudness, brightness, taste, pain, exertion, etc.). One important method is Magnitude Estimation (ME) where in- 101 dividuals without restrictions assign numerals in proportion to perceived intensities of whatever is being scaled, resulting in ratio data and the possibility to describe relations among sensory magnitudes (see, e.g., Stevens, 1975; Marks, 1974). In many applied set- tings, however, ratio scaling procedures such as ME are impractical to use. They also lack an important aspect present in more simple category scales with verbal anchors, the possibility of obtaining direct level determinations (of, for example, what is perceived as “weak” or “strong”). The Borg CR Scales (Category-Ratio) are “level-anchored ratio scales” developed to combine the advantages of category scales with those of ratio scales. Some important principles in scale construction have been Gunnar Borg’s Range model for interindividual comparisons, magnitude estimation for ratio data, choice of the most appropriate verbal anchors, and congruence between the verbal anchors and the ratio scale (G. Borg, 1982, R 1998, G. Borg, & E. Borg, 2001). The latest CR scale, the Borg centiMax⃝ Scale (0–100, also called CR100) is shown in Fig. 1. “Maximal” (100) is anchored in a previously experienced maximal perceived exertion (of, for example, lifting something so heavy so that you can just barely manage to lift it). This maximal perception constitutes a unit and the scale gives measures in centigrade of this maximum, hence the name “centiMax” (cM). The CR Scales have been validated by physiological variables and performance measures of perceived exertion, and in other sensory areas by comparison to ME, and have mainly been used to assess pain, perceived exertion, shortness of breath, muscle fatigue, etc. (see, for example, G. Borg, 1998, E. Borg, 2007, E. Borg et al., 2010, Dedering, N´emeth, & Harms-Ringdahl, 1999; Kendrick, Baxi, & Smith, 2000; Just et al., 2010). However, being general intensity scales, the Borg CR scales may be used also in the study and diagnosis of emotional variables such as those present in major depression. Because depression is diagnosed from the subjective symptoms and suffering of the patients it is important to be able to make as accurate and information-rich measurements as possible. R In a series of studies the Borg centiMax⃝ Scale was compared to the Beck De- pression Inventory (BDI, Beck et al., 1961) and found to work very well. The BDI is constructed to measure major depression with 21 items rated on four-point category scales. The result showed correlations of 0.754 and 0.824 between the two scales (Borg, Magalhaes, M¨ortberg, & Costa, 2016; Magalhaes, 2017). The Patient Health Questionnaire (PHQ-9) is another popular self-report instru- ment to measure depressive symptoms (Kroenke, Spitzer, & Williams, 2001). The scale uses the frequency of symptoms in a four-point category scale from “Not at all” (0) to “Nearly every day” (3), summed into a total score (0–27) of depression severity (None, Mild, Moderate, Moderately Severe and Severe) with a cut-off score of 10 for detecting cases of current Major Depressive Episode (Kroenke et al., 2009).≥ Reported sensitivity and specificity for PHQ-9 10 has been high and above 80% (see, e.g., Kroenke, Spitzer, & Williams, 2001; Kroenke,≥ Spitzer, Williams, & L¨owe, 2010; Mitchell, Yadegarfar, Gill, &Stubbs,2016).Themainpurposeofthisstudywastoexploreandimprovethemea- surement of depression. For this reason, a non-clinical sample was asked to complete awell-establisheddepressioninstrumentthatmeasuresfrequencyofdepressivesymp- toms (PHQ-9). Additionally, they were asked to respond to the same items on the Borg R centiMax⃝ Scale. 102 Method Participants A non-clinical convenience sample (n =71,40menand31women),meanage32(sd =11) years, participated. They were informed that the survey was anonymous and voluntary, for research purposes only, and that the survey could be terminated at any point. Participants that did not fulfil the entire questionnaire were excluded from the analysis. Materials and Procedure In an online questionnaire (administered in Survey & Report), depression was first mea- sured with The Patient Health Questionnaire (PHQ-9) (Kroenke, Spitzer, & Williams, 2001). The PHQ-9 is a self-administered diagnostic instrument for depression consisting of nine items with responses given in relation to how often the symptoms have bothered the person the last 2 weeks. Answers are given on a 4 categories rating scale (not at all (0), several days (1), more than half the days (2), nearly every day (3)) and added into a total score from 0–27 of depression severity for None, Mild (5–9 points), Moderate (10–14 points), Moderately Severe (15–19 points), and Severe depression ( 20 points). ≥R The second part the full instruction for the Borg centiMax⃝ Scale (Cr100, cM) was given, with a maximal perceived exertion as the main reference (G. Borg & E. Borg, 2001, 2016). The questions from the PHQ-9 were adapted to fit the centiMax Scale and subjects were asked how intense the feelings had been (in centigrade/cM of maximum). The sixth item on the PHQ-9 (“Feeling bad about yourself—or that you are a failure or have let yourself or your family down”) was separated into two items with the centiMax, due to it asking for two different emotions (low self-esteem and feelings of failure). The R R Fig. 1. The Borg centiMax Scale⃝ (CR100, cM) used in this article ⃝ G. Borg & E. Borg, 2001, 2016; E. Borg, 2007. See also www.borgperception.se. Printed with permission. 103 cM-values for these two items were then averaged so that for the analysis both scales had the same number of items. Results Descriptive statistics are presented in Table 1. The average PHQ-9 score for the total sample was 6.1 (sd =5.3) (Mild depression) and 20 cM (sd =16cM)ontheBorg centiMax Scale (just below Moderate, see Figure 1). In total, 13 persons (18%), 9 men (22.5%) and 4 women (12.9%) had PHQ-9 10 (moderate depression). Data for both scales was somewhat positively skewed (for≥ PHQ-9: 1.5; for centiMax: 1.6) with positive kurtosis (for PHQ-9: 1.9; for centiMax: 3.0). The Pearson correlation between the two scales was r =0.78 (p<0.001) (rs = 0.69,p < 0.001). Linear regression with PHQ-9 as independent variable and centiMax gave B0 =5.0(p =0.010) and B1 =2.4(p<0.001). By using this equation, a cut-off score of 29 cM (equivalent to PHQ = 10) was calculated for Moderate depression. This corresponds to an average feeling of the intensity of the symptoms between Moderate and Somewhat strong (Fig. 1). In the total sample, 12 persons had an average centiMax score 29cM and 8 of these were the same persons that had PHQ-9 10.
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