Adaptation and initial validation of the Patient Health Questionnaire – 9 (PHQ-9) and the Generalized Anxiety Disorder – 7 Questionnaire (GAD-7) in an Arabic speaking Lebanese psychiatric outpatient sample
Introduction
Mood and anxiety disorders are two of the most common and debilitating psychiatric disorders with a lifetime prevalence of 20.8% and 28.8% respectively, in the United States (Kessler et al., 2005). In Lebanon, the lifetime prevalence of mood and anxiety disorders is 12.6% and 16.7%, respectively (Karam et al., 2008). Patients with these disorders often rely on primary health care physicians and physicians in other specialties for diagnosis and treatment (Hijazi et al., 2011), which is sometimes problematic due to the low reliability of primary health care physicians in detecting psychiatric symptoms (El-Rufaie et al., 1997, Becker, 2004, Daradkeh et al., 2005). The availability of quick and reliable screening measures can therefore enhance the reliability and standardization of diagnoses especially when psychiatric services are not readily accessible. Brief screening tools are also useful in psychiatric clinics to help better detect depression and anxiety in patients with comorbid psychiatric illnesses and to prevent misdiagnoses. Two scales1 that have been widely used as both diagnostic tools and severity measures, are the Patient Health Questionnaire 9 (PHQ-9), and the Generalized Anxiety Disorder 7 (GAD-7).
The PHQ-9 is a 9-item self-report scale used to assess and monitor depression severity. It was developed as a screening tool for depressive symptomatology but is also used as a diagnostic measure of major depressive disorder (MDD) (Kroenke et al., 2001, Kroenke and Spitzer, 2002). The items on the PHQ-9 correspond to the 9 DSM-IV criteria used to diagnose a major depressive episode (DSM–IV–TR, 2000; American Psychiatric Association, 2000). The scale is shown to have high internal consistency (Chronbach's alpha between .86 and. 88) (Kroenke et al., 2001) and high test-retest reliability (Chronbach's alpha between .84 and .95) (Kroenke et al., 2001, Löwe et al., 2004). Most studies found evidence for the unidimensionality of the PHQ-9 although two-factor models were also supported (Williams et al., 2009, Huang et al., 2006, Cameron et al., 2011, Krause et al., 2008, Cannon et al., 2007).
Systematic reviews have established the scale's criterion validity against other measures of depression such as the Hamilton Rating Scale for Depression (HRSD, Cameron et al., 2011), Structured Clinical Interview for DSM disorders (SCID; Thekkumpurath et al., 2011, Wittkampf et al., 2007, Cannon et al., 2007), Beck Depression Inventory (BDI) (Martin et al., 2006, Cameron et al., 2011) and physician assessment (Becker, 2004, çorapçioglu and özer, 2004). Sensitivity and specificity measures ranged from 77 to 88% and 88–94%, respectively (Wittkampf et al., 2007, Gilbody et al., 2007, Kroenke et al., 2001). The PHQ-9 has been validated in community samples (Eack et al., 2006), psychiatric patients (Inoue et al., 2012), patients with specific medical conditions (McGuire et al., 2013, Kendel et al., 2010, Navinés et al., 2012, Monahan et al., 2008, Dum et al., 2008) as well as primary care patients and patients in general hospital settings (Daradkeh et al., 2005, Cameron et al., 2008, Persoons et al., 2003, Carballeira et al., 2007, Löwe et al., 2004, Eack et al., 2006, Diez-Quevedo et al., 2001). The PHQ-9 has also been translated into different languages and validated in various cultures (example Zhang et al., 2013, Inagaki et al., 2013, Osório et al., 2009, Persoons et al., 2003, Carballeira et al., 2007, Navinés et al., 2012, Karekla et al., 2012, Donnelly, 2007, Marc et al., 2014).
The GAD-7 is a 7-item self-report scale, also based on DSM-IV criteria, used to measure the severity of generalized anxiety disorders, and was also shown to be a reliable screening tool for panic, social anxiety and post-traumatic stress disorder (Kroenke et al., 2010, Kroenke et al., 2007). The GAD-7 exhibits excellent internal consistency (Chronbach's alpha between .89 and.92) (Löwe et al., 2008, Kertz et al., 2012, Spitzer et al., 2006), good convergent validity when compared to the Beck Anxiety Inventory (r=.72), Symptom Checklist 90 (SCI-90) anxiety subscale (r=.74) (Spitzer et al., 2006), Penn-State Worry Questionnaire (PSWQA-worry) (r=.64), Depression Anxiety Stress Scale (DASS-anxiety (r=.77)) and DASS-stress (r=.79) (Kertz et al., 2012). Studies also provide evidence for good sensitivity (83–89%) but questionable specificity (46–82%) (Spitzer et al., 2006, Kertz et al., 2012). All studies have shown the underlying structure to be unidimensional. The GAD-7, although not studied as extensively as the PHQ-9, has also been validated in community samples, psychiatric patients and patients in primary health care settings, and has been validated in various cultures (example García-Campayo et al., 2010, Löwe et al., 2008, Delgadillo et al., 2012, Dear et al., 2011, Donker et al., 2011, Sidik et al., 2012, Konkan et al., 2013).
Despite the wide use of these scales, no study has determined the validity and utility of these scales in the Lebanese population. Other measures of depression and anxiety are available in the Arabic language, but their validity and applicability in Lebanese psychiatric contexts remains uncertain. An Arabic version of the BDI-II was tested on samples of university students from different Arab countries (Alansari, 2005, Alansari, 2006, Al-Musawi, 2001), with results showing good internal consistency but lacking clear measures of validity. The PHQ depression, anxiety and somatization subscales were investigated in a sample of Saudi Arabia primary care patients with results showing high specificity and moderate sensitivity for the depression and somatoform subscales and high specificity but low sensitivity for the GAD and panic subscales, when compared to psychiatric assessment (Becker et al., 2002).
Two depression rating scales that have been validated in Lebanon are the Center for Epidemiologic Studies – Depression Scale (CES-D) (Kazarian and Taher, 2010) and the Hopkins Symptom Checklist – 25 (HSCL-25) (Mahfoud et al., 2013). The CES-D has shown very good internal consistency (alpha =.84) and a significantly higher correlation with a measure of social avoidance (r=.49) compared to social anxiety (r=.26) in a non-psychiatric community sample in Beirut. Factor analysis supported a two-factor solution, with the first factor representing Depressed Affect and the second Lack of Positive Affect. The Depressed Affect factor appeared to be a more accurate and reliable measure of depressive symptoms in the Lebanese population. The psychometric properties of the HSCL-25 were tested against the Mini International Neuropsychiatric Interview on a sample of women with medically unexplained vaginal discharge. Internal consistency was very good for the depression (.88) and anxiety (.85) subscales. Measures of sensitivity were very good for the depression (82%) and anxiety (84%) subscales at an optimal cutoff of 2.10 and 2.00, respectively. Specificity was good for the depression (70%) but fair (59%) for the anxiety subscale.
Although the CES-D and HSCL-25 can be useful screeners for depression and anxiety in the Lebanese population, their length limits their use with difficult or resistant patients and with patients with cognitive impairment. Long scales are also problematic in patient overloaded clinics and busy health care centers. The aim of this study was therefore to adapt and validate the PHQ-9 and GAD-7, two concise and widely used scales in clinical and research settings, as screening tools for depression and anxiety symptoms. The primary aim was to investigate the factor structure and reliability of the Arabic PHQ-9 and GAD-7 in a heterogeneous sample of Lebanese psychiatric outpatients. The second aim was to determine the scales’ sensitivity, specificity and convergent validity by comparing them to clinical diagnoses of depression and anxiety as well as to another self-report measure of depression, the Psychiatric Diagnostic Screening Questionnaire – Major Depressive Disorder (PDSQ-MDD subset. Supplementary material 1).
Section snippets
Participants
The study sample included 186 Lebanese adult psychiatric outpatients recruited between 2010 and 2012 during their first visit to the Department of Psychiatry at the American University of Beirut Medical Center (AUBMC). The study was approved by AUBMC's Institutional Review Board.
Measures and procedure
The PHQ-9 and GAD-7 were translated from English to Arabic by bilingual psychologists. Two forward translations from English to Arabic were produced for each scale, and then another bilingual psychologist backtranslated
Patient characteristics
A total of 186 patients participated in the study. The mean age of the sample was 35.6 years and did not differ with respect to gender distribution (p=.34). Mean PHQ-9 (n=179) and GAD-7 (n=116) scores were in the moderate symptom severity range. No gender difference in total score on either scale was found (Table 1). Clinician diagnoses were available for 176 of the patients. Fifty-nine percent of the sample (104/176) had a diagnosis of a depressive disorder and 38% (67/176) had a diagnosis of
Discussion
The aim of this study was to translate and provide psychometric properties for two quick screening measures of depression and anxiety to be used in medical settings around Lebanon for clinical and research purposes. Based on the distribution of scores across the scale items results show that participants endorsed more severe PHQ-9 symptoms of anhedonia and hopelessness compared to other symptoms, and more severe GAD-7 symptoms of nervousness and worry. Results support the reliability of the
Limitations
There are several limitations to the present study. The main limitation is that scale scores were compared to clinical diagnoses. Our clinicians do not have a common gold standard tool to make their diagnoses, such as a validated structured interview in Arabic. Diagnoses were therefore collected through chart reviews. Moreover, clinicians consisted of psychiatrists and clinical psychologists, with varying degrees of seniority. This may have also resulted in diagnostic variation, especially in
Acknowledgment
Work was funded by PFIZER WI74077 (ZN).
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