Comparison of unweighted and item response theory-based weighted sum scoring for the Nine-Questions Depression-Rating Scale in the Northern Thai Dialect.

BACKGROUND: The Nine-Questions Depression-Rating Scale (9Q) has been developed as an alternative assessment tool for assessing the severity of depressive symptoms in Thai adults. The traditional unweighted sum scoring approach does not account for differences in the loadings of the items on the actual severity. Therefore, we developed an Item Response Theory (IRT)-based weighted sum scoring approach to provide a scoring method that is more precise than the unweighted sum score. METHODS: Secondary data from a study on the criterion-related validity of the 9Q in the northern Thai dialect was used in this study. All participants were interviewed to obtain demographic data and screened/evaluated for major depressive disorder and the severity of the associated depressive symptoms, followed by diagnosis by a psychiatrist for major depressive disorder. IRT models were used to estimate the discrimination and threshold parameters. Differential item functioning (DIF) of responses to each item between males and females was compared using likelihood-ratio tests. The IRT-based weighed sum scores of the individual items are defined as the linear combination of individual response weighted with the discrimination and threshold parameters divided by the plausible maximum score based on the graded-response model (GRM) for the 9Q score (9Q-GRM) or the nominal-response model (NRM) for categorical combinations of the intensity and frequency of symptoms from the 9Q responses (9QSF-NRM). The performances of the two scoring procedures were compared using relative precision. RESULTS: Of the 1,355 participants, 1,000 and 355 participants were randomly selected for the developmental and validation group for the IRT-based weighted scoring, respectively. the gender-related DIF were presented for items 2 and 5 for the 9Q-GRM, while most items (except for items 3 and 6) for the 9QSF-NRM, which could be used to separately estimate the parameters between genders. The 9Q-GRM model accounting for DIF had a higher precision (16.7%) than the unweighted sum-score approach. DISCUSSION: Our findings suggest that weighted sum scoring with the IRT parameters can improve the scoring when using 9Q to measure the severity of the depressive symptoms in Thai adults. Accounting for DIF between the genders resulted in higher precision for IRT-based weighted scoring.

Attempted Suicide Triggers in Thai Adolescent Perspectives.

The study goal was to describe attempted suicide triggers in Thai adolescents. A descriptive exploratory qualitative study approach was used utilizing in-depth interviews with twelve adolescents who had attempted suicide and six of their parents. Content analysis was conducted. Attempted suicide triggers were (1) severe verbal criticisms and expulsion to die by a significant family member, (2) disappointed and unwanted by boyfriend in first serious relationship, (3) unwanted pregnancy, and (4) mental illness leading to intense emotions and irresistible impulses. These attempted suicide triggers should be of concern and brought into suicide prevention management programs such as emotional management, effective communication for adolescents and family.

Factor Structures in the Depressive Symptoms Domains in the 9Q for Northern Thai Adults and Their Association with Chronic Diseases.

Most of the common models to examine depression are one-factor models; however, previous studies provided several-factor structure models on each depressive symptom using the Patient Health Questionnaire-9 (PHQ-9). The Nine-Questions Depression-Rating Scale (9Q) is an alternative assessment tool that was developed for assessing the severity of depressive symptoms in Thai adults. This study aimed to examine the factor structure of this tool based on the factor structure models for the PHQ-9 provided in previous studies using confirmatory factor analysis (CFA). We also examined the association of chronic diseases and depressive symptoms using the Multiple Indicators Multiple Causes model among 1346 participants aged 19 years old or more without psychiatric disorders. The results show that the two-factor CFA model with six items in the cognitive-affective domain and three items in the somatic domain provided the best fit for depressive symptoms in the study population (RMSEA = 0.077, CFI = 0.953, TLI = 0.936). Dyslipidemia was positively associated with both cognitive-affective symptoms (ß = 0.120) and somatic depressive symptoms (ß = 0.080). Allergies were associated with a higher level of cognitive-affective depressive symptoms (ß = 0.087), while migraine (ß = 0.114) and peptic ulcer disease (ß = 0.062) were associated with a higher level of somatic symptoms. Increased age was associated with a lower level of somatic symptoms (ß = -0.088). Our findings suggested that considering depressive symptoms as two dimensions yields a better fit for depressive symptoms. The co-occurrence of chronic diseases associated with depressive symptoms should be monitored.

Services for depression and suicide in Thailand.

Depression, together with suicide is an important contributor to the burden of disease in Thailand. Until recently, depression has been significantly under-recognized in the country. The lack of response to this health challenge has been compounded by a low level of access to standard care, constraints on mental health personnel and inadequate dissemination of knowledge in caring for people with these disorders. In the past decade, significant work has been undertaken to establish a new evidence-based surveillance and care system for depression and suicide in Thailand that operates at all levels of health-care provision nationwide. The main components of the integrated system are: (i) community-level screening for depression in at-risk groups, using a two-question tool; (ii) assessment of the severity of depression using a nine-question scale; (iii) diagnosis and treatment by general practitioners; (iv) psychosocial care provided by psychiatric nurses; (v) continuous care for relapse and suicide prevention; and (vi) promotion of mental well-being and prevention of depression in at-risk populations. Factors such as appropriate financial mechanisms, capacity-building programmes for health-care workers, and robust treatment guidelines have contributed to the success and sustainability of this comprehensive surveillance and care system. By 2016, more than 14 million people at risk had been screened for depression and received mental health education; more than 1.7 million people with depression had received psychosocial interventions; 0.7 million diagnosed patients had received antidepressants; and 0.8 million were being followed up for relapse and suicide prevention. The application of this surveillance and care system has led to an enormous increase in the accessibility of standard care for people with depressive disorders, from 5.1% of those with depressive disorders in 2009 to 48.5% in 2016.

Development and psychometric properties of the Suicidality of Adolescent Screening Scale (SASS) using Multidimensional Item Response Theory.

Suicide prevention in adolescents by early detection using screening tools to identify high suicidal risk is a priority. Our objective was to build a multidimensional scale namely "Suicidality of Adolescent Screening Scale (SASS)" to identify adolescents at risk of suicide. An initial pool of items was developed by using in-depth interview, focus groups and a literature review. Initially, 77 items were administered to 307 adolescents and analyzed using the exploratory Multidimensional Item Response Theory (MIRT) to remove unnecessary items. A subsequent exploratory factor analysis revealed 35 items that collected into 4 factors: Stressors, Pessimism, Suicidality and Depression. To confirm this structure, a new sample of 450 adolescents were collected and confirmatory MIRT factor analysis was performed. The resulting scale was shown to be both construct valid and able to discriminate well between adolescents that had, and hadn't previous attempted suicide.