Innovations In Clinical Neuroscience

SEP-OCT 2014

A peer-reviewed, evidence-based journal for clinicians in the field of neuroscience

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Page 33 of 201

Innovations in CLINICAL NEUROSCIENCE [ V O L U M E 1 1 , N U M B E R 9 – 1 0 , S E P T E M B E R – O C T O B E R 2 0 1 4 ] 34 1) assessing the comparative administration times of the three instruments; 2) examining the concordance between the ISST-Plus and the S-STS, and 3) describing combinations of suicidal ideation that were captured on the S-STS and the ISST-Plus in this study but not on the C–SSRS. METHODS Sample. Forty adult subjects identified as having SIB with varying degrees of severity across the full range of suicidality from "not present" to "extremely severe" were recruited from inpatient, outpatient, and emergency room settings. Since accidents may be suicide attempts in disguise and the FDA required adjudication for suicidality of all accidents that occurred in antidepressant trials, we recruited an additional five subjects who had been involved in recent accidents. None of these subjects were suicidal. Participation was voluntary. The study was approved by the Institutional Review Board of the University of Alabama at Birmingham, and all subjects gave informed consent before the study interviews took place. Interviewers and training. Five raters, all qualified mental health professionals with experience working with suicidal patients, were used. The authors of each of the three scales trained and certified all of the raters and provided them with training slides and materials developed for each of the suicide assessment instruments (ISST-Plus, S-STS, and C–SSRS). Study design and procedures. Before administering the three scales, the research team collected demographic information and assessed each subject using a Clinical Global Impression Scale for Severity of Suicidality (CGI-SS) to ensure that the sample was balanced across the full range of SIB severity. Scale administration. Each patient was interviewed and rated on each scale (ISST-Plus, S-STS, and C–SSRS) on the same day. The S-STS patient-rated scale was first completed by all patients directly into the laptop computer prior to the administration of any clinician-rated scales. The three clinician-rated scales (ISST-Plus, S-STS, and C– SSRS) were then administered in a predetermined random order sequence by three independent raters who were blind to the ratings on the other scales (Figure 1). Direct data entry (electronic data capture) at the time of the visit was used to collect the ISST-Plus and S-STS data. This system precluded the possibility of missing values, double entries, legibility problems, and transcription errors. Since the C–SSRS did not have an equivalent direct entry format, all of the data for this scale were collected on the paper version and the categories endorsed were subsequently entered into the database for analysis. The clinician completed the clinician-rated version of the S-STS blind to the prior patient-rated version. When the clinician saved the clinician ratings, the laptop computer immediately generated a version of S-STS displaying any discrepancies between the clinician and patient versions and asked both patient and clinician to continue the interview to come to agreement in reconciling any differences (S-STS reconciled version). This led to the generation of data on the three variants of the S-STS (clinician-rated, patient-rated, and reconciled versions). It provided the study team with an opportunity to investigate the relative merits of each of these three possible a pproaches to assessing suicidality. The time frame for SIB assessment for all three instruments was the past seven days. Video recordings of subjects were completed with separate consent. Instrument mapping process. Figure 2 shows the FDA categories used for mapping. For completeness, we included the 11 categories in the FDA 2012 Draft Guidance and four additional categories from the original C-CASA and the FDA 2010 Draft Guidance that are of interest to regulatory agencies and are likely to occur in real-world experience with classification of suicide-like behavior (last 4 categories in Figure 2). The authors of each of the scales (ISST-Plus, S-STS, and C–SSRS) provided detailed instructions on the algorithms they used to map item responses on their scales to the FDA-CASA 2012 categories. (Table 1). Mapping was performed, using these algorithms, with a computer- coded procedure for the S-STS and ISST-Plus and by a trained individual at the site for the C–SSRS. Statistical analysis. We assessed baseline demographics and clinical characteristics using descriptive statistics. We used two approaches to evaluate agreement between the test instruments and the C–SSRS: Cohen's Kappa and the area under the receiver operating characteristic curve (AUC). Cohen's Kappa is a chance-corrected measure of agreement that ranges from 0 to 1. 15 Shrout et al, 16 after Fleiss, 17 suggest that Kappa values greater than approximately 0.75 indicate excellent agreement beyond chance, values below approximately 0.40 represent poor agreement beyond chance, and values in between indicate fair to good agreement beyond chance. We report the Kappa values with 95-percent confidence intervals (CI). While Kappa is often used as a measure of agreement, it is FIGURE 1. Study scale administration rate

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