Evidence-based guidelines for interpretation of the Panic Disorder Severity Scale.

BACKGROUND: The Panic Disorder Severity Scale (PDSS) is promising to be a standard global rating scale for panic disorder. In order for a clinical scale to be useful, we need a guideline for interpreting its scores and their changes, and for defining clinical change points such as response and remission. METHODS: We used individual patient data from two large randomized controlled trials of panic disorder (total n=568). Study participants were administered the PDSS and the Clinical Global Impression (CGI)--Severity and --Improvement. We applied equipercentile linking technique to draw correspondences between PDSS and CGI-Severity, numeric changes in PDSS and CGI-Improvement, and percent changes in PDSS and CGI-Improvement. RESULTS: The interpretation of the PDSS total score differed according to the presence or absence of agoraphobia. When the patients were not agoraphobic, score ranges 0-1 corresponded with "Normal," 2-5 with "Borderline," 6-9 with "Slightly ill," 10-13 with "Moderately ill," and 14 and above with "Markedly ill." When the patients were agoraphobic, score ranges 3-7 meant "Borderline ill," 8-10 "Slightly ill," 11-15 "Moderately ill," and 16 and above "Markedly ill." The relationship between PDSS change and CGI-Improvement was more linear when measured as percentile change than as numeric changes, and was indistinguishable for those with or without agoraphobia. The decrease by 75-100% was considered "Very much improved," that by 40-74% "Much improved," and that by 10-39% "Minimally improved." CONCLUSION: We propose that "remission" of panic disorder be defined by PDSS scores of five or less and its "response" by 40% or greater reduction.

Informatics tools to improve clinical research study implementation.

BACKGROUND: There are numerous potential sources of problems when performing complex clinical research trials. These issues are compounded when studies are multi-site and multiple personnel from different sites are responsible for varying actions from case report form design to primary data collection and data entry. METHODS: We describe an approach that emphasizes the use of a variety of informatics tools that can facilitate study coordination, training, data checks and early identification and correction of faulty procedures and data problems. The paper focuses on informatics tools that can help in case report form design, procedures and training and data management. CONCLUSION: Informatics tools can be used to facilitate study coordination and implementation of clinical research trials.

Independent evaluator knowledge of treatment in a multicenter comparative treatment study of panic disorder.

The purpose of this study was to examine independent evaluators' (IEs) blindness to treatment condition during a Multicenter Comparative Treatment Study of Panic Disorder. IEs were 15 doctoral- and masters-level clinicians in psychology, social work, and medicine. They conducted three post-treatment assessments with each patient. Immediately after each assessment interview, IEs completed a form indicating which of the five possible treatments they believed the patient had received and any specific information that provided IEs with information about a patient's treatment condition. These forms were completed for 170 patients. Analyses were conducted to determine the accuracy of guesses about treatment condition by IEs during post-treatment assessments, the relationship between accuracy of IE guessing and actual treatment assignment, the relationship between accurate guessing and outcome ratings, and contributors to the breaking of the blind. A significant relationship was found between IE guesses and actual treatment at all three assessment points, across individual IEs, treatment sites, and IE professional affiliations. IEs were no more accurate in their guessing about patients taking medication than those receiving behavior therapy. Patients and project staff inadvertently provided information to IEs that enhanced the rates of accurate guessing. Implications of these findings on interpretation of the treatment study are discussed, and recommendations are made for improving blindness procedures.

Incidence of tardive dyskinesia with atypical versus conventional antipsychotic medications: a prospective cohort study.

OBJECTIVE: Most previous studies of the incidence of tardive dyskinesia with atypical antipsychotics compared with conventional antipsychotics have not had tardive dyskinesia as their primary focus. The current study aimed to compare the incidence of tardive dyskinesia with atypical vs conventional antipsychotics using methods similar to those from a previous prospective cohort study at our site in the 1980s. METHOD: Three hundred fifty-two initially tardive dyskinesia-free psychiatric outpatients (diagnosed at baseline using the Structured Clinical Interview for DSM-IV) were examined for a new diagnosis of tardive dyskinesia (using the Abnormal Involuntary Movement Scale and Glazer-Morgenstern criteria) every 6 months for up to 4 years at a community mental health center. At baseline, subjects were receiving conventional antipsychotics only (23%), atypicals only (64%), or both (14%). Only 26 subjects had never received conventional antipsychotics. Baseline evaluations were conducted from November 2000 through May 2003. Follow-ups were conducted through February 2005. RESULTS: Compared with subjects treated with conventional antipsychotics alone since the previous visit, the adjusted tardive dyskinesia incidence rate-ratio for subjects treated with atypical antipsychotics alone was 0.68 (95% CI, 0.29-1.64). The incidence and prevalence of tardive dyskinesia was similar to previous findings at this site in the 1980s. CONCLUSIONS: The incidence of tardive dyskinesia with recent exposure to atypical antipsychotics alone was more similar to that for conventional antipsychotics than in most previous studies. Despite high penetration of atypical antipsychotics into clinical practice, the incidence and prevalence of tardive dyskinesia appeared relatively unchanged since the 1980s. Clinicians should continue to monitor for tardive dyskinesia, and researchers should continue to pursue efforts to treat or prevent it.

Predictors and time course of response among panic disorder patients treated with cognitive-behavioral therapy.

OBJECTIVE: Cognitive-behavioral therapy (CBT) is well documented as an efficacious treatment for panic disorder. We provided open CBT treatment to patients who subsequently participated in a maintenance treatment study. This article reports on predictors and trajectory of response in 381 participants who completed treatment at 4 sites. METHOD: Participants who met criteria for panic disorder with or without agoraphobia (N = 381) completed assessment and entered treatment. Of these, 256 completed 11 sessions of CBT delivered by trained and supervised research therapists. Raters trained to reliability obtained demographic data and administered structured diagnostic interviews and the Hamilton Rating Scales for Depression and Anxiety and the Panic Disorder Severity Scale (PDSS) measures at baseline and posttreatment. We obtained self-report (SR) measures of anxiety sensitivity and adult separation anxiety at baseline and posttreatment and PDSS-SR ratings weekly. The study was conducted between November 1999 and July 2002. RESULTS: Treatment response rate was 65.6% for completers and 44.1% for the intent-to-treat sample. Greater severity of panic disorder and lower levels of adult separation anxiety predicted response. Beginning at week 4, responders showed greater mean decreases in PDSS scores than non-responders and maintained the advantage throughout the treatment. By week 6, 76% of responders, compared to 36% of nonresponders, recorded PDSS scores at least 40% below baseline on 2 consecutive weeks (odds ratio = 5.42, 95% CI = 3.10 to 9.48). CONCLUSION: These results suggest that CBT is just as effective for more severe panic disorder patients as it is for those with less severe panic disorder, regardless of other comorbid disorders, including agoraphobia. However, patients experiencing adult separation anxiety disorder are less likely to respond. Our results further inform clinicians that many people who will respond to 11 weeks of treatment will have done so by the middle of the treatment.