Validation of the Investigator's Assessment Questionnaire, a new clinical tool for relative assessment of response to antipsychotics in patients with schizophrenia and schizoaffective disorder

Tandon, Rajiv; DeVellis, Robert F.; Han, Jian; Li, Hong; Frangou, Sophia; Dursun, Serdar; Beuzen, J.N.; Carson, William H.; Corey‐Lisle, Patricia K.; Falissard, Bruno; Jody, D.; Kujawa, Mary J.; L’Italien, G.; Marcus, Ronald N.; McQuade, Robert D.; Ray, Saurabh; Peborgh, Pascal Van

doi:10.1016/j.psychres.2005.05.006

Cited by 39 publications

(16 citation statements)

References 16 publications

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“…Therefore, training is required for performing a standardized evaluation [14]. Other user-friendly assessments include the Revised Global Outcome Assessment of Life in Schizophrenia (Revised GOALS) [15], the Investigator's Assessment Questionnaire (IAQ) [16] and the Targeted Inventory on Problems in Schizophrenia (TIP-Sz) [17], although they have some limitations in terms of methodology. We also believe that other important aspects of illness management should be supplemented with appropriate subjective scales as necessary [18].…”

Section: Discussionmentioning

confidence: 99%

Is there a linear relationship between the Brief Psychiatric Rating Scale and the Clinical Global Impression-Schizophrenia scale? A retrospective analysis

2010

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BackgroundAlthough the Brief Psychiatric Rating Scale (BPRS) is widely used for evaluating patients with schizophrenia, it has limited value in estimating the clinical weight of individual symptoms. The aim of this study was 4-fold: 1) to investigate the relationship of the BPRS to the Clinical Global Impression-Schizophrenia Scale (CGI-SCH), 2) to express this relationship in mathematical form, 3) to seek significant symptoms, and 4) to consider a possible modified BPRS subscale.MethodsWe evaluated 150 schizophrenia patients using the BPRS and the CGI-SCH, then examined the scatter plot distribution of the two scales and expressed it in a mathematical equation. Next, backward stepwise regression was performed to select BPRS items that were highly associated with the CGI-SCH. Multivariate regression was conducted to allocate marks to individual items, proportional to their respective magnitude. We assessed the influence of modifications to the BPRS in terms of Pearson's r correlation coefficient and r-squared to evaluate the relationship between the two scales. Utilizing symptom weighting, we assumed a possible BPRS subscale.ResultsBy plotting the scores for the two scales, a logarithmic curve was obtained. By performing a logarithmic transformation of the BPRS total score, the curve was modified to a linear distribution, described by [CGI-SCH] = 7.1497 × log10[18-item BPRS] - 6.7705 (p < 0.001). Pearson's r for the relationship between the scales was 0.7926 and r-squared was 0.7560 (both p < 0.001). Applying backward stepwise regression using small sets of items, eight symptoms were positively correlated with the CGI-SCH (p < 0.005) and the subset gave Pearson's r of 0.8185 and r-squared of 0.7198. Further selection at the multivariate regression yielded Pearson's r of 0.8315 and r-squared of 0.7036. Then, modification of point allocation provided Pearson's r of 0.8339 and r-squared of 0.7036 (all these p < 0.001). A possible modified BPRS subscale, "the modified seven-item BPRS", was designed.ConclusionsLimited within our data, a logarithmic relationship was assumed between the two scales, and not only individual items of the BPRS but also their weightings were considered important for a linear relationship and improvement of the BPRS for evaluating schizophrenia.

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Section: Discussionmentioning

confidence: 99%

Is there a linear relationship between the Brief Psychiatric Rating Scale and the Clinical Global Impression-Schizophrenia scale? A retrospective analysis

2010

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“…A number of simple scales exist to facilitate such measurement. 17,18 Additionally, the clinicianpatient dyad should engage in collaborative and informed decision-making on an ongoing basis, evaluating needs and preferences, measured effects of current treatments, and available treatment options at each stage.…”

Section: Optimizing Individual Outcomesmentioning

confidence: 99%

Bridging the Efficacy-Effectiveness Gap in the Antipsychotic Treatment of Schizophrenia: Back to the Basics

Tandon

2014

J. Clin. Psychiatry

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“…Therefore, training is required for performing a standardized evaluation [24]. Other user-friendly assessments include the Revised Global Outcome Assessment of Life in Schizophrenia (Revised GOALS) [25], the Investigator's Assessment Questionnaire (IAQ) [26] and the Targeted Inventory on Problems in Schizophrenia (TIP-Sz) [27], although they have some limitations in terms of methodology. We also believe that other important aspects of illness management should be supplemented with appropriate subjective scales as necessary [28].…”

Section: Figure 5 An Example Of a Potential Modified 18-item Bprs Mmentioning

confidence: 99%

A Modification of the Relative Weightings of Symptoms Utilizing a Logistic Function to Enhance the Linearity of the Brief Psychiatric Rating Scale: A Retrospective Analysis

Sawamura¹,

Morishita²,

Ishigooka³

2012

JBBS

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Introduction: Although the Brief Psychiatric Rating Scale (BPRS) is widely used for evaluating patients with schizophrenia, the meaning of the weights of the individual symptoms is ambiguous. The aims of the study were 1) to investigate whether the modification of relative weights of items of the BPRS is able to enhance its correlation with the Clinical Global Impression-Schizophrenia scale (CGI-SCH) and 2) to construct a potential modified BPRS. Methods: We evaluated 200 schizophrenia patients using the BPRS and the CGI-SCH and drew the scatter plot distributions of the two scales. Next, univariate regression for the CGI-SCH using individual symptoms of the BPRS was performed. Multivariate regression utilizing the "logistic function" was then conducted to allocate marks to each item and Pearson's r correlation coefficient and r-squared between the two scales were assessed. After that, we constructed an example of a potential modified BPRS. Results: With the scatter plot for the two scales, a logarithmic curve was obtained; this was described by [CGI-SCH] = 3.2248 × ln[18-item BPRS] -7.2044 (p < 0.001). Pearson's r for the relationship between the scales was 0.8216 and r-squared was 0.7718 (both p < 0.001). The univariate regression indicated a positive association between all symptoms of the BPRS and the CGI-SCH, although some of them were significant (p < 0.05) and others were not (p ≥ 0.05). Multivariate regression utilizing a logistic function provided the values "P i " that could express the relative weights of individual symptoms. Subsequently, modification of point allocations according to "P i " yielded a Pearson's r of 0.8491 and an r-squared of 0.7718 (not changed) (both p < 0.001). An example of a potential modified BPRS was constructed. Conclusions: Within the limits of our data, the weightings of items of the BPRS improved the correlation of the BPRS with the CGI-SCH for evaluating schizophrenia.

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Validation of the Investigator's Assessment Questionnaire, a new clinical tool for relative assessment of response to antipsychotics in patients with schizophrenia and schizoaffective disorder

Cited by 39 publications

References 16 publications

Is there a linear relationship between the Brief Psychiatric Rating Scale and the Clinical Global Impression-Schizophrenia scale? A retrospective analysis

Is there a linear relationship between the Brief Psychiatric Rating Scale and the Clinical Global Impression-Schizophrenia scale? A retrospective analysis

Bridging the Efficacy-Effectiveness Gap in the Antipsychotic Treatment of Schizophrenia: Back to the Basics

A Modification of the Relative Weightings of Symptoms Utilizing a Logistic Function to Enhance the Linearity of the Brief Psychiatric Rating Scale: A Retrospective Analysis

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