Six-item Version Research Articles

Balance Confidence and Falls Self-Efficacy in Older Breast Cancer Survivors.

The aim of the study was to examine the reliability, validity, and measurement error of balance confidence and fall-related self-efficacy measures in older breast cancer survivors. A cross-sectional study was performed. The Activities-Specific Balance Confidence Scale (ABC), the shorter, six-item version of the ABC (ABC-6), and the Modified Falls Efficacy Scale (MFES) were completed by 35 older breast cancer survivors. Absolute reliability was examined with Cronbach's alpha, test-retest reliability with intraclass correlation coefficient, and Pearson's correlation coefficient for construct validity. Absolute reliability was good for the ABC. Test-retest reliability was good for the ABC and the ABC-6 and moderate for the MFES. Construct validity was present for all measures. Breast cancer survivors' balance confidence measures should be assessed with either the ABC or the ABC-6, whereas falls self-efficacy should be examined with the MFES. Nurses and other health professionals who treat breast cancer survivors should include assessing psychological factors associated with falls using the ABC, the ABC-6, or the MFES as low balance confidence or falls self-efficacy contribute to increased falls risk.

Self-Esteem in 60 Seconds: The Six-Item State Self-Esteem Scale (SSES-6).

With 20 items, the State Self-Esteem Scale (SSES) can be cumbersome in settings that demand efficiency. The present research created an efficient six-item version of the SSES that preserves score reliability and validity and its three-dimensional structure: social, appearance, and performance self-esteem. Item response theory and confirmatory factor analyses identified the "best" six items-two from each dimension (Study 1). Participants completed the SSES four times at 2-week intervals (Studies 2 and 3). The six-item SSES' scores showed adequate test-retest reliability, explained substantial variance in trait-relevant measures, and showed convergent validity with related self-esteem measures. Participants completed the SSES and a laboratory experiment where they received negative feedback on an essay they had written and could retaliate against their evaluator by allocating hot sauce for them to consume (Study 4). The six-item SSES interacted with self-esteem instability in expected ways to predict hot sauce allocated.

Revisiting nutrition backlash: Psychometric properties and discriminant validity of the nutrition backlash scale.

Nutrition backlash is a disposition defined by negative feelings about dietary recommendations. Past research has measured nutrition backlash using the nutrition backlash scale (NBS) and found that it is negatively related to the consumption of fruits and vegetables. The aim of this study was to examine several aspects of the NBS, including factor structure, discriminant validity, and relationship to demographic characteristics and health behaviors. Adults were recruited to participate in two studies. Study 1 (N=480) included measures of nutritional backlash, information overload, worry, fatalism, and nutrition-related behaviors. Study 2 (N=399) was a follow-up that examined the factor structure of the NBS in a separate sample. In study 1, a six-item version of the NBS was found to be a good fit for the data and discriminant from overload, worry, and fatalism. NBS was higher for those with less education, non-white participants, and men. Individuals with higher backlash were less likely to look at nutritional labels and to use sunscreen. Study 2 confirmed the factor structure from study 1. A six-item version of the NBS was found to be reliable, discriminant from related measures, higher in underserved groups (less-educated, non-white, and male participants), and related to nutrition label use.

Uncovering psychobehavioural implications of SARS-CoV-2 infection in Iran.

Iran is the country in Western Asia most impacted by the COVID-19 outbreak. A survey was conducted among the general public in Iran aimed at investigating psychobehavioural issues related to the COVID-19 outbreak, namely (a) barriers to preventive measures against SARS-CoV-2 infection; (b) negative emotions towards SARS-CoV-2 infection; and (c) anxiety levels among the general public in Iran. A cross-sectional, web-based survey using an online questionnaire was carried out between 16 March and 1 April 2020. The six-item version of the State-Trait Anxiety Inventory (STAI-6) was used to assess anxiety levels. A total of 1,789 complete responses were received. Nearly 60% reported having difficulty in wearing a face mask to protect against SARS-CoV-2 infection. The mean and standard deviation (SD) for the total prevention barrier score was 35.8 (SD±7.1; range 18-68) out of a possible score of 72. Male respondents [odds ratio (OR)=1.25; 95% confidence interval (CI) 1.03-1.51] and respondents who perceived their health status as poor/fair (OR=1.49; 95% CI 1.31-1.82) were predictors of high prevention barriers. Negative emotions such as fear (74.6%) followed by depression (43.4%) and stigma (23.0%) associated with SARS-CoV-2 infection were reported. Respondents who perceived their health as poor/fair (OR=2.19; 95% CI 1.57-3.04) reported a higher likelihood of having higher negative emotions. Findings on anxiety level revealed 68.0% (95% CI 65.8-70.1) reported moderate to severe anxiety. Respondents who perceived their health as poor/fair (OR=3.46; 95% CI 12.22-5.40) and who were females (OR=1.91; 95% CI 1.55-2.36) were predictors of moderate to severe anxiety. In conclusion, psychobehavioural interventions are needed to facilitate management and control of the COVID-19 outbreak.

Revisiting the attitudes toward health care teams scale: Developing a short version for graduate health care education

ABSTRACT As interprofessional education (IPE) becomes more common in student training programs, reliable and valid scales are needed to measure students’ perceptions of the experience. The Attitudes Toward Health Care Teams Scale (ATHCTS) was developed to measure students’ attitudes toward IPE programs using 14 items loaded on two factors. In this paper, we used the ATHCTS scale to assess the effects of a three-semester long health care IPE program on three cohorts of nurse practitioner, occupational therapy, and physical therapy graduate students with three measurement points across two university sites (N = 367). Confirmatory factor analysis on the baseline data of the first cohort revealed unacceptable fit indices; in addition, not all items were applicable, some items had double or low factor loadings, and positively and negatively worded items loaded on separate factors, indicating potential answering bias, and both factors were highly correlated. We thus conducted further item analyses and propose a short version of the ATHCTS using six items with one reverse coded item, describing the quality of interprofessional care in a more parsimonious way. The factor structure of the six-item version was tested using confirmatory factor analysis on the baseline data of cohort 2 and 3. Results were compared to the 14-item version, and fit indices confirmed a better fit to the data than the old version. Using the shortened scale, student attitudes were compared over the course of the program and between both sites. Results showed that site 2 students’ attitudes remained very positive over time, while site 1 students’ attitudes declined significantly. We suggest this finding is related to the consistency of team membership at site 2 and discuss the implications for IPE program design.

Comparison of foot kinematics and the morphology of intrinsic musculature of the foot using a foot-type classification based on function.

[Purpose] The purpose of this study was to investigate a correlation between the morphology of the intrinsic musculature of the foot and foot kinematics during gait using a foot type classification based on the windlass function. [Participants and Methods] We examined 67 feet of 35 healthy participants in this study. We collected three-dimensional foot kinematic data during gait from the Oxford Foot Model and assessed the morphology of the flexor digitorum brevis, abductor hallucis, adductor halluces (oblique head), and abductor digiti minimi muscles using B-mode ultrasound. Using the Foot Posture Index (six-item version), we divided static foot postures into two groups: normal arch and flatfoot. Subsequently, we compared foot kinematics and the morphology of the intrinsic musculature among the four groups using the analysis of variance with the Bonferroni test. [Results] Foot kinematics of the flatfoot-adduction type during gait significantly differed from that of the normal arch-abduction type. The abductor digiti minimi of the flatfoot-adduction type was significantly thinner than that of the normal arch-abduction type. [Conclusion] There may be some variations in flatfoot, and the flatfoot-abduction type might not be a risk factor for overuse injuries.

Associations of chronotype with clock genes polymorphisms

AbstractIntroductionIndividuals with a later timing of circadian rhythms (evening types) tend to have unhealthier behaviors compared to those with an earlier timing (morning types). Previous studies have shown that evening types have unhealthier diets and later eating times than morning types. Furthermore, evening types bear higher odds for type 2 diabetes and weight gain (women). Circadian rhythms are controlled by clock genes which have an important role in regulating energy homeostasis. Thus far, a number of single nucleotide polymorphisms (SNP) of clock genes have been associated with metabolic disturbances, obesity and dietary habits (e.g., breakfast skipping and macronutrient intakes). Our aim was to examine chronotype associations with SNPs of the 20 known key clock genes which could help to clarify the underlying mechanisms behind chronotype phenotype.MethodsOur data included 8558 participants (aged 25–74 years, 52% of women) from the cross-sectional population-based National FINRISK 2007 and 2012 surveys. Chronotype was assessed with a shortened six-item version of Horne and Östberg's Morningness-Eveningness Questionnaire (sMEQ) accounting for 83% of the total variance of the original questionnaire. For comparison we used a single self-evaluation question on chronotype from the questionnaire. Genotyping was done using Illumina arrays (HumanCoreExome, Omniexpress and 610K). Linear and logistic regression was used for statistical analysis with the additive genetic model. The analyses were adjusted for age, sex, batch effects and five principal components to account for population structure. The false discovery rate method by the Benjamini-Yekutieli procedure was applied to correct for multiple comparisons.ResultsWe found 27 SNPs in two clock genes that were significantly (P < 0.05) associated with chronotype when assessed with the single question. Minor allele carriers of the NR1D2 (Rev-erbβ) polymorphisms (rs4131403A, rs4858095T, rs6794922G, rs4619734A, rs4589882A, rs4321479C, rs6779476A, rs6790557A, rs13095392A, rs4858098G, rs4858567C, rs11717862G, rs7431301A, rs5023610G, rs5847265C, rs5847266G, rs6550823A, rs9882735C, rs7371944A, rs55792500G) were associated with evening type, whereas minor allele carriers of the NFIL3 polymorphisms (rs2482704T, rs2989836T, rs2482356C, rs2440589T, rs9409419G, rs2482702G, rs2482357A) were more likely morning types. Findings were similar when chronotype was assessed with sMEQ but did not reach statistical significance.DiscussionOur findings indicated novel genetic associations of chronotype with two clock genes that have previously been associated with carbohydrate and lipid metabolism (NR1D2), and with lipid absorption and export in intestinal epithelial cells and hepatic gluconeogenesis (NFIL3). These results expand our knowledge of the genetic basis of chronotype and warrant further studies to replicate these findings.

Rasch Analysis of the Disability Acceptance Scale for Individuals With Cerebral Palsy.

Background: Acceptance of disability has been considered an important factor in rehabilitation procedures. The Disability Acceptance Scale (DAS) was used in a panel survey, and it is likely that this scale will be increasingly used. This study aimed to determine the psychometric characteristics of the DAS by applying a Rasch model, an application of item response theory.Methods: Data were collected using the DAS with 84 individuals with cerebral palsy. The response data were analyzed for item fitness and item difficulty, rating scale fit, and reliability.Results: Three of the nine DAS items had low fitness. Analysis of item difficulty showed that the item difficulty needs to be modified, suggesting the need to add some items with higher difficulty and some with lower difficulty. The 5-point Likert scale used in the evaluation questionnaires was not appropriate. An analysis of the six remaining items showed high levels of subject separation reliability and separation reliability of the items.Conclusions: This study is significant because it identified the psychometric characteristics of the DAS through item response theory-based Rasch analysis and suggested the need to modify the item fitness and difficulty level. A modified six-item version of the DAS with a 4-point Likert scale was proposed as being more suitable.

Urdu translation and validation of the Urogenital Distress Inventory (UDI-6) in women with urinary incontinence

ABSTRACTObjective: To provide an Urdu translation of the six-item version of the Urogenital Distress Inventory (UDI-6) and its validation in patients with urinary incontinence (UI), as the UDI-6 is a recognised, useful disease-specific questionnaire for the evaluation of UI in women.Patients and methods: We used a multi-step linguistic translation of the UDI-6, which comprised backward and forward translations coordinated by clinical investigators, followed by a pre-test in 10 patients. The final version was completed by a larger sample of women (n = 200), of which 100 had UI for the last 3 months and 100 had no UI. To appraise test–retest reliability the patients with UI were re-tested after 2 weeks. To test the questionnaire’s capacity to discriminate between women with or without UI, both cases (patients) and controls were included and assessed. The reliability of the UDI-6 was evaluated by internal consistency and was calculated using the Wilcoxon signed-rank test with P values, and test–retest reliability assessed by Spearman’s coefficient with P values.Results: The reliability of the UDI-6 was assessed for internal consistency and test–retest reliability was evaluated by Spearman’s coefficient, which showed significant P values.Conclusion: The present Urdu version of the UDI-6 is a linguistically valid instrument that can be reliably used in clinical practice and research.Abbreviations: IIQ-7: seven-item version of the Incontinence Impact Questionnaire; IQR: interquartile ranges; QoL: quality of life; UDI-6: six-item version of the urogenital distress inventory; UI: urinary incontinence

Development and Validation of a Polypharmacy Knowledge Assessment Instrument

Objective. To develop a brief instrument for academic pharmacists or physicians to use in assessing postgraduate residents' knowledge of polypharmacy. Methods. Five clinicians used a modified Delphi process to create a 26-item multiple-choice test to assess knowledge of polypharmacy in geriatric primary care. The test was distributed to 74 participants: 37 internal medicine (MD) residents, six nurse practitioner (NP) residents, nine primary care attendings, 12 pharmacists and pharmacy residents, and 10 geriatrics attendings and fellows. Construct validity was assessed using factor analysis and item response theory. Overall group differences were examined using a Kruskal-Wallis test, and between group differences were assessed using the Wilcoxon rank sum test. Results. The response rate for the survey was 89%. Factor analysis resulted in a one factor solution. Item response theory modeling yielded a 12-item and six-item test. For the 12-item test, the mean scores of geriatricians and pharmacists (88%) were higher than those of MD and NP residents (58%) and primary care attendings (61%). No differences were found between MD and NP residents and primary care attendings. Findings for the six-item test were similar. Conclusion. Both the 12-item and six-item versions of this polypharmacy test showed acceptable internal consistency and known groups validity and could be used in other academic settings. The similar scores between MD and NP residents and primary care attendings, which were significantly lower than scores for pharmacists and geriatricians, support the need for increased educational interventions.

MP40-09 RE-ENGINEERING THE INTERNATIONAL INDEX OF ERECTILE FUNCTION: EVALUATION OF A LARGE CLINICAL DATA SET

INTRODUCTION AND OBJECTIVES:The six-item version of the International Index of Erectile Function (IIEF6) is the predominant method of assessing erectile function in urology. There are, however, thr...

Re: The Masturbation Erection Index (MEI): .

Re: The Masturbation Erection Index (MEI): .

Rasch validation of the Danish version of the shoulder pain and disability index (SPADI) in patients with rotator cuff-related disorders.

The psychometric properties of the shoulder pain and disability index (SPADI) have been extensively evaluated using classical test theory, but very few studies have applied Rasch analysis. The purpose of this study was to validate the Danish version using Rasch analysis. Responses to the SPADI from 229 patients (48% female, mean age 54.5) were included in the Rasch analysis. Overall fit, individual item fit, local response dependence, dimensionality, targeting, reliability, and differential item functioning (DIF) were examined. After iterative analyses, good fit to the Rasch model was observed, with acceptable targeting and uni-dimensionality. SPADI should be reported as two separate subscales: Pain and Functional Disability. The pain subscale initially demonstrated misfit due to local dependence and DIF, but a log linear Rasch model showed good fit to the Rasch model with acceptable targeting and uni-dimensionality. A six-item version of the disability subscale exhibited adequate fit in the Danish version. The same items were also found to fit the Rasch model in the English version. The measurement properties of the Danish SPADI are similar to those of the English version. SPADI should be reported as two separate subscales. For the pain subscale, DIF with respect to age was disclosed, but the impact was small. The eight-item disability subscale did not fit the Rasch model. A six-item version of the disability subscale exhibited adequate fit in the Danish version. The same items were also found to fit the Rasch model in the English version.

The Masturbation Erection Index (MEI): validation of a new psychometric tool, derived from the six-item version of the International Index of Erectile Function (IIEF-6) and from the Erection Hardness Score (EHS), for measuring erectile function during masturbation.

To validate a psychometric instrument, the Masturbation Erection Index (MEI) able to evaluate erectile function (EF) during masturbation. In fact, although the evaluation of EF during masturbation is pivotal in evaluating erectile dysfunction (ED), to date no specific psychometric tools have been developed to measure it both in the routine clinical practice and in the experimental setting. Of 560 men attending our andrological outpatient clinic for the first time, 99 (17.7%) had ED. As a control group, we enrolled 102 sexually healthy men. All the men were requested to complete both the six-item version of the International Index of Erectile Function (IIEF-6) and the MEI. The MEI was used together with a standardised tool, the Erection Hardness Score (EHS). The MEI was validated in terms of content validity. Test-retest reliability was assessed using the intraclass correlation coefficient (ICC). Internal consistency was evaluated by Cronbach's α. The comparability between the MEI and IIEF-6 in measuring EF was tested by Bland-Altman analysis. The concordance correlation coefficient (CCC) between the two questionnaires was also determined. Internal consistency of the MEI was >0.93. Test-retest reliability was 0.982 (95% confidence interval [CI] 0.975-0.987). Bland-Altman analysis showed a good level of agreement between the IIEF-6 and MEI in the whole ED population, with stronger agreement in the organic-ED subpopulation. The estimated area under the curve of the MEI was 0.983 (P < 0.001; 95% CI 0.954-0.996), with a score of ≤27 as the optimal threshold to discriminate between the presence and absence of ED during self-induced masturbation. The CCC, Pearson ρ and bias correction factor (Cb) were 0.951 (95% CI 0.936-0.962), 0.968, and 0.982, respectively. The MEI showed good internal consistency and a good level of agreement with the IIEF-6. Hence, the MEI fulfills the major psychometric requirements for measuring EF during masturbation.

The validity and sensitivity of PANSS-6 in treatment-resistant schizophrenia.

To test the validity and sensitivity of the six-item version (PANSS-6) of the 30-item Positive and Negative Syndrome Scale (PANSS-30) in treatment-resistant schizophrenia (TRS). Using data from the clozapine phase (2E) of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study, we investigated the following: (i) The scalability of PANSS-6 and PANSS-30; (ii) The correlation between PANSS-6 and PANSS-30 total scores; (iii) Whether PANSS-6 could identify cross-sectional symptom remission; and (iv) The efficacy of clozapine, olanzapine, risperidone and quetiapine in TRS using the 'speed of change' on PANSS-6 and PANSS-30 (change in total score per week) as outcome measures. We found that (i) only PANSS-6 and not PANSS-30 was scalable; (ii) The correlation between PANSS-6 and PANSS-30 total scores was high (Spearman coefficient: 0.85), (iii) PANSS-6 accurately identified cross-sectional symptom remission as defined by the Andreasen et al. criteria; and (iv) The only antipsychotic that caused improvement (speed of change significantly lower than 0 during the first three months of treatment) was clozapine, both when using PANSS-6 (speed of change: -0.50 points/week; 95%CI: -0.84, -0.17) and PANSS-30 (speed of change: -1.41 points/week; 95%CI: -2.80, -0.02) as outcome measures. PANSS-6 validly measures severity, remission and antipsychotic efficacy in TRS.

The Very Efficient Assessment of Need for Cognition: Developing a Six-Item Version.

The need for cognition refers to people’s tendency to engage in and enjoy thinking and has become influential across social and medical sciences. Using three samples from the United States and the United Kingdom (N = 1,596), we introduce a six-item short version of the Need for Cognition Scale (NCS-18). First, we reduced the number of items from 18 to 6 based on the items’ discrimination values, threshold levels, measurement precision (item information curve), item–total correlations, and factor loadings. Second, we confirmed the one-factor structure and established measurement invariance across countries and gender. Finally, we demonstrated that while the NCS-6 provides significant time savings, it comes at a minimal cost in terms of its construct validity with external variables such as openness, cognitive reflection test, and need for affect. Overall, our findings indicate that the NCS-6 is a parsimonious, reliable, and valid measure of need for cognition.

Inter-rater reliability of ratings on the six-item Positive and Negative Syndrome Scale (PANSS-6) obtained using the Simplified Negative and Positive Symptoms Interview (SNAPSI)

Purpose: The six-item version of the Positive And Negative Syndrome Scale (PANSS-6) is a brief rating scale focusing on core symptoms of schizophrenia. In order to facilitate rating of PANSS-6 and selected items from other common psychiatric rating scales, we recently developed the Simplified Negative and Positive Symptoms Interview (SNAPSI). The objective of the present study was to test the inter-rater reliability of PANSS-6 ratings obtained using the SNAPSI.Materials and methods: Using the SNAPSI, seven raters (psychiatrists, first-year psychiatry residents and psychologists) performed a total of 56 PANSS-6 ratings of 12 in- or outpatients with schizophrenia. As a measure of inter-rater reliability, we calculated the intra-class correlation coefficient (ICC, ≥0.75 = excellent, 0.40–0.74 = fair to good, <0.40 = poor) for the PANSS-6 total score and individual item scores. Furthermore, for the PANSS-6 total scores obtained by the six noncertified PANSS raters, we calculated the median deviation from the PANSS-6 total scores obtained by the only certified PANSS rater.Results: The ICC for the PANSS-6 total score was 0.74 (F = 2.84, p = .03). The ICCs for the six individual PANSS-6 items ranged from 0.45 (N6 – Lack of spontaneity & flow of conversation) to 0.76 (P3 – Hallucinatory behavior). The PANSS-6 total scores obtained by the six noncertified PANSS raters deviated by a median of 12.7% (interquartile range: 6.2–20.0) from the PANSS-6 total scores obtained by the certified PANSS rater.Conclusions: We found a good level of inter-rater reliability of PANSS-6 ratings obtained using the SNAPSI for seven raters with varying levels of clinical and research experience.

Spanish Gratitude Questionnaire: Psychometric properties in adolescents and relationships with negative and positive psychological outcomes

The purpose of this paper was to investigate the psychometric properties of the Spanish version of the Gratitude Questionnaire (GQ; McCullough, Emmons, & Tsang, 2002) using two independent samples of Spanish adolescents. Sample 1 (N = 569, female n = 280) completed the Spanish GQ, along with scales assessing depression, happiness, suicidal ideation and trait hope. Sample 2 (N = 725, female n = 364) also completed the Spanish GQ, along with life satisfaction, hopelessness, optimism and anxiety questionnaires. The Spanish GQ showed a satisfactory internal consistency and was correlated with theoretically relevant constructs. Confirmatory factor analysis showed that the 5-item version of GQ possessed a better fit than the original six-item version. Also, the invariance of this structure across gender was demonstrated. Overall our findings suggest that the Spanish GQ is valid for the assessment of gratitude in Spanish-speaking populations.

Can the health related quality of life measure QOLIBRI- overall scale (OS) be of use after stroke? A validation study

BackgroundBrief measures of health-related quality of life (HRQOL) that assess both patient-reported functioning and well-being after stroke are scarce. The objective of this study was to examine reliability and validity of one of these measures, the patient-reported Quality of Life after Brain Injury–Overall Scale (QOLIBRI-OS), in patients after stroke.MethodsStroke survivors were examined prospectively using survey methods.Core survey data (n = 125) and retest data (n = 36) were obtained at 3 and 12 months, respectively. Item properties (distribution, floor and ceiling effects), psychometric properties (reliability and model fit), and validity (correlations with established measures of anxiety, depression and HRQOL) of the QOLIBRI-OS were examined.ResultsMissing responses on the questionnaire were low (0.5%). All items were positively skewed. No floor effects were present, whereas five out of six items showed ceiling effects. The summary QOLIBRI-OS score exhibited no floor or ceiling effects, and had excellent internal consistency (Cronbach’s α =0.93). All item-total correlations were high (0.73–0.88). The test-retest reliability of single items varied from 0.74 to 0.91 and was 0.93 for the overall score. The confirmatory factor analysis yielded an excellent fit for a five-item version and provided tentative support for the original six-item version. The convergent validity correlations were in the hypothesized directions, thus supporting the construct validity.ConclusionsThe brief QOLIBRI-OS is a valid and reliable brief health-related outcome measure that is appropriate for screening HRQOL in patients after stroke.

S46. THE VALIDITY AND SENSITIVITY OF PANSS-6 IN TREATMENT-RESISTANT SCHIZOPHRENIA

BackgroundA six-item version (PANSS-6: P1=Delusions, P2=Conceptual disorganization, P3=Hallucinations, N1=Blunted Affect, N4=Social withdrawal, N6=Lack of spontaneity/flow of conversation) of the 30-item Positive and Negative Syndrome Scale (PANSS-30) has shown promise in the measurement of symptom severity in acutely exacerbated- and chronic schizophrenia, but its validity in treatment-resistant schizophrenia remains unknown. Therefore, we tested the validity and sensitivity of PANSS-6 based on data from the clozapine phase of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study.MethodsI) The scalability of PANSS-6 and PANSS-30 (i.e., whether all items provide unique information regarding syndrome severity) was tested by means of item response theory analysis ad modum Rasch; II) The correlation between PANSS-6 and PANSS-30 total scores was investigated by means of Spearman correlation analysis; III) The accuracy of PANSS-6 in identifying symptom remission was tested by comparing remission on PANSS-6 (score of ≤3 on each of the six PANSS-6 items) with remission according to the Andreasen criteria (score of ≤3 on the 8 PANSS items considered in the Andreasen criteria); and IV) The antipsychotic effect of clozapine was compared to that of olanzapine, risperidone and quetiapine using the “speed of change” on PANSS-6 and PANSS-30 (change in total score per day) as outcomes.ResultsWe found that I) only PANSS-6 and not PANSS-30 was scalable; II) The correlation between PANSS-6 and PANSS-30 total scores was high (Spearman coefficient: 0.85), III) PANSS-6 did accurately classify syndrome remission as defined by the Andreasen criteria, and IV) The only antipsychotic that resulted in improvement (speed of change significantly lower than 0 during the first three months of treatment) was clozapine, both when using PANSS-6 (speed of change: -0.072 points/day; 95%CI: -0.121, -0.024) and when using PANSS-30 (speed of change: -0.201 points/day; 95%CI: -0.400, -0.002) as outcome measures.DiscussionThese findings suggest that PANSS-6 validly measures severity, remission and antipsychotic efficacy in treatment-resistant schizophrenia.