A SYMPTOM SELF-RATING SCALE FOR SCHIZOPHRENIA (4S): PSYCHOMETRIC PROPERTIES, RELIABILITY AND VALIDITY - Scala autoevaluarii simptomelor pentru schizofrenie (4S): proprietati psihometrice, fiabilitate si validitate

Eva Lindström*, Erik Jedenius**,  Sten Levander***

Abstract

Objective: To validate a self-administrated symptom rating scale for use in patients with schizophrenia spectrum disorders by item analysis, exploration of factor structure, and analyses of reliability and validity.

 Method: Data on 151 patients, initially treated by risperidone, obtained within the framework of a naturalistic Phase IV longitudinal study were analysed by comparing patient and clinician ratings of symptoms, side effects and global indices of illness.

Results: The 4S scale is psychometrically adequate (item analysis, internal consistency, factor structure). Side effect ratings were reliable. Symptom ratings displayed consistent associations with clinicians’ ratings of corresponding symptom dimensions, suggesting construct validity. Patients had most difficulties assessing negative symptom items.

Conclusion: Patients were well able to assess their own symptoms and drug side effects. The factor structure of symptom ratings differ between patients and clinicians as well as how they construe global indices of illness. Clinicians focus on psychotic, patients on affective symptoms. Use of symptom self-ratings is one way to improve communication and thereby strengthen the therapeutic alliance and increase treatment adherence.

Key words: psychosis, self-ratings, symptoms, side effects, risperidone, GAF, CGI.

 

Rezumat.

Obiective: Validarea unei scale de evaluare a simptomelor autoadministrata pacientilor cu schizofrenie pornind de la baza analizei itemilor, explorarea structurii factorilor, analiza fiabilitatii si a validitatii.

Metoda: Au fost analizate datele provenite de la 151 pacienti tratati initial cu risperidona, obtinute în cadrul unui studiu longitudinal naturalist de faza IV, prin compararea evaluarii evolutiei simptomelor de catre clinicieni si de catre pacienti, a efectelor secundare si a indicilor globali ai bolii.

Rezultate: Scala celor 4 S – uri este adecvata psihometric (analiza itemilor, consistenta interna, structura factorilor). Evaluarea efectelor secundare a fost relevanta. Evaluarile simptomelor de catre pacienti si de catre clinicieni au prezentat asocieri consistente în ceea ce priveste dimensiunile simptomelor în discutie, sugerând astfel valabilitatea conceptului. Pacientii au avut unele dificultati în a-si evalua simptomele negative.

Concluzii: Pacientii au fost capabili sa îsi evalueze propriile simptome si efectele secundare ale medicamentelor. Structura evaluarii simptomelor difera de la clinicieni la pacienti precum si în interpretarea indicilor globali ai bolii. Clinicienii s-au concentrat pe simptomele psihotice iar pacientii pe cele afective. Utilizarea unei scale autoadministrate de evaluare a simptomelor este o cale de îmbunatatire a comunicarii, de întarire a aliantei terapeutice si a cresterii aderentei la tratament.

Cuvinte cheie: psihoza, auto evaluare, simptome, efecte secundare, risperidona, GAF (Evaluarea Globala A Functionalitatii), CGI.

 

 

*Department of Neuroscience-Psychiatry, Uppsala University Hospital, Sweden

**Karolinska Institute, Department of Neurobiology, Caring Sciences and Society, Stockholm, Sweden

***Department of Health and Society, Malmö University, Sweden. Address correspondence:  Department of Psychiatry, U-MAS, SE 205 02, Malmö, Sweden

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