[French validation of the Verona Service Satisfaction Scale-VSSS-54F].
BACKGROUND
The Verona Service Satisfaction Scale-French version (13) was translated and adapted from the Italian version of Verona Service Satisfaction Scale (27). The VSSS makes it possible to evaluate the satisfaction of people with serious mental illness with respect to the services. The original VSSS-54 contained 7 dimensions: 1) Overall satisfaction, 2) Professionals' skills and behaviour, 3) Information, 4) Access to services, 5) Services efficacy, 6) Relatives' involvement and 7) Types of interventions. According to factorial analyses carried out by Ruggeri et al., the dimensions Information and Access to services were aggregated. However, no factorial analysis was carried out in order to verify the six dimension-structure of the VSSS. From an international perspective, the study entitled "The European Psychiatric Services: Inputs linked to Outcome Domains and Needs (EPSILON)" achieved the standardisation of different questionnaires in several languages (2). A new version of the VSSS entitled "Verona Service Satisfaction Scale-European version" (VSSS-EU) was developed and is now available in the following languages: Italian, Danish, German, English and Spanish. In order to compare in different countries the satisfaction of people with serious mental illness with respect to services, we undertook from 1998 to ascertain the psychometrical properties of the French version of the VSSS. (13). Confirmatory Factorial Analysis (CFA) was carried out on the six dimension-structure of the VSSS-54F: 1) Overall satisfaction, 2) Professionals' skills and behaviour, 3) Information and Access to services, 4) Services efficacy, 5) Relatives involvement and 6) Types of interventions. For each dimension, consistency analysis (Cronbach's alpha) was computed in order to bring forth additional psychometrical properties of the VSSS-54F.


METHODS



METHODS
150 clients involved in an intensive case management program and supported by 30 mental health workers, filled out the VSSS-54F questionnaire. These clients were comprised of 110 women and 40 men, their ages ranging from 22 to 90 years (M = 51.7, SD = 14.7). Among them, 65 (43.3%) had a diagnosis of schizophrenia or another form of psychosis, 56 (37.3%) had an affective disorder, 17 (11.3%) had anxious disorders and 7 (7.7%) other.


METHODS
Using the EQS Software (3), Confirmatory Factor Analyses (CFA) were carried out in this study. Thus, 'the evaluation of the models' fit with the empirical data was carried out by taking into account various statistical indices. In addition to the Chi square/df ratio, the indices of adjustment such as the "NonNormed Fit Index" (NNFI), the Comparative Fit Index (CFI), robust CFI (calculated starting from the Satorra-Bentler Chi Square) as well as the RMSEA (Root Mean Standard Error of Approximation) were used to measure the fit of the models. Moreover, the estimation method "Maximum Likelihood-Robust" was carried out in order to evaluate the models.


RESULTS
The original model with 6 dimensions (M1) does not present satisfactory fit indices. Indeed, the Chi Square/df ratio is above 2, the NNFI, CFI and CFI robust indices are lower than. 90 and the RMSEA is higher than. 08. Most items from Types of intervention dimension presented saturation lower than.30, and consequently indicate that these items are not correlated significantly with their dimension. We notice also some correlations between error terms of the three items of Overall Satisfaction scale and other items of the VSSS questionnaire. Considering these last results and the direction taken in VSSS-EU by breaking down by profession items of Professionals' skills and behaviour scale, we obtained a new model (M2). The five dimensions of this model are as follow: 1) Psychiatrists/Psychologists' skills and behaviour (7 items), 2) Nursing staff/social workers' skills and behaviour (7 items), 3) Information and access to services (3 items), 4) Services efficacy (5 items), 5) Relatives' involvement (3 items). When we test this model, the fit indices are satisfactory: the Chi Square/df is 1.36, the NNFI, CFI and robust CFI indices are near or higher than 0.90, respectively 0.88, 0.89 and 0.94. Finally, the RMSEA index is 0.08. In addition, the correlations between five dimensions are significant and vary from 0.58 to 0.87 (p < 0.05). The internal consistency coefficients for each new scale are all satisfactory, and vary from .83 to .91, except for the Information and access to services scales. But this latter finding shall be evaluated knowing that acceptable alpha can be close to .60 when scales count less than four items (16).


CONCLUSIONS
This study confirms with some adjustments the factorial structure of the VSSS. The results indicate five dimensions (25 items): Psychiatrists/Psychologists' skills and behaviour, Nursing staff/social workers' skills and behaviour, Information and access to services, Services efficacy, Relatives' involvement. Even if the Type of interventions dimension was not retained in the model, we suggest preserving it for eventual clinical evaluation based on each item. We also suggest, for future studies, the adaptation of the VSSS-54F to the European version, VSSS-EU. Indeed, the results of our study sustain the European version because the VSSS-EU is more focused since it separates the skills and behaviour of psychiatrists, psychologists, nurses and social workers (e.g. items 3a and 3b or items 22a and 22b). The next step in the validation process would be to measure Inter-rater and test-retest reliability as well as concurrent, convergent and discriminant validity of the VSSS-EU. Furthermore, a multicultural comparison of the VSSS-EU would be required if the instrument is used for interesting comparisons of survey.
Corbière
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Research Associate Mental Health Evaluation & Community Consultation Unit (MHECCU), University of British Columbia, Dept. of Psychiatry, St Paul's Hospital, 1081 Burrard Street, Comox Building, Room 306, Vancouver, BC, V6Z 1Y6 Canada.
Lesage
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A
Lauzon
S
S
Ricard
N
N
Reinharz
D
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002170:Canada; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D008605:Mental Health Services / Q000592:standards*; D008875:Middle Aged; D017060:Patient Satisfaction; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires