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ScienceDirect Comprehensive Psychiatry xx (2014) xxx – xxx www.elsevier.com/locate/comppsych
Cultural translation and Tunisian validation of the Drug Attitude Inventory (DAI-30) in outpatients with schizophrenia Jaafar Nakhli⁎, Badii Amamou, Salem Mlika, Saoussen Bouhlel, Marwan Trifi, Selma Ben Nasr, Yousri El Kissi, Béchir Ben Hadj Ali Farhat Hached University hospital, Psychiatric department, Sousse, Tunisia
Abstract Background: Non-adherence to treatment in patients with schizophrenia is associated with increased hospitalization, higher health care costs, and poorer long-term outcomes in terms of relapse rates. It is established that a negative drug attitude was a risk factor for nonadherence in long-term schizophrenia. The scale “Drug Attitude Inventory" is one of the scales designed to assess this concept. It has been translated and validated in different languages. However, its psychometric properties have not yet been studied in our sociocultural context. Objectives: The aims of this study were to translate into Tunisian Arabic dialect the scale “Drug Attitude Inventory" with 30 dichotomous items (DAI-30) and validate it in Tunisian sociocultural context in patients with schizophrenia. Materials and methods: This study was performed in 234 outpatients with schizophrenia, recruited through a random drawing. These patients are in remission and meet remission criteria proposed by “The Remission in schizophrenia Working Group". We recruited 30 patients for pretest and 204 patients for linguistic validation. Forward and backward translation of the DAI-30 was performed according to the protocol of the “MAPI Research Institute". This final version was submitted to 24 experts and followed by a pretest. Construct validity has been established by performing a principal component analysis factor on a sample of 204 patients. Internal consistency was assessed by Cronbach alpha coefficient and inter-rater reliability was assessed by the use of Intra-Class Correlation coefficient (ICC). For the test–retest reliability evaluation, the “r” Pearson's coefficient was used between the DAI scores obtained in the initial evaluation and those obtained at 15 days. Results: Regarding construct validity, factor analysis revealed seven factors that were responsible for 59.9% of the variance. The study of internal consistency between the 30 items was rated good (α = 0.88). The test–retest reliability was satisfactory (r = 0.99, p b 10 −3), as well as inter-rater reliability (ICC = 0.99). Conclusion: In the Tunisian cultural context, the DAI-30 presented seven factors with good consistency and an inter-rater reliability. © 2014 Elsevier Inc. All rights reserved.
1. Introduction Treatment non-adherence in patients with schizophrenia has serious impacts on the course of the illness, including worsening of symptoms, more relapses, suicidal attempts, higher period of hospitalization, and poor functional outcomes [1,2]. Many studies had estimated that 25% to 70% of all schizophrenic patients are non-compliant [3–6].
⁎ Corresponding author at: Farhat Hached University Hospital, Psychiatric department, Rue Ibn Jazzar, 4002, Sousse, Tunisia. Tel.: +216 73221411. E-mail address: [email protected] (J. Nakhli). http://dx.doi.org/10.1016/j.comppsych.2014.09.002 0010-440X/© 2014 Elsevier Inc. All rights reserved.
Since the development of second-generation antipsychotics (SGAs), it was established that patients' subjective response and acceptance were generally more likely to be positive [7–9] and many research has shifted from objective to more subjective factors that may influence adherence to medication in order to gain insight into underlying motivational processes in treatment [10]. Patients’ attitudes toward drug treatment were most studied and showed a positive correlation with treatment adherence [6,10]. Several scales were established to explore patient attitudes toward medication such as Drug Attitude Inventory 30-items and 10-items (DAI-30 and DAI-10) [11,12] and the Subjective Wellbeing under Neuroleptics treatment scale (SWN) [13]. DAI-30 is the most widely used questionnaire
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in literature to explore attitudes towards medication. It’s a self-rating scale developed by Hogan et al. [11]. It has been translated and validated in different languages [14–16]. However, in Tunisia, as well as in other Arabic countries there are no validated studies of this scale yet. The aim of the present study was to translate DAI-30 into Tunisian Arabic, to adapt it cross-culturally and to assess its reliability and validity. 2. Methods 2.1. Study sample and procedure Subjects were recruited from outpatient psychiatric unit at the university general hospitals in Souse-Tunisia through a random drawing. Interviews with all schizophrenic patients were conducted by clinically experienced psychiatrists. The study protocol was written, evaluated and approved by the Ethics Committee of Medicine School in Sousse. We recruited 204 outpatients, 140 (68.6%) males and 64 (31.4%) females, with a diagnosis of schizophrenia according to the DSM-IV-TR criteria [17], having a duration of illness of at least three years (since 84.6% of patients from North Africa & Middle east can achieve response at 3-year follow up and a large proportion of people achieve continuous remission [18]) and meeting the remission criteria offered by "The Remission in schizophrenia Working Group" with a score less than or equal to 3 in the 8 specific items (P1, P2, P3, G9, G5, N1, N4, N6) on the positive and Negative Syndrome Scale (PANSS) [19] and no history of hospitalization during the last six months [20]. Exclusion criteria were mental retardation, personal or family history of any neurological disorder, history of head injury, alcohol or substance abuse in the preceding six months. Basic demographic and clinical data were obtained from the participants’ medical records. All the patients were taking an antipsychotic medication at the time of assessment. 2.2. Instruments 2.2.1. Attitude toward medication To assess patient attitude toward medication, we used the 30-item version of the self-report Drug Attitude Inventory (DAI). For non educated patients (n = 16) we asked a relative of them to read the scale item by item literally (and if the patient hadn’t understood an item the relative had to read the corresponding item again not to explain) since the scale was translated to the Tunisian dialect (a spoken language). The Drug Attitude Inventory (DAI-30) can provide unique information of clinical relevance for monitoring treatment adherence among people diagnosed with schizophrenia [21]. The total score of the DAI-30 ranges between −30 and +30. A negative score represents adverse beliefs relating to drugs [11]. This instrument measures patient beliefs and experiences about and with medications. It has been elaborated and validated by Hogan et al. in a sample of 150 outpatients with schizophrenia. His intrinsic
validity was 0.93 and reflected a good correlation between the items. There was also a good test–retest validity of 0.82 [11]. Since this time, it was translated and validated in 4 different languages: French, Italian, Spanish and Chinese [14–16,22]. 2.2.2. Treatment compliance Patient treatment compliance was assessed using the third factor of the Schedule for the Assessment of Insight-Expanded version (SAI-E). It is represented by 2 items: Treatment acceptance and Spontaneous request for treatment [23]. The SAI-E is a semi-structured interview which consists of 11 items, with a standardized mode of rating of the items by the interviewer. Items 1–6, 10, and 11 are rated from 0 to 2, while items 7–9 are rated from 0 to 4, with higher scores indicating better insight. All the items are summed to reach a total score, ranging from 0 to 28 [23]. The scale has proven validity and reliability in patients with psychosis [23,24]. It was validated in Tunisian Arabic language in outpatients with schizophrenia. SAI-E Tunisian version had three factors compatible with the insight dimensions [25]. 2.2.3. The Positive and Negative Syndrome Scale (PANSS) This scale was developed and standardized by Kay et al. [20]. It consists of 30 items devoted to measure different types of psychopathology for schizophrenia. An interviewer rates the items on a Likert type scale from 1 to 7. 2.3. Translation–Adaptation We applied the original DAI-30 index forward/backward translation procedure. For Translation–Adaptation, we considered it necessary to obtain the consent of the designer of the DAI-30 (G. Awad) about validation. He gave us permission and answered all our questions and suggestions. For this step, we used the manual published by the linguistic validation “Mapi Research Institute" (MAPI) [26]. The translation was made from English to Tunisian Arabic dialect by two bilingual translators. The choice of Tunisian Arabic dialect and not of Standard Arabic aims for a better understanding by patients of the 30 items. The stage of the translation was completed by assembling meeting translators, an experienced psychiatrist and a psychologist in addition to the authors of this study. The items were tested one by one to find the most appropriate terms. Each term was chosen after the approval of the involved parties. The second stage was the back-translation of the translated text from Tunisian Arabic dialect to English and the verification of compliance with the original scale. This back-translation was done by a bilingual translator and followed by a meeting of all parties involved. The 30 backtranslated items were compared with the original English version of the DAI-30 scale. Twenty four psychiatrists had agreed to judge our translation. Their suggestions for items that could pose a problem were encouraged. Their responses and comments were taken into consideration in the revision of the Arabic version of the scale.
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2.4. Pre-testing For pre-testing, a sample of 30 outpatients with schizophrenia answered the translated questionnaire in order to test for the misunderstanding and acceptability of questions. Patients were randomly selected and not part of the sample statistical validation. 2.5. Reliability Reliability in terms of internal consistency of the DAI-30 was evaluated with Cronbach's alpha coefficient. This can be considered as adequate when values greater than 0.7 are obtained. For the test–retest reliability evaluation, the “r" Pearson’s coefficients were used between the DAI-E scores obtained in the initial evaluation and those obtained at 15 days. It had concerned 67 outpatients from the same sample of 204 patients. A “p” value of b 0.05 was considered to be statistically significant. To determine inter-rater reliability, the DAI-30 was administered by two investigators to 60 schizophrenic outpatients. The Intra-class Correlation Coefficient (ICC), with Two-way Random Effect Model and absolute agreement definition, was adopted for the analysis of inter-rater reliability according to the recommendations of Shrout and Fleiss [27]. 2.6. Validity For content validity, we applied a factorial analysis to verify if the Tunisian Arabic version of DAI-30 scale had a similar factorial structure to the original version. We performed principal components analysis (considering Eigen values N 1) with VARIMAX rotation and Kaiser Normalization [28]. Convergent validity was assessed by correlating the translated DAI-30 scale with the score of the third dimension (treatment compliance) of the SAI-E. The scores of both measures should correlate positively and significantly.
3. Results 3.1. Translation and expert opinion After the forward/backward translation and meeting for all participants, we found that the Tunisian Arabic version of the DAI-30 is similar to the original version. All suggestions of experts focused on items containing inappropriate language from or not relevant to our sociocultural context have been taken into consideration. 3.2. Pre-testing Thirty schizophrenic outpatients participated in this step. The pilot study resulted in few linguistic changes in the instrument. Incomprehensible terms were changed. A final translated version was obtained.
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Table 1 Demographic and clinical characteristics of patients with schizophrenia (n = 204). Age (years) Male (%) Education (%) Professional activity (%) Age of onset illness (years) Second generation antipsychotics (%) PANSS Total Score DAI-30 total score Negative attitude toward treatment (%)
40.4 68.6 93 38.4 25.7 16.7 48.2 19.1 6.9
± 12.8
± 8.6 ± 11.4 ± 11.1
3.3. Subjects' demographic and clinical characteristics (Table 1) The mean age of our sample was 40.4 ± 12.8 years. The sex ratio was 2.2 and 38.4% of them had professional activity. The mean age of illness onset was 25.7 ± 8.6 years. 16.7% of them received second generation antipsychotics. The mean PANSS total score was 48.2 ± 11.4 and the mean DAI-30 total score was 19.1 ± 11.1. The attitude toward treatment was negative in 6.9% of our sample (14 outpatients).
Table 2 Test–retest and inter-rater reliability of the DAI-30 Tunisian version. DAI-30 items
“r" Pearson coefficient
95 % CI
ICC
Item 1 Item 2 Item 3 Item 4 Item 5 Item 6 Item 7 Item 8 Item 9 Item 10 Item 11 Item 12 Item 13 Item 14 Item 15 Item 16 Item 17 Item 18 Item 19 Item 20 Item 21 Item 22 Item 23 Item 24 Item 25 Item 26 Item 27 Item 28 Item 29 Item 30 Total items
0.91⁎ 0.88⁎ 1⁎ 1⁎ 0.89⁎ 1⁎ 0.9⁎ 1⁎ 0.91⁎ 0.77⁎ 1⁎ 0.93⁎ 1⁎ 0.96⁎ 1⁎ 0.94⁎ 1⁎ 0.92⁎ 0.89⁎ 0.96⁎ 1⁎ 1⁎ 0.88⁎ 1⁎ 0.95⁎ 0.72⁎ 1⁎ 0.91⁎ 1⁎ 0.85⁎ 0.99⁎
0.93–0.97 0.84–0.93 0.96–0.99 0.95–0.98 0.90–0.97 0.98–0.99 0.88–0.95 0.98–0.99 0.86–0.95 0.73–0.90 0.98–0.99 0.98–0.99 0.97–0.99 0.95–0.99 0.98–0.99 0.91–0.96 0.98–0.99 0.89–0.96 0.80–0.92 0.94–0.97 0.98–0.99 0.98–0.99 0.98–0.99 0.98–0.99 0.98–0.99 0.74–0.90 0.98–0.99 0.98–0.99 0.84–0.94 0.47–0.77 0.98–0.99
0.95 0.90 0.98 0.97 0.94 0.99 0.92 0.99 0.91 0.83 0.99 0.99 0.98 0.98 0.99 0.94 0.99 0.93 0.87 0.96 0.99 0.99 0.99 0.99 0.99 0.84 0.99 0.99 0.90 0.65 0.99
CI: Confidence Interval (95%), ICC: Intra-class correlation (Two-way Random Effect mode, absolute agreement definition). ⁎ p b 10 −3.
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3.4. DAI-30 reliability In regards to internal consistency of the scale, Cronbach's alpha was 0.88 for the entire sample. The lower α value was 0.62 (item 13) and the higher α was 0.91 (items 18 and 29). The test–retest reliability for two weeks of interval between administrations was calculated based on a subsample of 67 outpatients with schizophrenia. The total “r" Pearson’s coefficient between both administrations was r = 0.99 (p b 10 −3). It was between 0.72 and 1 (Table 2). The inter-rater reliability was calculated in a subsample of 60 patients. The ICC for the 30 items was 0.99. It was between 0.65 and 0.99 (Table 2).
(MAPI) [26] which consists of three steps: translation, backtranslation and pre-testing. In this method, we only need three translators (two for translation and one for the backtranslation). This seems to be advantageous over other methods because it can solve the problem of non-availability of experts. Translators must have a good knowledge of the source language and the target language and culture [29–31]. For the pre-test, in contrast to the procedure described by Schuman [32], we decided to administer all items to 30 patients. All the remarks made by patients concerning the comprehension of certain expressions were taken into account and investigators are allowed to change incomprehensible expressions [29,32].
3.5. DAI-30 validity
4.2. Reliability
The factorial analysis showed seven factors that explained 59.9% of the variance of the scores (Table 3). Keiser–Meyer– Olkin index (KMO) in our study was 0.85 and Bartlett's Sphericity test was significant (p b 10 −3). In relationship to the validity of convergent construct, Pearson's correlation coefficient between the DAI-30 total score and SAI-E total score was positive and significant (r = 0.38, p b 10 −3). We found also a positive correlation between DAI-30 total score and the three dimensions of the insight (awareness of mental illness, ability to relabel unusual mental events as pathological and treatment compliance, both expressed and observed). Pearson's correlation coefficients were respectively r = 0.33, p b 10 −3; r = 0.24, p = 0.004 and r = 0.53, p b 10 −3. Good insight and treatment compliance were associated with positive attitude toward treatment.
8.8%
In our study, we noted a good internal consistency between the 30 items of the scale DAI-30 in its Tunisian version with a total Cronbach α of 0.88. All items appear to be consistent which helps to maintain a homogeneous structure of the Tunisian version of the DAI-30 scale, and to measure the concept of attitude toward treatment. The internal consistency of the scale DAI-30 was 0.93 in the original English validation study [11] and 0.57 in the Spanish validation study [16]. For the test–retest reliability, “r" Pearson’s coefficient values ranging from 0.7 to 0.9 are considered by authors as “good” [33,34]. In our study, we found a coefficient “r" Pearson equal to 0.99 with p b 10 −3, which indicates the stability of the patient's response during this time period. In the original validation study of the DAI-30 conducted by Hogan et al., the test–retest reliability was 0.82 [11]. The inter-rater reliability was calculated on a subsample of 60 subjects. We judge it enough to make this measurement. In fact, there was no consensus to fix the exact number of patients to measure inter-rater reliability [26]. In our study, apart from item 30 (ICC = 0.65), all items showed homogeneous values (from 0.83 to 0.99), and for the total DAI score it was excellent (ICC = 0.99). The low Intra-class Correlation Coefficient (ICC) of item 30 can be explained by the semantically inappropriate translation (the translation of this item was judged unclear and not discriminative) and so that item belonged to none of the seven dimensions of the scale. Robles et al., in their study of Spanish validation of the DAI in 80 patients with schizophrenia, found that the ICC was 0.61 [16].
3, 7, 11, 12, 14, 25
7.4%
4.3. Validity
2, 5, 6, 8 17, 24 16, 21 25, 27
4.9% 4.5% 3.8% 3.4%
Factor analyses of the scale showed that a seven-factor solution gave the best account of the data. This was in line with the original scale’s structure [11]. These factors in our study were: 1) positive subjective feelings related to antipsychotics, 2) health/illness-dependent drug intake, 3) negative subjective feelings related to antipsychotics, 4) sensation of treatment control, 5) patient's confidence in physician, 6) cognitive effect of treatment, and 7) potential
4. Discussion 4.1. Translation and pre-test In our study, we chose to use the linguistic validation methodology described by “The Mapi Research Institute" Table 3 Factor analysis of the DAI-30 Tunisian version. Seven Factors of DAI-30
Eigen Concerned values items
1. Positive subjective feelings 8.14 related to antipsychotics 2. Health/illness-dependent 2.63 drug intake 3. Negative subjective feelings 2.21 related to antipsychotics 4. Sensation of treatment control 1.46 5. Patient's confidence in physician 1.36 6. Cognitive effects of treatment 1.14 7. Potential toxic effects of 1.02 treatment (harm) Accumulated variance 59.9%
6, 9, 10, 15, 18, 21, 23, 26, 29 1, 4, 13, 19, 22
Percentage of the variance 27.1%
Extraction method: Principal components analysis. Rotation Method: Varimax with kaiser Normalization. Values ≤ 0.40 were eliminated from the statistical analysis.
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toxic effects of treatment (harm). The only difference with the original version concerned factor 6. It was “prevention of relapse” in the original version study [11,33], whereas in our study, it was formed by items 16 and 21 and represented “cognitive effects of treatment”. Therefore, the Tunisian version of the DAI-30 appears in correspondence with the concept of attitude toward treatment established by Hogan et al. [11]. In the French validation of the DAI-30 scale, Bonsack et al. had concluded the existence of seven factors that were subsequently grouped into two main factors (overall subjective effect and specific subjective effect) [14]. In the Italian validation, authors noted the existence of seven factors responsible for 62.5% of the variance. These factors were subsequently grouped into two main constructs: “Subjective response to treatment" construct (grouping factors 1 and 2) and "attitude to medication" construct (which is the result of five factors) [15]. This result was also found in the Spanish validation study of the scale DAI-30 [16]. Chang and Yu found three factors related to the Chinese version of the DAI, namely: subjective positive attitude, dysphoric response, and subjective negative attitudes [22]. In relationship to the validity of convergent construct, treatment compliance was associated with positive attitude toward treatment in our study. This correlation was found in several studies [10,35–37]. Many other studies showed a positive correlation between treatment adherence and patients’ attitude toward medication [6,10,38].
5. Conclusion This study shows that the Tunisian version of the DAI-30 is a valid and reliable instrument to measure attitude toward medication in outpatients with schizophrenia. This scale has good internal consistency, strong inter-rater reliability, and featured a seven-factor structure similar to the English original version. References [1] Ascher-Svanum H, Zhu B, Faries D, Lacro JP, Dolder CR. A prospective study of risk factors for nonadherence with antipsychotic medication in the treatment of schizophrenia. J Clin Psychiatry 2006;67(7):1114-23. [2] Lindenmayer JP, Liu-Seifert H, Kulkarni PM, Kinon BJ, Stauffer V, Edwards SE, et al. Medication nonadherence and treatment outcome in patients with schizophrenia or schizoaffective disorder with suboptimal prior response. J Clin Psychiatry 2009;70(7):990-6. [3] Fenton WS, Blyler CR, Heinssen RK. Determinants of medication compliance in schizophrenia: empirical and clinical findings. Schizophr Bull 1998;23(4):637-51. [4] Garavan J, Browne S, Gervin M, Lane A, Larkin C, O'Callaghan E. Compliance with neuroleptic medication in outpatients with schizophrenia; relationship to subjective response to neuroleptics, attitudes to medication and insight. Compr Psychiatry 1998;39(4):215-9. [5] Marder SR. Facilitating compliance with antipsychotic medication. J Clin Psychiatry 1998;59(3):21-5.
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[6] Lacro JP, Dunn LB, Dolder CR, Leckband SG, Jeste DV. Prevalence of and risk factors for medication nonadherence in patients with schizophrenia: a comprehensive review of recent literature. J Clin Psychiatry 2002;63(10):892-909. [7] Kim JH, Kim SY, Ahn YM, Kim YS. Subjective response to clozapine and risperidone treatment in outpatients with schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2005;30(2):301-5. [8] Tempier R, Pawliuk N. Influence of novel and conventional antipsychotic medication on subjective quality of life. J Psychiatry Neurosci 2001;26(2):131-6. [9] Voruganti L, Cortese L, Owyeumi L, Kotteda V, Cernovsky Z, Zirul S, et al. Switching from conventional to novel antipsychotic drugs: results of a prospective naturalistic study. Schizophr Res 2002;57(2–3):201-8. [10] Rocca P, Crivelli B, Marino F, Mongini T, Portaleone F, Bogetto F. Correlations of attitudes toward antipsychotic drugs with insight and objective psychopathology in schizophrenia. Compr Psychiatry 2008;49(2):170-6. [11] Hogan TP, Awad AG, Eastwood R. A self-report scale predictive of drug compliance in schizophrenics: reliability and discriminative validity. Psychol Med 1983;13(1):177-83. [12] Nielsen RE, Lindstrom E, Nielsen J, Levander S. DAI-10 is as good as DAI-30 in schizophrenia. Eur Neuropsychopharmacol 2012; 22(10):747-50. [13] Naber D, Karow A, Lambert M. Subjective well-being under the neuroleptic treatment and its relevance for compliance. Acta Psychiatr Scand 2005;427:29-34. [14] Bonsack C, Conus P, Philippoz R, Bovet J, Spagnoli J, Dufour H. Subjective perception of the effect of neuroleptics by outpatient schizophrenic patients: a cross-sectional study. Encéphale 1998;24(4): 315-23. [15] Rossi A, Arduini L, De Cataldo S, Stratta P. Subjective response to neuroleptic medication: a validation study of the Italian version of the Drug Attitude Inventory (DAI). Epidemiol Psichiatr Soc 2001;10(2): 107-14. [16] Robles García R, Salazar Alvarado V, Páez Agraz F, Ramírez Barreto F. Assessment of drug attitudes in patients with schizophrenia: psychometric properties of the DAI Spanish version. Actas Esp Psiquiatr 2004;32(3):138-42. [17] American Psychiatric Association. DSM-IV-TR. Diagnostic and statistical manual of mental disorders. Washington: APA; 2000. [18] Novick D, Haro JM, Hong J, Brugnoli R, Lepine JP, Bertsch J, et al. Regional differences in treatment response and three year course of schizophrenia across the world. J Psychiatr Res 2012;46(7):856-64. [19] Andreasen NC, Carpenter Jr WT, Kane JM, Lasser RA, Marder SR, Weinberger DR. Remission in schizophrenia: proposed criteria and rationale for consensus. Am J Psychiatry 2005;162(3):441-9. [20] Kay SR, Fiszbein A, Opler LA. The positive and negative syndrome scale (PANSS) for schizophrenia. Schizophr Bull 1987;13(2):261-76. [21] Stjernswärd S, Persson K, Nielsen R, Tuninger E, Levander S. A modified Drug Attitude Inventory used in long-term patients in sheltered housing. Eur Neuropsychopharmacol 2013;23(10):1296-9. [22] Chen HL, Yu YW. Validation of the Chinese version of the Drug Attitude Inventory. Kaohsiung J Med Sci 1997;13(6):370-7. [23] David AS, Morgan KD, Mallet R, Leff J, Murray RM. Insight: unitary or multidimensional phenomenon? Schizophr Res 2003;60(1):14. [24] David AS. Insight and psychosis. Br J Psychiatry 1990;156:798-808. [25] Nakhli J, Mlika S, Bouhlel S, Amamou B, Chaieb, Ben Nasr S, et al. Translation into Arabic and validation of the Schedule for the Assessment of Insight–Expanded Version (SAI-E) for use in Tunisia. Compr Psychiatry 2014;55(4):1050-4. [26] Mapi research institute. Linguistic validation of a patient reported outcomes measure. Available online at, http://www.mapigroup.com/ Services/Linguistic-Validation2005. [27] Shrout PE, Fleiss JL. Intra class correlations: uses in assessing rater reliability. Psychol Bull 1979;86(2):420-8. [28] Reise SP, Waller NG, Comrey AL. Factor analysis and scale revision. Psychol Assess 2000;12(3):287-97.
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[29] Flaherty JA, Gavira FM, Pathak D, Mitchell T, Wintrob R, Richman JA, et al. Developing instruments for cross-cultural psychiatric research. J Nerv Ment Dis 1988;176(5):257-63. [30] Triandis HC, Brislin RW. Cross-cultural psychology. Am Psychol 1984;39(3):1006-16. [31] Bullinger M, Anderson D, Cella D, Aaronson N. Developing and evaluating cross-cultural instruments for minimal requirements to optimal models. Qual Life Res 1993;2(6):451-9. [32] Schuman H. The random probe: a technique for evaluation of quality of closed questions. Am Sociol Rev 1966;31(2):218-22. [33] Marx RG, Menezes A, Horovitz L, Edward EC, Warren RF. A comparison of two time intervals for test–retest reliability of health status instruments. J Clin Epidemiol 2003;56(8):730-5. [34] Hofer A, Kemmler G, Eder U, Honeder M, Hummer M, Fleischhacker WW. Attitudes toward antipsychotics among outpatient clinic attendees with schizophrenia. J Clin Psychiatry 2002;63(1):49-53.
[35] Day JC, Bentall RP, Roberts C, Randall F, Rogers A, Cattell D, et al. Attitudes toward antipsychotic medication: the impact of clinical variables and relationship with health professionals. Arch Gen Psychiatry 2005;62(7):717-24. [36] Freudenreich O, Cather C, Evins AE, Henderson DC, Goff DC. Attitudes of schizophrenia outpatients toward psychiatric medications: relationship to clinical variables and insight. J Clin Psychiatry 2004; 65(10):1372-6. [37] Mohamed S, Rosenheck R, McEnvoy J, Swartz M, Stroup S, Lieberman JA. Cross-sectional and longitudinal relationships between insight and attitudes toward medication and clinical outcomes in chronic schizophrenia. Schizophr Bull 2009;35(2):336-46. [38] Yang J, Ko YH, Paik JW, Lee MS, Han C, Joe SH, et al. Symptom severity and attitudes toward medication: impacts on adherence in outpatients with schizophrenia. Schizophr Res 2012; 134(2–3):226-31.
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Cultural translation and Tunisian validation of the Drug Attitude Inventory (DAI-30) in outpatients with schizophrenia Jaafar Nakhli⁎, Badii Amamou, Salem Mlika, Saoussen Bouhlel, Marwan Trifi, Selma Ben Nasr, Yousri El Kissi, Béchir Ben Hadj Ali Farhat Hached University hospital, Psychiatric department, Sousse, Tunisia
Abstract Background: Non-adherence to treatment in patients with schizophrenia is associated with increased hospitalization, higher health care costs, and poorer long-term outcomes in terms of relapse rates. It is established that a negative drug attitude was a risk factor for nonadherence in long-term schizophrenia. The scale “Drug Attitude Inventory" is one of the scales designed to assess this concept. It has been translated and validated in different languages. However, its psychometric properties have not yet been studied in our sociocultural context. Objectives: The aims of this study were to translate into Tunisian Arabic dialect the scale “Drug Attitude Inventory" with 30 dichotomous items (DAI-30) and validate it in Tunisian sociocultural context in patients with schizophrenia. Materials and methods: This study was performed in 234 outpatients with schizophrenia, recruited through a random drawing. These patients are in remission and meet remission criteria proposed by “The Remission in schizophrenia Working Group". We recruited 30 patients for pretest and 204 patients for linguistic validation. Forward and backward translation of the DAI-30 was performed according to the protocol of the “MAPI Research Institute". This final version was submitted to 24 experts and followed by a pretest. Construct validity has been established by performing a principal component analysis factor on a sample of 204 patients. Internal consistency was assessed by Cronbach alpha coefficient and inter-rater reliability was assessed by the use of Intra-Class Correlation coefficient (ICC). For the test–retest reliability evaluation, the “r” Pearson's coefficient was used between the DAI scores obtained in the initial evaluation and those obtained at 15 days. Results: Regarding construct validity, factor analysis revealed seven factors that were responsible for 59.9% of the variance. The study of internal consistency between the 30 items was rated good (α = 0.88). The test–retest reliability was satisfactory (r = 0.99, p b 10 −3), as well as inter-rater reliability (ICC = 0.99). Conclusion: In the Tunisian cultural context, the DAI-30 presented seven factors with good consistency and an inter-rater reliability. © 2014 Elsevier Inc. All rights reserved.
1. Introduction Treatment non-adherence in patients with schizophrenia has serious impacts on the course of the illness, including worsening of symptoms, more relapses, suicidal attempts, higher period of hospitalization, and poor functional outcomes [1,2]. Many studies had estimated that 25% to 70% of all schizophrenic patients are non-compliant [3–6].
⁎ Corresponding author at: Farhat Hached University Hospital, Psychiatric department, Rue Ibn Jazzar, 4002, Sousse, Tunisia. Tel.: +216 73221411. E-mail address: [email protected] (J. Nakhli). http://dx.doi.org/10.1016/j.comppsych.2014.09.002 0010-440X/© 2014 Elsevier Inc. All rights reserved.
Since the development of second-generation antipsychotics (SGAs), it was established that patients' subjective response and acceptance were generally more likely to be positive [7–9] and many research has shifted from objective to more subjective factors that may influence adherence to medication in order to gain insight into underlying motivational processes in treatment [10]. Patients’ attitudes toward drug treatment were most studied and showed a positive correlation with treatment adherence [6,10]. Several scales were established to explore patient attitudes toward medication such as Drug Attitude Inventory 30-items and 10-items (DAI-30 and DAI-10) [11,12] and the Subjective Wellbeing under Neuroleptics treatment scale (SWN) [13]. DAI-30 is the most widely used questionnaire
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in literature to explore attitudes towards medication. It’s a self-rating scale developed by Hogan et al. [11]. It has been translated and validated in different languages [14–16]. However, in Tunisia, as well as in other Arabic countries there are no validated studies of this scale yet. The aim of the present study was to translate DAI-30 into Tunisian Arabic, to adapt it cross-culturally and to assess its reliability and validity. 2. Methods 2.1. Study sample and procedure Subjects were recruited from outpatient psychiatric unit at the university general hospitals in Souse-Tunisia through a random drawing. Interviews with all schizophrenic patients were conducted by clinically experienced psychiatrists. The study protocol was written, evaluated and approved by the Ethics Committee of Medicine School in Sousse. We recruited 204 outpatients, 140 (68.6%) males and 64 (31.4%) females, with a diagnosis of schizophrenia according to the DSM-IV-TR criteria [17], having a duration of illness of at least three years (since 84.6% of patients from North Africa & Middle east can achieve response at 3-year follow up and a large proportion of people achieve continuous remission [18]) and meeting the remission criteria offered by "The Remission in schizophrenia Working Group" with a score less than or equal to 3 in the 8 specific items (P1, P2, P3, G9, G5, N1, N4, N6) on the positive and Negative Syndrome Scale (PANSS) [19] and no history of hospitalization during the last six months [20]. Exclusion criteria were mental retardation, personal or family history of any neurological disorder, history of head injury, alcohol or substance abuse in the preceding six months. Basic demographic and clinical data were obtained from the participants’ medical records. All the patients were taking an antipsychotic medication at the time of assessment. 2.2. Instruments 2.2.1. Attitude toward medication To assess patient attitude toward medication, we used the 30-item version of the self-report Drug Attitude Inventory (DAI). For non educated patients (n = 16) we asked a relative of them to read the scale item by item literally (and if the patient hadn’t understood an item the relative had to read the corresponding item again not to explain) since the scale was translated to the Tunisian dialect (a spoken language). The Drug Attitude Inventory (DAI-30) can provide unique information of clinical relevance for monitoring treatment adherence among people diagnosed with schizophrenia [21]. The total score of the DAI-30 ranges between −30 and +30. A negative score represents adverse beliefs relating to drugs [11]. This instrument measures patient beliefs and experiences about and with medications. It has been elaborated and validated by Hogan et al. in a sample of 150 outpatients with schizophrenia. His intrinsic
validity was 0.93 and reflected a good correlation between the items. There was also a good test–retest validity of 0.82 [11]. Since this time, it was translated and validated in 4 different languages: French, Italian, Spanish and Chinese [14–16,22]. 2.2.2. Treatment compliance Patient treatment compliance was assessed using the third factor of the Schedule for the Assessment of Insight-Expanded version (SAI-E). It is represented by 2 items: Treatment acceptance and Spontaneous request for treatment [23]. The SAI-E is a semi-structured interview which consists of 11 items, with a standardized mode of rating of the items by the interviewer. Items 1–6, 10, and 11 are rated from 0 to 2, while items 7–9 are rated from 0 to 4, with higher scores indicating better insight. All the items are summed to reach a total score, ranging from 0 to 28 [23]. The scale has proven validity and reliability in patients with psychosis [23,24]. It was validated in Tunisian Arabic language in outpatients with schizophrenia. SAI-E Tunisian version had three factors compatible with the insight dimensions [25]. 2.2.3. The Positive and Negative Syndrome Scale (PANSS) This scale was developed and standardized by Kay et al. [20]. It consists of 30 items devoted to measure different types of psychopathology for schizophrenia. An interviewer rates the items on a Likert type scale from 1 to 7. 2.3. Translation–Adaptation We applied the original DAI-30 index forward/backward translation procedure. For Translation–Adaptation, we considered it necessary to obtain the consent of the designer of the DAI-30 (G. Awad) about validation. He gave us permission and answered all our questions and suggestions. For this step, we used the manual published by the linguistic validation “Mapi Research Institute" (MAPI) [26]. The translation was made from English to Tunisian Arabic dialect by two bilingual translators. The choice of Tunisian Arabic dialect and not of Standard Arabic aims for a better understanding by patients of the 30 items. The stage of the translation was completed by assembling meeting translators, an experienced psychiatrist and a psychologist in addition to the authors of this study. The items were tested one by one to find the most appropriate terms. Each term was chosen after the approval of the involved parties. The second stage was the back-translation of the translated text from Tunisian Arabic dialect to English and the verification of compliance with the original scale. This back-translation was done by a bilingual translator and followed by a meeting of all parties involved. The 30 backtranslated items were compared with the original English version of the DAI-30 scale. Twenty four psychiatrists had agreed to judge our translation. Their suggestions for items that could pose a problem were encouraged. Their responses and comments were taken into consideration in the revision of the Arabic version of the scale.
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2.4. Pre-testing For pre-testing, a sample of 30 outpatients with schizophrenia answered the translated questionnaire in order to test for the misunderstanding and acceptability of questions. Patients were randomly selected and not part of the sample statistical validation. 2.5. Reliability Reliability in terms of internal consistency of the DAI-30 was evaluated with Cronbach's alpha coefficient. This can be considered as adequate when values greater than 0.7 are obtained. For the test–retest reliability evaluation, the “r" Pearson’s coefficients were used between the DAI-E scores obtained in the initial evaluation and those obtained at 15 days. It had concerned 67 outpatients from the same sample of 204 patients. A “p” value of b 0.05 was considered to be statistically significant. To determine inter-rater reliability, the DAI-30 was administered by two investigators to 60 schizophrenic outpatients. The Intra-class Correlation Coefficient (ICC), with Two-way Random Effect Model and absolute agreement definition, was adopted for the analysis of inter-rater reliability according to the recommendations of Shrout and Fleiss [27]. 2.6. Validity For content validity, we applied a factorial analysis to verify if the Tunisian Arabic version of DAI-30 scale had a similar factorial structure to the original version. We performed principal components analysis (considering Eigen values N 1) with VARIMAX rotation and Kaiser Normalization [28]. Convergent validity was assessed by correlating the translated DAI-30 scale with the score of the third dimension (treatment compliance) of the SAI-E. The scores of both measures should correlate positively and significantly.
3. Results 3.1. Translation and expert opinion After the forward/backward translation and meeting for all participants, we found that the Tunisian Arabic version of the DAI-30 is similar to the original version. All suggestions of experts focused on items containing inappropriate language from or not relevant to our sociocultural context have been taken into consideration. 3.2. Pre-testing Thirty schizophrenic outpatients participated in this step. The pilot study resulted in few linguistic changes in the instrument. Incomprehensible terms were changed. A final translated version was obtained.
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Table 1 Demographic and clinical characteristics of patients with schizophrenia (n = 204). Age (years) Male (%) Education (%) Professional activity (%) Age of onset illness (years) Second generation antipsychotics (%) PANSS Total Score DAI-30 total score Negative attitude toward treatment (%)
40.4 68.6 93 38.4 25.7 16.7 48.2 19.1 6.9
± 12.8
± 8.6 ± 11.4 ± 11.1
3.3. Subjects' demographic and clinical characteristics (Table 1) The mean age of our sample was 40.4 ± 12.8 years. The sex ratio was 2.2 and 38.4% of them had professional activity. The mean age of illness onset was 25.7 ± 8.6 years. 16.7% of them received second generation antipsychotics. The mean PANSS total score was 48.2 ± 11.4 and the mean DAI-30 total score was 19.1 ± 11.1. The attitude toward treatment was negative in 6.9% of our sample (14 outpatients).
Table 2 Test–retest and inter-rater reliability of the DAI-30 Tunisian version. DAI-30 items
“r" Pearson coefficient
95 % CI
ICC
Item 1 Item 2 Item 3 Item 4 Item 5 Item 6 Item 7 Item 8 Item 9 Item 10 Item 11 Item 12 Item 13 Item 14 Item 15 Item 16 Item 17 Item 18 Item 19 Item 20 Item 21 Item 22 Item 23 Item 24 Item 25 Item 26 Item 27 Item 28 Item 29 Item 30 Total items
0.91⁎ 0.88⁎ 1⁎ 1⁎ 0.89⁎ 1⁎ 0.9⁎ 1⁎ 0.91⁎ 0.77⁎ 1⁎ 0.93⁎ 1⁎ 0.96⁎ 1⁎ 0.94⁎ 1⁎ 0.92⁎ 0.89⁎ 0.96⁎ 1⁎ 1⁎ 0.88⁎ 1⁎ 0.95⁎ 0.72⁎ 1⁎ 0.91⁎ 1⁎ 0.85⁎ 0.99⁎
0.93–0.97 0.84–0.93 0.96–0.99 0.95–0.98 0.90–0.97 0.98–0.99 0.88–0.95 0.98–0.99 0.86–0.95 0.73–0.90 0.98–0.99 0.98–0.99 0.97–0.99 0.95–0.99 0.98–0.99 0.91–0.96 0.98–0.99 0.89–0.96 0.80–0.92 0.94–0.97 0.98–0.99 0.98–0.99 0.98–0.99 0.98–0.99 0.98–0.99 0.74–0.90 0.98–0.99 0.98–0.99 0.84–0.94 0.47–0.77 0.98–0.99
0.95 0.90 0.98 0.97 0.94 0.99 0.92 0.99 0.91 0.83 0.99 0.99 0.98 0.98 0.99 0.94 0.99 0.93 0.87 0.96 0.99 0.99 0.99 0.99 0.99 0.84 0.99 0.99 0.90 0.65 0.99
CI: Confidence Interval (95%), ICC: Intra-class correlation (Two-way Random Effect mode, absolute agreement definition). ⁎ p b 10 −3.
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3.4. DAI-30 reliability In regards to internal consistency of the scale, Cronbach's alpha was 0.88 for the entire sample. The lower α value was 0.62 (item 13) and the higher α was 0.91 (items 18 and 29). The test–retest reliability for two weeks of interval between administrations was calculated based on a subsample of 67 outpatients with schizophrenia. The total “r" Pearson’s coefficient between both administrations was r = 0.99 (p b 10 −3). It was between 0.72 and 1 (Table 2). The inter-rater reliability was calculated in a subsample of 60 patients. The ICC for the 30 items was 0.99. It was between 0.65 and 0.99 (Table 2).
(MAPI) [26] which consists of three steps: translation, backtranslation and pre-testing. In this method, we only need three translators (two for translation and one for the backtranslation). This seems to be advantageous over other methods because it can solve the problem of non-availability of experts. Translators must have a good knowledge of the source language and the target language and culture [29–31]. For the pre-test, in contrast to the procedure described by Schuman [32], we decided to administer all items to 30 patients. All the remarks made by patients concerning the comprehension of certain expressions were taken into account and investigators are allowed to change incomprehensible expressions [29,32].
3.5. DAI-30 validity
4.2. Reliability
The factorial analysis showed seven factors that explained 59.9% of the variance of the scores (Table 3). Keiser–Meyer– Olkin index (KMO) in our study was 0.85 and Bartlett's Sphericity test was significant (p b 10 −3). In relationship to the validity of convergent construct, Pearson's correlation coefficient between the DAI-30 total score and SAI-E total score was positive and significant (r = 0.38, p b 10 −3). We found also a positive correlation between DAI-30 total score and the three dimensions of the insight (awareness of mental illness, ability to relabel unusual mental events as pathological and treatment compliance, both expressed and observed). Pearson's correlation coefficients were respectively r = 0.33, p b 10 −3; r = 0.24, p = 0.004 and r = 0.53, p b 10 −3. Good insight and treatment compliance were associated with positive attitude toward treatment.
8.8%
In our study, we noted a good internal consistency between the 30 items of the scale DAI-30 in its Tunisian version with a total Cronbach α of 0.88. All items appear to be consistent which helps to maintain a homogeneous structure of the Tunisian version of the DAI-30 scale, and to measure the concept of attitude toward treatment. The internal consistency of the scale DAI-30 was 0.93 in the original English validation study [11] and 0.57 in the Spanish validation study [16]. For the test–retest reliability, “r" Pearson’s coefficient values ranging from 0.7 to 0.9 are considered by authors as “good” [33,34]. In our study, we found a coefficient “r" Pearson equal to 0.99 with p b 10 −3, which indicates the stability of the patient's response during this time period. In the original validation study of the DAI-30 conducted by Hogan et al., the test–retest reliability was 0.82 [11]. The inter-rater reliability was calculated on a subsample of 60 subjects. We judge it enough to make this measurement. In fact, there was no consensus to fix the exact number of patients to measure inter-rater reliability [26]. In our study, apart from item 30 (ICC = 0.65), all items showed homogeneous values (from 0.83 to 0.99), and for the total DAI score it was excellent (ICC = 0.99). The low Intra-class Correlation Coefficient (ICC) of item 30 can be explained by the semantically inappropriate translation (the translation of this item was judged unclear and not discriminative) and so that item belonged to none of the seven dimensions of the scale. Robles et al., in their study of Spanish validation of the DAI in 80 patients with schizophrenia, found that the ICC was 0.61 [16].
3, 7, 11, 12, 14, 25
7.4%
4.3. Validity
2, 5, 6, 8 17, 24 16, 21 25, 27
4.9% 4.5% 3.8% 3.4%
Factor analyses of the scale showed that a seven-factor solution gave the best account of the data. This was in line with the original scale’s structure [11]. These factors in our study were: 1) positive subjective feelings related to antipsychotics, 2) health/illness-dependent drug intake, 3) negative subjective feelings related to antipsychotics, 4) sensation of treatment control, 5) patient's confidence in physician, 6) cognitive effect of treatment, and 7) potential
4. Discussion 4.1. Translation and pre-test In our study, we chose to use the linguistic validation methodology described by “The Mapi Research Institute" Table 3 Factor analysis of the DAI-30 Tunisian version. Seven Factors of DAI-30
Eigen Concerned values items
1. Positive subjective feelings 8.14 related to antipsychotics 2. Health/illness-dependent 2.63 drug intake 3. Negative subjective feelings 2.21 related to antipsychotics 4. Sensation of treatment control 1.46 5. Patient's confidence in physician 1.36 6. Cognitive effects of treatment 1.14 7. Potential toxic effects of 1.02 treatment (harm) Accumulated variance 59.9%
6, 9, 10, 15, 18, 21, 23, 26, 29 1, 4, 13, 19, 22
Percentage of the variance 27.1%
Extraction method: Principal components analysis. Rotation Method: Varimax with kaiser Normalization. Values ≤ 0.40 were eliminated from the statistical analysis.
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toxic effects of treatment (harm). The only difference with the original version concerned factor 6. It was “prevention of relapse” in the original version study [11,33], whereas in our study, it was formed by items 16 and 21 and represented “cognitive effects of treatment”. Therefore, the Tunisian version of the DAI-30 appears in correspondence with the concept of attitude toward treatment established by Hogan et al. [11]. In the French validation of the DAI-30 scale, Bonsack et al. had concluded the existence of seven factors that were subsequently grouped into two main factors (overall subjective effect and specific subjective effect) [14]. In the Italian validation, authors noted the existence of seven factors responsible for 62.5% of the variance. These factors were subsequently grouped into two main constructs: “Subjective response to treatment" construct (grouping factors 1 and 2) and "attitude to medication" construct (which is the result of five factors) [15]. This result was also found in the Spanish validation study of the scale DAI-30 [16]. Chang and Yu found three factors related to the Chinese version of the DAI, namely: subjective positive attitude, dysphoric response, and subjective negative attitudes [22]. In relationship to the validity of convergent construct, treatment compliance was associated with positive attitude toward treatment in our study. This correlation was found in several studies [10,35–37]. Many other studies showed a positive correlation between treatment adherence and patients’ attitude toward medication [6,10,38].
5. Conclusion This study shows that the Tunisian version of the DAI-30 is a valid and reliable instrument to measure attitude toward medication in outpatients with schizophrenia. This scale has good internal consistency, strong inter-rater reliability, and featured a seven-factor structure similar to the English original version. References [1] Ascher-Svanum H, Zhu B, Faries D, Lacro JP, Dolder CR. A prospective study of risk factors for nonadherence with antipsychotic medication in the treatment of schizophrenia. J Clin Psychiatry 2006;67(7):1114-23. [2] Lindenmayer JP, Liu-Seifert H, Kulkarni PM, Kinon BJ, Stauffer V, Edwards SE, et al. Medication nonadherence and treatment outcome in patients with schizophrenia or schizoaffective disorder with suboptimal prior response. J Clin Psychiatry 2009;70(7):990-6. [3] Fenton WS, Blyler CR, Heinssen RK. Determinants of medication compliance in schizophrenia: empirical and clinical findings. Schizophr Bull 1998;23(4):637-51. [4] Garavan J, Browne S, Gervin M, Lane A, Larkin C, O'Callaghan E. Compliance with neuroleptic medication in outpatients with schizophrenia; relationship to subjective response to neuroleptics, attitudes to medication and insight. Compr Psychiatry 1998;39(4):215-9. [5] Marder SR. Facilitating compliance with antipsychotic medication. J Clin Psychiatry 1998;59(3):21-5.
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[6] Lacro JP, Dunn LB, Dolder CR, Leckband SG, Jeste DV. Prevalence of and risk factors for medication nonadherence in patients with schizophrenia: a comprehensive review of recent literature. J Clin Psychiatry 2002;63(10):892-909. [7] Kim JH, Kim SY, Ahn YM, Kim YS. Subjective response to clozapine and risperidone treatment in outpatients with schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2005;30(2):301-5. [8] Tempier R, Pawliuk N. Influence of novel and conventional antipsychotic medication on subjective quality of life. J Psychiatry Neurosci 2001;26(2):131-6. [9] Voruganti L, Cortese L, Owyeumi L, Kotteda V, Cernovsky Z, Zirul S, et al. Switching from conventional to novel antipsychotic drugs: results of a prospective naturalistic study. Schizophr Res 2002;57(2–3):201-8. [10] Rocca P, Crivelli B, Marino F, Mongini T, Portaleone F, Bogetto F. Correlations of attitudes toward antipsychotic drugs with insight and objective psychopathology in schizophrenia. Compr Psychiatry 2008;49(2):170-6. [11] Hogan TP, Awad AG, Eastwood R. A self-report scale predictive of drug compliance in schizophrenics: reliability and discriminative validity. Psychol Med 1983;13(1):177-83. [12] Nielsen RE, Lindstrom E, Nielsen J, Levander S. DAI-10 is as good as DAI-30 in schizophrenia. Eur Neuropsychopharmacol 2012; 22(10):747-50. [13] Naber D, Karow A, Lambert M. Subjective well-being under the neuroleptic treatment and its relevance for compliance. Acta Psychiatr Scand 2005;427:29-34. [14] Bonsack C, Conus P, Philippoz R, Bovet J, Spagnoli J, Dufour H. Subjective perception of the effect of neuroleptics by outpatient schizophrenic patients: a cross-sectional study. Encéphale 1998;24(4): 315-23. [15] Rossi A, Arduini L, De Cataldo S, Stratta P. Subjective response to neuroleptic medication: a validation study of the Italian version of the Drug Attitude Inventory (DAI). Epidemiol Psichiatr Soc 2001;10(2): 107-14. [16] Robles García R, Salazar Alvarado V, Páez Agraz F, Ramírez Barreto F. Assessment of drug attitudes in patients with schizophrenia: psychometric properties of the DAI Spanish version. Actas Esp Psiquiatr 2004;32(3):138-42. [17] American Psychiatric Association. DSM-IV-TR. Diagnostic and statistical manual of mental disorders. Washington: APA; 2000. [18] Novick D, Haro JM, Hong J, Brugnoli R, Lepine JP, Bertsch J, et al. Regional differences in treatment response and three year course of schizophrenia across the world. J Psychiatr Res 2012;46(7):856-64. [19] Andreasen NC, Carpenter Jr WT, Kane JM, Lasser RA, Marder SR, Weinberger DR. Remission in schizophrenia: proposed criteria and rationale for consensus. Am J Psychiatry 2005;162(3):441-9. [20] Kay SR, Fiszbein A, Opler LA. The positive and negative syndrome scale (PANSS) for schizophrenia. Schizophr Bull 1987;13(2):261-76. [21] Stjernswärd S, Persson K, Nielsen R, Tuninger E, Levander S. A modified Drug Attitude Inventory used in long-term patients in sheltered housing. Eur Neuropsychopharmacol 2013;23(10):1296-9. [22] Chen HL, Yu YW. Validation of the Chinese version of the Drug Attitude Inventory. Kaohsiung J Med Sci 1997;13(6):370-7. [23] David AS, Morgan KD, Mallet R, Leff J, Murray RM. Insight: unitary or multidimensional phenomenon? Schizophr Res 2003;60(1):14. [24] David AS. Insight and psychosis. Br J Psychiatry 1990;156:798-808. [25] Nakhli J, Mlika S, Bouhlel S, Amamou B, Chaieb, Ben Nasr S, et al. Translation into Arabic and validation of the Schedule for the Assessment of Insight–Expanded Version (SAI-E) for use in Tunisia. Compr Psychiatry 2014;55(4):1050-4. [26] Mapi research institute. Linguistic validation of a patient reported outcomes measure. Available online at, http://www.mapigroup.com/ Services/Linguistic-Validation2005. [27] Shrout PE, Fleiss JL. Intra class correlations: uses in assessing rater reliability. Psychol Bull 1979;86(2):420-8. [28] Reise SP, Waller NG, Comrey AL. Factor analysis and scale revision. Psychol Assess 2000;12(3):287-97.
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[29] Flaherty JA, Gavira FM, Pathak D, Mitchell T, Wintrob R, Richman JA, et al. Developing instruments for cross-cultural psychiatric research. J Nerv Ment Dis 1988;176(5):257-63. [30] Triandis HC, Brislin RW. Cross-cultural psychology. Am Psychol 1984;39(3):1006-16. [31] Bullinger M, Anderson D, Cella D, Aaronson N. Developing and evaluating cross-cultural instruments for minimal requirements to optimal models. Qual Life Res 1993;2(6):451-9. [32] Schuman H. The random probe: a technique for evaluation of quality of closed questions. Am Sociol Rev 1966;31(2):218-22. [33] Marx RG, Menezes A, Horovitz L, Edward EC, Warren RF. A comparison of two time intervals for test–retest reliability of health status instruments. J Clin Epidemiol 2003;56(8):730-5. [34] Hofer A, Kemmler G, Eder U, Honeder M, Hummer M, Fleischhacker WW. Attitudes toward antipsychotics among outpatient clinic attendees with schizophrenia. J Clin Psychiatry 2002;63(1):49-53.
[35] Day JC, Bentall RP, Roberts C, Randall F, Rogers A, Cattell D, et al. Attitudes toward antipsychotic medication: the impact of clinical variables and relationship with health professionals. Arch Gen Psychiatry 2005;62(7):717-24. [36] Freudenreich O, Cather C, Evins AE, Henderson DC, Goff DC. Attitudes of schizophrenia outpatients toward psychiatric medications: relationship to clinical variables and insight. J Clin Psychiatry 2004; 65(10):1372-6. [37] Mohamed S, Rosenheck R, McEnvoy J, Swartz M, Stroup S, Lieberman JA. Cross-sectional and longitudinal relationships between insight and attitudes toward medication and clinical outcomes in chronic schizophrenia. Schizophr Bull 2009;35(2):336-46. [38] Yang J, Ko YH, Paik JW, Lee MS, Han C, Joe SH, et al. Symptom severity and attitudes toward medication: impacts on adherence in outpatients with schizophrenia. Schizophr Res 2012; 134(2–3):226-31.
