Psychometric of DDS in cancer patients.final

Psychometric Evaluation of Death Depression Scale Iranian’ Cancer Patients Development and Psychometric Evaluation of a Persian Version of the Death Depression Scale- Revised: A Cross-Cultural Adaptation in Patients with End-Stage Cancer Introduction: Patients with advanced cancer commonly experience multiple symptoms like such as death depression which is highly prevalent in this population Thus, assessing depression in these patients who are facing death can be somewhat challenging SoTherefore, it is crucial to use valid and reliable instruments in order to measure this concept The present study aims to determine the psychometric properties of the Death Depression Scale in Iranian patients with end-stage cancer Methods: In the present methodological study, 497 of cancer patients completed a Persian version of the 21-item Death Depression Scale-Revised The face, content, and construct validity of the scale was ascertained Also reliability was assessed using Cronbach’s alpha coefficient, construct reliability and intra correlation coefficient Results: The construct validity of the scale showed one factor with eigenvalues greater than one The model had a good fit (χ2 (179, N= 248) = 520.345, p < 001; χ2/df= 2.907, CFI= 916, TLI = 902 Psychometric Evaluation of Death Depression Scale Iranian’ Cancer Patients , IFI = 917, SRMR= 049, and RMSEA= 088 (90% confidence interval = 079–.097)) with all factors loadings greater than and statistically significant The Cronbach’s alpha and construct reliability were greater than 70 Convergent validity of construct of the scale was fulfilled Conclusion: Findings revealed that the Persian version of the death depression scale was a valid and reliable instrument that can be used in assessment and evaluation of death depression in Iranian cancer patients Keywords: Psychometric, Death Depression, Cancerpatients, Iran Introduction Despite the advanced technology in health care systems as well as higher achievement in patients’ survival of risky situations, death is an always inescapable fact fact AlongsideNotwithstanding the aforementioned inevitability of death, patients with a diagnosis of cancer are compelled to deal with their death which may be at a time of where death is nor normally regarded as a normal dayto-day consideration Diagnosing The diagnosis of cancer can be equated to despair, pain, fear, and death Most cancer patients may also suffer be affected from by psychological problems in to varying degrees The main factors influencing the intensity and frequency of these psychological threats are patients' socio demographic characteristics (e.g., gender, age and education level) , social support , disease-related factors , and contextual/cultural factors and religiosity Common complications, after treatment, that impairs psychosocial aspects of the life of cancer survivors, includesing fatigue, cognitive changes, body image, sexual health, fear of recurrence, social, economic, health problem, pain, depression and anxiety of death Evidence shows that cancer patients are more susceptible than the general population in terms of overall mental health such as depression, anxiety; interpersonal sensitivity, and psychosis Concerns about death may Psychometric Evaluation of Death Depression Scale Iranian’ Cancer Patients potentiate negative affect, negatively impact communication, distort perceptions about recovery, and distance patients from their care providers The continuation of this situation leads to anxiety and depression, particularly death depression that which is considered as one of the most common psychological effects and one of the important diagnose for this group of patients The results of some studies have shown that depression is a highly prevalent symptoms which is estimated to cover 10 to 20 percent of patients during illness Depression in cancer patients is very harmful due to its requirement of the submission to the disease Depressed Ppeople who are depressed may not attempt to survive and they will may lose better opportunities to live the rest of their lives post recovery In general, simultaneous occurrence of depression with cancer leaves negative and multiple effects on different areas of individual and social life, mental and physical health, treatment, and disease progression So, it seems that prevention, diagnosis and timely intervention on of depression in cancer patients may be important and necessary According to the importance of death depression in alleviating symptoms as well as managing process recovery, there is a need to use a specialized tool of death associated with depression in cancer patients with the capacity to detect and provide a detailed assessment So, this tool can be helpful to for use in care programs Empirical research hases indicated that the death depression scale has been evaluated in different languages (e.g Spanish and English) within a sample of healthy population To the authors’ knowledge, no other studies have examined death depression scale as they relate to cancer patients within Iran Thus, Iran’s regional and cultural context may have a significant effect on people’s perception about the death depression concept Nevertheless, there is no standard tool for assessing death depression in these patients in Iran Therefore, it is essential to have a specialized tool related to death depression in cancer patients which has an accurate Psychometric Evaluation of Death Depression Scale Iranian’ Cancer Patients assessment and diagnosis capacity This has implications for health practitioners who may design more effective care plans based on the outcomes of a death depression specific assessment Therefore, the present study aims to determine the psychometric properties of the DDS in Iranian patients with end-stage cancer Methods This cross-cultural adaptation methodological study with quantitative approach was conducted in 2016 (March-June); 497 patients with end-stage cancer in oncology units of Imam Khomeini hospital (Sari, Iran) and the oncology center of Kerman (Iran) were included to in the study with a random sampling method employed In this period of timetime period (4 months), about 900 patients were admitted to these hospitals Among these, 690 patients meet the inclusion criteria’s In order for a participant to be included in this study, he/she was required to meet the following criteria: (i) being eligible for receiving surgery, radiotherapy or chemotherapy, (ii) being able to read and write Persian, (iii) and have no physical or psychiatric problems—other than cancer—which could restrict participation in the study (such as schizophrenia, post-traumatic stress disorder, dementia, major depressive disorder) Some of the patients were excluded from our study due to (i) transfer to another hospital, (ii) havinge critical conditions (such low GCS, drug or alcohol addiction, verbal, mental, and physical problems) The minimum sample size for conducting factor analysis is equal to 5–10 times more than the number of the items of the intended instrument Consequently, 497 patients were recruited A demographic questionnaire and the Death Depression Scale (DDS) were used for data collection The DDS was used for assessing death depression Initially, written permission was obtained from the developer of the scale, i.e Templer, for using the DDS in this study Then, Tthe World Health Organization protocol was used to translate the DDS into Persian We Psychometric Evaluation of Death Depression Scale Iranian’ Cancer Patients employed the forward-backward translation technique for translating the scale from English into Persian Accordingly, two English-Persian translators were invited to independently translate the DDS An expert panel consisting of the authors of this paper and the two translators assessed and unified the two translations and produced a single Persian translation of DDS Thereafter, a Persian-English translator was asked to back-translate the Persian DDS into English This English version of the DDS was sent to Dr Templer He confirmed the correctness of translations and the similarity of our English DDS with the original English DDS The DDS includes twenty one items which are scored on a five-point Likert scale from (Completely disagree) to (Completely agree) Consequently, the total score of the scale ranges from 21 to 105 Lower scores show indicate lower levels of depression For validity assessment of this scale, face and content validity (Qualitative and Quantitative) and construct validity (Exploratory and Confirmatory) have been used Face validity assessment The face validity of the Persian DDS was assessed both qualitatively and quantitatively 1.1 Qualitative face validity assessment For assessing the qualitative face validity of the Persian DDS, ten cancer patients were invited to assess and comment on the appropriateness, difficulty, relevance, and ambiguity of the items Moreover, the necessary time for completing the scale was determined in this step The scale was amended according to patients’ comments 1.2 Quantitative face validity assessment The item impact technique was adopted for assessing the quantitative face validity of the Persian DDS Consequently, the same ten patients were asked to determine the importance of the items on a Likert-type scale from (Not important) to (Completely important) The item Psychometric Evaluation of Death Depression Scale Iranian’ Cancer Patients impact score of each item was calculated by using the following formula, Importance  Frequency (%) In this formula, frequency is equal to the number of patients who had ascribed a score of or to the intended item and importance was equal to scores or If the impact score of the each item was greater than 1.5, the item was considered as suitable and it was maintained in the scale Content validity assessment The content validity of the Persian DDS was also assessed both qualitatively and quantitatively as explained below 2.1 Qualitative content validity assessment In this step, the Persian DDS was provided to fifteen experts (nine nursing doctorates, two psychiatrists, two clinical psychologists, and two oncologists) and they were asked to assess and comment on the wording, item allocation, and scaling of the items We revised the DDS according to their comments 2.2 Quantitative content validity assessment The quantitative content validity of the scale was assessed through calculating Content Validity Ratio (CVR) and Content Validity Index (CVI) for the items CVR reflects whether the items are essential or not Accordingly, fifteen experts (which is mentioned above) were asked to rate the essentiality of the DDS items on a three-point scale as follows: Not essential: 1; Useful but not essential: 2; and Essential: The CVR of each item was calculated by using the following formula: CVR = (ne – (N/2)) / (N/2) In this formula, N and ne are respectively equal to the total number of experts and the number of experts who score the intended item as ‘Essential’ ‘Essential’ According to Lawshe (1975), when the number of panelists is fifteen, the minimum acceptable CVR is equal to 0.49 Psychometric Evaluation of Death Depression Scale Iranian’ Cancer Patients On the other hand, CVI shows the degree to which the items of the intended scale are simple, relevant, and clear CVI can be calculated for each item of a scale (Item-level or I-CVI) and for the overall scale (Scale-level or S-CVI) Accordingly, we asked the same fifteen panelists to rate the simplicity, relevance, and clarity of the DDS items on a four-point scale from to For instance, the four points for rating the relevance of the items were ‘Not relevant, ‘Somewhat relevant’, ‘Quite relevant’, and ‘Highly relevant’ which were scored as 1, 2, 3, and 4, respectively The I-CVI of each item was calculated by dividing the number of panelists who had rated that item as or by the total number of the panelists Lynn et al (2006) noted that when the number of panelists is equal to fifteen, the items which acquire an I-CVI value of 0.79 or greater are considered as appropriate Construct validity assessment To assess construct validity, the factor structure of the Persian DDS was examined by conducting an exploratory factor analysis (EFA) by performing a maximum likelihood followed by a varimax rotation with SPSS 22 (SPSS Inc., Chicago, IL, USA) Patients were asked to complete the Persian DDS The Kaiser-Meyer-Olkin (KMO) test and the Bartlett’s test of sphericity were used to check the appropriateness of the study sample and the factor analysis model The number of factors was determined based on eigenvalues and scree plot Items with absolute loading values of 0.3 or greater were regarded as appropriate (eigenvalues of one or less should be ignored) The factor structure obtained from the EFA was then examined with using a confirmatory factor analysis (CFA) conducted with AMOS 19 Jaccard and Wan (1996) have recommended that most common indexes of goodness a fitting model in CFA are χ2 goodness-of-fit index (CMIN), Root Mean Square Error of Approximation (RMSEA), Normed fit index (NFI), Psychometric Evaluation of Death Depression Scale Iranian’ Cancer Patients Adjusted Goodness of Fit Index (AGFI), TLI (Tucker-Lewis index), Parsimonious comparative fit index (PCFI), and the chi-square divided by the df value (CMIN/DF) Cut-off criteria of model fit indices for latent variable models were shown in the first table Convergent validity was assessed by estimating average variance extracted (AVE) To establish convergent validity, the AVE of constructs should exceed 50 Reliability assessment The reliability of the Persian DDS was first assessed through evaluating its internal consistency and calculating Cronbach’s alpha Alpha values of 0.7 or greater show satisfactory internal consistency Then, the construct reliability (CR) of factor were assessed CR of the model was determined whereby values between 0.6 and 0.7 can be accepted providing other indicators are good Multivariate normality and outliers Univariate distributions were examined for outliers, skewness, and kurtosis Multivariate distributions were evaluated for normality and multivariate outliers Multivariate normality can be evaluated through the use of Mardia’s coefficient of multivariate kurtosis A Mardia’s coefficient greater than was an indication of violation kurtosis Multivariate outliers can be evaluated through evaluation of Mahalanobis distance Mahalanobis distance specified typically by a p< 001 Ethical considerations The study was approved by the Ethics Committee of Mazandaran University of Medical Sciences, Sari, Iran (Ethics Code: IR.MAZUMS.REC.95.106) Patients were informed about the study aims and procedures Moreover, they were ensured that participation was voluntary and Psychometric Evaluation of Death Depression Scale Iranian’ Cancer Patients that it would not affect the course of their treatments The confidentiality of patients’ information was guaranteed Informed consent was obtained from all participants Results Table describes the demographic profiles of the respondents The respondents were predominately married (n = 354, 71.2 %) with a mean age of 47.54 years Among them, 52.1 % (n = 259) were female The impact score, CVR, and I-CVI values of all 21 items of the Persian DDS were respectively greater than 1.5, 0.49 and 0.79 Therefore, none of the items were excluded in these steps of psychometric evaluation Table shows the results of performing maximum likelihood EFA on the DDS using the first dataset consisting of 249 participants The KMO was 951, and the Bartlett’s test of sphericity was significant (p < 001, 4485.458, df = 210) indicating that the sampling was adequate Using a scree plot, which is shown in Figure and considering factors with eigenvalue greater than one, EFA extracted one factor consisting of 21 items together accounting for 58.21% of the variance The factor loading of all items was greater than ranging from 529 to 833 [Insert Figure here] [Insert Table here] Next, the factor structure obtained with EFA was assessed and validated using maximum likelihood CFA and the second dataset with 248 samples Based on the modification indices, ten pairs of measurement errors (between items and 3, and 9, and 10, 10 and 13, 11 and 12, 12 Psychometric Evaluation of Death Depression Scale Iranian’ Cancer Patients and 13, 13 and 14, 15 and 16, 16 and 17, and between items 19 and 21) were allowed to freely covary Figure shows the final model after reviewing model modification indices for sources of model misfit The results of performing CFA on DDS specified as a single factor consisting of 21 items indicated a good fit (χ2 (179, N= 248) = 520.345, p < 001; χ2/df= 2.907, comparative fit index (CFI) = 916, Tucker Lewis index (TLI) = 902, incremental fit index (IFI) = 917, standardized root mean square residual (SRMR) = 049, and root mean square error of approximation (RMSEA) = 088 (90% confidence interval = 079–.097)) All item loadings were significant and greater than varying from 522 to 811 The construct showed a good internal consistency measured by Cronbach’s alpha (α=.966) and good construct reliability (.966) Moreover, the results in table showed that the average variance extracted (AVE) of the construct exceeded 0.5 and also construct reliability was greater than AVE, fulfilling the requirements of convergent validity [Insert Figure here] Discussion The purpose of the present study was to evaluate the psychometric properties of the Persian version of the DDS among Iranian patients with cancer Exploratory factor analysis and confirmatory factor analysis were used to investigate and then confirm the underlying structure of the scale Exploratory factor analysis showed that the DDS is a one-dimensional construct among cancer patients Based on principal component analysis (PCA) and Varimax rotation, a single-factor solution was selected, explaining 58.210% of the variance Tomas-Sabado et al (2005), who investigated the Spanish form of the scale, showed that it has four-dimensional structure These factors were called Anergia and vacuum, death sadness, others’ death, and 10 Psychometric Evaluation of Death Depression Scale Iranian’ Cancer Patients anhedonia, respectively Two other researches studies on the health population also confirmed the four-dimensionality of the scale Based on the items loading in the exploratory factor analysis, this factor was labeled “death sadness” It comprised of items reflecting feelings of losing energy, hopelessness, and sadness when thinking about death Previous studies have also identified this factor for the death depression scale Also, Kubler-Ross (1969) stated sadness alongside with some features like suffering, hopelessness as well as loss as components of depression in response to the idea of self-death, the death of significant others, and death in general that has been reported by health professionals who work directly with advanced or dying cancer patients Moreover, factors such as the severity of disease, witnessing others’ death, and separation from beloved ones and things can heighten patients’ death-related worries and sadness Also, patients’ worry and despair may be related to rapid passage of time, shortness of life, imminent painful death, and fear of the unknown So, the human thought and manner towards death may be affected by the cognition originated from his personal and social point of view, hope, fear and concerns about death nature and meaning A CFA model was used in order to determine the validity of the Persian version of the DDS It confirmed the final factor construct of the present scale To the best of our knowledge, no study could find to compare the results with the present one Chi-square goodness of fit test was almost significant in the sample size with more than 200 participants Cronbach’s alpha and CR of the DDS showed that the Persian version of the DDS has good reliability among cancer patients Tomás-Sábado et al (2005) stated that the scale’s internal consistency of Spanish form is appropriate Four weeks test-retest correlation estimated to be 11 Psychometric Evaluation of Death Depression Scale Iranian’ Cancer Patients 87 Cronbach’s alpha coefficient of original version was 92 reported by Templer He stated that the significant correlation between this tool and depression and anxiety had an appropriate quality and the relation between the Likert form and the true-false part was 0.85 as well Moreover, two other researches studies undertaken done in Iran calculated Cronbach’s alpha coefficients and test re-test method and reported as 0.93 and 0.76 respectively The present study estimated AVE for assessment of convergent validity It was shown with construct fulfilled for the factor Actually, when a construct is related to other theoretically relevant constructs it is said to have convergent validity So, DDS was studied by its relationships with other theoretically related constructs such anxiety, and hopelessness in some researches studies Previous studies have also supported a four-factor model for the DDS, with factors tapping into death sadness, anergia, existential vacuum, and anhedonia Implications for practice The Persian version of the Death Depression Scale – Revised has been demonstrated in this article to be a useful tool in evaluating the psychological condition of patients experiencing very difficult and potentially life-changing illness The psychometric properties of this Scale demonstrateindicate that this is a reliable measure which can be used in the Persian population as was designed by the original scale authors Limitations This study used 497 patients with end stage cancer in Iran Therefore, the study is limited to that sample and generalizability therefore becomes less robust outside this sample Farsi is spoken in other geographical areas but the measure may not be accurate with a separate group of patients 12 Psychometric Evaluation of Death Depression Scale Iranian’ Cancer Patients Conclusions This study confirmed adequate psychometric properties and factor structure of the DDS With this structure, the scale can be used as a valid and reliable tool for the assessment of death depression experienced by Iranian cancer patients Acknowledgments This study was funded by Mazandaran University of Medical Sciences, Sari, Iran and an extension of Taylor’s University Research Grant (TRGS/ERFS/1/2015/TBS/014) We want to hereby extend our sincere gratitude to the patients who helped to make this research possible Declaration of conflicting interests The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article References Soleimani MA, Yaghoobzadeh A, Bahrami N, Sharif SP, Sharif Nia H Psychometric evaluation of the Persian version of the Templer's Death Anxiety Scale in cancer patients Death studies 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OMEGA-Journal of Death and Dying 1993;26(2):113-8 60 Hintze J, Templer DI, Cappelletty GG, Frederick W Death depression and death anxiety in HIVinfected males Death studies 1993;17(4):333-41 61 Templer DI, Lavoie M, Chalgujian H, Thomas‐Dobson S The measurement of death depression Journal of Clinical Psychology 1990;46(6):834-9 62 Al-Sabwah MN, Abdel-Khalek AM Religiosity and death distress in Arabic college students Death studies 2006;30(4):365-75 16 ... common indexes of goodness a fitting model in CFA are χ2 goodness -of- fit index (CMIN), Root Mean Square Error of Approximation (RMSEA), Normed fit index (NFI), Psychometric Evaluation of Death... shows the final model after reviewing model modification indices for sources of model misfit The results of performing CFA on DDS specified as a single factor consisting of 21 items indicated... Therefore, none of the items were excluded in these steps of psychometric evaluation Table shows the results of performing maximum likelihood EFA on the DDS using the first dataset consisting of 249 participants