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BMC Psychiatry 2005, le 2: Convergent and divergent validity of the PTDS and its DSM-III-R precursor PSS-SRAuthorsPSS/PTDS ScalesFoa et al. (1993) [8]Stieglitz et al. (2001) [9]Foa et al. (1997) [3]IES TotalscoreIESIntrusionIESAvoidanceBDIPSS Total scoreReexperiencingAvoidanceHyperarousalPSS Total score.81.81.71.70.67 & .65.53.47.52.45.61 & .57ReexperiencingAvoidanceHyperarousalTotal scoreReexperiencingAvoidanceHyperarousal.63 & .59.56 & .55.52 & .49.80.77.72.74.53 & .47.50 & .51.47 & .45.66.51.69.58.80.66.73.75.61 only at first measurement(a few days after the accident).45.50.60.79.67.77.73checklist versions of the DSM-IV criteria. The introductionof the PTDS would therefore mean providing cliniciansand researchers with a sound Bosnian version of an internationally accepted PTSD self-rating instrument. The goalof this paper is to report first results of the psychometricevaluation of the Bosnian PTDS.78.68.75.70duced in Appendix 1. (The checklist also included othersignificant life events relevant to life in post-war BosniaHerzegovina. As these items are not relevant to this study,they are not discussed here.)Diagnostic assessmentAlthough all applied measures are questionnaires, not allsubjects proved literate enough to complete them on theirown. Therefore in some cases the interviewers had to readsome of the questions to them and sometimes to reread orreformulate the questions. Thus the administration deviated slightly from the standard procedures.To obtain a Bosnian version we applied the proceduressuggested by Vijver and Hambleton for the translations ofpsychological assessment measures [18]. That is, we performed an alternating procedure of translations and backtranslations until no significant differences could bedetected. In a second step we field-tested the resultingpilot versions to further check the appropriateness of thewording to the Bosnian language and the cultural context.The resulting modifications were then back-translatedagain.The instrument under assessment was the PosttraumaticStress Diagnostic Scale [3,17] which allows, as mentionedbefore, a diagnosis of PTSD as well as an estimation ofsymptom severity. The PTDS consists of four parts. Part 1has 12 items in the original and asks about possible traumatic events (A1 criterion of DSM-IV). In part 2 the timeof occurrence of the "most upsetting" event, together withthe respondent's assessment of whether the event was lifethreatening and whether it was accompanied by feelingsof helplessness and intense fear are all evaluated (A2-criterion). Part 3 asks about symptoms of reexperiencing (5items; criterion B), avoidance (7 items, criterion C), andarousal (5 items, criterion D). Part 4 explores the durationof the disturbance (criterion E) and the consequences ofthe symptomatology for important areas of functioning(criterion F). Since the original PTDS was designed for acivilian population in times of peace we replaced part 1with a checklist of traumatic events specific to the war inBosnia and Herzegovina 1992–5, the Checklist of WarRelated Experiences, CWE, the items of which are repro-The Impact of Event Scale [IES; [19]] is a questionnairewhich assesses the frequency of intrusion and avoidancephenomena as a consequence of experiencing a particularevent. In the more than 20 years since its publication ithas very frequently been used to diagnose PTSD; however,that is neither the intended nor an appropriate use for it.The IES consists of 15 items each to be answered on afour-point scale assessing the frequency of the occurrenceof stress reactions in the preceding week (0 not at all; 1 occasionally; 3 sometimes; 5 frequently). This meansthat total scores for the IES range between 0 and 75, withhigher scores indicating more frequent intrusion andavoidance reactions. The IES has been applied in nearlyevery kind of traumatisation [for an overview, see [20]]and has been translated into many languages. The IES isone the most frequently used traumatic stress questionnaires internationally. The version used in the presentstudy was almost identical to one which has been used inother studies in the region during and after the war andwhich has since been subject to a validation study [21]MethodsPage 3 of 10(page number not for citation purposes)

BMC Psychiatry 2005, le 3: Overview of samples usedSampleRegionSampling procedureNA 1998B 1998C 1998D 1999E 1999F 1999G 1999H 1999SarajevoSarajevoSarajevoSarajevoSarajevoBanja LukaBanja LukaPrijedorrandomised via maps of Sarajevo areaadmission to psychological treatmentadmission to medical treatmentrandomly selected repatriates to B&H from lists held by local councilsrandomly selected displaced or formerly displaced persons from lists held by local councilsrandomly selected subjects who stayed in the Banja Luka throughout the war, selected via maps of arearandomly selected returned displaced persons, selected from lists of residentsrandomly selected from lists of residents in collective centres981149910397100100100Table 4: Sample descriptionyears of educationagesexemployment statusfamily statusreligionNMinimumMaximumMeanStd. 47810703834531180916.0068.00%52.5 %47.5 %100.0 %21.9 %44.3 %33.7 %100.0 %44.8 %55.2 %100.0%8.7 %47.3 %5.6 %38.4 %100.0 employed or waiting listother (housewife, student)employedTotalsinglemarried or long-term land found to have satisfactory factor structure andreliability.The Symptom Checklist-90-R [SCL-90-R; [22]] is a 90item self report questionnaire for measuring subjectivepsychological and somatic stress in the preceding sevendays. Like the IES, the SCL-90-R is used widely internationally and has been used in a large number of researchprojects in a very wide variety of applications [for an overview, see [23]]. The SCL-90-R consists of nine scales andthree global indices, of which the GSI, the Global SeverityIndex, is the most widely used.Beck Depression Inventory (BDI)The Beck Depression Inventory [BDI; [24]] is probably thebest documented self-report method of measuring theintensity of depression [25,26]. By 1998 more than 2000studies had been published using the BDI [27]. The cur-0023rent, revised, version consists of 21 items whose scoresvary between 0 and 3 [24]. Zero indicates that the symptom is not present whereas three indicates the mostextreme level of symptoms. Clients are instructed toreport on how they felt in the preceding seven days.SamplesThe following data was collected between February 1998and October 1999 in Sarajevo, Banja Luka and Prijedor,which are all in Bosnia-Herzegovina. Sarajevo is in theFederation of Bosnia and Herzegovina, namely that partof Bosnia and Herzegovina which has a predominantlyMuslim and Catholic population, and Banja Luka and Prijedor are in the other part, the Republika Srpska, which ispredominantly Serbian Orthodox. The samples were stratified by age and sex. The number of years of schooling wasalso recorded. All subjects participated voluntarily andgave fully informed consent. Table 3 shows sampling pro-Page 4 of 10(page number not for citation purposes)

BMC Psychiatry 2005, le 5: Details of which instruments were given to which sub-samplesBDIIESnot given missing1998 samples, Sarajevonon-displaced random samplenon-displaced medical treatmentnon-displaced psychologicaltreatment1999 samples, Sarajevoreturnees from outside FormerYugoslaviadisplaced or former displaced1999 samples, Banja Luka andPrijedorBanja Luka displaced or formerdisplacedBanja Luka non-displacedPrijedor displaced in campsTable Total1availablePTDSnot given missing98981142414064402176211availableSCLmissing available 01003611001008051001008081001008121450cedures, region, and numbers for each sub-sampleincluded in the following analysis. Table 4 provides adescription of the demographics.In total 812 persons participated. Inclusion criteria for allwere a) age between 16 and 65, b) not suffering from apsychotic disorder and c) literate enough to answer thequestionnaires with help. All subjects completed thePTDS and the SCL-90-R; therefore correlations for thesesubscales are based on the data of all the subjects. However for reasons of economy, in 1999 the full package ofquestionnaires including the BDI and IES were onlyadministered to a random selection of participants in onlythe two Sarajevo sub-samples. All other participants in1999 only answered a smaller package of questionnairesincluding the PTDS. Correlations between the PTDS andBDI and IES are therefore based on a smaller dataset.In 20 cases an entire instrument was missing, as detailedin table 5. In the remaining cases, the number of individual missing values for individual items was small (muchless than 5%), so it was deemed acceptable to form thetotal scores for the scales simply by multiplying the meanitem score for each individual, allowing for any missingitems, by the total number of items on each scale. So inthe case of the inter-scale correlations the Ns are merelyreduced by the number of completely missing questionnaires. In the case of the reliability analyses for the subscales of the PTDS, instruments with any missing items onthe scale in question were excluded from the analyses, ineach case slightly reducing the Ns.844174InterviewersThe medical and psychological samples were assessedthrough a total of 15 experienced counsellors/therapists,who were working at a variety of clinics and counsellingcentres in Sarajevo. All other samples were assessed bypairs of final year and third year students of Psychology atSarajevo University and Banja Luka University. All interviewers were trained in the use of the questionnaires. Twopilot studies were performed to insure the appropriate useof the assessment. During the studies constant supervision for all interviewers was provided.Statistical analysisTo obtain an estimation of internal consistency Cronbach's alpha was calculated for the total scores and thesubscales of the PTDS. Convergent and divergent validitywere estimated by using Spearman correlations betweenthe scales. Spearman correlations were used because mostof the distributions were not normal. For the principalcomponents analysis, oblimin oblique rotation was used.Results and discussionThe standardised Cronbach's alphas for the Bosnian PTDSwere .93 for the total symptom score, .89 for the reexperiencing subscale, .84 for the avoidance subscale and .84 forthe arousal subscale. The results correspond well withother published results.The Spearman's correlations between the total scale andthe subscales were all quite high at .89, .93 and .87 for reexperiencing, avoidance and hyperarousal respectively; reexperiencing correlated .74 and .67 with avoidance andPage 5 of 10(page number not for citation purposes)

BMC Psychiatry 2005, le 6: Item characteristics of the PTSD symptom items of the Bosnian PTDSsexfemaleMeanB1 intrusionsB2 bad dreamsB3 reexperiencingB4 upset after rememberingB5 physical reaction after rememberingC1 attempt not to think about itC2 avoiding places peopleC3 not being able to remember detailsC4 less interest in activitiesC5 detachment estrangementC6 restricted affectC7 foreshortened futureD1 difficulty falling or staying asleepD2 irritabilityD3 difficulty concentratingD4 hypervigilanceD5 exaggerated startle responsetotal score on subscale b (reexperiencing)total score on subscale c (avoidance)total score on subscale d (arousal)total score on all symptom subscalesmaleStandard 3.7711.73MeantotalStandard anStandard .46The items were scored on a scale of 0 (not at all or once a month) to 4 (5 or more times a week /almost always).Table 7: Rotated factor pattern of the PTSD symptom items of the Bosnian PTDSLoadingsSymptomFactor 1: Arousal / NumbingFactor 2: IntrusionFactor 3: .438.397.326.063-.031-.017-.122-.003b1 intrusionsb2 bad dreamsb3 reexperiencingb4 upset after rememberingb5 physical reaction after rememberingc1 attempt not to think about itc2 avoiding places peoplec3 not being able to remember detailsc4 less interest in activitiesc5 detachment, estrangementc6 restricted affectc7 foreshortened futured1 difficulty falling or staying asleepd2 irritabilityd3 difficulty concentratingd4 hypervigilanced5 exaggerated startle responseFactor loadings greater than 0.40 are shown in bold underline.Page 6 of 10(page number not for citation purposes)

BMC Psychiatry 2005, le 8: Convergent and divergent validity of the Bosnian PTDSIES TotalPTDS TotalReexperiencingAvoidanceHyperarousalSpearman's rhoNSpearman's rhoNSpearman's rhoNSpearman's rhoNIES Intrusion.709439.634439.651439.573439hyperarousal; and the correlation between avoidance andhyperarousal was .72.The item characteristics for the symptom items and subscale totals are shown in table 6. The characteristics areacceptable, with the lowest standard deviation being .77for the item about not being able to remember details,which also had the lowest mean (.36 on a scale of 0 to 4).The items from the symptom subscales were submitted toa principal components analysis with oblimin obliquerotation. Factors with eigenvalues greater than 1 wereretained. Items were considered as belonging to a factor iftheir loadings on that factor were above 0.4. (see table 7).The first solution had three factors explaining a total of61.41% of the variance and was deemed to be satisfactory,so that no further solutions were sought. The first factor,which explains 47.64% of the variance, was labelledArousal / Numbing. It contains all the items from theDSM-IV arousal scale and three DSM-IV avoidance items,two of which (detachment/estrangement and restrictedaffect) are also associated with numbing [11]. The secondfactor, explaining 7.85% of the variance, was labelledIntrusion and includes all the items from the DSM-IVintrusion scale together with one item ("attempting not tothink about it") from the DSM-IV avoidance scale. Thethird factor, which explains 5.92% of the variance, waslabelled Avoidance. It contains all the items from theDSM-IV avoidance scale except for two items which loadon Arousal/Numbing. Every item loaded on at least onefactor and only two items loaded on more than one factor(the item "attempt not to think about it" loaded on theIntrusion and Avoidance factors, and the item "detachment, estrangement" loaded on the Arousal/Numbingand Avoidance factors).In short, the three DSM-IV scales can be broadly identified, except that three DSM-IV avoidance items includingtwo of the somewhat contentious numbing items load onthe arousal scale, which replicates well the findingsreported above [11-13].703438.687438.603438.574438IES Avoidance.619439.491439.610439.493439BDISCL 02.595803Table 8 provides the correlations between the variousother measures of psychopathology and the BosnianPTDS. With samples of this size, correlations even as smallas approximately .1 are significant, so all the correlationsare highly significant and thus the significances are notreported here.The correlations between the PTDS and the IES are somewhat lower than in the two American publications, closerto those in the German article. Re-experiencing on thePTDS correlates higher with intrusion than with avoidance on the IES, and avoidance on the PTDS correlateshigher with avoidance on the IES than with intrusion onthe IES, all of which are desirable results in that they support construct validity. The correlations between the reexperiencing and avoidance scales of the IES and theavoidance scale of the PTDS are quite similar, possiblyindicating weak specificity of the latter, which washowever also the case for all except the oldest of the threeprevious studies.The correlation between the BDI total and the PTDS/PSStotal is high, as reported in the literature. In fact the Bosnian version seems to differentiate a little better betweenPTSD and depression than do the American and Germanversions; nevertheless the specificity is still quite weak.In the same way there are also quite high correlations withthe SCL-90-R. Although the Bosnian version of the BDIand SCL have also not been adequately validated before,validating one new instrument against other instrumentswhich are also not validated is not a meaningless affairbut on the contrary the only possible procedure in a situation such as the one we (and our local and internationalresearcher colleagues) found ourselves in, namely thatvery few world-standard instruments existed. If one doesfind, as we did, inter-instrument correlations similar tothose for the corresponding instruments in other languages then that provides at least some provisional evidence for the psychometric quality and construct validityof all of those instruments.Page 7 of 10(page number not for citation purposes)

BMC Psychiatry 2005, 5:11http://www.biomedcentral.com/1471-244X/5/11One of the main uses of the PTDS is to provide a PTSDdiagnosis in an economical way. As the PTDS assesses inquestionnaire form all the information necessary for thediagnosis according to DSM-IV, the PTDS prevalences canbe easily calculated and are in fact 24.72% for the wholesample, 31.37% for women and 17.40% for men.Authors' contributionsThe most important factor which restricts the interpretation of these results is that the PTDS was not comparedwith clinical interview, which would have been standardprocedure in this kind of study. However, when we beganthe study there was no suitable validated interview available in the Bosnian language, which meant that we wouldhave had to translate and extensively validate such aninterview ourselves, and again we would have run into theproblem of validating the interview against instrumentswhich had also not been validated at that time. It alsoshould be stressed that this study says very little about thecultural or contextual validity of the instrument or theconstruct PTSD which it is intended to measure.Both authors worked on and approved the finalmanuscript.RR participated in the design of the study, and drafted themanuscript.SP carried out the actual study and performed the statistical analysis.Appendix 1The war traumatic event items of the Checklist of WarEvents (which replaces the standard traumatic eventchecklist in the PTDS)group 0: injury to selfWere you severely injured during the war?group 1: sexual violence to selfWere you raped or sexually assaulted during the war?On the other hand, the samples are quite large and takentogether quite heterogeneous, and the selection methodologies in each case provided a reasonable approximationto randomness, so that all in all the data can be consideredto be of good quality.During the war, were you sexually assaulted by a memberof your close family who had been forced to do that?During the war, were you sexually assaulted by a memberof your close family who was not forced to do that?ConclusionIn conclusion it can be said that the psychometric properties of the Bosnian version of the PTDS are as good asthose published for other languages. The internal consistencies are at least as good and the Bosnian version appearseven to distinguish a little better than the American andGerman versions between PTSD as measured by the IESand depression as measured by the BDI. The principalcomponents revealed by an exploratory analysis arebroadly consistent with the DSM-IV subscales except thatthey reproduce some previously reported difficulties withthe "numbing" items from the avoidance subscale; thisissue might explain the poor specificity of the avoidancescale with respect to the IES subscales. None of the analyses revealed anything unusual or indicated problemseither with the translation or with the application of theconcepts inherent in the instrument to the post-war Bosnian population, all of which indicates that the BosnianPTDS can be given the green light for further applicationin the future. Yet our results are only a necessary first stepin the validation of the applied measures; a comparisonwith a validated translation of a Bosnian interview measure for PTSD still needs to be done.group 2: torture to selfWere you tortured during the war?group 3: other threat to selfDuring the war, were you in a situation in which youstrongly believed you would be severely injured or killed?During the war, did a bullet come so close to you that youcould have been severely injured or killed?During the war, did a bomb or grenade explode so closeto you that you could have been severely injured or killed?During the war, did anyone threaten to kill you or severelyinjure you?Were you captured or held in a detention camp during thewar?During the war, were you without food or water for solong that you strongly believed you would die?Competing interestsThe author(s) declare that they have no competinginterests.During the war, were you so cold that you stronglybelieved you would die?Page 8 of 10(page number not for citation purposes)

BMC Psychiatry 2005, 5:11During the war, did you stay in a cellar longer than 3weeks without a roup 6: losses, nuclear familyWas your father killed in the war?During the war, were you assaulted in a non-sexual way bya member of your close family who had been forced to dothat?Was your mother killed in the war?Was your spouse killed in the war?During the war, were you assaulted in a non-sexual way bya member of your close family who had not been forcedto do?Was a child of yours killed in the war?Was a brother or sister of yours killed in the war?Were you in the ar

between SCID and PTDS diagnosis was 82 % and kappa was .65. Overall, the criterion validity of the PTDS with respect to SCID was encouraging. Table 2 provides an overview of convergent and divergent validity for the PTDS and some other self-report measures of trauma related psychopathology. The symptom items of the PTDS, which reflect more or