Independent validation of the Non motor Symptoms Scale for Parkinson's disease in Brazilian patients

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<ul><li><p>rrtiarceSo</p><p>Accepted 22 August 2012</p><p>Keywords:Non motor symptomsParkinsons diseaseNMSSValidation</p><p>PD progresses, but some of these NMS, such as depression, olfactoryproblems, REMbehavior disorders and constipation,maybe presentin the premotor phase of the disease [3]. In addition, NMS havea deep impact on PD patients quality of life [4].</p><p>Recently, two complementary instruments to assess nonmotor symptoms in PD have been developed: the Non Motor</p><p>have to care for a larger number of patients with PD. The primaryobjective of this study was to assess the clinimetric properties ofthe cross-culturally NMSS Brazilian adaptation in a sample of PDpatients.</p><p>2. Subjects and methods</p><p>2.1. Design</p><p>Unicenter, observational, cross-sectional study.* Corresponding author. Tel.: 34 618684738.</p><p>Contents lists available at</p><p>Parkinsonism and R</p><p>lse</p><p>Parkinsonism and Related Disorders 19 (2013) 115e119E-mail address: (F.J. Carod-Artal).Parkinsons disease (PD) is a progressive neurological disorderthat gradually results in accumulating disability [1] and hasa considerable impact on the psychosocial functioning of patients[2]. Nonmotor symptoms (NMS) are common inPDpatients; studieshave found NMS as presenting complaint of the disease in 21% ofpatients and prevalence around 90% after seven years of diseaseduration [1]. Themost common nonmotormanifestations in PD aremood disorders, cognitive and neuropsychiatric symptoms, sleepdisturbances, autonomic dysfunction, fatigue, and sensory symp-toms [2]. Many patients experience an increased number of NMS as</p><p>screening purposes whereas the NMSS is used for NMS burdenassessment [7].</p><p>Suitable and clinimetrically sound instruments to assess NMS inPD are still lacking in Brazil. Although some Brazilian studies havepreviously assessed the impact of cognition [8] and autonomicsymptoms [9], no study has validated a specic Non motor Symp-toms Scale for PD patients. With the increase in life expectancy,changes in the projected age distribution of the Brazilian pop-ulation are also expected. The demographic change may havea greater effect on the prole of disease as Brazil health systemwill1. Introduction1353-8020/$ e see front matter 2012 Elsevier Ltd. disease-Motor (SCOPA-M), Autonomic, Cognition, and Psychosis; Hoehn and Yahr staging(H&amp;Y); Berg Balance Scale; PD Sleep Scale; Clinical Impression of Severity Index for PD (CISI-PD); PDQ-39; and EQ-5D. The following clinimetric attributes were explored for the NMSS: acceptability, scalingassumptions, reliability, construct validity, and precision.Results: 150 patients were assessed (mean age 63.1 years; 56.7% males; mean duration of illness 8.7years; HY median: 2). Mean NMSS was 48.9 (SD 36.3; median 42; skewness 1.3). Neither oor nor ceilingeffect was observed on the NMSS total score. For domains, the Cronbachs alpha coefcient ranged from0.40 to 0.82. The NMSS total score correlated signicantly with SCOPA-AUT (rS 0.65) and with thosescales measuring related constructs (rS 0.46e0.57). NMSS signicantly increased as the H&amp;Y stageincreased (KruskaleWallis, p &lt; 0.0001). These values were quite close to those from the original vali-dation studies.Conclusions: The NMSS is a reliable and valid measure to evaluate non motor symptoms in Brazilian PDpatients.</p><p> 2012 Elsevier Ltd. All rights reserved.</p><p>Symptoms Questionnaire (NMSQuest) [5], and the Non motorSymptoms Scale (NMSS) [6]. The NMSQuest was developed forReceived in revised form7 August 2012Methods: Parkinsons disease (PD) patients were evaluated by means of the Scales for Outcomes inArticle history:Received 27 June 2012</p><p>Objective: Independent validation of the Non motor Symptoms Scale in Parkinsons disease (NMSS) basedon a cross-culturally adapted Brazilian version.Independent validation of the Non motoin Brazilian patients</p><p>Francisco Javier Carod-Artal a,*, Pablo Martinez-MaaMedicine and Health Sciences Faculty, Universitat Internacional de Catalunya (UIC), BbAD Research Unit and CIBERNED, Carlos III Institute of Health, Alzheimer Centre Reina</p><p>a r t i c l e i n f o a b s t r a c t</p><p>journal homepage: www.eAll rights reserved.Symptoms Scale for Parkinsons disease</p><p>n b</p><p>lona, Spaina Foundation, Madrid, Spain</p><p>vier .com/locate/parkreldisSciVerse ScienceDirect</p><p>elated Disorders</p></li><li><p>Construct convergent validity of the NMSS with other measures for the same orrelated constructs [21] was explored by means of Spearmans rank correlation coef-cient (rS). Moderate to high associations between NMSS total score and othermeasures for assessment of NMS in PD (SCOPA-AUT, SCOPA-PC, and SCOPA-COG totalscores) was predicted (rS &gt; 0.35). Also, an a priori high correlation (rS &gt; 0.50) withHRQoL measures (PDQ-39, EQ-5D) and moderate correlation (rS &gt; 0.35e0.50)between NMSS and scales for PD severity (HY, SCOPA-M, CISI-PD)was expected [6,7].</p><p>The KruskaleWallis test was used to assess the discriminative validity of theNMSS to distinguish among PD patients grouped by H&amp;Y staging.</p><p>Correlations between domains were calculated to determine the NMSS internalvalidity; Spearmans correlation coefcient values 0.30e0.70 were deemed satis-factory [22].</p><p>Precision for the NMSS domains was calculated by means of the standard errorof measurement for a single observed score (SEM) [23] [SEM standard devia-tion O(1alpha)]. A SEM value &lt; standard deviation was used as criterion ofacceptable precision. The lower the precision of the NMSS, the greater the SEM ofthe scale will be.</p><p>Statistical Package for the Social Science 13.0 for Windows (SPSS, Chicago, IL)was used for data analysis.</p><p>3. Results</p><p>Seven PD patients were excluded due to concomitant severeillness: neumonia, 1 patient; sequela status of stroke, 1 patient; andsevere PD dementia resulting in inability to answer the questions, 5patients.</p><p>One hundred and fty PD patients (mean age 63.1 11.1 years;56.7% males; years of education 9.4 5.3) were included in thestudy. Age at onset was 54.4 12.4 and duration of the disease was8.7 5.5 years (range: 1e28). The median H&amp;Y stage was 2, and20% of patients had an H&amp;Y stage 1, 43.3% H&amp;Y stage 2, 28% H&amp;Ystage 3, and only 8.7% had an H&amp;Y stage 4e5. The description ofpatients assessment is shown in Table 1.</p><p>CISI-PD, cognitive function 1.8 1.2 1 5</p><p>onism and Related Disorders 19 (2013) 115e1192.2. Patients</p><p>One hundred and fty PD patients who were consecutively admitted at theoutpatient Neurology Clinic of the Sarah Hospital in Brasilia DF, between October2007 and September 2008, were included in the study.</p><p>2.3. Denition and inclusion/exclusion criteria</p><p>Consecutive PD patients diagnosed by neurologists with competence in move-ment disorders, according to the United Kingdom Parkinsons Disease Society BrainBank Criteria [10], with age &gt; 40 years at onset of disease.</p><p>Those patients with any concomitant severe illness, acute disorder or injury,pharmacological effect (e.g., dopamine antagonists), sensorial decit (e.g., blind-ness) or sequela status (e.g., hemiplegia) that could interfere with or signicantlymodify the evaluation of the effects caused by PD were excluded from the study. Inaddition, those PD patients illiterate or with disability due to other neurologicaldisorders such as, for instance, stroke or dementia (according to DSM-IV criteria),were also excluded from assessment.</p><p>The study protocol was approved by the institutional review board andinformed consent was obtained from all the patients before their participation in thestudy.</p><p>2.4. Assessments</p><p>The following socio-demographic data and historical information was retrievedfrom patients through interview: age, gender, marital status, education, and occu-pation; age at onset, duration of PD, and pharmacological treatment. Functionalassessment of PD patients included neurologist-based and patient self-assessments.In patients with uctuations, the assessments were performed during on state.</p><p>Neurologist-based assessments included, in addition to the NMSS [6], the Scalesfor Outcomes in Parkinsons disease-Motor (SCOPA-M) [11], SCOPA-Cognition(SCOPA-COG) [12], SCOPA-Psychiatric complications (SCOPA-PC) [13], ClinicalImpression of Severity Index for Parkinsons disease (CISI-PD) [14], Hoehn and Yahrstaging (H&amp;Y) [15], and Berg balance Scale (BBS) [16].</p><p>Patients self-assessment included the SCOPA-Autonomic scale (SCOPA-AUT)[17], the Parkinsons Disease Sleep Scale (PDSS) [18], the Parkinsons DiseaseQuestionnaire (PDQ-39) [19] and the EQ-5D [20].</p><p>For some rating scales (SCOPA-M, SCOPA-PC, CISI-PD, H&amp;Y, SCOPA-AUT, PDQ-39,and EQ-5D index), higher scores reect higher severity on the construct beingmeasured, whereas for the rest of scales the meaning of the higher scores is just theopposite.</p><p>The NMSS [6] is a 30-item measure whose items are grouped in nine relevantdomains: Cardiovascular (2 items); Sleep/fatigue (4 items); Mood/apathy (6 items);Perceptual problems/hallucinations (3 items); Attention/memory (3 items);Gastrointestinal tract (3 items); Urinary function (3 items); Sexual function (2items); and Miscellaneous (4 items). Score for each item is based on a multiple ofseverity (from 0 to 3) and frequency scores (from 1 to 4). The scale can thereforecapture symptoms that are severe but relatively infrequent (e.g., hallucinations) andthose that may be less severe but persistent (e.g., constipation, fatigue, or lowmood). The time frame is the past month.</p><p>2.5. Cross-cultural adaptation of the NMSS</p><p>The NMSS was cross-culturally adapted following a protocol for translation andback-translation used previously [8]. First, the NMSS was translated into BrazilianPortuguese by 2 independent native speakers with excellent knowledge of English,and then a rst NMSS version was obtained by consensus. Second, the consensusversion was back translated into English by an English native who had goodknowledge of Portuguese and without access to the original English version. Third,the rst back-translation was compared to the original version by the NMSSdevelopers and modications were made in order to eliminate all discrepanciesbetween the original and the back-translated version. The nal joint translation wasnamed NMSS Brazilian Portuguese version.</p><p>2.6. Data analysis</p><p>The following clinimetric attributes were explored for the NMSS: acceptability;scaling assumptions; reliability; construct and discriminative validity, and precision.Criterion values for analysis were as in the original validation study [7].</p><p>Quality of data was considered satisfactory if more than 95% of NMSS data werefully computable. To establish the acceptability of the NMSS Brazilian version, therange of scores (observed versus possible score ranges), the oor and ceiling effects(proportion of patients who obtained minimum and maximum scores, respectively;maximum acceptable for both, 15%), and skewness (limits: 1 to 1) werecalculated.</p><p>Internal consistency of the NMSS domains was explored by corrected iteme</p><p>F.J. Carod-Artal, P. Martinez-Martin / Parkins116domain correlation corrected for overlapping and Cronbachs alpha. Values 0.30and 0.70, respectively, were considered appropriate.SCOPA-COG total score 21.2 7.6 2 38SCOPA-Psychosis 1.9 2.3 0 14PD Sleep scale 83.4 28.4 9 144PDQ-39Mobility 42.5 26.4 0 100Activities of daily living 41.9 27.9 0 100Emotional well being 41.8 24.6 0 100Stigma 29.6 25.7 0 100Social support 18.3 24.5 0 100Cognition 38.1 21.9 0 87.5Communication 30.6 22.4 0 83.3Bodily discomfort 40.4 27.0 0 100PDQ-39 Summary Index 35.4 18.4 2.6 86.8</p><p>EQ-5D index 0.51 0.22 0.1 0.8EQ-5D VAS 64.4 19.6 0 100</p><p>Min, minimum; Max, maximum; SD, standard deviation.ADL, Activities of daily living; CISI-PD, Clinical impression severity index- Parkin-sons disease; EQ-5D, EuroQol-5 dimensions; PDQ-39, Parkinsons disease quality oflife questionnaire; SCOPA-COG, Scales for Outcomes in Parkinsons disease- cogni-Fully NMSS data were computable for the 99.9% of the sample.The acceptability and reliability of the NMSS and the distribution ofscores on the nine NMSS domains are displayed in Table 2. The</p><p>Table 1Motor and functional evaluation of PD patients.</p><p>Mean SD Min Max</p><p>SCOPA-MotorSCOPA-M, motor impairment 8.1 5.4 1 28SCOPA-M, ADL 5.9 4.0 0 18SCOPA-M, motor complications 2.9 3.1 0 12SCOPA-M, total score 16.8 10.3 2 47</p><p>Non motor Symptoms Scale 48.9 36.3 1 211Berg balance scale 46.6 11.8 4 56CISI-PD, total score 8.9 4.2 1 18CISI-PD, motor signs 3.0 1.0 1 5CISI-PD, disability 2.1 1.4 1 5CISI-PD, motor complications 1.1 1.7 1 5tive questionnaire; SCOPA-Motor, Scales for Outcomes in Parkinsons disease-motorscale; VAS, visual analog scale.</p></li><li><p>mean NMSS score was 48.9 36.3 points (range: 1 e 211;median 42; difference meanmedian 6.9 points, 3.3% of themaximum observed score). No differences in the NMSS total scorewere observed by sex (male: 47.4 37.3; female: 50.8 35.1;p 0.5). The mean scores of NMSS domains ranged from 1.4(Cardiovascular) to 11.2 (Mood/apathy). Skewness was 1.3 for theNMSS total score.</p><p>Neither oor nor ceiling effect was observed on the NMSS totalscore (Table 2). A oor effect was observed in most NMSS domains,with the exception of Sleep/fatigue and Urinary function. Percep-tual problems/hallucinations (72%), Sexual function (64%), andCardiovascular function (56%) had themost prominent oor effects.No ceiling effect was observed on the NMSS domains.</p><p>Internal consistency of NMSS domains is shown in Table 2.Cronbachs alpha ranged from 0.37 (Gastrointestinal) to 0.82</p><p>(rS 0.17; p 0.04). NMSS total scores were signicantly higher inthose patients with more than 10 years of evolution (44.7 38.1</p><p>4. Discussion</p><p>This study explored the metric properties of the NMSS Brazilianversion. As the NMSS includes several items per domain, each itemscoring severity and frequency, the NMSS may provide a more</p><p>n disease.</p><p>Reliability Precision</p><p>ss Flooreffect, %</p><p>Ceilingeffect, %</p><p>Item-domaincorrelation</p><p>Cronbachsalpha</p><p>Standard errorof measurement</p><p>56.0 0.7 0.12e0.41 0.57 2.17.3 0.7 0.17e0.54 0.40 6.6</p><p>26.0 0.7 0.46e0.72 0.82 5.872.0 1.3 0.26e0.31 0.52 2.634.7 0.7 0.42e0.53 0.70 4.134.7 0.7 0.17e0.34 0.37 5.314.0 0.7 0.32e0.41 0.71 4.864.0 2.0 0.32e0.41 0.76 3.121.3 0.7 0.20e0.50 0.54 6.10.7 1.3 e e e</p><p>Table 3Correlationsa between Non motor Symptoms Scale mean scores and related scales.</p><p>SCOPA-AUT SCOPA-PC SCOPA-COG PDSS</p><p>NMSS, domainsCardiovascular 0.29 0.23 0.13 0.31Sleep/fatigue 0.51 0.39 0.21 0.66Mood/apathy 0.41 0.35 0.27 0.33Perceptual problems/</p><p>hallucinations0.36 0.46 0.23 0.42</p><p>Attention/memory 0.17 0.33 0.17 0.22Gastrointestinal 0.55 0.32 0.21 0.29Urinary 0.46 0.32 0.19 0.31Sexual function 0.23 0.15 0.09 0.12Miscellaneous 0.38 0.34 0.09 0.44NMSS, total score 0.65 0.55 0.33 0.55</p><p>NMSS, Non motor Symptom Scale in Parkinson disease; PDSS, Parkinson diseaseSleep Scale; SCOPA-AUT, Scales for Outcomes in Parkinsons disease- autonomic;</p><p>F.J. Carod-Artal, P. Martinez-Martin / Parkinsonism and Related Disorders 19 (2013) 115e119 117(Mood/apathy). Five domains (Cardiovascular, Sleep/fatigue,Perceptual problems/hallucinations, Gastrointest...</p></li></ul>