approximately 795,000 
 individuals suffer a stroke each year , which translates to an average of one case every 40 
 seconds3 . in a study addressing 291 
 health conditions , stroke is one of the first 
 health conditions to attract the attention of research groups seeking to investigate 
 functionality using the structure proposed by the international classification of 
 functioning , disability and health ( icf)5 , 6 , which is based on a biopsychosocial 
 approach integrating the biological , individual and social dimensions of health . based on the conceptual framework of the icf7 , participation is considered the most complex component to evaluate 
 using existing assessment tools8 , 9 . recently , our research group10 , 11 
 demonstrated that the stroke specific quality of life ( ss - qol ) scale appears to be the most 
 complete measure for assessing social participation among stroke survivors . however , only 26 
 of the 49 items on the scale address participation capacity10 . it is therefore necessary to perform an accurate evaluation of the 
 psychometric properties of the ss - qol items that only assess participation . the aims of the present study were to investigate the validity of the scoring standards of 
 the ss - qol items and patient responses , pinpoint the drawbacks of the measure , and propose 
 the revision or exclusion of any items that do not exhibit suitable psychometric qualities . this study sought to lend scientific credibility to the process of evaluating individuals 
 with hemiparesis stemming from a stroke by providing important data for the development of 
 appropriate treatment plans aimed at enhancing social participation among stroke 
 survivors . a preliminary analysis was performed of the ss - qol items that address the icf participation 
 category . for this , a methodological cross - sectional study was carried out involving 33 
 stroke survivors with chronic hemiparesis . the subjects were recruited from the outpatient 
 clinic of the physical therapy department of the university nove de julho ( brazil ) . the following were the inclusion criteria : clinical diagnosis of primary or recurrent 
 stroke with a history of more than six months and weakness and/or spasticity on the affected 
 side of the body . the exclusion criteria were the presence of another clinical condition 
 associated with hemiparesis caused by stroke , motor or comprehension aphasia and cognitive 
 impairment established using the mini - mental state examination with the cutoff points 
 proposed by bertolucci12 . all participants signed a statement of informed consent and were informed of the 
 possibility of dropping out of the study at any time without penalty . this study received 
 approval from the human research ethics committee of the university nove de julho ( so 
 paulo , brazil ) under protocol number protocol 313.776/13 . identification of the items of the ss - qol that address the icf participation component was 
 based on a study by silva et al.11 , who 
 found that 26 of the 49 ss - qol items evaluated participation , spanning eight subscales 
 ( family roles , language , mobility , self - care , social roles , thinking , upper extremity 
 function , and work / productivity ) . five response options are offered for each item , with item 
 scores ranging from 1 to 5 . thus , the minimum overall score for the questionnaire is 26 
 ( lowest social participation ) , and the maximum score is 130 ( highest social 
 participation)11 . the volunteers were evaluated by a single examiner who had undergone training for the 
 administration of the data collection instruments through theoretical and practical 
 exercises . considering the sociocultural characteristics of the sample , the participants 
 could opt to have the questionnaires administered in interview form . descriptive statistics were performed for characterization of the sample and distribution 
 of the scores . measures of central tendency ( mean ) and dispersion ( standard deviation ) were 
 used for quantitative variables , and frequency was used for categorical variables . rasch analysis allows calibration of the difficulty of items and the level of ability of 
 individuals on a simple linear continuum at equal intervals along which each item and each 
 individual are aligned13 , 14 . in the present study , the basic assumption was that 
 individuals with a better participation capacity would achieve higher scores on all items of 
 the ss - qol scale , regardless of whether the tasks addressed were easy or difficult , whereas 
 any individual is likely to achieve a higher score on items addressing easy tasks15 . when all items of a test meet these 
 expectations , the test is then fitted to a measurement model15 , and those individuals with greater competence in the domain of a 
 given function ( participation , in the present case ) are more likely to achieve higher scores 
 than those with lesser competence . these principles are only applicable if the set of items 
 measures a one - dimensional skill16 . in the present study , the analysis of the calibration of the ss - qol items was carried out 
 using the bigsteps program . this program calculates mnsq values and 
 associated t values , which indicate whether the relationship between an individual s ability 
 and item difficulty fulfill the assumptions of the model . linacre and wright17 suggest mnsq = 1  0.3 
 with an associated t =  2 as reasonable values indicating the suitability of items . test - retest reliability was assessed using the intraclass correlation coefficients ( iccs ) 
 which were interpreted as follows : less than 0.40 = poor reliability , 0.40 to 0.75 = 
 moderate reliability , 0.75 to 0.90 = good reliability , and greater than 0.90 = excellent 
 reliability18 . in all inferential 
 analyses , sixty - four individuals with chronic hemiparesis were recruited for the present study , 10 of 
 whom were excluded due to aphasia , nine of whom were excluded due to cognitive impairment , 
 and 12 of whom were excluded due to other adverse health conditions associated with stroke . table 1table 1.demographic and clinical characteristics of the subjectsvariable(n=33)male19 ( 54%)female14 ( 46%)age ( years)5915time since stroke ( years)43affected hemisphereright13 ( 40%)left20 ( 60%)marital statusmarried22 ( 67%)single5 ( 15%)divorced4 ( 12%)widower2 ( 6%)schooling ( years)43mini - mental state examination23 ( 22/28)data expressed as absolute and relative frequencies , mean  sd , for parametric 
 variables and medians and interquartile ranges ( 25% and 75% ) for nonparametric 
 variables . data expressed as absolute and relative frequencies , mean  sd , for parametric 
 variables and medians and interquartile ranges ( 25% and 75% ) for nonparametric 
 variables . table 2table 2.calibration of ss - qol items that assess icf participation componentsiteminfitoutfitmeasureerrormnsqmnsqi devoted less time leisure*1.260.161.322.6sex less often*1.010.141.281.89i have found many friends0.860.141.211.29difficulty doing the work before0.780.140.800.73it was hard to concentrate0.670.130.860.77do not participate in leisure with family0.360.131.241.19lost balance lower0.290.141.241.28difficulty writing or typing0.210.140.891.01difficulty walking0.170.140.951.28had to be repeated0.110.141.211.26difficulty buttoning clothes**0.070.140.740.69difficulty standing**0.050.150.690.85help to prepare food0.110.160.850.83difficulty doing housework**0.110.160.610.66difficulty in completing tasks0.110.160.860.89difficulty putting on socks0.160.160.770.70difficulty climbing stairs0.190.160.780.81difficulty using a zipper0.240.170.800.76difficulty speaking0.270.171.201.25help to eat**0.330.170.620.72difficulty opening a jar**0.450.190.530.47difficult to raise0.530.200.781.16difficulty talking on the phone0.570.201.301.29help to dress**0.610.210.670.71help with bathing**1.060.281.000.48help using toilet*1.140.301.782.63 * erratic item ( mnsq > 1.3 and t > 2 ) ; * * deterministic item 
 ( mnsq < 0.7 ) displays the results of the rasch analysis , in which the mnsq 
 and t ( infit and outfit ) calibration 
 values were discriminated for each item . for example , item 15 ( i did my hobbies and 
 recreation for shorter periods of time than i would like ) had the lowest gross 
 score ( 62 ) , and item 14 ( did you need help to use the toilet ? ) had the 
 highest gross score ( 156 ) . three of the 26 items ( items 14 , 15 , and 17 ) did not fulfill the 
 expectations of the model ( mnsq > 1.3 and t > * erratic item ( mnsq > 1.3 and t > 2 ) ; * * deterministic item 
 ( mnsq < 0.7 ) the separation index for individuals was 2.58 , indicating that the items divided the 
 individuals on more than one level of participation . the separation index for the items was 
 3.19 ( three levels of difficulty : low , medium , and high ) . the estimate of the internal 
 consistency ( stability of the calibrations ) was 0.91 for items and 0.87 for individuals . 1.map illustrating the distribution of individuals in relation to the difficulty of 
 ss - qol items and different levels of participation displays a map that illustrates the level of difficulty of the items in relation to 
 the participation of the individuals in the sample , with the participation continuum of the 
 sample on the left of the map and item difficulty on the right . the items are well 
 distributed toward the top of the continuum in terms of difficulty . two items toward the 
 bottom proved very easy , and no individuals exhibited such a low degree of 
 participation . map illustrating the distribution of individuals in relation to the difficulty of 
 ss - qol items and different levels of participation all items demonstrated moderate to excellent ; statistically significant reliability ( icc  
 0.60 ) . the global coefficient of ss - qol reliability was 0.91 , which indicates stability with 
 regard to item calibration . for individuals , this coefficient was 0.87 , which means that the 
 answers of the subjects were also reliable . the rasch analysis detected three items ( 11.5% ) with erratic behavior ( items 14 , 15 , and 
 17 ) , which is higher than the recommended rate ( 5% ) indicating that an instrument measures a 
 one - dimensional concept . however , one should consider that the implementation of some 
 activities among the ss - qol items for the assessment of participation may not be sufficient 
 to explain the real involvement of individuals in a social context , representing only an 
 evaluation of  activity  and not participation ,  which may be a limitation of the use of 
 this instrument for this purpose . with regard to item 14 ( did you need help to use the toilet ? ) , patients 
 with more severe motor impairment had higher scores . this finding may be related to the fact 
 that the sample was composed of patients in the chronic phase of hemiparesis , when 
 individuals learn to cope with the limitations of their conditions , which seems to have a 
 positive effect on functional independence and the performance of activities daily of 
 living19 , 20 , such as using the toilet without assistance . for item 15 ( i did my hobbies and recreation for shorter periods of time than i would 
 like ) , low scores were found even though the sample was composed of individuals with 
 moderate to high degrees of participation . however , one must consider that leisure 
 activities depend on the habits of each individual and may not necessarily reflect an 
 inability to perform , but rather a lack of practice or resources ( family support and the use 
 of quality transportation ) . indeed , this was a common complaint among the subjects in the 
 present study . another problem was found regarding item 17 ( i had less sex than i would like 
 to ) . however , sexual issues may not have been fundamental due to the age of the 
 participants or the fact that 33% of the subjects did not have a partner . in contrast , most 
 married men reported wanting to have more sex regardless of their health state and 
 functioning . the diversity of factors that can influence one s opinion regarding this item 
 explains the considerable variability in responses , making this an item erratic . a previous study evaluated the calibration of the ss - qol items and concluded that it is a 
 clinically useful instrument for the assessment of health - related quality of life among 
 stroke survivors21 . however , the study 
 found four erratic items , among which only item 17 ( i had sex less often than i would like ) 
 was also considered to be erratic in the present study . thus , changes to item 17 ( after 
 consultation and approval from the authors ) followed by subsequent studies to assess the 
 behavior of the revised item are suggested . moreover , other erratic items should be 
 monitored to determine if the problems found in the present study persist . if so , such items 
 should also be revised or possibly even eliminated . the value found for the separation index of individuals ( 2.58 ) indicates that the sample 
 was divided into more than two levels of participation : low , medium , and high . in the 
 analysis of a test such as the ss - qol , a small number of individuals would be expected in 
 the upper portion of the continuum ( i.e. , few individuals with a high degree of 
 participation ) as well as the lower portion of the continuum ( i.e. , few highly impaired 
 individuals with a low degree of participation ) . most would be distributed along the middle 
 third of the continuum , characterizing a moderate degree of participation , which was indeed 
 found in the present study ( fig . others inferences can be made from the distribution of individuals along the continuum 
 displayed in fig . 1 . the inclusion of both easy 
 and difficult items constitutes an advantage of the ss - qol scale . the former ensure that 
 this measure can be administered to more debilitated or institutionalized individuals , and 
 the latter allow its use for individuals with a higher degree of participation . the ss - qol 
 items that assess the participation component of the icf demonstrated an adequate 
 distribution along the continuum , with easy items for the assessment of individuals with 
 more participation restrictions and difficult items for the assessment of those with fewer 
 restrictions . item 6 ( did you lose your balance 
 when bending over or reaching for something ? ) and item 16 ( i did nt see as many of my 
 friends as i would like ) had the lowest correlation coefficients ( 0.64 and 0.60 , 
 respectively ) ; but nonetheless demonstrated acceptable reliability18 . the present findings are important to the field of physical therapy and can contribute to 
 effective assessment of social participation among stroke survivors , allowing the 
 rehabilitation process to be directed at specific objectives focused on the individual .
[ purpose ] the aim of the present study was to analyze the psychometric properties of the 
 stroke specific quality of life ( ss - qol ) scale for the assessment of social participation 
 following a stroke . [ methods ] a preliminary analysis was performed of the ss - qol items 
 that address the participation category . for this , the scoring patterns of the answers of 
 individuals and internal consistence were determined using the rasch model . 
 reliability 
 was assessed by intraclass correlation coefficients ( icc ) . 
 [ results ] the reliability 
 coefficients analyzed by the rasch model were 0.91 for the items and 0.87 for the 
 patients . 
 the separation index was 3.19 for the items and 2.58 for the patients . 
 the 
 findings indicate that the items separated the patients into three levels of 
 participation : low , medium , and high . among the 26 items addressing participation 
 , three 
 did not fit the model . 
 all items showed adequate reliability ( icc  0.60 ) . 
 [ conclusion ] 
 the rasch analysis detected three items with erratic behavior ; however , the erratic 
 patterns of these items may be explained by individual peculiarities among the patients . 
 these items should be monitored to determine if the problems found in the present study 
 persist . 
 if so , the items should also be revised or possibly even eliminated .