the short and long - term benefits of early intervention for childhood developmental disorders have been demonstrated in numerous studies ( 16 ) and an increasing urge has been developed for their early identification ( 6 ) .
however , it is now well - known that relying on a clinician s clinical instincts and experience can be misleading in the early differentiation between normal and abnormal development ( 1 , 610 ) .
several studies have supported the observation that parents can give accurate information about their child s development ( 1013 ) and thus there is increasing tendency for production and application of questionnaires that are based on parents reports and some authors have confirmed their use ( 14 ) . in the present study the asq , a parent - report questionnaire , was chosen because it has been proven to be a valid and/or reliable screening test , even in its translated and culturally adapted versions in different populations of children ( 7 , 1422 ) .
however , few studies have examined the psychometric properties of asq in cultures outside the united states . this test has not been validated and standardized before in iran .
this study was conducted for the purpose of cultural adaptation , validation and standardization of the asq questionnaire for 460 months - old iranian children and children with similar socio - cultural backgrounds , such as all those living in the middle east .
the questionnaire was translated to the persian language and then back - translated by two independent native translators who also had experience in the field of child development . by comparing the two , the discrepant parts were identified and corrected . the resulting persian questionnaire was then assessed in terms of content validity by a panel of seven , including four pediatricians , a psychologist , a speech pathologist , and a psychometrist .
it was tried hard to maintain the meaning of the original items , however some changes were inevitable for improving clarity of meaning in the persian language or for adapting culturally .
a pilot study was carried out on 100 parents of 460 month - old iranian children , recruited by convenient sampling in tehran , in order to determine the degree of 
clarity of items , cultural appropriateness , to detect ambiguous items and to identify dilemmas in the process of test implementation .
after identifying and resolving problematic issues in the previous phase , the revised version of the persian test was performed for 38 children , two from each of the 19 age groups , once by the mother and once by the father , in order to determine the inter - rater reliability . in order to perform the test on a national sample , we trained a group of physicians from selected cities in the country , which were selected purposively , trying to provide a widespread and an evenly - spread selection , covering the main socio - cultural and geographic divisions of the country , and also based on the presence of skilled physicians in health care centers willing to supervise the implementation of the research . for implementation of the test at the national level the sample was determined to be 11000 children but turned out to be 10516 children actually .
our inclusion criteria were 460 months age , iranian nationality , lacking gross developmental disorders , and parents educational level at least elementary school .. informed consent was acquired from parents of children . for assessment of psychometric properties of the test , the cronbach s alpha coefficient was calculated for each of the five domains and then totally , in all nineteen age groups for determining reliability . in order to determine the construct validity of the questionnaires using factor analysis , first the kmo ( kaiser - meyer - olkin measure of sampling adequacy )
was measured and was calculated to be 0.865 meaning the sampling was adequate for performing the factor analysis . in order to prove the correlation matrices between test items did not equal zero , the bartlett s test of sphericity was utilized .
therefore , performing the factor analysis based on correlation matrices between items of the questionnaire was explicable .
then , factor analysis was performed using the principal components analysis ( pc ) method . in order to determine that the items of the asq questionnaires were saturated with significant factors ,
after extraction of significant factors and performing the varimax rotation , the factor loadings ( correlation of test items with the extracted factors ) were calculated and the percentage of explained variances was determined .
to arrive at cut - off values for the iranian sample , the mean scores minus 2sds for each domain in every age - specific questionnaire were determined ( 15 ) .
we were unable to assess the criterion - referenced validity of the questionnaire using a gold standard diagnostic developmental test because no such tests were available in iran .
the minimum number of children belonged to the 60-month s age group   and the maximum number belonged to the 12-month olds . in terms of the cronbach s alpha values of reliability , the lowest values for reliability appeared at 22-months in the problem - solving ( 0.55 ) and at 18-months in the social - personal domains ( 0.55 ) .
conversely , the highest values were detectable at 14-months in the gross motor ( 0.80 ) and at 36 and 60 months in the fine motor domains ( 0.80 ) .
the highest and lowest total reliability values belonged to the 36-months ( 0.86 ) and 18 months ( 0.76 ) questionnaires , respectively .
the inter - rater reliability values obtained were 0.88 , 0.91 , 0.88 , 0.89 , and 0.86 for the communication , gross motor , fine motor , problem - solving , and social - personal domains , respectively , and 0.93 totally .
the results of the principal component analysis ( pc ) are demonstrated in table 1 which shows the calculated factor loadings with values larger than 0.3 , along with the rotated eigen value and the percentage of explained variance by each significant extracted factor .
these figures for factor loadings of the test items demonstrate that the extracted factors are capable of assessing the five different developmental domains in iranian children .
table 2 demonstrates the results of the iranian children s mean scores in comparison to the mean scores in the normative sample and those derived from three studies conducted in norway , spain ( galicia ) , and korea .
the results of only 10 age groups have been presented here because in the normative sample , data have been provided only on these 10 age groups .
also , for the purpose of easier comparison , the standard error ( se ) results in the korean study have been converted and demonstrated as standard deviation ( sd ) results ( using the formula : se= sd/n ) . in table 2 ,
when we consider significant differences that are occurring repeatedly uni - directionally between iranian mean scores and those of at least three of the four other countries , the results are : - iranian children demonstrate significantly higher scores at 12 months in all domains except the gross motor ; at 16 months in the communication , problem - solving , and social - personal ; at 8 months in the problem - solving and social - personal and at 20 months in the communication and problem - solving domains .
iranian children demonstrate significantly lower scores at 24 and 36 months in the gross and fine motor , at 48 months in the problem - solving and at 60 months in the fine motor and problem - solving domains . in the communication domain ,
the iranian mean scores are significantly higher at 12 , 16 , 20 , and 24 months ; in gross motor they are significantly lower at 24 and 36 months ; in fine motor they are significantly lower at 12 , 24 , 36 , and 60 months ; in problem - solving s they are significantly higher at 8 , 12 , 16 , and 20 , and significantly lower at 48 and 60 months ; and finally in the social - personal domain they are significantly higher at 8 , 12 , and 16 months . at other
age ranges than those mentioned above , significant differences between iranian figures and those of the other four countries seem to be randomly distributed and no specific pattern can be detected . when comparing only with the normative sample results , at 8 and 12 months , iranian children demonstrated significantly higher scores in at least three domains ( including the fine motor , problem - solving and social - personal domains ) .
whereas at 36 months they showed significantly lower scores in the same domains as well as the gross motor . at other age ranges , the significant differences did not seem to follow any specific pattern .
when considering each domain separately across all age groups , one considerable result is the significantly lower iranian mean scores in the fine motor domain in six different age groups of 16 , 20 , 24 , 30 , 36 and 60 months .
in terms of cultural and linguistic appropriateness for iranian children , several items underwent modifications , most of which were in the  communication domain .
a similar process of item modifications took place in two studies performed on korean ( 21 ) and turkish children ( 22 ) .
conversely , in two separate studies performed on norwegian and dutch children no needs for modifications in the contents of the test were reported ( 18 , 23 ) . unlike the authors of the turkish study who have concluded that despite the modifications , their study supports the idea of cultural independence of the test ( 25 ) , we believe that considering the several modifications that were needed in order to prepare asq for implementation in the iranian society as well as the korean and turkish studies , it can not be considered totally culture - free , especially considering countries outside the western zone . in terms of validity and reliability ,
this finding is consistent with several other studies ( 7 , 1423 ) which have generally shown the test validity and /or reliability lying in the range of 70% to 100% . in the two studies that have covered the full age range of 4 to 60 months ,
the figures reported for sensitivity , specificity and reliability respectively have been 75.8% , 87.5% , and 94% in the us study ( 15 ) , and 94% , 85% , 82.1%(test - retest reliability ) and 87%(inter - rater reliability ) in the turkish study ( 22 ) .
one pattern that can be noted when comparing the mean scores of the iranian children with that of the other four countries is that iranian children seem to be at a higher developmental level than children of the other four countries are at ages below 24 months , after which they seem to decline developmentally and demonstrate lower developmental status .
a similar phenomenon was reported after developmental assessment of filipino infants using the griffiths mental development scales and comparing the results with those of british infants .
the researchers suggested that differences in such factors as : genetics , nutrition and breastfeeding , environmental stimulation and mother - child interaction , socio - economic status and maternal intelligence quotient played a role ( 24 ) . in another study ,
scores obtained on the revised bayley scales of infant development ii by children from low - income families were compared with those of the normative sample .
this study showed that in infants , scores were consistent in the two groups , whereas the toddlers of the former group obtained lower mental , motor and behavioral scores .
black concluded that this was either explained by a lack of enriching care - giving practices for toddlers in low - income families which did not development is guided by species - specific self - righting processes that protect infants from fulfill the requirements of toddlerhood , or the canalization theory in which early many environmental influences ( 25 ) .
in addition , it must also be noted that in iran , the ministry of health has continuously promoted exclusive breast - feeding from about 20 years ago .
. it may be possible that after complete weaning , that is at about 24 months , the iranian childrens nutritional requirements are not ideally met which may also affect their development .
another pattern that was noted when comparing the mean scores is that iranian children seem to be at a better - off situation in terms of the communication , problem - solving and social - personal domains respectively , especially before 24 months .
the domain showing the least signs of significant differences with children in other countries appears to be the gross motor domain , and the fine motor domain seems to be the domain at which iranian children are the weakest developmentally .
our finding is not consistent with the findings of the korean study , which showed significantly lower mean scores in the communication and problem - solving domains at several age intervals ( 21 ) .
our finding is also inconsistent with the findings of the dutch study performed only at 48-months , which showed that problem - solving scores were higher in the us sample ( 17 ) , while fine motor scores were higher in the norwegian samples ( 24 ) .
a major strength of this study was that it was based on prospective data acquired from a very large and random nation - wide sample including the diverse cultures and socio - economic groups existing in the iranian population and that it included all of the 19 age - specific questionnaires of the asq .
the major limitation of this study however , was our inability to determine concurrent validity of the test with a gold standard due to inaccessibility , as explained before .
the reliability of asq ranged from 0.76 to 0.86 , and the validity was satisfactory .
the developmental status of iranian children tended to be higher in the communication , problem - solving and personal - social domains , especially under the age of 24 months , after which it seemed to deteriorate , especially in the gross and fine motor domains .
ethical issues ( including plagiarism , informed consent , misconduct , data fabrication and/or falsification , double publication and/or submission , redundancy , etc ) have been completely observed by the authors .
 backgroundto provide the validated and standardized form of the persian version of the ages and stages questionnaires as an appropriate developmental screening tool for evaluation of iranian children s development.methods:this was a cross - sectional study . 
 translation and back - translation , content validity determination , cultural and lingual modifications , pilot study on 100 parents and inter - rater reliability determinations were performed , respectively . 
 the national and final stage was carried out 11000 , 460 month - old children in selected cities throughout the country in order to determine the validity , standard deviation , reliability , sensitivity , specificity , and mean scores points of the test.results:the reliability , determined by cronbach s alpha ranged from 0.76 to 0.86 and the inter - rater reliability was 0.93 . 
 the validity determined by factor analysis was satisfactory . 
 the mean scores of iranian children were identified and compared with those of the normative sample as well as with three other populations of children . 
 the developmental status of iranian children was higher in the communication , problem - solving and personal - social domains , especially under the age of 24 months , after which their developmental status seems to deteriorate , especially in the motor domains.conclusion:the persian version of the asq has appropriate validity and reliability for screening developmental disorders in iran . 
Introduction
Materials and Methods
Results
Discussion
Conclusion
Ethical considerations