The challenge of screening for autism spectrum disorder in a culturally diverse society

Abstract

The American Academy of Pediatrics (AAP) recently issued a set of guidelines for conducting routine, autism-specific screening in primary care with a standardized tool at 9-, 18- and 24- or 30-month visits (1). We accept the need for screening. We also recognize that this is not as straightforward as some might think. The heterogeneity of behavioural expectations across diverse cultures within the United States and worldwide complicates the formulation of a tool to screen for this behaviourally defined disorder. In this article, we ask that cultural issues be considered. Screening is important for several reasons, including the opportunity for earlier diagnosis and behavioural intervention. Such intervention has been demonstrated to lead to better outcome (2). In addition, both screening and diagnostic prevalence of autism spectrum disorders (ASD) can be used by epidemiologists worldwide to understand the distribution of the disorder in terms of person, place and time. This in turn will help to identify potential etiologic clues for this neuro-developmental disorder. Largely through dissemination of the Diagnostics and Statistics Manual (DSM)-IV and International Classification of Disease (ICD)-10 and their widespread acceptance, one can be comfortable that children given an autism spectrum diagnosis, whether from the United States, India, Kenya or Germany, will exhibit a recognizable pattern of symptoms. However, agreement on the relevant behavioural criteria for screening for ASD is more elusive. The goal of screening is to identify those children whose behavioural profiles render them at risk for a diagnosis of ASD. In order for a one-size-fits-all screening instrument to be universally effective, the relevant behaviours must be consistent across all groups of children who are screened. Given the heterogeneity of culturally defined behavioural expectations, one set of behaviours is unlikely to identify those at risk of ASD. Identifying that specific set of behaviours across all cultures and ethnicities, while still maintaining acceptable standards for sensitivity and specificity in a screening tool, may be difficult to achieve. Standards of behaviour vary and the social, cultural and ethnic background and socio-economic status of the child being screened may determine the recognition of that behaviour as an indicator of autism. For example, the AAP lists the absence of eye contact as an item that can be used to identify very young children (age 18 months) as high risk for ASD. However, direct eye contact among young children in China and Japan is uncommon, because looking directly into someone's eyes is considered shameful in these parts of East Asia (3). In China and Japan, therefore, this behaviour will not identify that group of children who may be at higher risk of ASD. Lack of back and forth babbling is listed by the AAP as another “earlier subtle sign” to be used in routine developmental screening. In India, however, the belief that the male Indian child speaks later is common (4), and so male children in India who do not babble would not be identified as requiring further evaluation. Unique cultures have begun adapting the popular western screening tools for their own use. For example, Hong Kong researchers have modified the Checklist for Autism in Toddlers (CHAT) and Modified Checklist for Autism in Toddlers (M-CHAT), into the CHAT-23 (5). Adapting screening tools developed in one culture, which has a very specific set of behavioural norms and expectations, for another culture, which has a different set of behavioural norms and expectations, poses difficulties. We advise that all newly devised instruments be assessed to determine the construct validity of all (borrowed and added) parent-response items. We might be surprised to see that cross-cultural differences are less than we expected. For example, the children's version of the autism-spectrum quotient (AQ) appears to be as valid in Japan as in the UK (6). Nevertheless, it is essential that we continue to pursue culturally relevant screening instruments in order to gather accurate data in societies with a rich mix of cultures and ethnicities. Screening must continue even as we engage in this process of refining the screening tools, as the validity of a tool is never fully established. Ultimately, we may be forced to recognize that behavioural norms are too varied to support a single screening tool in all but the most homogeneous societies.