Background:

There has been recent interest in the relationship between socioeconomic status, urbanicity level and the diagnosis of autism in children. Studies in the United States have found lower rates of autism diagnosis associated with lower socioeconomic status, while studies in other countries report no association, or the opposite. In a large Danish register-based cohort the urbanicity level was critical, with an earlier age of ASD diagnosis in urban areas. No specific studies on the socioeconomic factors and urban context associated with the age at ASD diagnosis have been conducted in Italy. Since a diagnostic delay may depend on a heterogeneous functioning of the local health care systems in term of waiting times, a more specific connection for our targets of interest is the age at first medical contact for diagnostic suspicion rather than age at diagnosis. 

Aim:

The focus of this pilot study is the association between age at first medical contact for diagnostic suspicion and socioeconomic status and urbanicity level in Lombardy Region, the most populous and rich Region in Italy.  

Methods:

Twenty ASD cases referred to our Institute for rehabilitation from 2020 to 2021 coming from 16 municipalities were entered in the study. The age at first medical contact for parental concern was determined from parents’ reports. Family socioeconomic status was calculated from four factor index of social status (mother and father education achievement level and occupation level). Age and place of birth of parents (North, Centre, South Italy), city size where the family lived, and child gender were other variables used for input data. Machine learning systems were employed to predict different classes of age at first medical contact (<30 months vs >30 months). 

Results:

The study group was composed by 12 males and 8 females (mean age 7.19 yrs.; range 2-11 yrs.) diagnosed with autism according to DSM V criteria. The age at first medical contact for parental concern ranged between 13 and 79 months (mean= 32.8 months) while the age at diagnosis ranged between 23 and 91 months (mean= 43 months). The delta time between these two ages was in mean 10 months with a peak of 42 months. Family socioeconomic status index ranged from 4 to 15 (mean= 10.25). Mother education years, family SES and father education years were the variables with the highest inverse correlation (R= -45; - 0.43; -0.41 respectively; p= 0.046; 0.058; 0.072 respectively) with age at first medical contact for parental concern. A machine learning model selected years of mother education, city size and parents geographical origin to build up a model predicting age at first contact higher or lower than 30 months with an overall accuracy of 88.69% (85.72 %sensitivity and 91.67% specificity). 

Conclusion:

This pilot study suggests that socioeconomic status and urban-rural environment play an important role in influencing positively the decision to seek medical help for ASD suspicion and consequently the age at diagnosis. A machine learning model built on selected study variables can predict class of age at first contact with a high accuracy. 

Notes:

1 - Villa Santa Maria Foundation, Tavernerio (Como), Italy