Population Disparities in Autism Spectrum Disorder (ASD) Diagnosis in Southern Israel

Background: The rising incidence of ASD has become a major public health concern. In Israel, ASD rates vary remarkably across geographic regions and ethnic populations with one of the largest gaps observed between the Jewish and Bedouin populations in southern Israel.

Objective: To identify the reasons for the population disparities in ASD rates in southern Israel.

Methods: A total of 3343 toddlers (996 Jewish and 2347 Bedouin) at age 16-36 months were screened for ASD using the M-CHAT/F at 35 maternal child health centers. Toddlers who failed the M-CHAT/F were referred for diagnosis at the Soroka University Medical Center (SUMC). The diagnosis at SUMC included several meetings with social workers, developmental psychologists, and expert physicians who eventually provided a diagnosis according to DSM-5 criteria. Univariate and multivariate survival analyses were used to assess population differences in different parts of the diagnosis process.

Results: Overall, 39 Jewish (3.9%) and 70 Bedouin (3.0%) toddlers failed the M-CHAT/F (p=0.165). Of these, 32 Jewish (82.1%) and 56 Bedouin (80.0%) started diagnosis at SUMC (p=0.795). Notably, only 32 (57.1%) of the Bedouins completed the diagnosis process compared to 27 (84%) of the Jewish toddlers (p<0.001). In addition, the time from referral until the first diagnosis meeting was longer for Bedouins (7.86 vs. 5.53 respectively; p=0.040). Consequently, the adjusted “risk” of Jewish toddlers who failed the M-CHAT/F to get a diagnosis of ASD was 2.8 higher than Bedouin toddlers (HR=2.8, 95%CI=1.01-7.75; p=0.049)

Conclusions: The observed population disparities in ASD prevalence between Jewish and Bedouin toddlers are likely stemming from their delayed diagnosis and higher loss to follow-up rates. Raising awareness and better case management for toddlers with suspected ASD from the Bedouin population would help reducing the ethnic gap in ASD prevalence in southern Israel.