Thursday, May 20, 2010: 10:30 AM
Grand Ballroom AB Level 5 (Philadelphia Marriott Downtown)
10:00 AM
Background: Recent reports indicate that very young low birth weight (LBW) survivors are at higher risk of screening positive for ASD. Thus far, however, there have been no reports of the diagnostic prevalence of ASD in LBW populations. This presentation is a preliminary report of screening and diagnostic findings for ASD in a large LBW cohort assessed in adolescence and young adulthood.
Objectives: To determine the diagnostic prevalence of ASD in adult survivors of LBW .
Methods: 623 surviving members of a regional LBW cohort (<2000g; n = 1,105 births) , were screened for ASD at age 16 using the Social Communications Questionnaire (SCQ), the Autism Spectrum Screening Questionnaire (ASSQ), and parental report of professionals’ diagnosis. Liberal cut-points on the SCQ (9) and ASSQ (12) were employed to maximize sensitivity 117 (18.8%) screened positive on at least one of the three screens.
201 of the screened participants were evaluated as young adults (mean age = 21.4) with the Autism Diagnostic Observation Schedule (ADOS) and/or Autism Diagnostic Interview-Revised (ADI-R) by research staff trained and certified on both instruments. We were able to assess 65.8% (77/117) of young adults who had screened positive at 16 and 24.5% (124/506) of the negative screens. The two groups were comparable in gender distribution both at age 16 and in young adulthood.
Results: Of the 77 screen positives , 11 had ASD ; of the 124 screen negatives, 3 had ASD
To estimate the prevalence of ASD in the original sample of 16-year-olds (n= 623), the numbers of screen positives and negatives at 16 were weighted by the proportions of screen positives and negatives evaluated as young adults who were found to have ASD as shown in the table below:
Thus, the best estimate of the prevalence of ASD in this LBW population is 29/623 or 4.7%.
Conclusions: The diagnostic prevalence of ASD in this young adult LBW cohort is nearly five times the highest reported prevalence for the US general population . Previous suggestions of increased risk for ASD in the LBW population were based either on case-control studies or prospective studies of ASD symptoms (not diagnoses) in very early childhood.
Objectives: To determine the diagnostic prevalence of ASD in adult survivors of LBW .
Methods: 623 surviving members of a regional LBW cohort (<2000g; n = 1,105 births) , were screened for ASD at age 16 using the Social Communications Questionnaire (SCQ), the Autism Spectrum Screening Questionnaire (ASSQ), and parental report of professionals’ diagnosis. Liberal cut-points on the SCQ (9) and ASSQ (12) were employed to maximize sensitivity 117 (18.8%) screened positive on at least one of the three screens.
201 of the screened participants were evaluated as young adults (mean age = 21.4) with the Autism Diagnostic Observation Schedule (ADOS) and/or Autism Diagnostic Interview-Revised (ADI-R) by research staff trained and certified on both instruments. We were able to assess 65.8% (77/117) of young adults who had screened positive at 16 and 24.5% (124/506) of the negative screens. The two groups were comparable in gender distribution both at age 16 and in young adulthood.
Results: Of the 77 screen positives , 11 had ASD ; of the 124 screen negatives, 3 had ASD
To estimate the prevalence of ASD in the original sample of 16-year-olds (n= 623), the numbers of screen positives and negatives at 16 were weighted by the proportions of screen positives and negatives evaluated as young adults who were found to have ASD as shown in the table below:
ESTIMATED PREVALENCE OF ASD IN TOTAL COHORT( N = 623) | |||
| ASD prevalence in young adults by screening status | Screening status prevalence in total cohort | Estimated N and prevalence of ASD in total cohort | |
| Screen positive | 14.3% (11/77) | 18.8% (117/623) | 17 (14.3% x 117) |
| Screen negative | 2.4% (3/124) | 71.2% (506/623) | 12 (2.4% x 506) |
| TOTAL | 7.0% (14/201) | 4.7% (29/623) | |
Conclusions: The diagnostic prevalence of ASD in this young adult LBW cohort is nearly five times the highest reported prevalence for the US general population . Previous suggestions of increased risk for ASD in the LBW population were based either on case-control studies or prospective studies of ASD symptoms (not diagnoses) in very early childhood.