Table 6.
Prevalence rates (per 1000) of individual diagnoses within fetal alcohol spectrum disorders (FASD) and total FASD by three methods of estimation from a second sample in South African communities.
| Oversample of Children ≤25th Centile on Height, Weight, or OFC | Random Sample Rate of FASD Diagnoses and Estimated Cases in the Non-Consented Children | Combined Rate from Cases in Consented Sample (n = 1088) and Estimated Cases in Non-Consented Sample (n = 365) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| (a) Total Cases Diagnosed n | Low Estimated Rate: School Enrollment Rate 1 (n = 1448) | Consented Student Rate 2 (n = 1088) | Cases Found among Randomly-Selected Controls n | Proportion of FASD Cases in Random Sample (n = 276) | (b) Estimated Cases in Non-Consented Sample (n = 365) | Rate of FASD from Random Sample Only 3 | 95% CI | (a + b) Total Estimated Cases (n = 399) | High Estimated Rate: Estimated Rate for All Enrolled Students 4 | 95% CI | |
| FAS | 129 | 89.1 | 118.6 | 44 | 0.1594 | 58 | 159.4 | 116.2 to 202.6 | 187 | 129.1 | 111.8 to 146.4 |
| PFAS | 100 | 69.1 | 91.9 | 28 | 0.1014 | 37 | 101.4 | 65.8 to 137.1 | 137 | 94.6 | 79.5 to 109.7 |
| ARND | 55 | 37.9 | 50.6 | 15 | 0.0543 | 20 | 54.3 | 27.6 to 81.1 | 75 | 51.8 | 40.4 to 63.2 |
| Total FASD | 284 | 196.1 | 261.0 | 87 | 0.3152 | 115 | 315.2 | 260.4 to 370.0 | 399 | 275.5 | 252.5 to 298.6 |
1 Denominator is all children attending first grade in local schools. Rate per 1000 based on entire enrollment in 1st grade classrooms (n = 1448). 2 Denominator is the total number of children with consent to participate. Rate per 1000 based on the sample consented and screened (n = 1088). 3 Calculated as the FASD cases diagnosed from the randomly-selected control candidates (numerator) over total number of randomly-selected children ×1000. 4 Rate per 1000 children calculated from FASD cases diagnosed in the consented sample (a) added to the estimated cases in the non-consented sample utilizing the proportional diagnostic distribution of FASD cases among randomly-selected children (b), and divided by all 1st grade children enrolled in the schools (n = 1448).