From: Validation of the diagnosis of autism in general practitioner records
 |  |  | Regression |  | |||
---|---|---|---|---|---|---|---|
 |  |  | No (N = 136) | Yes (N = 43) | P | ||
 |  |  | N | % | N | % |  |
Male Sex | 114 | 83.8 | 32 | 74.4 | .166 | ||
Birth year | 1973 – 1977 | 8 | 5.9 | 3 | 7.0 | .789(trend) | |
 | 1978 – 1982 | 12 | 8.9 | 3 | 7.0 |  | |
 | 1983 – 1987 | 31 | 23.0 | 12 | 27.9 |  | |
 | 1988 – 1992 | 56 | 41.5 | 12 | 27.9 |  | |
 | 1993 – 1997 | 28 | 20.7 | 13 | 30.2 |  | |
Past or current epilepsy | 21 | 15.4 | 7 | 16.3 | .895 | ||
Overall level of language2 | Mute | 21 | 15.9 | 10 | 23.3 | .065 (trend) | |
 | Single words | 27 | 20.5 | 11 | 25.6 |  | |
 | Few phrases | 28 | 21.2 | 11 | 25.6 |  | |
 | Phrase speech | 56 | 42.4 | 11 | 25.6 |  | |
Estimated intellectual functioning | Normal IQ | 35 | 27.8 | 7 | 17.5 | .054 (trend) | |
 | Mild MR | 61 | 48.4 | 17 | 42.5 |  | |
 | Moderate MR | 22 | 17.5 | 12 | 30.0 |  | |
 | Severe MR | 8 | 6.3 | 4 | 10.0 |  | |
Age of parental recognition (months) | 0 – 12 | 45 | 43.3 | 15 | 35.7 | .897 (trend) | |
 | 13 – 24 | 45 | 43.3 | 23 | 54.8 |  | |
 | 25 – 36 | 12 | 11.5 | 4 | 9.5 |  | |
 | 36+ | 2 | 1.9 | - | - |  | |
Language delay | Yes probable/definite | 122 | 97.6 | 40 | 93.0 | .163 | |
 | Regression |  | |||||
 | No (N = 136) | Yes (N = 43) | P | ||||
 | N | Mean | SD | N | Mean | SD |  |
Age at first GPRD diagnosis (years) | 127 | 5.39 | 4.01 | 40 | 5.63 | 4.29 | .746 |
Age at first letter (years) | 133 | 3.66 | 2.75 | 41 | 2.76 | 1.02 | .002 |
Age at last report on note (years) | 134 | 10.61 | 5.65 | 42 | 10.15 | 5.56 | .646 |
Mean number of DSM-IV PDD symptoms | Â | Â | Â | Â | Â | Â | Â |
   –Total | 136 | 7.51 | 3.94 | 43 | 8.35 | 3.67 | .221 |
   –Language/communication | 136 | 2.08 | 1.43 | 43 | 2.37 | 1.29 | .236 |
   –Social interaction | 136 | 3.04 | 1.66 | 43 | 3.14 | 2.02 | .738 |
   –Repetitive behaviours | 136 | 2.40 | 1.73 | 43 | 2.84 | 1.68 | .144 |