TABLE 3

Cumulative Incidence of Gastrointestinal Symptoms in Autism Case and Matched Control Subjects

Gastrointestinal Diagnosis CategoryAutism Case Subjects (N = 121)Matched (2:1) Control Subjects (N = 242)RR (95% CI)P
No. of Patients With a DiagnosisCumulative Incidence, %aNo. of Patients With a DiagnosisCumulative Incidence, %a
By 1 yBy 5 yBy 10 yBy 15 yBy 20 yBy 1 yBy 5 yBy 10 yBy 15 yBy 20 y
Any of the diagnoses of interest8720.746.558.467.277.216715.736.849.962.072.21.21 (0.93–1.57).15
Constipation351.76.717.726.633.9400.47.010.915.817.61.97 (1.25–3.10).003
Diarrhea5710.734.040.346.550.39312.424.831.236.141.11.34 (0.96–1.86).085
Gastroesophageal reflux and vomiting264.17.514.921.325.3382.14.58.313.116.91.55 (0.94–2.55).088
Abdominal discomfort and irritability445.812.417.029.244.9923.310.419.231.941.31.03 (0.72–1.47).87
Feeding issues and food selectivity285.010.918.224.524.5331.75.07.512.116.11.95 (1.18–3.24).009
  • a The cumulative incidence estimates were calculated by using the Kaplan-Meier method to take into account the varying duration of follow-up across the subjects.