Research and statistics: cohort studies.
Hernandez
Raquel G
RG
Division of General Pediatrics & Adolescent Medicine, Johns Hopkins University, Baltimore, Md., USA.
Rowe
Peter C
PC
D015746:Abdominal Pain / Q000453:epidemiology / Q000523:psychology*; D002648:Child; D015331:Cohort Studies; D006801:Humans; D008297:Male; D015588:Observer Variation; D018579:Patient Selection; D012574:Schools; D013315:Stress, Psychological / Q000453:epidemiology*