However, in a separate study of more than 36, 000 patients' records, Mr Richard Sainsbury, a consultant at Huddersfield Royal Infirmary, found that delays between referral by a GP and initial treatment had no significant effect on survival rates.

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"With this data now available from more than one study, it really becomes the responsibility of parents, physicians, and teachers to pay attention to the relative-age effect and not intervene with treatment and labeling of children who it's no fault of their own what time of year they were born, " Garland says.

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