The relationship between childhood leukaemia and childhood asthma: A pharmacoepidemiological study from the Netherlands

Abstract Background It has been suggested that childhood asthma lowers the risk of childhood leukaemia. Studies have found an inverse association between these conditions. However, most studies on this relationship are based on questionnaires and telephone interviews, introducing recall bias. Therefore, we conducted a matched case–control study based on drug prescription data to assess the relationship between both conditions. Methods In a large database, covering more than one million individuals, we identified cases of children who had been prescribed 6‐mercaptopurine (6‐MP). This drug is us... Mehr ...