1. School of Health Sciences and Social Work; University of Portsmouth; Portsmouth UK
2. MRC Lifecourse Epidemiology Unit; University of Southampton; Southampton UK
3. David Hide Asthma and Allergy Research Centre; Newport Isle of Wight UK
4. Division of Allergy and Immunology; Cincinnati Children's Hospital Medical Centre; Cincinnati OH USA
5. Graduate School; University of Portsmouth; Portsmouth UK
6. Onze Lieve Vrouwe Gasthuis; Amsterdam The Netherlands
7. Department for Evidence-Based Medicine and Clinical Epidemiology; Danube University Krems; Krems Austria