Epidemiological studies are like cherries, one draws another

Falcão, 2003, Drug allergy in university students from Porto, Portugal, Allergy, 58, 1210, 10.1034/j.1398-9995.2003.00291.x Lunet, 2005, Self-reported food and drug allergy in Maputo, Mozambique, Public Health, 119, 587, 10.1016/j.puhe.2004.07.013 Olayemi, 2003, Pattern of chloroquine-induced pruritus in antenatal patients at the University College Hospital, Ibadan, J Obstet Gynaecol, 23, 490, 10.1080/0144361031000153693 Ajayi, 1998, Knowledge, attitude and practice of prednisolone prevention of chloroquine induced pruritus among Nigerian health workers, Trop Doct, 28, 210, 10.1177/004947559802800407 Laufer, 2006, Return of chloroquine antimalarial efficacy in Malawi, N Engl J Med, 355, 1959, 10.1056/NEJMoa062032 Gama H, Ismael A, Sitoi F, Matola A, Barros H, Lunet N. Factors associated with chloroquine induced pruritus during malaria treatment in Mozambican University students. Gac Sanit. 2009. doi:10.1016/j.gaceta.2009.02.014. Gama, 2009, Questionnaire design and the recall of pharmacological treatments: a systematic review, Pharmacoepidemiol Drug Saf, 18, 175, 10.1002/pds.1703 Lunet, 2008, Recall of drug utilization depends on subtle structural questionnaire characteristics, Pharm World Sci, 30, 175, 10.1007/s11096-007-9161-8 Bowling, 2005, Mode of questionnaire administration can have serious effects on data quality, J Public Health (Oxf), 27, 281, 10.1093/pubmed/fdi031 2001, 196