Bruinsma et al. BMC Public Health 2011, 11(Suppl 5):S7 http://www.biomedcentral.com/1471-2458/11/S5/S7 contact then happens directly between the participant and the research team. In Australia, private practitioners are not obliged to keep records of children once they reach 25 years of age or seven years after last contact. This provision protects privacy and trust in the doc- tor-patient relationship however, it also opens the possi- bility of gate-keeping by clinicians. This issue requires further ethical consideration as a clinician may decide the research is not appropriate, or that the patient would not be interested or that participation would not be in the patient’s best interests, thus removing choice from the individual. These provisions have implications for investigating and reporting the long-term safety and outcomes of treatment. In the Tall Girls Study, we ascertained through Tall Girls Inc and the Australian Endocrinology Society that at least 51 other Australian doctors pro- vided treatment. The research team traced and sought assistance from 35 doctors (16 were either in nursing homes or deceased) to determine whether they had trea- ted tall girls, still had the girls’ medical records and would be willing to recruit these women to the Tall Girls Study. Thirty-two doctors responded to the request: seven were willing to assist and could identify up to 100 eligible women; eight doctors had retained their medical records but could not readily identify those of tall girls; 12 doctors treated women but their records had been destroyed or were no longer in their possession; two doctors were unwilling to recruit women; and three had no recollection of having treated or assessed girls. Researchers investigating outcomes fol- lowing use of DES faced similar challenges, with records destroyed, ineligible records or physicians being unwill- ing to participate [44]. In the case of the Tall Girls study, agreement was made between the private medical practitioners and the research team that the medical practitioners would release a small amount of information to researchers for tracing purposes (with no medical or treatment details) with appropriate human ethics committee approval. Once a current address was obtained, the medical prac- titioner would contact women on the researchers’ behalf. During the tracing phase of the study, the specia- list with the largest number of records died, however his family, in-line with his wishes, allowed the project to continue. Ethical approval was obtained for a modifica- tion to the approach in that the letter was sent by the researchers outlining how the woman’s details had been obtained. While this meant that we were directly con- tacting the majority of women (a small number of whom were uncomfortable about this), it also had bene- fits. Some women were angry about their treatment and may not have responded to an approach directly from their doctor. The research team took particular care to Page 4 of 8 emphasise that while collaborating with, and in contact with both clinicians and Tall Girls Inc., the research was conducted by an independent research team. In all cases, women were initially contacted by mail using a standardised letter. The opening paragraph incorporated minor modifications according to whether the research team was conducting the woman directly, as a result of a self-referral to the study, the research team were directly conducting women who were former patients of the deceased practitioner or a clinician was sending the letter to a former patient on behalf of the research team. Tracing and recruitment One of the greatest challenges the study faced was tra- cing women between 14 and 40 years after they were assessed or treated for tall stature. Much of the informa- tion from medical records was out of date, as parents were unlikely to still be living at the same address and most women would have changed their surname with marriage. Despite assistance from the Australian Elec- toral Commission (AEC), who performed record linkage on name and date of birth, tracing women using the medical record data to try and link names and addresses over time involved tedious and time-consuming trawling through years of public records including electoral rolls, telephone books and death notices, all on microfiche. The National Death Index (NDI) was also used to record link registered Australian deaths with the names and dates of birth of women. Tracing and contacting women to invite them into the study was crucial to help minimise selection bias and to build confidence in the study findings. Considerable effort was made in locating women who may have changed their name. Once again, this experience had many parallels with the experience and strategies used in the Diethylstilbes- trol-Adenosis (DESAD) project conducted by Nash and colleagues [44]. The Tall Girls Study traced 87% of women identified as eligible from medical records [1], a great result given the limited information available and the duration of time to follow-up and similar to that traced by Nash et al (1983) [44]. The effectiveness of different strategies will vary greatly between countries; it is important to tailor strategies according to local cir- cumstances to obtain optimal results. For instance, in Australia, voting is compulsory so use of the electoral roll provides good population coverage, where voting is not compulsory this will not be the case. In some instances, following detailed tracing, research- ers were still hesitant about the accuracy of the match. In order to safeguard privacy, and due to the sensitivity of the topic, ethics approval was obtained to send a very generic letter (with no information regarding the research topic) verifying the accuracy of the match. Once the match was verified, the initial recruitment