Hints for MEDLINE searching

Although many OSLER (Ovid Search: Link to Electronic Resources) users called or sent emails with questions about our recent contest (see Another contest from your friends at OSLER, CMAJ 2000;162[2]:251), we received fewer entries than expected.

Perhaps the question was too challenging for those new to MEDLINE searching. Was sending the answer by email the difficult part? If the step-by-step solution provided below still seems mysterious, please contact me for some telephone training on OSLER commands, limits and functions.

This year's challenge was: Is there any evidence that zinc lozenges shorten the duration and severity of the common cold in children? That question contained 2 concepts, zinc lozenges and common cold, plus an age limitation that reduced the results to studies involving children.

Successful searching requires an analysis of the question before moving to the keyboard. Begin by typing zinc lozenges into the keyword box. When the Ovid mapping screen appears, select zinc as well as zinc lozenges.mp. This method, searching by both MeSH heading and text words, is certain to pick up anything on the topic. Once the results have been obtained, perform the next search using the MeSH term common cold.

Combine the results of the searches by typing '1 and 2' into the keyword box. The results each contain the concepts zinc and common cold. Have a quick look at the citations by clicking on the "display" link in the search history box. Since they look useful, the next step is to limit the search to children. Click on the Limits icon in the Ovid Toolbar. When the Limits screen appears, you will see your search history with buttons beside each search statement. Scroll to the Age Groups box. Using the down arrow, find the groups representing childhood and adolescence. Hold down the Ctrl key as you click on these, to ensure that all appropriate age groups are selected. Click the Limit Search button at the top left. When the Limit function is complete, 2 relevant references will have been found. Neither reports that zinc lozenges shorten the duration of symptoms, so it is necessary to expand the years searched. Select the Change Database icon and run the search again in MEDLINE 1966-2000. This retrieves 5 references; the abstract for one of them reports the finding being sought. FIGURE

Figure.

To send references by email, select them, then scroll to the Citation Manager at the bottom of the Titles Display page. Choose the Citation plus abstract fields, include the search history, then select the Email function in the right column. Add your address to the screen that appears, then click on Send Mail.

Send questions or comments to cmalibrary{at}sympatico.ca.