Development of a Search Strategy for an Evidence Based Retrieval Service

BackgroundPhysicians are often encouraged to locate answers for their clinical queries via an evidence-based literature search approach. The methods used are often not clearly specified. Inappropriate search strategies, time constraint and contradictory information complicate evidence retrieval.AimsOur study aimed to develop a search strategy to answer clinical queries among physicians in a primary care settingMethodsSix clinical questions of different medical conditions seen in primary care were formulated. A series of experimental searches to answer each question was conducted on 3 commonly advocated medical databases. We compared search results from a PICO (patients, intervention, comparison, outcome) framework for questions using different combinations of PICO elements. We also compared outcomes from doing searches using text words, Medical Subject Headings (MeSH), or a combination of both. All searches were documented using screenshots and saved search strategies.ResultsAnswers to all 6 questions using the PICO framework were found. A higher number of systematic reviews were obtained using a 2 PICO element search compared to a 4 element search. A more optimal choice of search is a combination of both text words and MeSH terms. Despite searching using the Systematic Review filter, many non-systematic reviews or narrative reviews were found in PubMed. There was poor overlap between outcomes of searches using different databases. The duration of search and screening for the 6 questions ranged from 1 to 4 hours.ConclusionThis strategy has been shown to be feasible and can provide evidence to doctors’ clinical questions. It has the potential to be incorporated into an interventional study to determine the impact of an online evidence retrieval system.研究背景 临床医师常被鼓励通过循证文献检索解答临床疑问，但实际采用的检索方法往往未明确规范。不当的检索策略、时间限制与信息矛盾均会增加证据获取的难度。 研究目的 本研究旨在开发一套适用于基层医疗场景中医师解答临床疑问的检索策略。 研究方法 本研究拟定了6个针对基层医疗常见病症的临床问题，在3种主流推荐的医学数据库中开展针对各问题的系列实验检索。针对不同PICO（patients, intervention, comparison, outcome）要素组合的问题，基于PICO框架对检索结果进行对比；同时分别比较单纯使用文本词、医学主题词（Medical Subject Headings, MeSH）以及二者结合的检索效果。所有检索过程均通过截图记录并保存检索策略。 研究结果 基于PICO框架，所有6个临床问题均找到对应解答。相较于包含4项PICO要素的检索，仅包含2项PICO要素的检索可获得更多系统评价。最优的检索方案为文本词与医学主题词结合的检索方式。尽管使用了系统评价筛选器，PubMed检索结果中仍存在大量非系统评价或叙述性综述。不同数据库的检索结果重合度较低。6个问题的检索与筛选耗时为1至4小时不等。 研究结论 本研究所开发的检索策略具备可行性，可为医师解答临床疑问提供循证依据。该策略有望应用于干预性研究，以评估在线证据检索系统的实际应用效果。