The PICO model is a general model in building problems of evidence-based medicine (EBM). However, with the deepening and refinement of the medical research and the rising of qualitative research, the PICO model could not satisfy all problems. This article introduces the expansions of the PICO model and puts forward the SPIDER model according to the qualitative problem and its relationship with the PICO model, which can build the best search strategy of clinical problems in a short time.
In the process of guideline development and construction of clinical questions, it is necessary to guide clinicians to propose clinical problems into PICO (population, intervention, control, outcome) structured clinical questions. However, there are still unclear criteria to define and judge the appropriateness of the width of the PICO elements of a clinical question. Either too wide or too narrow can make the PICO question unsuitable to be a question for clinical practice guidelines to answer. We graded the clinical questions to be eight grades (3, 2, 1, 0, −1, −2, −3, mixed) according to the number of the PIC elements, which obviously needed to be adjusted to evaluate applicability of the appropriateness of the width of the clinical questions. Our work can provide methodological references for clinicians and guideline developers.
GRADE要求明确说明相关的背景、人群、干预措施和对照，同时要求不论研究结果能否形成证据，均需详述所有重要结果。对某一特定管理问题，人群、干预措施及结果应在不同研究间足够类似，才能认为得到相似的效应量合乎情理。指南制定者在收集证据前应先详细说明各结局的相对重要性，同样地，证据总结完成时也需要详细说明这一点。考虑到替代结局的重要性，对采用替代指标描述且对患者很重要的结局，作者应评估其重要性，并进而降低这种间接结果的证据质量等级。