Making diagnostic recommendations when evidence is lacking: A proposed framework

Developing recommendations about test strategies is believed to be challenging, especially when there is no data about the accuracy of the test to diagnose the condition or longitudinal evidence about the effects of the tests on patient important outcomes. We therefore developed a framework to facilitate the discussions of a guideline panel to make diagnostic recommendations. This framework was used when making recommendations for the use of diagnostic tests for post-COVID-19 Condition (PCC) (also known as Long Covid). The framework includes six questions. Four questions address desirable effects: Does a test 1) increase/decrease suspicion of PCC, 2) increase/ decrease suspicion of comorbidities associated with PCC, 3) confirm/ rule out other diagnoses, and 4) change the management. Two questions address undesirable effects: Does a test 1) increase the risk of healthcare overuse, and 2) cause important harm. Answers inform the final judgments about desirable and undesirable effects of a test and are incorporated in the Evidence to Decision Framework to make the recommendation. The proposed framework has been used to make 15 recommendations in one condition and therefore, additional research is needed to assess its application in other conditions and to validate it. Such a framework could play a major role in assisting panels to navigate the tradeoffs between the benefits and harms of tests; enhance transparency in what may have driven the decision; and, help users to better understand how conclusions were reached to make a recommendation. Plain language Summary: When making recommendations for the use of diagnostic tests for post-COVID-19 Condition (PCC), the Canadian Testing, Identification & Diagnosis Related to PCC guideline group members struggled with making judgments on the benefits and harms of the tests. Therefore, a group of guideline methodologists and clinical experts created a framework to help the guideline panel make judgments about whether using a test to diagnose PCC or PCC-related comorbidities would lead to benefits or harms. The framework guided discussions to make recommendations. This framework was used during the development of tests in one guideline only, and it will need further validation. However, the framework could help other guideline panels make recommendations where there is a similar lack of evidence about the effects of the tests.