Dunja Dreesens

20 regard systematic reviews and randomized clinical trials as the highest level of evidence. This has led to a disregard of other evidence, such as qualitative research. Another reason for the overreliance on research evidence is that research has shown that a very low percentage of studies in most medical journals meet the strict scientific standards. Ioannidis claimed in 2005 that most published research findings were false (28, 29). Chalmers et al added to this that patients and healthcare professionals are not involved in setting the research agenda, which means that research questions relevant to these groups are not being studied (as much) and important outcomes to patients and professionals are not addressed. Moreover, there exists a publication bias. In 2011, Schunemann et al reported that over half of the studies has never been published in full and studies with disappointing results were underreported (30, 31). The research evidence we use is biased. That makes the other pillars in EBM even more important. In addition, because e.g. not everything can be studied in a RCT, it is hard for clinicians to predict the preferences of patients whilst deciding about their care (32), and in daily practice, it is essential to be able to translate the knowledge to the individual patient using also clinical expertise. The world of clinical practice guidelines Another approach to translate knowledge into practice are clinical practice guidelines. CPGs distil, synthesize and interpret the best available evidence. The tool clinical practice guideline serves several purposes. The most important one being, as stated by the IoM in 1990: “… to assist practitioner and patient [making] decisions about appropriate health care for specific clinical circumstances” (33). A lot of medical associations regard CPGs as a way to professionalize and to lay a sound foundation for their quality of care (34). This way, CPGs contribute to 1/ maintaining the level of quality of care; 2/ the warranted uniformization of care nationwide (by decreasing unwarranted practice variation (35)); and 3/ make more effective use of health care resources (36). The adherence to CPGs can be assessed during peer reviews or medical audits, which makes CPGs part of the quality (improvement) cycle (PDCA-cycle). Professionals can be held accountable for their performance by their peers and management (37). Other parties can also employ CPGs. The government can decide on reimbursement and health coverage using CPGs, and healthcare insurers can use them for contracting healthcare providers. However, not everybody is pleased when CPGs are being used for other purposes than the intended ones (38, 39). Even though the earliest developed clinical practice guidelines are completely different from the recent ones – progressing from consensus guidelines to evidence-based guidelines – and despite all the CPG-improvements over the years regarding content and methodology (40) (41), the implementation of CPGs still leaves room for improvement (35, 42, 43). Possible reasons are that healthcare professionals e.g. worry that CPGs are conducive to “cookbook medicine”, decrease their autonomy and income, conflicts of interests are not always made transparent, and increase medico-legal liability. Furthermore, CPGs can rarely define optimal care with certainty, due to poor science, imperfect analytic processes, and differences in patients (44). These concerns were voiced in the early 1990s and still echo in 2010s (45). The earlier mentioned review of 62 clinical practice guidelines also showed that not all knowledge sources are used when developing CPGs, begging the question how evidence-based and applicable Chapter 1