This chapter presents an overview of the quantity and quality of clinical research in CAM and publication bias. Descriptive studies and their systematic reviews on CAM, e.g., prevalence and reasons for CAM use, have been widely conducted worldwide. The findings of the efficacy of herbal medicine, traditional Chinese medicine and acupuncture for treating various illnesses, have been highly published. Publications of CAM safety are limited. A number of clinical studies of CAM in treating kidney diseases were lower than other illnesses. Studies of Ayurveda and other CAMs are still lacking. The quality of CAM publications is described based on systematic reviews of assessing CAM publications. Publication bias is explained in terms of selective publications and location bias, language bias and conflict of interest. The mainstream journals are more likely to publish positive findings. Predatory open access and recommendations for assessing predatory journals are addressed in this chapter.
TopIntroduction
The amount of complementary and alternative medicine (CAM) research has been rapidly increasing over recent years (Figure 1). CAM publications slowly increased in number prior to 2000, dramatically rising in number after 2000. Several aspects of CAM research have been explored, e.g. prevalence of use, attitudes of CAM users and practitioners, the efficacy, safety, and cost-effectiveness of CAM, methodologies used in CAM research, and CAM regulation. In addition, the number of systematic reviews and meta-analyses of CAM research has been growing since 2010. High quality CAM research has been accepted for publishing in mainstream biomedical journals, e.g. Annals of Internal Medicine, British Medical Journal, The Lancet, The Journal of the American Medical Association, and The New England Journal of Medicine (Fontanarosa, 2001). This chapter gives an overview of CAM publications worldwide, any publication bias, their quality, and presents the common types and research topics of CAM published. This chapter will also identify any gaps in CAM research.
Figure 1. Trends in publications on CAM in the medical literature
TopOverview Of Global Publications In Cam
Five major publishers based in Europe and the US, i.e. Elsevier, Springer, Wiley, Tayor & Francis, and Sage, dominate CAM publishing. The prominent journals based on their impact factors in this area are the Journal of Ethnopharmacology, Phytomedicine, The American Journal of Chinese Medicine, Chinese Medicine, and Complementary Therapies in Medicine (Fan, 2015). Other reliable journals in this field are The Journal of Alternative and Complementary Medicine, Evidence Based Complementary and Alternative Medicine, BMC Complementary and Alternative Medicine, Journal of Manipulative and Physiological Therapeutics, Alternative Medicine Review, Integrative Cancer Therapies, Alternative Therapies in Health and Medicine, Forsch Komplementmed, Homeopathy, and Chinese Journal of Integrative Medicine (Fu et al., 2011).
The Cochrane CAM group have been collecting details of published randomised controlled trials in CAM since 1996 in order to support the development of systematic reviews of CAM. The Cochrane Central Register of Controlled Trials (CENTRAL) indicates that the most frequent studies of CAM were non-vitamin, non-mineral dietary supplements, such as glucosamine or fish oil; Chinese herbal medicine, diet-based therapies; vitamin and mineral interventions; and acupuncture. This may be due to the Cochrane CAM group being based at the University of Maryland, and collaborates with the National Center for Complementary and Integrative Health in the US where researchers are more likely to focus on dietary supplements. Frequently reported medical purposes for using CAM by the Cochrane CAM group were heart and circulation, pain, mental health, and endocrine and metabolic conditions. In addition, the group published several systematic reviews regarding treating kidney diseases (see Chapter 7). Regarding the quality of CENTRAL, this database covers controlled trials in CAM from the Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica Database (EMBASE) and non-MEDLINE resources; 28% of CAM RCTs in CENTRAL were not included in either MEDLINE or EMBASE (Wieland et al., 2013). Therefore, CENTRAL is more likely to cover a higher number of controlled trials in CAM than MEDLINE or EMBASE.