Traditional Chinese Medicine Injection for Angina Pectoris: An Overview of Systematic Reviews

Traditional Chinese medicine (TCM) injection is widely used to treat angina pectoris in China. This overview aims to systematically summarize the general characteristics of systematic reviews (SRs) on TCM injection in treating angina, and assess the methodological and reporting quality of these reviews. We searched PubMed, Embase, the Cochrane Library and four Chinese databases from inception until March 2013. Data were extracted according to a preset form. The AMSTAR and PRISMA checklists were used to explore the methodological quality and reporting characteristics of included reviews, respectively. All data analyses were descriptive. 46 SRs involving over 57,463 participants with angina reviewing 23 kinds of TCM injections were included. The main outcomes evaluated in the reviews were symptoms (43/46, 93.5%), surrogate outcomes (42/46, 91.3%) and adverse events (41/46, 87.0%). Few reviews evaluated endpoints (7/46, 15.2%) and quality of life (1/46, 2.2%). One third of the reviews (16/46, 34.8%) drew definitely positive conclusions while the others (30/46, 65.2%) suggested potential benefits mainly in symptoms, electrocardiogram and adverse events. With many serious flaws such as lack of a protocol and inappropriate data synthesis, the overall methodological and reporting quality of the reviews was limited. While many SRs of TCM injection on the treatment of angina suggested potential benefits or definitely positive effects, stakeholders should not accept the findings of these reviews uncritically due to the limited methodological and reporting quality. Future SRs should be appropriately conducted and reported according to international standards such as AMSTAR and PRISMA, rather than published in large numbers.