Abstract
STUDY OBJECTIVES: Sleep research has grown substantially in recent decades, producing a large amount of data and an increasing number of meta-analyses. This study sought to establish the volume of meta-analyses in this area and assess how this level of material has developed over time. METHODS: A bibliographic search of the Web of Science database was conducted (1945-2019). The total number of articles and the total number of meta-analyses were extracted for both sleep medicine and a combination of 6 other medical specialties (cardiology, neurology, psychiatry, pulmonology, otorhinolaryngology, and pediatrics). RESULTS: A total of 262,384 articles and 1,152 meta-analyses related to sleep medicine were identified. Considering the whole period under analysis, meta-analyses represented 0.44% of the total number of sleep medicine-related articles. Throughout this period, the proportion of meta-analyses published has been increasing in both sleep medicine and the other fields, but it is greater in the other fields. In 2019, meta-analyses in sleep medicine represented 1.10% of the publication output in this area but represented 1.62% of the other areas. However, sleep medicine's growth rate has been consistently higher than in the other fields. The United States, China, and the United Kingdom have been the top meta-analysis producers. CONCLUSIONS: Meta-analyses in sleep medicine are underused. As a recent medical field, sleep medicine has more potential to grow and is likely to grow faster than other fields. Researchers should be encouraged to perform and publish meta-analyses on sleep medicine, as long as the analyses are reasonable and feasible from methodological, statistical. and practical perspectives.