Smoking and mental illness: A bibliometric analysis of research output over time

Introduction: The prevalence of smoking among persons with a mental illness has remained unchanged, being 2-3 times higher than the general population in high-income countries. Assessment of the volume and characteristics of research output over time can assist in identifying research priorities to promote progress within a field. The aim of this study was to undertake such an assessment in the field of smoking and mental illness. Methods: A descriptive repeat cross-sectional study was conducted of peer-reviewed publications in Medline and PsycINFO for the periods 1993-1995, 2003-2005, and 2013-2015. Publications were classified as data- or non-data-based; data-based publications were further categorized by study type, population, setting, and for intervention-focused publications by level of evidence and research translation phase. Results: Included were 547 articles published in 1993-1995 (n = 65), 2003-2005 (n = 153), and 2013-2015 (n = 329). The number and proportion of data-based publications significantly increased over time, although their focus remained predominantly descriptive (=83%); less than 14% of publications in any period had an intervention focus. The proportion of publications reporting on study populations with multiple diagnostic categories and recruiting from nonmental health settings, significantly increased from 1993-1995 to 2003-2005, however then plateaued by 2013-2015. The level of evidence provided by intervention-focused publications was suggested to increase over time, however there was no evident variation in translation phase. Conclusions: Research has increased over time to characterize smoking among those with a mental illness; however more is needed to inform the development and implementation of effective cessation interventions for this group. Implications: This is the first study to examine the volume and characteristics of research publications in the field of smoking and mental illness over time. The number of publications increased fivefold between 1993-1995 and 2013-2015. Between 1993-1995 and 2003-2005, progression was also indicated by increased: data-based publications, diagnostic diversity of samples, and variation in study settings; however further increases in such measures were not evident in 2013-2015. Notably, it continues to be the case that few intervention studies are undertaken. To achieve meaningful changes in the smoking prevalence of this group, a greater focus on research that assesses the effectiveness and implementation of tailored cessation interventions is required.