To our knowledge, this is the first study to quantitatively examine the proportion of qualitative research in journals of general medicine over a 10 year period. Our results suggest that although there appears to be growing interest in qualitative research, the actual publication of original qualitative studies remains low 
. Hence, despite a 3.4-fold increase in qualitative publications over a 10 year period, only 4.1% of research was qualitative in 2007. This low proportion of qualitative research may inhibit comprehensively addressing important questions pertaining to general medicine, such as understanding patient-doctor communication, patients' medication compliance and treatment decisions, dissemination of evidence into clinical practice, or physicians' utilization of electronic medical records in complex health care settings 
. Furthermore, the dominance of quantitative research may hinder gaining insight into how to improve health care services or delivery of care, or understand the effects of interventions as experienced by health care providers and patients 
Results from the present study indicate that the journals' policies regarding publication of qualitative research, as reflected by specific reference or guidelines pertaining to qualitative research or appearance of methodological papers and editorials on the subject; independently predict a higher probability of publishing original qualitative research. These findings underscore the paramount role journals' policies play in determining the proportion of qualitative research in journals of general medicine, irrespective of other variables, such as the journals' impact factor. It is difficult, however, to determine whether journals that publish methodological and editorial articles or refer to qualitative research in their policy statements are more receptive to this type of research; or alternatively whether qualitative researchers are more inclined to submit (and subsequently publish) their work in these journals because of prior publications and policy statements.
Few studies have quantitatively examined the publication of qualitative research in medical journals. McKibbon & Gadd (2004) comprehensively assessed the publication of qualitative studies in clinical journals during the year 2000 
, in comparison to a 10-year period in our study. McKibbon & Gadd found a 3.1 times higher proportion of qualitative research than in the current study (1.86% compared to 0.6% of all articles for the same year). However, methodological differences hinder this comparison; e.g. difference in the ‘study population’ (journal type) between the current study (journals of general and internal medicine) and the McKibbon & Gadd study (wide variety of clinical journals) 
. Petticrew et al. (2008) examined the differences in journals' acceptance rates of quantitative and qualitative studies that were previously presented in scientific conferences 
. No significant differences were found and the authors concluded that there was no publication bias against qualitative research. However, they only tested whether a paper was eventually published in an academic journal or not. Indicators of journals' quality or characteristics were not taken into account.
An additional result stemming from the current study points to differences in the proportion of qualitative research between journals published in the UK, US, and the rest of the world; though these differences are of borderline significance. This might stem from differences in research traditions and culture between the US and Europe, with qualitative research being more common in Europe and the UK 
. Additionally, funding agencies in the UK might be more receptive and willing to fund qualitative research (resulting in more publications) than in the US. However, scant evidence exists assessing funding rates of qualitative versus quantitative submissions in both countries to support this supposition 
Our study has both strengths and limitations that need to be taken into account. We examined trends pertaining to the proportion of qualitative research published in 67 journals of general and internal medicine over a 10 year period. Previous studies either did not assess the proportion of qualitative studies longitudinally 
, or utilized a limited number of general medicine journals 
. Moreover, we assessed the association between journal characteristics (as independent variables) and the proportion of qualitative research (as an outcome measure); other variables (beyond journal characteristics) are likely to impact publication of qualitative research, such as topic of research, and editorial decisions or policies not reflected in the journals' website. Since the primary objective of the study was to examine the proportion of qualitative research in the medical literature, we did not assess the quality of qualitative research (i.e. the numerator) nor did we assess the quality of the quantitative research (i.e. a component of the denominator). Moreover, we did not differentiate between mixed-methods and qualitative studies since we sought to examine the acceptability of qualitative research even when combined with a quantitative approach. The current study only focused on journals of general-internal medicine; other medical and health related disciplines were excluded. Previous research has shown that qualitative studies are more prevalent in other health-related fields, such as nursing 
. Nonetheless, our findings are novel, and our study is the first to describe secular trends in the proportion of qualitative research in medical journals and correlates associated with its publication utilizing multivariable analysis; thereby enabling the determination of which variables are independently associated with the outcome measure. Our results suggest that even though the importance of qualitative research has been emphasized by several editorials and methodological papers in leading medical journals 
, the proportion remains low. This finding indicates that medical sciences have been leaning heavily towards the quantitative view of research. Although it is hard to determine the right balance between different types of research, this dominance of the quantitative approach could potentially inhibit discovery and explanation in general medicine 
Results of our multivariable analysis underscore the impact journal policies have on the publication of qualitative research. For the proportion of qualitative research to continue to increase in the medical literature, more journals would need to clearly indicate that this methodology is an acceptable mode of inquiry, by providing specific reference and guidelines to authors pertaining to qualitative research. Future research should continue to monitor the proportion of qualitative research in medicine, assess whether the proportion continues to grow or stabilize, and examine the quality of published studies along with quantity. Additionally, the association between the journals' country of publication and the actual publication of qualitative research should be explored further; perhaps via interviews and/or surveys with European and American journal editors, researchers, and funding agencies to elucidate potential differences in perceptions of the acceptability of qualitative research as a legitimate method of inquiry. Interviews with journal editors and authors may also help explain the association between journal policy statements, publication of editorials on qualitative research, and the proportion of qualitative studies. These interviews may shed light on editorial practices when receiving qualitative studies and authors' choices of journals for qualitative paper submissions.
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