Publication trends of shared decision making in 15 high impact medical journals: a full-text review with bibliometric analysis

Abstract

Background: Shared Decision Making (SDM) is increasingly advocated as a model for medical decision making. However, there is still low use of SDM in clinical practice. High impact factor journals might represent an efficient way for its dissemination. We aimed to identify and characterize publication trends of SDM in 15 high impact medical journals.

Methods: We selected the 15 general and internal medicine journals with the highest impact factor publishing original articles, letters and editorials. We retrieved publications from 1996 to 2011 through the full-text search function on each journal website and abstracted bibliometric data. We included publications of any type containing the phrase "shared decision making" or five other variants in their abstract or full text. These were referred to as SDM publications. A polynomial Poisson regression model with logarithmic link function was used to assess the evolution across the period of the number of SDM publications according to publication characteristics.

Results: We identified 1285 SDM publications out of 229,179 publications in 15 journals from 1996 to 2011. The absolute number of SDM publications by journal ranged from 2 to 273 over 16 years. SDM publications increased both in absolute and relative numbers per year, from 46 (0.32% relative to all publications from the 15 journals) in 1996 to 165 (1.17%) in 2011. This growth was exponential (P < 0.01). We found fewer research publications (465, 36.2% of all SDM publications) than non-research publications, which included non-systematic reviews, letters, and editorials. The increase of research publications across time was linear. Full-text search retrieved ten times more SDM publications than a similar PubMed search (1285 vs. 119 respectively).

Conclusion: This review in full-text showed that SDM publications increased exponentially in major medical journals from 1996 to 2011. This growth might reflect an increased dissemination of the SDM concept to the medical community.

Figure 1

Flow diagram of publications evaluated for inclusion in bibliometric analysis¹ and comparison of both search methods. ¹Adapted from the flow diagram in the PRISMA Statement. ²CMAJ: publications not available in full text for years 1996-1999, identified through PubMed Central. ³Search limited to years 1996-2010 due to technical reasons.

Figure 2

Absolute numbers of SDM publications over time. The curve was estimated in a Poisson model; with the number of SDM publications in a year as a dependent variable (N) and year since 1996 as an independent variable (t). N = exp(3.64 + 0.21 ∗ t - 0.02 ∗ t² + 0.001 ∗ t³). All coefficients P < 0.01.

Figure 3

Relative numbers of SDM publications over time. The curve was estimated in a Poisson model; with the percentage of SDM publications over the total of the year as a dependent variable (100 ∗ N/Total) and year since 1996 as an independent variable (t). 100 ∗ N/Total = 100 ∗ exp(-5.92 + 0.16 ∗ t - 0.02 ∗ t² + 0.0008 ∗ t³). All coefficients P < 0.05, except for t² coefficient P < 0.10.

Figure 4

Absolute numbers of SDM publications over time according to publication type. The curve was estimated in a Poisson model; with the number of non-research publications in a year and the number of research publications in a year as dependent variables (N₀ and N₁, respectively) and year since 1996 as an independent variable (t). N₀ = exp(3.37 + 0.22 ∗ t - 0.04 ∗ t² + 0.002 ∗ t³). N₁ = exp(2.17 + 0.22 ∗ t - 0.01 ∗ t²). All coefficients P ≤ 0.001.

Figure 5

Absolute numbers of SDM publications over time and publications assessing decision aids. The curve was estimated in a Poisson model; with the number of other publications in a year and the number of publications assessing decision aids in a year as dependent variables (N₀ and N₁, respectively) and year since 1996 as an independent variable (t). N₀ = exp(3.60 + 0.21 ∗ t - 0.02 ∗ t² + 0.001 ∗ t³). N₁ = exp(0.58 + 0.21 ∗ t - 0.02 ∗ t² + 0.001 ∗ t³). All coefficients P < 0.01.