To test the dimensionality of Type-D personality, using taxometric procedures, to assess if Type-D personality is taxonic or dimensional. Type-D personality is treated as a categorical variable and caseness has been shown to be a risk factor for poor prognosis in coronary heart disease. However, at present, there is no direct evidence to support the assumption that Type D is categorical and able to differentiate true cases from noncases.
In total, 1012 healthy young adults from across the United Kingdom and Ireland completed the DS14, the standard index of Type D, and scores were submitted to two taxometric procedures MAMBAC and MAXCOV.
Graphical representations (comparing actual with simulated data) and fit indices indicated that Type D is more accurately represented as a dimensional rather than categorical construct.
Type D is better represented as a dimensional construct. Implications for theory development and clinical practice with respect to Type D are examined as well as the wider use of taxometrics within psychosomatic medicine (e.g., to investigate if there are medically unexplained syndrome taxons, such as a Gulf War Syndrome taxon).
NA = negative affectivity;
SI = social inhibition;
MAMBAC = mean above minus below a cut;
MAXCOV = maximum covariance;
MAXEIG = maximum Eigenvalue;
L-MODE = L-mode factor analysis;
CCFI = curve comparison fit index.