Comparative analysis of a-priori and a-posteriori dietary patterns using state-of-the-art classification algorithms: a case/case-control study.
OBJECTIVE
To compare the accuracy of a-priori and a-posteriori dietary patterns in the prediction of acute coronary syndrome (ACS) and ischemic stroke. This is actually the first study to employ state-of-the-art classification methods for this purpose.


METHODS
During 2009-2010, 1000 participants were enrolled; 250 consecutive patients with a first ACS and 250 controls (60±12 years, 83% males), as well as 250 consecutive patients with a first stroke and 250 controls (75±9 years, 56% males). The controls were population-based and age-sex matched to the patients. The a-priori dietary patterns were derived from the validated MedDietScore, whereas the a-posteriori ones were extracted from principal components analysis. Both approaches were modeled using six classification algorithms: multiple logistic regression (MLR), naïve Bayes, decision trees, repeated incremental pruning to produce error reduction (RIPPER), artificial neural networks and support vector machines. The classification accuracy of the resulting models was evaluated using the C-statistic.


RESULTS
For the ACS prediction, the C-statistic varied from 0.587 (RIPPER) to 0.807 (MLR) for the a-priori analysis, while for the a-posteriori one, it fluctuated between 0.583 (RIPPER) and 0.827 (MLR). For the stroke prediction, the C-statistic varied from 0.637 (RIPPER) to 0.767 (MLR) for the a-priori analysis, and from 0.617 (decision tree) to 0.780 (MLR) for the a-posteriori.


CONCLUSIONS
Both dietary pattern approaches achieved equivalent classification accuracy over most classification algorithms. The choice, therefore, depends on the application at hand.
School of Medicine, University of Ioannina, University Campus, 45110 Ioannina, Greece; Department of Nutrition and Dietetics, Harokopio University, 70 Eleftheriou Venizelou Str., 17671 Athens, Greece.
Christina-Maria
CM
Kastorini
George
G
Papadakis
Haralampos J
HJ
Milionis
Kallirroi
K
Kalantzi
Paolo-Emilio
PE
Puddu
Vassilios
V
Nikolaou
Konstantinos N
KN
Vemmos
John A
JA
Goudevenos
Demosthenes B
DB
Panagiotakos
D054058:Acute Coronary Syndrome / Q000175:diagnosis; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016022:Case-Control Studies; D004032:Diet; D005260:Female; D006801:Humans; D008297:Male; D020521:Stroke / Q000175:diagnosis
A-posteriori dietary patterns; A-priori dietary patterns; Classification algorithms; Coronary heart disease; Stroke