The modified Stroop paradigm as a measure of selective attention towards pain-related stimuli among chronic pain patients: a meta-analysis

Department of Medical, Clinical and Experimental Psychology, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands. J.Roelofs@dep.unimaas.nl

Although the modified Stroop paradigm is considered to be a prominent paradigm for investigating selective attention in emotional disorders, relatively few studies have applied this paradigm to examine selective attention in chronic pain patients. Moreover, the results from these studies are not robust. The purpose of this article is to review the evidence for attentional bias in chronic pain patients, by means of a meta-analysis. Data from five studies were pooled and summarized into a mean difference (MD). Significant MD estimations (in milliseconds) were found for both sensory pain words (MD=26.7; 95% confidence interval (CI) 10.0-42.9) and affective pain words (MD=28.1; 95% CI 0.4-55.8). Meta-regression analysis indicated that methodological quality did not significantly affect the pooled MD estimation for both sensory pain words and affective pain words. Thus, the results from the present meta-analysis on studies applying the modified Stroop paradigm suggest that chronic pain patients selectively attend to both pain sensory and pain affective stimuli. Furthermore, the MD estimation did not depend on the methodological quality, tentatively indicating that even though studies differed in methodology, the results were rather consistent. Implications of the results are discussed. Copyright 2002 European Federation of chapters of the International Association for the Study of Pain. Published by Elsevier Science Ltd.