A Cumulative Impact of Psychological and Sensitization Risk Factors on Pain-Related Outcomes

Risk constructs based on psychological risk factors (eg, pain catastrophizing, PC) and sensitization risk factors (eg, pressure pain threshold, PPT) are important in research and clinical practice. Most research looks at individual constructs but does not consider how different constructs might interact within the same individual. An evaluation of the cumulative impact of psychological and sensitization risk factors on pain-related outcomes may help guide us in the risk assessment of patients with pain conditions. The aim of this study is to evaluate the cumulative impact of these psychological (PC) and sensitization (PPT) risk factors on pain-related outcomes (activity avoidance, pain severity, and disability) considering covariates.

We included 109 participants (70.60% women; mean ± SD age 53.6 ± 12.3 years) with chronic musculoskeletal pain for data analysis, who completed all measures of this study. Participants completed a single testing session that included measures of risk factors (PC and PPT) and pain-related outcomes (self-reported avoidance, functional avoidance, disability, and pain severity). Subgroups were constructed by dichotomizing of PC and PPT scores, resulting in four groups: (1) low catastrophizing and low sensitivity (N = 26), (2) high catastrophizing and low sensitivity (N = 27), (3) low catastrophizing and high sensitivity (N = 25), and (4) high catastrophizing and high sensitivity (N = 31).

One-way analysis of variance (ANOVA) revealed significant group differences (P < 0.05, η²  = 0.08 to 0.14) in all outcomes of this study (except functional avoidance), and post hoc analysis indicated the significant differences are between group 1 and 4. A cumulative impact is reflected by large effect sizes between group 1 and 4 (d = 0.8 to 1). The group 2 and 3 (one risk dimension groups: either high-PC or high-PPT) represent 47% of the total participants.

The study suggests both higher level of PC and pressure sensitivity have a cumulative impact on risk screening for pain-related outcomes, considering gender in functional avoidance (task-related outcome). A clinical presentation with high-PC (one dimension of risk) is not associated with high-PPT (another dimension of risk). This finding has important clinical and theoretical implications.