Keypoint: In a meta-analysis, older and female children were likely to recall acute pain more intensely than was experienced, especially in a clinical context.
Children aged 18 years and younger tend to overestimate pain memory when comparing the experienced vs recalled intensity of acute pain, with only sex and age predictive of pain memory accuracy, according to study results published in Pain.
Following PRISMA guidelines, investigators conducted a systematic review and meta-analysis with a meta-regression to analyze accuracy of the memory of pain and the variables that may influence it in children with acute, experimental, and chronic pain. They searched 5 databases (MEDLINE/PubMed, Embase, CINAHL, Web of Science, and APA PsychInfo) from inception to February 11, 2022, and performed a statistical analysis using RStudio software (Rstudio, PBC, Boston, Mass.) and shared the Rscript and data on the Open Science Framework. The quality of the evidence was evaluated using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) framework. Standardized mean differences (SMDs) and 95% CIs for continuous variables were calculated to assess clinical effects, with subgroup analyses using a fixed-effects model conducted to discern differences in pain-related context (clinical vs experimental). Additional robustness checks included a leave-one-out method and checks for publication bias using visual and quantitative tools. Heterogeneity was assessed using I2 index, Cochran Q test, and meta-regression analysis, with effect-size heterogeneity applied to predict the accuracy of childrens’ memory of pain based on the study characteristics.
The review evaluated the accuracy of pain memory in children across various pain types (acute, experimental, and chronic). Meta-regression analysis was used to explore the relationship between memory accuracy and factors such as age, anxiety, fear, and delay in recall.
Included in the review were 15 articles with a total of 942 participants, 49% of whom were girls. There were 12 observational studies and 3 randomized controlled trials. Only 3 studies focused on the memory of experimental pain in healthy children. The remaining 12 studies analyzed the memory of acute pain in diverse pediatric populations, including children with leukemia (study not included in meta-analysis because it only provided change scores); children undergoing dental procedures, venipuncture, and vaccinations; and children undergoing surgeries such as tonsillectomy, spinal fusion, and pectus repair. Data on pain memory were collected at various intervals, from 1 day up to 1 year following the pain event. Pain assessments were generally made at baseline, pretreatment/preintervention, immediately or several days post-treatment/postintervention, and at follow-up weeks to months after the given painful treatment/experimental intervention.
Despite heterogeneity among studies, there was no evidence of publication bias.
Results showed that the recalled intensity of acute pain tended to be overestimated, with a slight standardized mean difference (SMD) of 0.28 (95% CI, 0.08-0.49). This overestimation was more pronounced in clinical contexts (SMD= 0.33; 95% CI, 0.09-0.58), with a statistically significant heterogeneity (P <.01) vs experimental contexts, in which no significant difference between experienced vs recalled pain intensity was found.
Age (β=0.08 [95% CI, 0.01-0.14]; F(1,17)=6.68, P =.02, R2*=28.28%) and the proportion of girls (β=0.03 [95% CI, 0.01-0.05]; F(1,17)=7.55, P =.01, R2*=32.62%) were significant predictors of this overestimation, suggesting that older children and a higher percentage of female participants may be more likely to recall pain more intensely than was experienced.
Other factors, such as the period of time since pain was experienced, expected and recalled fear, anxiety sensitivity, and trait anxiety, did not significantly predict the accuracy of pain memory. High collinearity between participants’ mean age and the percentage of girls prevented conduction of a multiple meta-regression analysis.
The meta-regression analysis did not show a significant relationship between anxiety factors (expected and recalled fear, anxiety sensitivity, and trait anxiety) and the accuracy of pain memories, challenging initial hypotheses. This result might be due to the fact that most of the included studies focused on the sensory dimension of pain, potentially overlooking influence of anxiety on affective aspects of pain. Individual differences in attentional style or coping strategies, not controlled for in several of the evaluated studies, could also have obscured potential relationships. Notably, a significant relationship was identified between the effect size and the mean age of participants and the proportion of girls, suggesting age and gender may influence pain memory bias. Younger children’s cognitive limitations and the unsuitability of certain pain assessment tools for different age groups highlight the need for age-appropriate evaluation methods.
In discussing the meta-analysis, the investigators noted that their identification of gender differences in pain memory, with girls often reporting higher pain intensity than boys, aligns with previous findings in adolescents with cancer. These differences, they said, could be attributed to several factors: girls tend to catastrophize pain more than boys, possibly developing a stronger self-concept as individuals who experience pain, which could enhance their pain memories. Additionally, girls may experience more distress or anxiety related to pain, negatively affecting their memory of the pain experience. Stereotypical gender roles, which portray men as less susceptible to pain and women as more sensitive, could also influence these perceptions. This suggests that gender differences in cognitive processing of pain experiences may significantly impact pain memories.
Study limitations included that only memory of acute and experimental pain was assessed and not all baselines were assessed immediately after the end of the painful experience.
The investigators concluded, “Children showed an overestimation in pain memory between the experienced and recalled intensity of acute pain, especially in a clinical context.” They added, “Furthermore, only gender and age were [accurate] predictors of pain memory. These results highlight the relevance of pain memory to medical practice and future research, as biased pain memory may lead to avoidance in the use of health care systems and the possible development of chronic pain.”
Note: This article originally appeared on Clinical Pain Advisor
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