Mean pain intensity alone is insufficient to describe pain phenotypes in sickle cell disease (SCD). The objective of this study was to determine impact of day-to-day intraindividual pain variability on patient outcomes in SCD. We calculated metrics of pain variability and pain intensity for 139 participants with <10% missing data in the first 28 days of the Pain in Sickle Cell Epidemiology Study. We performed Spearman rank correlations between measures of intraindividual pain variability and outcomes. We then used k-means clustering to identify phenotypes of pain in SCD. We found that pain variability was inversely correlated with health-related quality of life, except in those with daily or near-daily pain. Pain variability was positively correlated with affective coping, catastrophizing, somatic symptom burden, sickle cell stress, health care utilization, and opioid use. We found 3 subgroups or clusters of pain phenotypes in SCD. Cluster 1 included individuals with the lowest mean pain, lowest temporal instability and dependency, lowest proportion of days with pain and opioid use, and highest physical function. Cluster 2 included individuals with the highest mean pain, highest temporal dependency, highest proportion of days with pain and opioid use, and lowest physical function. Cluster 3 included individuals with high levels of mean pain, highest temporal instability, but with lower temporal dependency, proportion of days with pain and opioid use, and physical function compared with cluster 2. We conclude that intraindividual pain variability is associated with patient outcomes and psychological characteristics in SCD and is useful in delineating phenotypes of pain in SCD.

仅平均疼痛强度不足以描述镰状细胞病 (SCD) 的疼痛表型。本研究的目的是确定日常个体疼痛变异性对 SCD 患者预后的影响。我们计算了 139 名参与者的疼痛变异性和疼痛强度指标，这些参与者在镰状细胞流行病学疼痛研究的前 28 天内缺失数据 <10%。我们对个体内疼痛变异性和结果之间的斯皮尔曼等级相关性进行了分析。然后我们使用 k 均值聚类来识别 SCD 中的疼痛表型。我们发现，疼痛变异性与健康相关的生活质量呈负相关，但每天或几乎每天都会疼痛的人除外。疼痛变异性与情感应对、灾难化、躯体症状负担、镰状细胞应激、医疗保健利用和阿片类药物使用呈正相关。我们在 SCD 中发现了 3 个疼痛表型亚组或集群。第 1 组包括平均疼痛最低、时间不稳定性和依赖性最低、疼痛和阿片类药物使用天数比例最低以及身体功能最高的个体。第 2 组包括平均疼痛最高、时间依赖性最高、疼痛和阿片类药物使用天数比例最高以及身体功能最低的个体。与聚类 2 相比，聚类 3 包括平均疼痛水平较高、时间不稳定性最高的个体，但时间依赖性较低、疼痛和阿片类药物使用的天数比例以及身体功能较低。我们得出的结论是，个体内疼痛变异性与患者结果相关，并且SCD 的心理特征，有助于描述 SCD 的疼痛表型。