Intraindividual pain variability and phenotypes of pain in sickle cell disease: a secondary analysis from the Pain in Sickle Cell Epidemiology Study

What interval of daily pain assessment is required to reliably diagnose chronic pain in SCD? The Pain in Sickle Cell Epidemiology Study

Objectives

Chronic pain in SCD has been defined as pain on most days over 6 months. In the landmark Pain in Sickle Cell Epidemiology Study, 60% of patients submitted <5 of the expected 6 months of pain diaries. Identifying chronic SCD pain using this long daily assessment interval is impractical. We therefore examined whether shorter, less burdensome intervals could accurately identify chronic SCD pain.

Methods

As the gold-standard sample, we chose the 116 Pain in Sickle Cell Epidemiology Study patients who submitted >5 months of diaries (153) and >49% of diaries during all months from 1 to 4. Using the same dataset, we tested daily diary assessment over shorter intervals: 2 weeks, 1 month, 2 months, 3 months, and 4 months. We defined chronic pain as intensity rated as >0 on >50% of diary days, regardless of interval. We then calculated the sensitivity and specificity of each diary interval.

Results

Among the gold-standard sample, 51.3% of patients had diary-defined chronic pain. Collection intervals of 2 months or more yielded similar chronic pain prevalences with identically high sensitivity (98.3%) and specificity (93%). Intervals of 1 month and 2 weeks yielded increasingly lower specificity (80.7%, 73.7%, respectively), but preserved sensitivity (≥96.6%).

Conclusion

In the Pain in Sickle Cell Epidemiology Study, intervals of 2 months or more of daily diary collection yielded high sensitivity and specificity, compared to an interval of 5-6 months. One may reasonably diagnose chronic SCD pain using 2 months of daily diaries.

High-impact chronic pain in sickle cell disease: insights from the Pain in Sickle Cell Epidemiology Study (PiSCES)

ABSTRACT

The US National Pain Strategy recommends identifying individuals with chronic pain (CP) who experience substantial restriction in work, social, or self-care activities as having high-impact chronic pain (HICP). High-impact chronic pain has not been examined among individuals with CP and sickle cell disease (SCD). We analyzed data from 63 individuals with SCD and CP who completed at least 5 months of pain diaries in the Pain in Sickle Cell Epidemiology Study (PiSCES). Forty-eight individuals met the definition for HICP, which was operationalized in this study as reporting pain interference on more than half of diary days. Compared with individuals without HICP, individuals with HICP experienced higher mean daily pain intensity, particularly on days without crises. They also experienced a greater proportion of days with pain, days with healthcare utilization, and days with home opioid use and higher levels of stress. They did not have a statistically significantly higher proportion of days with crises or experience higher mean daily pain intensity on days with crises. Individuals with HICP experienced worse physical functioning and worse physical health compared with those without HICP, controlling for mean pain intensity, age, sex, and education. The results of this study support that HICP is a severely affected subgroup of those with CP in SCD and is associated with greater pain burden and worse health outcomes. The findings from this study should be confirmed prospectively in a contemporary cohort of individuals with SCD.

The Contribution of Sleep Quality and Psychological Factors to the Experience of Within-Day Pain Fluctuations Among Individuals With Temporomandibular Disorders

We assessed the impact of day-to-day sleep quality and psychological variables (catastrophizing, negative affect, and positive affect) to within-day pain fluctuations in 42 females with painful temporomandibular disorders (TMD) using electronic diaries. More specifically, we examined the contribution of these variables to the likelihood of experiencing pain exacerbations defined as 1) an increase of 20 points (or more) in pain intensity on a 0 to 100 visual analog scale from morning to evening, and/or 2) a transition from mild-to-moderate pain over the course of the day; and pain decreases defined as 3) a decrease of 20 points (or more) in pain intensity (visual analog scale) from morning to evening, and/or 4) a reduction from moderate-to-mild pain over the day. The results indicated significantly main effects of sleep on both pain exacerbation outcomes (both P's < .05), indicating that nights with better sleep quality were less likely to be followed by clinically meaningful pain exacerbations on the next day. The results also indicated that days characterized by higher levels of catastrophizing were associated with a greater likelihood of pain exacerbations on the same day (both P's < .05). Daily catastrophizing was the only variable significantly associated with within-day pain decrease indices (both P's < .05). None of the other variables were associated with these outcomes (all P's > .05). These results underscore the importance of addressing patients' sleep quality and psychological states in the management of painful TMD. PERSPECTIVE: These findings highlight the significance of sleep quality and pain catastrophizing in the experience of within-day pain fluctuations among individuals with TMD. Addressing these components through tailored interventions may help to alleviate the impact of pain fluctuations and enhance the overall well-being of TMD patients.

Understanding the biopsychosocial knee osteoarthritis pain experience: an ecological momentary assessment

Introduction

Psychological, social, and lifestyle factors contribute to the knee osteoarthritis (OA) pain experience. These factors could be measured more accurately using smartphone ecological momentary assessment (EMA).

Objectives

The objective of this study was to characterise the pain experiences of those with knee OA by a smartphone EMA survey and explain how momentary psychological and social states influence knee OA pain experiences.

Methods

A smartphone EMA survey was designed and piloted. Eligible participants completed smartphone EMA assessing the knee OA pain experience 3 times daily for 2 weeks. Descriptive statistics were used to characterise factors involved in knee OA pain followed by the development of mixed-effects location scale models to explore heterogeneity and relationships between symptoms involved in the knee OA pain experience.

Results

Eighty-six community-dwelling volunteers with knee OA were recruited. Pain, psychosocial, and lifestyle factors involved in knee OA pain experience were heterogeneous and variable. Those with greater variability in pain, fatigue, negative affect, and stress had worse levels of these symptoms overall. In addition, fatigue, negative affect, stress, anxiety, loneliness, and joint stiffness demonstrated within-person relationships with knee OA pain outcomes.

Conclusions

Knee OA pain is a heterogeneous biopsychosocial condition. Momentary experiences of psychological, social, fatigue, and joint stiffness explain individual and between-individual differences in momentary knee OA pain experiences. Addressing these momentary factors could improve pain and functional outcomes in those with knee OA. Validation studies, including individuals with more severe knee OA presentations, are required to support findings and guide clinical interventions to improve outcomes for those with knee OA.

Increased Pain Variability in Patients With Chronic Pain: A Role for Pain Catastrophizing

Pain is an inherently negative perceptual and affective experience that acts as a warning system to protect the body from injury and illness. Pain unfolds over time and is influenced by myriad factors, making it highly dynamic. Despite this, statistical measures often treat any intraindividual variability in pain ratings as noise or error. This is consequential, especially for research on chronic pain, because pain variability is associated with greater pain severity and depression. Yet, differences in pain variability between patients with chronic pain and controls in response to acute pain has not been fully examined-and it is unknown if dispositional factors such as pain catastrophizing (negative cognitive-affective response to potential or actual pain in which attention cannot be diverted away from pain) relate to pain variability. In the current study, we recruited chronic-pain patients (N = 30) and pain-free controls (N = 22) to complete a 30-second thermal pain task where they continually rated a painful thermal stimulus. To quantify pain variability and capture potential dynamics, we used both a traditional intraindividual standard deviation (iSD) metric of variability and a novel derivatives approach. For both metrics, patients with chronic pain had higher variability in their pain ratings over time, and pain catastrophizing significantly mediated this relationship. This suggests patients with chronic pain experience pain stimuli differently over time, and pain catastrophizing may account for this differential experience. PERSPECTIVE: The present study demonstrates (using multiple variability metrics) that chronic pain patients show more variability when rating experimental pain stimuli, and that pain catastrophizing helps explain this differential experience. These results provide preliminary evidence that short-term pain variability could have utility as a clinical marker in pain assessment and treatment.

Sleep Disruption Moderates the Daily Dynamics of Affect and Pain in Sickle Cell Disease

Persons with sickle cell disease (SCD) often experience pain that can interfere with quality of life and daily activities. Pain can modulated by affect and sleep continuity; however, few studies have explored how these factors complementarily influence pain in adults with SCD. The study aims were to investigate 1) whether pain levels were heightened on days characterized by low positive affect and high negative affect, and 2) whether the relationship between affect and pain was intensified following nights of disrupted sleep. Adults with SCD (N = 25) completed ecological momentary assessments and daily sleep diaries. Mixed models were used to analyze the main and interactive effects of daily affect (positive affect and negative affect) and sleep disruption (wake after sleep onset and frequency of awakenings) on both daily average pain and daily maximum pain. Results suggested that daily average pain and maximum pain tended to be higher on days of low positive affect and high negative affect. Furthermore, the frequency of nocturnal awakenings moderated the relationship between positive affect and pain. On days where there were higher frequencies of nocturnal awakenings, low positive affect was associated with both average and maximum pain; however, this association was not observed with lower frequencies of nocturnal awakenings. The association between negative affect and maximum pain was also stronger at higher levels of awakenings. Results highlight the relevance of adjunctive interventions that target affect among populations with SCD and further suggest that sleep continuity may further facilitate these interventions, highlighting the importance of multimodal treatments. PERSPECTIVE: This study examined the effects of affect and sleep on pain among adults with sickle cell disease (SCD). Higher pain occurred on days of low positive affect and high negative affect, particularly following nights of more frequent awakenings. These findings emphasize the importance of addressing affect and sleep in SCD treatment.

Daily Pain Experiences in Chronic Pancreatitis: Identifying Pain Phenotypes

OBJECTIVES

Pain, the hallmark symptom of chronic pancreatitis (CP), remains difficult to assess. To capture the variability of pain that patients can experience day to day, this study used pain diaries to describe daily pain experiences and identify pain phenotypes.

METHODS

This study is a secondary data analysis from a pilot trial examining cognitive behavioral therapy for pain treatment in CP. Before treatment, patients completed an online daily pain diary using the Brief Pain Inventory for 7 days. Using indicators of pain magnitude, pain variability, pain synchrony along with least, worst, and average pain intensity levels, we identified pain patterns using K-means clustering.

RESULTS

Of 30 patients in the pilot trial, a total of 27 patients (mean age of 49.8 years, 80% women) had complete data to include in this report. Four clusters were identified: cluster 1, lowest pain magnitude (n = 3); cluster 2, moderate pain magnitude and high pain variability (n = 4); cluster 3, moderate pain magnitude and low pain variability (n = 9); and cluster 4, highest pain magnitude and lowest pain variability (n = 11).

CONCLUSIONS

Daily pain diaries offer a novel way of evaluating the dynamic pain experiences in CP. Although 4 distinct pain patterns were identified, further studies are needed to validate these findings.

Intraindividual pain variability metrics for youth with sickle cell disease: Relations to health outcomes

BACKGROUND

While the majority of pediatric sickle cell disease (SCD) research has used mean pain intensity as the only pain metric, recent evidence suggests this metric alone is inadequate in describing the intraindividual variability in SCD pain experiences and subsequent impact. There is limited information on other intraindividual pain metrics in youth with SCD, or how they relate to health outcomes in this population. The aims of this study were to describe differing patterns of intraindividual pain metrics derived from ecological momentary assessments (EMAs) of youth with SCD and to characterize the unique relationships between these metrics and health outcomes.

METHODS

Eighty-eight youth with SCD, aged 8-17 (mean age = 11.6), were recruited from three regional pediatric SCD clinics in the United States. At baseline, youth and their guardians reported on demographic and disease information. Then youth completed twice daily EMAs for up to 4 weeks. Pain metrics derived from EMA data were calculated including mean daily pain intensity (DP), SD-DP (standard deviation of DP), proportion of pain days (PPD), and 90th percentile of DP (p90). Pearson correlations were calculated between pain metrics and health outcomes.

RESULTS

High DP and SD-DP were correlated with more anxiety symptoms, while high SD-DP and p90 were correlated with more depression symptoms. High SD-DP was correlated with low self-esteem, and high DP and PPD were correlated with low sickle cell self-efficacy. For healthcare utilization due to pain, high p90 was correlated with more emergency department visits, while high DP, p90, and PPD were correlated with more healthcare contacts.

CONCLUSION

There are distinct associations between pain variability metrics beyond DP and health outcomes. Collectively, the patterns of associations suggest the utility of these pain metrics for determining risk in relation to specific health outcomes for youth with SCD.

Feasibility and Acceptability of a Preoperative Multimodal Mobile Health Assessment in Spine Surgery Candidates

BACKGROUND

Rapid growth in smartphone use has expanded opportunities to use mobile health (mHealth) technology to collect real-time patient-reported and objective biometric data. These data may have important implication for personalized treatments of degenerative spine disease. However, no large-scale study has examined the feasibility and acceptability of these methods in spine surgery patients.

OBJECTIVE

To evaluate the feasibility and acceptability of a multimodal preoperative mHealth assessment in patients with degenerative spine disease.

METHODS

Adults undergoing elective spine surgery were provided with Fitbit trackers and sent preoperative ecological momentary assessments (EMAs) assessing pain, disability, mood, and catastrophizing 5 times daily for 3 weeks. Objective adherence rates and a subjective acceptability survey were used to evaluate feasibility of these methods.

RESULTS

The 77 included participants completed an average of 82 EMAs each, with an average completion rate of 86%. Younger age and chronic pulmonary disease were significantly associated with lower EMA adherence. Seventy-two (93%) participants completed Fitbit monitoring and wore the Fitbits for an average of 247 hours each. On average, participants wore the Fitbits for at least 12 hours per day for 15 days. Only worse mood scores were independently associated with lower Fitbit adherence. Most participants endorsed positive experiences with the study protocol, including 91% who said they would be willing to complete EMAs to improve their preoperative surgical guidance.

CONCLUSION

Spine fusion candidates successfully completed a preoperative multimodal mHealth assessment with high acceptability. The intensive longitudinal data collected may provide new insights that improve patient selection and treatment guidance.

Identifying Chronic Pain Subgroups in Pediatric Sickle Cell Disease: A Cluster-Analytic Approach

OBJECTIVES

Youth with sickle cell disease (SCD) and chronic pain, defined in this study as pain on most days for 3 months, experience variability in daily pain and physical and psychosocial functioning. This study aimed to (1) empirically derive chronic pain subgroups based on pain characteristics among youth with chronic SCD pain; and (2) investigate derived subgroups for differences in sociodemographics, clinical characteristics, and psychosocial and functional outcomes.

MATERIALS AND METHODS

Youth with chronic SCD pain (n=62, Mage =13.9, SD=2.5, 10 to 18 y; 58% female, 60% HbSS) completed a battery of questionnaires. Clinical characteristics (eg, medications, treatments) and health care utilization were abstracted from electronic medical records. Hierarchical cluster analysis informed the number of clusters at the patient level. k-means cluster analysis used multidimensional pain assessment to identify and assign patients to clusters.

RESULTS

Cluster 1 (n=35; Moderate Frequency, Moderate Pain) demonstrated significantly lower worst pain intensity, number of pain days per month, number of body sites affected by pain, and pain quality ratings. Cluster 2 (n=27; Almost Daily, High Pain) reported high ratings of worst pain intensity, almost daily to daily pain, greater number of body sites affected by pain, and higher ratings of pain quality (all P 's <0.05). There were no differences between subgroups by sociodemographics, clinical characteristics, or health care utilization. The Almost Daily, High Pain subgroup reported significantly higher pain interference, depressive symptoms, and pain catastrophizing than the Moderate Frequency, Moderate Pain subgroup.

DISCUSSION

Identifying chronic SCD pain subgroups may inform tailored assessment and intervention to mitigate poor pain and functional outcomes.