Consistency of ASCQ-Me Scores Across Repeated Measures in Sickle Cell Disease

Abstract

Background

Reliable longitudinal measurement is essential for tracking quality of life (QoL) in sickle cell disease (SCD). The multiple domains of the Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me) have not been evaluated for their longitudinal consistency across repeated observations in real-world SCD cohorts with chronic pain

Objective

The objective of this study was to evaluate the consistency of ASCQ-Me scores across repeated observations over 18 months and to examine their association with average pain intensity.

Methods

It is a repeated-measures longitudinal observational study among adults with SCD. Participants (N= 186, mean age 36.6±11.7 years, 62% female) completed ASCQ-Me measures at four time points, approximately six months apart. Average pain intensity (API; 0–10) was computed as the mean of pain now, the least pain in the last 24 hours, and the worst pain in the last 24 hours. Analysis included Cronbach’s alphas, intraclass correlation coefficient (ICC), and linear regression mixed models.

Results

Cronbach’s alphas were high and stable across all domains (0.73–0.92), except for Pain Episodes Severity (α = 0.63). Means ± SD across time varied by no more than 2.2 points with moderate to high ICC (0.42 - 0.68), indicating consistent score behavior across time points. Average pain intensity was strongly associated with every ASCQ-Me subscale (p < 0.001 for all, except Pain Episodes Severity, p = 0.002).

Conclusion

ASCQ-Me scores were consistent over 18 months and demonstrated clinically coherent associations with pain burden in adults with SCD. These findings support the use of ASCQ-Me for monitoring QoL trajectories and for clinical studies targeting symptoms and function in SCD.

Take Away Summary

ASCQ-Me demonstrates consistency in scores across four research visits among outpatient adults with sickle cell disease and chronic pain. ASCQ-Me shows a clinically coherent association with pain burden: higher pain is significantly associated with worse quality of life

The complexity of sickle cell disease (SCD) requires a valid and reliable patient-reported outcome (PRO) measure that captures all aspects of patients’ lived experiences. The Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me) was developed by the National Institutes of Health (NIH) to address these unmet needs in adults with SCD.¹ Prior research has focused more on the validity and internal consistency of ASCQ-Me, yet little is known about its score consistency over repeated observations in usual care. The literature on this property is scarce. Most published studies have focused on preliminary psychometrics and construct validity against other PROs. Bridging this gap would build strong support for ASCQ-Me as a tool for both cross-sectional assessment and long-term monitoring of health-related quality of life (HRQOL) outcomes in clinical and research settings. The purpose of this study was to evaluate the consistency of ASCQ-Me scores over time and their association with pain in adults with SCD.

ASCQ-Me has been validated in numerous studies, both within and outside the United States, and its use is increasing. In a US SCD sample, Cronbach’s alpha was above 0.90 for all short forms (SF) subscales, and exceeded 0.70 for the pain episodes subscale, with evidence of good construct validity and discriminant validity comparable to Patient-Reported Outcomes Measurement Information System (PROMIS) measures of disease severity.² Among SCD adults in Jamaica, the SF subscales’ internal consistency reliability ranged from 0.81 to 0.91, whereas the fixed form showed lower reliability (α = 0.57 - 0.66).³ In the UK population, most subscales demonstrated very high internal consistency (0.92 - 0.96), except for sleep impact (α = 0.78), along with good construct and convergent validity.⁴ These findings indicate that ASCQ-Me exhibits robust reliability and validity across diverse cultural and geographic contexts, supporting its use for both research and clinical assessments. Yet, less is known about its score consistency over time.

Pain is known as the hallmark symptom of SCD and a primary determinant of patients’ quality of life (QoL). Prior studies have shown that pain intensity correlates with functional limitations, emotional distress, and social participation.^5–7 However, the extent to which overall pain intensity is associated with ASCQ-Me scores across repeated visits remains underexplored. Understanding this association is crucial, as it may inform targeted interventions for individuals experiencing high pain burden and declines in QoL. More research is needed to determine whether the observed changes are likely to reflect true clinical changes or expected variability. Implementing a longitudinal study of ASCQ-Me and quantifying its association with pain will provide insights into its ability to track changes in patients’ QoL over time and clarify how much overall pain burden relates to patient-reported functioning in usual care. The findings will enhance confidence in the interpretability of ASCQ-Me scores for longitudinal monitoring, clinical trials, and personalized care planning, providing a framework for integrating patient-reported outcomes into routine SCD management.

Purpose

The purpose of the study was to evaluate the consistency of ASCQ-Me subscale scores over 18 months in adults with SCD and chronic pain, and to examine their association with average pain intensity, a related clinical measure of pain burden, over the study period.

Materials and Methods

Design and Participant Characteristics

A repeated-measures longitudinal observational study was conducted at 4 time points over 18 months, among adults with SCD chronic pain. Participants were recruited principally from the outpatient department of the University of Illinois Hospital and Health Sciences System (UI), and the Institutional Review Board (IRB) of the University of Illinois at Chicago (UIC) approved the study. Approval to conduct this data analysis was obtained from the University of Florida (UF) as an exempt study of de-identified data, with an official data use agreement between UIC and UF and a confidentiality agreement between the UIC and UF investigators to maintain the confidentiality of the patients’ identities.

Participants were eligible if they were at least 18 years old; had chronic SCD pain, defined using a clinically meaningful threshold of greater than 3 on a 0–10 pain intensity scale in the previous 12 months, and pain present (> 0) on at least half of the days in the prior 3 months; able to speak and read English; and were of African descent.

Exclusion criteria included individuals who were legally blind, physically unable to complete study measures, or diagnosed with a polyneuropathy or diabetes mellitus recorded in their medical records.

The pain threshold is consistent with prior SCD literature,^8,9 in which pain intensity scores of greater than 3 are commonly used to indicate clinically important or moderate pain. The duration and frequency criteria were used to distinguish chronic from episodic pain. Study participants were limited to individuals who self-identified as African American, consistent with the parent study design. This restriction and exclusion of the specified diagnoses aimed to reduce variability in quantitative sensory testing (QST) outcomes.⁹ Although QST outcomes are not reported in this manuscript, the analytic sample was drawn from the QST-focused parent study.

Procedure

Research specialists were trained in all the study procedures before participant recruitment. During routine clinic visits at the UI outpatient department, potential participants were informed about the study, and consent to participate was obtained. Upon signing informed consent, participants scheduled a research visit at a convenient time to complete self-report assessments, PAINReportIt, and the 30-item ASCQ-Me questionnaire using a pen tablet computer. Following the completion of the self-report assessments, participants were reminded about the next research visit, scheduled 6 months later. Participants received $50/visit as reimbursement for their time and travel expenses.

Study measures

Participants Demographics

Participants completed demographic questionnaires, including age, sex, race, ethnicity, marital status, education, and income level, as a module within PAINReportIt, a tablet-based computerized pain assessment tool used to assess patients’ pain perception. Participants’ SCD genotypes information was obtained from the electronic medical record.

Quality of Life Measures

In our study, participants’ QoL was defined as their HRQOL. Participants completed the 30-item ASCQ-Me at 4-time points. ASCQ-Me is a validated and reliable disease-specific measure developed to assess HRQOL among adults living with SCD.¹ It has 6 domains, which include five-item impact subscales (also known as short forms, SF) that assess Pain Impact, Emotional Impact, Sleep Impact, Social functioning Impact, and Stiffness Impact, drawn from the corresponding ASCQ-Me item banks; and ASCQ-Me fixed forms which consist of Pain Episode Frequency (two items) and Pain Episode Severity (three items).¹⁰ ASCQ-Me was developed using the same protocol as the PROMIS measures, with a 7-day recall period, except for Social Functioning Impact, which has a 30-day recall period.^1,10 These items were designed to assess the impact of SCD on physical (pain impact, sleep impact, and stiffness impact), mental (emotional impact), and social (social functioning impact) well-being of adults with SCD.

In our study, the SF items were scored in a reverse order on Likert scales of 0 to 4 (from “never” to “always” or “not at all” to “very much”). This was re-coded based on NIH scoring guides (5 to 1; from “never” to “always” or “not at all” to “very much”) to create a score range from 5 to 25 for each subscale. Item responses are transformed into T scores with a mean of 50 and a standard deviation (SD) of 10.^10,11 Higher scores indicate a better HRQOL status or less impact, whereas lower scores mean worse HRQOL status. For the pain episodes domain (fixed forms), the pain episodes frequency and severity items were recoded according to the NIH scoring guides. Pain episode frequency scores have a range of 0 to 11, and pain episode severity scores have a range of 0 to 22. Higher scores for pain episodes indicate worse HRQOL status.^10,11 Internal consistency reliability was between 0.80 and 0.73 for the fixed form and 0.94 to 0.90 for SF.²

Associations between Average Pain Intensity and Quality of Life Outcomes

Participants’ average pain intensity was measured using the Pain Intensity Number Scale (PINS). PINS is a valid and reliable self-report pain measure on a scale of 0 (no pain) to 10 (pain as bad as it could be), derived from PAINReportIt.¹² Participants’ measure of current pain (pain now), the least pain in the past 24 hours, and the worst pain in the past 24 hours were assessed with PINS, the average of which was used to determine their average pain intensity. The PINS is a valid measure of SCD chronic pain,¹³ and the average pain intensity predicts acute care utilization for SCD pain.⁸

Analysis

Data analysis was performed with SAS statistical software. Descriptive statistics (frequency and percentages) were used to summarize participants’ demographic characteristics. ASCQ-Me raw scores were converted to T-scores using conversion tables in the ASCQ-Me Scoring Manual.¹¹ Two main objectives were addressed: 1) consistency of ASCQ-Me subscale scores across four visits, and 2) the longitudinal association between average pain intensity (API) and each ASCQ-Me subscale.

First, we obtained descriptive statistics (mean, SD, min, max) of ASCQ-Me scores across four time points to provide an overview of trends and variability over time. We then estimated Intraclass correlation coefficients (ICCs) from random-intercept models fit separately for each subscale using restricted maximum likelihood (REML). ICC was interpreted as the proportion of variance attributed to between-person differences over the study interval, reflecting the consistency of scores across repeated observations. We report ICC and 95% confidence interval for all ASCQ-Me domains. Cronbach’s alphas were used to assess the internal consistency reliability of ASCQ-Me subscale items at each time point.

To examine the association between API and ASCQ-Me subscales, we fitted linear mixed-effects models with a subject-specific random intercept and API included as a time-varying fixed effect for each subscale. These models estimated concurrent longitudinal associations between pain intensity and HRQOL across repeated observations. Models were estimated by REML with Kenward–Roger degrees of freedom for small-sample bias adjustment. Analyses used all available observations from participants who contributed ≥1 visit under a missing-at-random (MAR) assumption. This approach allowed inclusion of incomplete cases without listwise deletion and provided valid estimates when the probability of missingness depends on observed data.

Results

Participant Demographics

Of the 186 study participants aged 18 years and above, the mean age was 36.6±11.7 years, with 67 (36%) participants between the ages of 25 and 34 years, and only 2 (1%) participants were 65 years or above. Most participants were female (62%), had the HbSS genotype (71%), identified as African American (98%), were not Hispanic/Latino (97%), or were single (70%). Similar proportions of the sample had educational levels up to high school (43%) or some college or vocational (45%). The sample’s annual income was variable, with the largest proportion reporting up to $10,000 (40%) (Table 1).

Table 1.

Participants’ demographics

	Mean Age ± SD (N = 186)	Min - Max
	36.6 ± 11.7	19 – 74
Variable	Category	Frequency (%)
Age Group	18–24	30 (16)
	25–34	67 (36)
	35–44	38 (20)
	45–54	38 (21)
	55–64	11 (6)
	65+	2 (1)
Sex	Female	116 (62)
	Male	70 (38)
Genotype	HbSC	34 (18)
	HbSS	132 (71)
	HbSß+ Thalassemia	8 (4)
	Other	7 (4)
	Missing	5 (3)
Race	African American	183 (98)
	Other	3 (2)
Ethnicity	Hispanic/Latino	5 (3)
	Not Hispanic/Latino	181 (97)
Marital Status	Divorced/Separated	6 (3)
	Married / Partnered	43 (23)
	Single	130 (70)
	Widowed	3 (2)
	Missing	4 (2)
Education	High school or less	79 (43)
	Some college or vocational	84 (45)
	College graduate or higher	19 (10)
	Other / Missing	4 (2)
Income	$10,000 or less	74 (40)
	$11,000 - $20,000	52 (28)
	$21,000 - $30,000	17 (9)
	$31,000 - $40,000	11 (6)
	$41,000 - $50,000	10 (5)
	more than $50,000	12 (7)
	Missing	10 (5)

Internal Consistency of ASCQ-Me Domains

Cronbach’s alpha was used to assess the internal consistency of the ASCQ-Me subscales on item-level responses across 4 time points. All ASCQ-Me short forms (impact domains) demonstrated good to excellent reliability (α ranges from 0.84 to 0.93) across time points (Table 2). Specifically, the internal consistency alphas were: Emotional Impact 0.84 (time 1) and 0.85 (time 4), Pain Impact 0.92 (time 1) and 0.90 (time 4), Sleep Impact 0.92 (time 1 and time 4), Social Impact 0.88 (time 1) and 0.90 (time 4), and Stiffness Impact 0.91 (time 1) and 0.90 (time 4). The Pain Episode Frequency had lower but acceptable internal consistency (α = 0.73 at time 1 and 0.80 at time 4), whereas Pain Episodes Severity showed a moderate internal consistency (α = 0.63 at time 1 and 0.68 at time 4).

Table 2.

ASCQ-Me Domains Cronbach’s alpha

ASCQME SUBSCALES	# Items	ALPHA TIME 1	ALPHA TIME 2	ALPHA TIME 3	ALPHA TIME 4
Emotional Impact	5	0.84	0.84	0.86	0.85
Pain Impact	5	0.92	0.93	0.93	0.90
Sleep Impact	5	0.92	0.90	0.91	0.92
Social Impact	5	0.88	0.88	0.87	0.90
Stiffness Impact	5	0.91	0.89	0.91	0.90
Pain Episodes Frequency	2	0.73	0.72	0.77	0.80
Pain Episodes Severity	3	0.63	0.68	0.59	0.63

Alpha computed from responses at each time point; higher values indicate greater internal consistency; alphas ≥ 0.70 to ≥ 0.90.

Descriptive Statistics of ASCQ-Me Domains across Time Points

Descriptive statistics for unadjusted mean (mean ± SD) using all available data for the ASCQ-Me subscales across time points are presented in Table 3, with scores centered near the population mean of 50. Across study time points, the mean (SD) scores varied by no more than 2.2 points. Pain impact ranged from 47.5 ± 7.8 (time 1) to 48.8 ± 7.8 (time 4), sleep impact ranged from 49.1±8.7 (time 1) to 49.4±8.9 (time 4), stiffness impact ranged from 48.4±8.7 (time 1) to 49.4±8.5 (time 4), and emotional, social impact, and pain episodes averaged around 50 across time points. The number of observations decreased across time points, from approximately 182–184 at Time 1 to 151–155 at Time 3, indicating modest attrition over the study period.

Table 3.

Descriptive statistics by Time Points (observed data)

Subscale	Time 1 Mean ± SD (Min–Max), N	Time 2 Mean ± SD (Min–Max), N	Time 3 Mean ± SD (Min–Max), N	Time 4 Mean ± SD (Min–Max), N
Emotional Impact	48.9±7.9 (26.8–65.6),182	50.8±7.9(30.8–65.6),171	51.1±8.4(30.8–65.6),167	51.1±8.2(26.8–65.6),153
Pain Impact	47.5±7.8 (24.8–63.8),184	48.9±8.3(24.8–63.8),169	49.0±8.7(24.8–63.8),166	48.8±7.8(33.0–63.8),154
Sleep Impact	49.1±8.7 (27.9–69.1),183	49.6±8.3(27.9–69.1),173	49.1±8.7(27.9–69.1),167	49.4±8.9(27.9–69.1),155
Social Impact	49.7±7.9 (26.0–69.8),183	50.5±8.1(32.5–69.8),172	50.7±8.5(26.0–69.8),167	50.4±8.6(26.0–69.8),155
Stiffness Impact	48.4±8.7(24.9–65.4),183	48.2±7.9(29.0–65.4),173	48.5±8.7(29.0–65.4),167	49.4±8.5(24.9–65.4),155
Pain Episodes Frequency	52.3±8.7(24.6–63.5),180	52.2±9.0(24.6–63.5),170	51.7±9.6(20.8–63.5),166	51.2±9.5(24.6–63.5),151
Pain Episodes Severity	49.2±9.7(21.9–66.3),183	50.5±9.4(26.6–66.3),167	51.4±8.9(26.6–66.3),165	50.2±9.1(28.9–66.3),154

Unadjusted descriptive statistics by visit. Values are ASCQ-Me T-scores (M=50, SD=10 by design). N is the number of non-missing observations for that subscale and visit. No model adjustments were applied; the results reflect the observed data only. All available data were used (records with missing values for a given subscale/visit were excluded for that cell only).

Longitudinal Stability of ASCQ-Me Domains

Random-intercept intraclass correlation coefficients (ICC = between-person variance ÷ total variance) were moderate to high. ICCs ranged from 0.42 for Pain Episodes Severity to 0.68 for Stiffness Impact, with most subscales around 0.56–0.63 (Table 4). Interpreted as variance proportions, approximately 42–68% of the variability in scores was attributed to between-person differences, with the remainder reflecting within-person variability and measurement error. These findings indicate substantial between-person consistency in ASCQ-Me scores across repeated observations, relative to within-person fluctuations over time.

Table 4.

Intraclass Correlations for longitudinal stability of ASCQ-Me domains

Subscale/N=186	ICC (95% CI)
Emotional Impact	0.58 (0.49, 0.68)
Pain Impact	0.58 (0.49, 0.67)
Sleep Impact	0.60 (0.51, 0.69)
Social Impact	0.56 (0.46, 0.65)
Stiffness Impact	0.68 (0.60, 0.75)
Pain Episodes Frequency	0.63 (0.55, 0.71)
Pain Episodes Severity	0.42 (0.33, 0.53)

ICC: Intraclass Correlations Coefficient, 95% CI = 95% Confidence Intervals

Association between Average Pain Intensity (API) and Quality of Life Outcomes

Across 186 participants (667–678 observations per model), average pain intensity (API; 0–10), computed as the mean of pain now, least pain in the last 24 hours, and worst pain in the last 24 hours, was strongly related to every ASCQ-Me subscale in a single mixed-effects regression model. A 1-point higher API was associated with changes of magnitudes of 0.5 to 1.4 T-score points in a subscale (see Table 5): −1.43 for Pain Impact (95% CI −1.65 to −1.21), −0.92 for Emotional Impact (−1.15 to −0.68), −0.89 for Stiffness Impact (−1.11 to −0.66), −0.88 for Social Impact (−1.13 to −0.63), −0.72 for Sleep Impact (−0.98 to −0.47), 0.76 for Pain Episodes Frequency (0.50 to 1.02), and 0.48 for Pain Episodes Severity (0.17 to 0.78); p < 0.001 for all API effects except Pain Episodes Severity (p = 0.002). Direction of β follows each subscale’s scoring (negative for the “impact” domains, where higher scores indicate less impact or good health, and positive for the episodes domains, where higher scores indicate more impact or worse health).

Table 5.

Average pain intensity predicting ASCQ-Me subscales (N Subjects = 186)

Subscale	N (observations)	API β (95% CI), SE	p (API)
Emotional Impact	673	−0.92 (−1.15, − 0.68), 0.12	<.001
Pain Impact	673	−1.43 (−1.65, −1.21), 0.11	<.001
Sleep Impact	678	−0.72 (−0.98, − 0.47), 0.13	<.001
Social Impact	677	−0.88 (−1.13, −0.63), 0.13	<.001
Stiffness Impact	678	−0.90 (−1.11, −0.66), 0.11	<.001
Pain Episodes Frequency	667	0.77 (0.50, 1.02), 0.13	<.001
Pain Episodes Severity	669	0.48 (0.17, 0.78), 0.16	0.002

Models were a single linear mixed-effects regression fit separately for each ASCQ-Me T-score subscale (REML; Kenward–Roger df): T-score = β₀ + β(API) + random intercept for subject. API was computed as the mean of “pain now”, “least pain in the last 24 hours”, and “worst pain in the last 24 hours” (0–10 each) at each visit. The table reports changes in subscale T-score per 1-point increase in API (95% CI, Standard Error, and p-value from Kenward–Roger df). N(subjects) = 186; N(observations) is the number of analytic rows per model.

API: Average Pain Intensity; β(API): the slope for Average Pain Intensity in mixed model; CI: Confidence interval; SE: Standard Error

Discussion

This longitudinal, repeated-measures methodological study, to the best of our knowledge, is the first to report the stability of ASCQ-Me as a measure of QoL among adults with SCD and chronic pain over 18 months of usual care, with four measurements. In our SCD cohort, the ASCQ-Me subscales demonstrated strong internal consistency, stability across four visits, and clinically coherent associations with pain burden, indicating good construct validity.

Our findings extend earlier psychometric evaluations of ASCQ-Me. The high internal consistency in our sample shows that the items within each domain measure a cohesive construct, even in the context of chronic pain. This finding aligns with prior reports that ASCQ-Me item banks yield α values in good to excellent range among adults with SCD.² As in earlier work, reliability was comparatively lower for the fixed form measures (Pain Episodes Frequency/Severity), a pattern commonly attributed to fewer items, event-driven variability, and restricted ranges over short recall windows rather than flaws in scale construction.^2,4 The slightly low alpha coefficient for pain episode severity across time points (0.59 to 0.68) may reflect heterogeneity in how adults with chronic SCD pain conceptualize episodic pain versus persistent pain, a pattern observed in other studies.^2,4,14 Yet, our results indicate that at the item level, the instrument remains coherent in contemporary clinical samples, suggesting that the pain episode severity domain may warrant further refinement, particularly in chronic pain samples.

In this study, consistency of ASCQ-Me scores across repeated observations, as indicated by unadjusted means, showed minimal drift across time points with small between-visit differences (differences of no more than 2.2 points). We also found moderate to high ICCs for most ASCQ-Me domains with relatively narrow confidence intervals, indicating that a substantial proportion of variance reflects between-person differences over the study interval. Prior to our study, no studies were available on longitudinal use of ASCQ-Me among adults with SCD; hence, it was concluded that ASCQ-Me could only be used as a one-time measure.¹⁵ Taken together, minimal cohort-level drift and moderate-to-high ICCs suggest that ASCQ-Me subscale scores demonstrate consistent behavior over repeated observations, supporting their use in longitudinal observational studies without planned interventions. A recent longitudinal study using multiple HRQoL instruments, including ASCQ-Me,¹⁶ reported persistently impaired but stable QoL over time in adults with SCD experiencing recurrent Vaso-occlusive crises. While that study reflects disease burden in a high-severity subgroup over a shorter follow-up period, the present study extends this evidence by demonstrating the consistency of ASCQ-Me scores over repeated observations using a disease-specific measure.

Our results mirror cross-sectional assessments of ASCQ-Me domains among the SCD cohort with acute pain, which also found small changes in means (1.4 to 2.8 T-score points) over routine follow-up in the absence of major clinical events.^17,18 The moderate-to-high ICCs indicate that a substantial proportion of variance is attributable to between-person differences, suggesting that individuals tend to maintain their relative ranking within the cohort over time. These findings reflect score consistency across repeated observations in a chronic pain cohort, rather than formal test–retest reliability in a clinically unchanged sample. In addition, the distinct variance pattern observed across domains suggests that capture multiple dimensions of SCD-related experiences rather than reflecting a single global construct.^4,10

Intriguingly, the association of ASCQ-Me with average pain intensity (API: pain now, least, and worst pain in the last 24 hours) demonstrated consistent concurrent relationships across domains. Higher average pain intensity has been consistently associated with worse QoL scores in the expected directions. This pattern provides evidence consistent with construct coherence, demonstrating that ASCQ-Me aligns with pain burden reported at the same time, even when paired with a pragmatic three-item pain composite. The 0.5–1.4 T-score points per 1-point API can be clinically interpreted as individuals reporting higher pain levels also report correspondingly worse functioning, highlighting the ability of ASCQ-Me to capture HRQOL dimensions closely connected to day-to-day pain experiences, an important construct in SCD. These graded associations are consistent with previous evidence that pain burden is closely related to HRQoL in SCD.^7,19,20 Aligning with the foundational work on ASCQ-Me validation, Keller and colleagues found that ASCQ-Me scores explained unique variance in SCD severity and were more sensitive than PROMIS measures,² suggesting that ASCQ-Me is not only valid and reliable, but often more tied to disease burden than generic measures, ^2,15 reinforcing the clinical coherence of the pain–QoL gradient observed. This association also suggests that average pain intensity and ASCQ-Me capture related but distinct aspects of patients’ health status

Prior work on patient QoL has focused more on the acute pain crises as an indicator of health status.^17,21,22 Our findings contribute to the body of knowledge by demonstrating that ASCQ-Me is not only consistently associated with the frequency and severity of pain crises^17,21,22 but also associated with persistent pain in routine care, capturing the underlying pain burden in this population. Co-monitoring persistent pain intensity and ASCQ-Me can help identify patients with a higher pain burden and address potential declines in QoL outcomes. Because pain intensity and ASCQ-Me were measured at the same time points, these findings should be interpreted as concurrent associations rather than evidence of temporal prediction or causal relationships.

The findings of consistency over time are primarily based on between-person differences observed over four routine visits of usual SCD care; they may not be generalized to longer or more eventful periods. Thus, the observed consistency of scores across repeated observations should be interpreted as time and context-specific, rather than as proof of invariance. Moreover, consistency of scores does not imply a lack of sensitivity to change, but rather reflects patterns observed across repeated measurements in usual care with a small cohort-level mean shift in the absence of additional interventions designed to improve pain. Furthermore, our model assumes that data are missing at random (MAR), whereas some SCD patients may have missed study visits due to severe pain and may have decided to self-manage their pain at home, which could lead to missing not at random (MNAR) and biased estimates. Given the modest attrition observed across time points, these findings should be interpreted with caution, as missingness related to symptom severity could influence estimates. We did not perform formal comparisons of completers versus non-completers or sensitivity analyses. Furthermore, our study did not evaluate item-level psychometric properties (e.g., measurement invariance, differential item functioning, or IRT-based analyses); therefore, conclusions are limited to score-level behavior over time. Finally, our study sample reflects a single-site cohort of adults with SCD and chronic pain. Therefore, findings may not generalize to all individuals with SCD, particularly those without chronic pain, or in different geographic or clinical settings. Future work should consider these limitations and pair consistency metrics with responsiveness analyses to solidify ASCQ-Me’s role not only as a consistent longitudinal outcome for cohorts but also as a responsive measure of clinically meaningful change at the patient level.

Conclusion

Although early guidance emphasized baseline use, our findings indicate that ASCQ-Me demonstrates consistent score behavior across repeated observations and clinically coherent associations with daily pain burden, thereby confirming its suitability as a disease-specific outcome measure in adults with SCD and chronic pain in usual care. Future studies should explore the responsiveness of ASCQ-Me to change.

Data Sharing Statement:

The data that support the findings of this study are available from the Senior author upon reasonable request. The data are not publicly available due to privacy or ethical restrictions. Please contact Dr. Diana Wilkie at diwilkie@ufl.edu