Abstract
Introduction
Insomnia is highly prevalent among older adults with chronic low back pain (cLBP), contributing to a cycle of heightened pain sensitivity, impaired physical function, and reduced quality of life. Auricular Point Acupressure (APA), a nonpharmacologic intervention for pain, has shown emerging evidence of improving sleep. We compared the effectiveness of targeted APA (T-APA) versus non-targeted APA (NT-APA) on insomnia in older adults with cLBP.
Methods
This secondary analysis used data from a parent RCT, including 99 adults aged 60 or older with cLBP and clinical insomnia (Insomnia Severity Index [ISI]>7). Participants received four weeks of T-APA or NT-APA. Sleep outcomes (ISI, PROMIS-29 sleep disturbance) and pain outcomes (intensity, interference) were assessed at baseline and post-intervention, with pain examined as a mediator of sleep change.
Results
The T-APA (n = 45) and NT-APA (n = 54) groups had similar baseline characteristics. Both groups showed significant reductions in sleep disturbance, pain interference, and pain intensity (p < 0.05). However, only the NT-APA group demonstrated significant improvement in ISI scores (p < 0.001, d = 0.50). No significant mediation effect of pain on sleep outcomes was found.
Conclusions
APA may be an effective nonpharmacologic approach for improving sleep among older adults with cLBP. Unexpectedly, NT-APA showed greater improvements in insomnia compared to T-APA, suggesting mechanisms beyond traditional somatotopic theory. Further research is warranted to confirm these findings and explore the potential of point-specific versus non-specific APA protocols in treating insomnia.
Trial ID
NCT03589703 (registration date: May 22, 2018).
URL
Keywords: Insomnia, Sleep disturbance, Auricular point acupressure, Auricular acupressure, Ear acupoints, Chronic low back pain
Graphical abstract
Highlights
-
•
Insomnia is highly prevalent among individuals with chronic low back pain (cLBP).
-
•
Existing pharmacological and behavioral interventions for sleep are limited, highlighting the need for more accessible and safer alternatives.
-
•
Auricular point acupressure (APA) is a noninvasive, non-drug approach showing promise in symptom management.
-
•
APA may help improve insomnia in older adults with cLBP, but more study is needed on point-specific effects.
1. Introduction
Insomnia, a condition characterized by persistent difficulties with sleep initiation, maintenance, or achieving restorative sleep despite adequate opportunity [1], is a pervasive issue among old adults with chronic low back pain (cLBP), contributing to a vicious cycle that exacerbates both conditions. While insomnia affects approximately 30 % of the general adult population [2], up to 90 % of individuals with chronic pain also experience sleep disruption, including prolonged sleep latency, frequent nocturnal awakenings, and non-restorative sleep [3]. These disturbances not only heighten pain sensitivity and impair daily functioning, but also contribute to depression, anxiety, and diminished responsiveness to pain management strategies [4,5]. Moreover, inadequate sleep disrupts endogenous pain regulation mechanisms, including the opioid and orexinergic systems, reducing pain tolerance and limiting the effectiveness of analgesic medications [6]. The economic burden of insomnia in individuals with chronic pain is substantial, with related healthcare costs, lost productivity, and reduced quality of life exceeding $100 billion annually in the U.S. alone [2].
The American Academy of Sleep Medicine (AASM) recommends cognitive behavioral therapy for insomnia (CBT-I) as first-line treatment [7]. However, limited access to trained clinicians, cost, and patient barriers often constrain implementation [8]. Pharmacologic agents such as zolpidem or suvorexant are frequently used but carry risks of sedation, dependence, and falls, particularly in older adults [[9], [10], [11]]. Auricular point acupressure (APA), a modality of auriculotherapy rooted in Traditional Chinese Medicine (TCM), has been primarily studied for chronic pain and is hypothesized to influence sleep through autonomic and neuroendocrine modulation. Yet, evidence for APA's effect on sleep remains limited, and mechanisms underlying its sleep-regulating potential are poorly defined [12,13]. Standardized protocols for APA in insomnia are also lacking [14].
In our parent randomized trial of older adults with cLBP, both a targeted APA arm (T-APA; low-back–mapped points) and a non-targeted arm (NT-APA; gastrointestinal-related points) improved pain and sleep disturbance versus control [15,16]. Building on those data, the present work is a secondary, exploratory analysis that is hypothesis-generating for the effect of APA on sleep outcomes. Our exploratory aims were to: (1) compare within-group pre-to post-intervention changes in insomnia (ISI) and sleep disturbance (PROMIS) for T-APA and NT-APA; and (2) examine pain intensity and interference as potential mediators of sleep changes.
2. Methods
2.1. Conceptual framework
The conceptual framework for this secondary analysis outlines both direct and indirect pathways relating the intervention (T-APA vs. NT-APA) to primary sleep-related outcomes and highlights the potential impact of acupoint specificity in APA (Fig. 1). The primary intervention condition (T-APA vs. NT-APA) drives subsequent changes in pain and sleep. Given the bidirectional relationship between pain and sleep, pain intensity and interference serve as intermediary mechanisms that may relay APA's effect on sleep [3]. Insomnia is the primary outcome of interest. This model (Fig. 1) illustrates both direct and indirect pathways linking APA to sleep outcomes. Although APA may regulate sleep indirectly by reducing pain, there is also a potential direct effect of APA on sleep, independent of pain modulation, such as via autonomic nervous system regulation. Acupoint specificity is a key conceptual mechanism that differentiates the two intervention arms and examines whether these effects are point-specific. While the T-APA group received auricular stimulation at points related to the low back in accordance with somatotopic ear mapping, the NT-APA group received stimulation at discrete points unrelated to pain. This contrast allows for assessment of the anatomical relevance of APA's effect on sleep outcomes.
Fig. 1.
Conceptual framework.
2.2. Study design and participants
This is a secondary data analysis of a three-arm randomized controlled trial (RCT) that examined the effects of 4-week APA in managing cLBP among older adults (Registration No. NCT03589703 on May 22, 2018). The parent study was approved by the Johns Hopkins Medicine Institutional Review Board (IRB00175409) and recruited community-dwelling adults aged 60 years and older who had experienced cLBP for at least three months. Participants were recruited from outpatient clinicals affiliated with academic medical centers in Baltimore, Maryland between June 2018 and December 2022. The full study protocol including complete information on the study design, timeline, measures, and participant selection has been previously published [15]. In short, a total of 272 participants were enrolled in the parent study and randomized into three groups, with 92 in the T-APA group, 91 in the NT-APA group, and 89 in the control group. For this secondary analysis, participants were selected based on the following inclusion criteria: (1) an Insomnia Severity Index (ISI) score >7, indicating presence of insomnia, (2) received 4 weeks of APA (were randomly assigned to either N-APA or NT-APA), (3) have completed the 4-week APA intervention; and (4) have completed sleep outcome questionnaire at baseline and post-intervention.
2.3. Randomization and blinding
Participants in the parent trial were randomized (1:1:1 ratio) to T-APA, NT-APA, or Control, using a pre-generated list of group assignments created by a systems analyst with statistical software. A subset of participants meeting additional eligibility criteria was included in this analysis and no further randomization was performed. Due to the nature of the intervention, in the parent study, blinding was not feasible for participants assigned to APA groups versus Control. However, participants were blinded to group assignment between the two APA arms (T-APA vs. NT-APA), as both procedures were identical in appearance, duration, and schedule. This design minimized expectancy effects and allowed for partial blinding within the intervention conditions. Data collectors were blinded to group assignments, whereas interventionists were aware of group assignments. Data analysts were not blinded to group allocation.
2.4. Intervention
2.4.1. Treatment rationale
Auricular point acupressure (APA), derived from Traditional Chinese Medicine (TCM), is a non-invasive adaptation of auricular acupuncture that involves applying small seeds to specific ear points instead of using needles. According to TCM meridian theory, the outer ear contains nerve points that correspond to specific areas of the brain, and these areas have a reflex connection with specific parts of the body [12,17]. Participants in the T-APA received ear seeds placements on auricular points specific to low back, including lower back region, Shenmen, sympathetic, and nervous subcortex points. Participants in the NT-APA group received intervention on points unrelated to low back including mouth, stomach, duodenum, internal ear, and tonsil point, which were intentionally selected for their anatomical distance from low back pain-related auricular points to prevent unintended stimulation and therapeutic effects (Fig. 2).
Fig. 2.
Selection of ear acupoints for T-APA and NT-APA group.
The figure displays the auricular acupoints selected for both the T-APA intervention and the NT-APA groups.
2.4.2. Treatment protocol
Participants received four weekly APA sessions. Each week consists of a 15-min session of interventionist-administered APA, followed by five days of self-administered stimulation of ear seeds. Bilateral ear points were selected for treatment. Participants were instructed to remove the ear seeds five days after each application. This intervention cycle was repeated over a four-week period. Detailed information on the APA treatment protocol, including the dose of treatment and intervention procedure, has been previously published [15]. The interventionists were trained by Dr. Chao Hsing Yeh, a nurse scientist and APA expert in auricular medicine, using a standardized curriculum with competency assessments and fidelity monitoring. Proficiency was assessed through written and oral exams, and interventionists were observed and mentored throughout the training process. To ensure treatment fidelity, interventionists were asked to take photos of each participant's ear after seeds placement, which were sent to the PI for comparison with the treatment protocol to ensure at least 95 % accuracy for the first 20 participants. Following this, photos were randomly selected for accuracy checks monthly throughout the study.
2.4.3. Other components of treatment
Other than the specified APA protocol, no other components of treatment (e.g., lifestyle advice, herbal medicine, moxibustion, etc.) were administered during the study. Participants were permitted to continue usual care for chronic low back pain, including medications such as opioids, during the study period. Concomitant treatments were not restricted and were monitored through assessments.
2.5. Outcomes
Data for this secondary analysis were extracted from the parent trial's dataset, including demographic and clinical characteristics, as well as pain and sleep assessments collected at baseline and immediately following a 4-week intervention. Primary outcomes were insomnia severity, sleep disturbance, pain intensity, and pain interference.
Insomnia severity was assessed using the Insomnia Severity Index (ISI) at baseline and post-intervention. The ISI is a self-reported instrument that evaluates difficulties with sleep onset, sleep maintenance, and early awakening, as well as sleep satisfaction, the impact of sleep disturbance on daily functioning, perceived severity of sleep problems, and distress related to sleep issues. It consists of seven items, each rated on a Likert scale from 0 to 4, with total scores ranging from 0 to 28, where higher scores indicate more severe insomnia. The ISI has demonstrated strong psychometric properties, with high internal consistency (α = 0.74) [18].
Sleep disturbance was evaluated using the sleep disturbance domain of the Patient-Reported Outcomes Measurement Information System (PROMIS)-29, a validated self-reported tool developed by the National Institutes of Health. This domain consists of four items, each rated on a 5-point Likert scale, assessing self-reported overall sleep quality. The total raw score ranges from 4 to 20, which is then converted to a standardized T-score (typically ranging from 40 to 60), with higher scores indicating greater sleep disturbance. The PROMIS-29 sleep disturbance domain has demonstrated good internal consistency (α = 0.77–0.88) [19].
Pain intensity was assessed using a single numeric rating scale (NRS) item from the PROMIS-29. The item is a single question where patients are asked to rate their pain level on a scale from 0 to 10. The scale is designed to measure the average pain experienced over the past seven days, with 0 representing “no pain" and 10 corresponding to “the worst imaginable pain”, with higher scores indicating greater level of pain severity.
Pain interference was measured using the pain interference domain of PROMIS-29. This domain consists of 4 questions with five response options rating from 1 to 5 for each question. The instrument assesses self-reported consequences of pain on relevant aspects of one's life over the past seven days, including the extent to which pain hinders engagement with social, cognitive, emotional, physical, and recreational activities. The total raw score is calculated, ranging from 4 to 20, which is then translated to a standardized T-score, with higher scores indicating greater pain interference with daily activities, with a mean score of 50 and a standard deviation of 10. The PROMIS-29 pain interference domain has demonstrated excellent internal consistency (α = 0.95) [19].
2.6. Statistical methods
Data analysis was performed using SPSS Version 29.0.2.0 (IBM Corporation). Descriptive statistics were computed to summarize demographic and baseline clinical characteristics, reported as means and standard deviations (SD) for continuous variables and frequencies with percentages for categorical variables. Baseline comparisons between groups were conducted using appropriate statistical tests: independent t-tests for continuous variables such as age, BMI and baseline ISI scores; Chi-square tests for categorical variables, including comorbidities, gender, race, education, and employment; and Kruskal-Wallis tests for non-normally distributed variables such as smoking and opioid use.
Changes in sleep and pain-related outcomes, including insomnia severity, sleep disturbance, pain intensity and interference, were assessed within each group using paired t-tests. Given the secondary nature of this data analysis and relatively small sample size, a sensitivity analysis was conducted to assess the robustness of within-group changes. The nonparametric Wilcoxon signed-rank test was used in addition to Paired t-test to account for potential deviation from normality in sleep and pain outcomes. Consistency between these two approaches was examined to assess the stability of observed treatment effects. Mediation analysis was performed using SPSS PROCESS macro to evaluate the indirect effect of APA on sleep outcomes through pain as a mediator. A p-value less than 0.05 was considered statistically significant.
2.7. Sample size and power analysis
This secondary data analysis used an existing dataset from the parent trial that evaluated pain intensity, pain interference, and physical function at one-month post-intervention with a total of 272 participants (90 % statistical power, Cohen's d = 0.65 for function, 30 % attrition assumed). As this was a secondary analysis, no additional sample size calculation was performed; the sample size of this analysis was determined by the number of eligible participants with complete data for the outcomes of interest.
3. Results
A total of 99 participants who met the inclusion criteria were selected for this secondary data analysis to investigate the effectiveness of acupressure at different ear acupoints on insomnia. Of these, 54 participants in the NT-APA group and 45 participants in the T-APA group completed the post-intervention assessment and were included in the final analysis (Fig. 3).
Fig. 3.
Modified CONSORT diagram for the secondary analysis.
3.1. Baseline demographic and clinical characteristics
To assess potential selection bias, we first compared participants who met the inclusion criteria to those who were not selected. Baseline characteristics, including age, BMI, number of comorbidities, BMI category, gender, race/ethnicity, education, employment, smoke and opioid use were examined across the two groups (Table 1). No statistically significant differences were observed between the selected and non-selected participants across these variables (p > 0.05).
Table 1.
Demographic and Baseline Clinical Characteristics of selected and non-selected participants.
| Variables | Categories | Non-Selected participants (n = 173) | Selected Participants (n = 99) | t/Chi-Square | p |
|---|---|---|---|---|---|
| Age (Mean ± SD) | 70.28 ± 7.36 | 69.10 ± 6.73 | 1.31† | 0.19 | |
| BMI (Mean ± SD) | 31.21 ± 8.10 | 31.33 ± 8.46 | −0.12† | 0.91 | |
| BMI cat n (%) | <30 | 83 (48 %) | 48 (48 %) | 2.33‡ | 0.31 |
| ≥30 | 86 (50 %) | 51 (52 %) | |||
| Gender n (%) | Female | 117 (68 %) | 57 (58 %) | 2.81‡ | 0.25 |
| Male | 55 (32 %) | 41 (41 %) | |||
| Race n (%) | Non-white | 108 (62 %) | 60 (61 %) | 0.10‡ | 0.95 |
| White | 62 (36 %) | 37 (37 %) | |||
| Ethnicity n (%) | Hispanic or Latino | 4 (2 %) | 0 (0 %) | 2.35‡ | 0.31 |
| Non-Hispanic or Latino | 137 (79 %) | 81 (82 %) | |||
| Unreported | 32 (18 %) | 18 (18 %) | |||
| Education n (%) | Without degree | 86 (50 %) | 62 (63 %) | 2.60‡ | 0.11 |
| With degree | 78 (45 %) | 37 (37 %) | |||
| Employment n (%) | Not working now | 148 (86 %) | 92 (93 %) | 3.30‡ | 0.07 |
| Working now | 25 (14 %) | 7 (7 %) | |||
| Number of Comorbidities n (%) | 0 | 89 (51 %) | 39 (39 %) | 3.67‡ | 0.06 |
| ≥1 | 84 (49 %) | 60 (61 %) | |||
| Smoke n (%) | Never smoked | 72 (42 %) | 31 (31 %) | 4.97‡ | 0.08 |
| Current smoker | 24 (14 %) | 23 (23 %) | |||
| Quit smoking | 77 (45 %) | 45 (45 %) | |||
| Opioid Use n (%) | No | 96 (55 %) | 43 (43 %) | 3.63‡ | 0.16 |
| Yes | 69 (40 %) | 52 (53 %) | |||
| Not sure | 8 (5 %) | 4 (4 %) | |||
Notes: SD: standard deviation. Values are presented as Mean ± SD for continuous variables and n (%) for categorical variables. †Independent samples t-test; ‡ Chi-Square test.
Comparisons of baseline characteristics between the T-APA and NT-APA groups. Most variables were similar between groups (Table 2). Mean age (70.29 ± 6.72 vs 68.11 ± 6.63) and BMI (32.66 ± 9.79 vs 30.22 ± 7.07) did not differ, nor did sex, race, education, employment, smoking, opioid use, or APA use parameters (all p > 0.05). Mean ISI scores were comparable at baseline (T-APA 13.69 ± 3.71; NT-APA 14.22 ± 5.18; p = 0.55). However, the distribution of ISI severity categories differed significantly (χ2 = 8.35, p < 0.05), with a higher proportion classified as “severe” in NT-APA. On average, ISI means fell in the subthreshold-to-borderline moderate range at baseline. In addition, ethnicity differed due to missingness, more NT-APA participants did not report ethnicity (30 % vs 7 %; p < 0.05), suggesting a reporting imbalance rather than a true distributional difference. These baseline imbalances (ISI severity categories; ethnicity missingness) may influence change estimates and should be considered when interpreting between-group differences.
Table 2.
Comparisons of Demographic and clinical characteristics between the T-APA and NT-APA group.
| Variables | Categories | T-APA (n = 45) | NT-APA (n = 54) | t/Chi-Square | p |
|---|---|---|---|---|---|
| Age (Mean ± SD) | 70.29 ± 6.72 | 68.11 ± 6.63 | 1.62† | 0.11 | |
| BMI (Mean ± SD) | 32.66 ± 9.79 | 30.22 ± 7.07 | 1.43† | 0.16 | |
| BMI cat n (%) | <30 | 20 (44 %) | 28 (52 %) | 0.54‡ | 0.46 |
| ≥30 | 25 (56 %) | 26 (48 %) | |||
| Gender n (%) | Female | 26 (58 %) | 31 (57 %) | 1.24‡ | 0.54 |
| Male | 18 (40 %) | 23 (43 %) | |||
| Race n (%) | Non-white | 24 (53 %) | 36 (67 %) | 1.84‡ | 0.39 |
| White | 20 (44 %) | 17 (31 %) | |||
| Ethnicity n (%) | Non-Hispanic or Latino | 42 (93 %) | 38 (70 %) | 8.35‡ | 0.004 |
| Hispanic or Latino | 0 | 0 | |||
| Unreported | 3 (7 %) | 16 (30 %) | |||
| Education n (%) | Without degree | 24 (53 %) | 38 (70 %) | 3.04‡ | 0.08 |
| With degree | 21 (47 %) | 16 (30 %) | |||
| Employment n (%) | Not working now | 43 (96 %) | 49 (91 %) | 0.92‡ | 0.34 |
| Working now | 2 (4 %) | 5 (9 %) | |||
| Number of Comorbidities n (%) | 0 | 16 (36 %) | 23 (43 %) | 0.51‡ | 0.48 |
| ≥1 | 29 (64 %) | 31 (57 %) | |||
| Smoke n (%) | Never smoked | 17 (38 %) | 14 (26 %) | 1.66‡ | 0.44 |
| Current smoker | 9 (20 %) | 14 (26 %) | |||
| Quit smoking | 19 (42 %) | 26 (48 %) | |||
| Opioid Use n (%) | No | 16 (36 %) | 27 (50 %) | 2.09‡ | 0.35 |
| Yes | 27 (60 %) | 25 (46 %) | |||
| Insomnia Severity (Mean ± SD) | 13.69 ± 3.71 | 14.22 ± 5.18 | −0.60† | 0.55 | |
| Insomnia Severity n (%) | Subthreshold | 25 (56 %) | 33 (61 %) | 8.34‡ | 0.02 |
| Moderate | 19 (42 %) | 12 (22 %) | |||
| Severe | 1 (2 %) | 9 (17 %) | |||
| APA Frequency, times/day (Mean ± SD) | 6.04 ± 20.46 | 4.99 ± 7.49 | 0.68† | 0.49 | |
| APA Duration, mins/session (Mean ± SD) | 2.80 ± 0.96 | 4.04 ± 8.36 | 0.001† | 0.05 | |
Notes: SD: standard deviation. Values are presented as Mean ± SD for continuous variables and n (%) for categorical variables. †Independent samples t-test; ‡ Chi-Square test.
3.2. Pre- and post-changes in sleep and pain outcomes within T-APA and NT-APA group
To evaluate changes in sleep and pain-related outcomes, paired T-tests were conducted within each group comparing pre- and post-intervention scores on the ISI, sleep disturbance, pain intensity, and interference (Table 3). In the T-APA group, insomnia severity, measured by the Insomnia Severity Index (ISI), decreased by 11 % from baseline to post-intervention, although this change was not statistically significant (p = 0.095, d = 0.25). However, PROMIS-29 sleep disturbance scores showed a significant decrease (p = 0.048) with a moderate effect size (d = 0.30). Significant reductions were observed in both pain intensity and pain interference with respective decreases of 8 % and 28 % (p < 0.001 for both), with moderate to large effect sizes (d = 0.89 and 0.78, respectively).
Table 3.
Pre-to post-intervention changes in ISI, sleep disturbance, and pain (T-APA and NT-APA arms).
| Outcomes | T-APA (n = 45) |
NT-APA (n = 54) |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Study Visit (Mean ± SD) |
Change (T5-T1) |
Study Visit (Mean ± SD) |
Change (T5-T1) |
|||||||
| Pre (T1) | Post (T5) | % | p | Effect Size | Pre (T1) | Post (T5) | % | p | Effect Size | |
| Insomnia Severity Index | 13.69 ± 3.71 | 12.24 ± 5.57 | −11 | 0.095 | 0.25 | 14.26 ± 5.22 | 11.64 ± 5.94 | −18 | <0.001 | 0.50 |
| Sleep Disturbance | 58.39 ± 5.56 | 55.39 ± 8.66 | −5 | 0.048 | 0.30 | 58.32 ± 6.67 | 55.10 ± 6.96 | −6 | <0.001 | 0.55 |
| Pain intensity | 6.07 ± 1.59 | 4.34 ± 2.43 | −28 | <0.001 | 0.89 | 6.34 ± 2.04 | 4.15 ± 2.55 | −35 | <0.001 | 0.93 |
| Pain interference | 63.72 ± 5.81 | 58.58 ± 6.76 | −8 | <0.001 | 0.78 | 64.52 ± 6.07 | 58.31 ± 7.81 | −10 | <0.001 | 0.73 |
Note: Bold values are significant values (p < 0.05).
% change = ((T5−T1)/T1) × 100; negative values indicate improvement (reduction in severity). p values are from two-sided paired t-tests within group (α = 0.05). Effect size is Cohen's d for paired samples (mean change ÷ SD of the change; ≈0.2 small, 0.5 moderate, 0.8 large).
The NT-APA group demonstrated significant reductions across all sleep and pain-related outcomes. Both the ISI and PROMIS-29 sleep disturbance scores significantly decreased with moderate effect size (p < 0.001, d = 0.50; p < 0.001, d = 0.55). ISI score decreased by 18 % and sleep disturbance scores decreased by 6 %. Similarly, pain intensity and interference decreased significantly by 10 % and 35 %, respectively (p < 0.001 for both), with moderate to large effect sizes (d = 0.73 and 0.93, respectively). Overall, results suggest that both T-APA and NT-APA groups experienced improvements in sleep disturbance and pain, with the NT-APA group demonstrating significant improvement (p < 0.001) in insomnia severity.
3.3. Sensitivity analysis
To assess the robustness of the within-group findings, we conducted Wilcoxon signed-rank tests as a nonparametric sensitivity analysis. Pre-to post-intervention changes in sleep and pain outcomes for each group are summarized in Table 4. In the T-APA group, ISI scores decreased but did not reach significance (p = 0.111), whereas sleep disturbance, pain intensity, and pain interference each showed significant reductions (p ≤ 0.04). In the NT-APA group, significant improvements were observed across all outcomes (p < 0.001 for all). Overall, the Wilcoxon results are consistent with the primary paired t-test findings, confirming that both groups improved on sleep disturbance and pain outcomes, with the NT-APA group additionally showing a significant reduction in insomnia severity.
Table 4.
Nonparametric sensitivity analysis (Wilcoxon signed-rank test) of pre-to post-intervention changes by group.
| Outcomes | T-APA (n = 45) |
NT-APA (n = 54) |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Study Visit (Mean ± SD) |
Wilcoxon signed Rank Test |
Study Visit (Mean ± SD) |
Wilcoxon signed Rank Test |
|||||||
| Pre (T1) | Post (T5) | Z | p | Effect Size | Pre (T1) | Post (T5) | Z | p | Effect Size | |
| Insomnia Severity Index | 13.69 ± 3.71 | 12.24 ± 5.57 | −1.60 | 0.111 | 0.24 | 14.26 ± 5.22 | 11.64 ± 5.94 | −3.45 | <0.001 | 0.47 |
| Sleep Disturbance | 58.39 ± 5.56 | 55.39 ± 8.66 | −2.05 | 0.04 | 0.31 | 58.32 ± 6.67 | 55.10 ± 6.96 | −3.85 | <0.001 | 0.52 |
| Pain intensity | 6.07 ± 1.59 | 4.34 ± 2.43 | −4.67 | <0.001 | 0.70 | 6.34 ± 2.04 | 4.15 ± 2.55 | −5.24 | <0.001 | 0.72 |
| Pain interference | 63.72 ± 5.81 | 58.58 ± 6.76 | −4.37 | <0.001 | 0.65 | 64.52 ± 6.07 | 58.31 ± 7.81 | −4.99 | <0.001 | 0.68 |
Note: Bold values are significant values (p < 0.05).
Z and p from two-sided Wilcoxon signed-rank tests within group (α = 0.05). Effect size r was computed as Z/√ (N pairs) and interpreted as ≈0.1 small, 0.3 medium, 0.5 large.
3.4. Mediation effect between APA, pain and insomnia
The mediation analysis revealed that the indirect effects of acupressure on sleep outcomes measured by Insomnia Severity Index and Sleep Disturbance, mediated by pain-related variables including pain intensity and pain interference were not statistically significant (p > 0.05). Specifically, the result demonstrated that the indirect effect of acupressure on ISI through pain intensity and pain interference were both insignificant (p = 0.673 and p = 0.825). Similarly, the indirect effects of acupressure on PROMIS-29 Sleep Disturbance mediated by average pain intensity and pain interference also showed no significance (p = 0.672 and p = 0.874). These findings indicated that both pain intensity and pain interference did not significantly mediate the relationship between APA and sleep outcomes (Table 5).
Table 5.
Mediation Analysis: The indirect effect of pain on the relationship between APA and Sleep outcomes.
| Mediator | Outcome | Indirect Effect | p | 95 % CI | Direct Effect | p | 95 % CI |
|---|---|---|---|---|---|---|---|
| Pain intensity | Insomnia Severity | −0.149 | 0.673 | [-0.842, 0.544] | 0.658 | 0.003 | [0.217, 1.100] |
| Sleep Disturbance | −0.234 | 0.672 | [-1.317, 0.849] | 1.030 | 0.001 | [0.442, 1.618] | |
| Pain interference | Insomnia Severity | −0.081 | 0.825 | [-0.800, 0.638] | 0.232 | 0.002 | [0.085, 0.381] |
| Sleep Disturbance | −0.059 | 0.874 | [-0.788, 0.670] | 0.217 | 0.037 | [0.013, 0.421] |
4. Discussion
4.1. Main findings
This secondary analysis provides exploratory evidence that APA may improve sleep-related outcomes in older adults with cLBP. Both T-APA (somatotopic points corresponding to low back) and NT-APA (gastrointestinal-related points) groups showed significant within-group improvements in PROMIS sleep disturbance and pain outcomes after a 4-week APA intervention. Only the NT-APA group showed significantly greater improvements in insomnia severity measured by the ISI. However, the parent trial was not powered for sleep outcomes, and the analytic sample was modest (n = 99), limiting precision, particularly for between-arm comparisons. In addition, baseline ISI severity categories differed significantly between groups (more “severe” cases in NT-APA), although baseline mean ISI did not differ; this pattern could contribute to greater ISI change in NT-APA via regression to the mean or expectancy/nonspecific effects, rather than acupoint specificity alone. To assess robustness, we conducted nonparametric sensitivity analyses (Wilcoxon signed-rank), which replicated the primary paired t-test results, including the significant ISI reduction in NT-APA.
4.1.1. APA and pain management
The observed improvements in pain intensity and interference are consistent with previous research supporting APA as an effective modality for managing chronic pain [13,20,21]. Prior studies have highlighted the physiological underpinnings of APA, which may include modulation of inflammatory markers such as IL-2 and β-endorphins, activation of endogenous pain inhibition pathways, and regulation of autonomic nervous system responses [22,23]. Our results replicate and reinforce these findings, as both T-APA and NT-APA groups showed substantial reductions in pain-related outcomes, with large effect sizes ranging from 0.73 to 0.93.
4.1.2. APA and sleep outcomes
This study extends prior work by examining APA's effects on sleep outcomes in older adults with chronic pain. While insomnia frequently coexists with chronic pain, it is often underassessed in pain-focused trials. In our analysis, both groups demonstrated within-group improvements in PROMIS sleep disturbance, and the NT-APA group showed greater improvement in ISI scores. These findings suggest that APA may benefit sleep, although the mechanisms warrant further investigation. The unexpected finding that NT-APA produced greater improvements in insomnia severity than T-APA should be interpreted cautiously. This pattern raises questions regarding acupoint specificity and highlights the possibility that nonspecific or expectancy-related effects may have contributed to the observed outcomes. Prior acupuncture research has shown that tactile stimulation, therapist attention, and participant expectation can elicit clinically meaningful improvements even in sham conditions [24,25]. Since both interventions involved tactile stimulation and therapist interaction, improvements may partially reflect effects of attentional engagement, or regression to the mean.
4.1.3. Potential mechanisms beyond pain mediation
One exploratory finding from the mediation analysis was that reductions in pain did not appear to mediate the observed changes in sleep outcomes. This raises the possibility that auricular point acupressure (APA) may influence sleep through mechanisms that extend beyond pain relief. Given the exploratory nature of these analyses, the potential pathways discussed below should be viewed as hypotheses requiring further validation (Fig. 4).
Fig. 4.
Potential pathways between APA, pain, and sleep.
One hypothesis is that auricular stimulation may modulate the central autonomic network, which contributes to circadian regulation and sleep–wake balance. Prior studies have suggested that stimulation of auricular points such as Shenmen and the sympathetic point may enhance parasympathetic tone, reduce hyperarousal, and influence melatonin secretion, processes relevant to insomnia pathophysiology [12,17]. Another possibility is that the non-targeted acupoints used in the NT-APA group, although not selected for low-back pain, might have produced broader autonomic or visceral effects. Traditional Chinese Medicine posits that gastrointestinal harmony supports restorative sleep, and recent work in neuroscience highlights the emerging concept of the gut–brain–sleep axis [26]. Because several NT-APA points were located on the ear concha, an area innervated by the auricular branch of the vagus nerve, it is plausible that mild vagal stimulation contributed indirectly to sleep regulation. Finally, in the context of Dr. Paul Nogier's three-phase auricular mapping system [27], some NT-APA points correspond to regions implicated in autonomic and emotional regulation (Phase 2). Stimulation of these areas could theoretically influence sleep through stress-related or parasympathetic pathways [28]. While intriguing, these interpretations are speculative and not directly tested in this study. Future mechanistic research integrating physiological markers, such as heart-rate variability, salivary cortisol, or melatonin, will be necessary to determine whether these hypothesized pathways underlie APA's effects on sleep and to clarify whether specific auricular zones differentially modulate sleep versus pain processes.
4.1.4. Variability in sleep outcome and measures
Although the T-APA group did not show a statistically significant change in ISI scores, improvements in PROMIS-29 Sleep Disturbance scores suggested changes in perceived overall sleep quality. The discrepancy between these two measures may reflect differences in their conceptual focus: the ISI targets core insomnia symptoms such as sleep initiation, maintenance, and daytime impact [29], whereas the PROMIS-29 assesses broader perceptions of sleep quality and satisfaction [30]. It is possible that participants experienced subjective improvements in sleep without corresponding changes in specific insomnia symptoms. These findings suggest the value of including multiple validated instruments when assessing sleep outcomes, as distinct tools may capture complementary dimensions of sleep experience [[30], [31], [32]].
4.2. Strengths and limitations
This study has several strengths. First, it leveraged data from a rigorously conducted randomized controlled trial with standardized intervention delivery, fidelity monitoring, and detailed documentation of acupoint placement verified by an expert in auricular point acupressure. Second, the inclusion of both targeted and non-targeted APA groups provided a unique opportunity to explore the role of acupoint specificity and to compare physiologically versus nonspecifically selected points under otherwise identical procedures. Third, the use of validated and widely accepted patient-reported outcome measures for insomnia, sleep disturbance, and pain enhanced the reliability and clinical relevance of the findings. Fourth, by incorporating both parametric and nonparametric sensitivity analyses, the study ensured robustness of results despite modest sample size and potential deviations from normality. Finally, the mediation analysis offered novel, hypothesis-generating insights into possible mechanisms linking APA, pain, and sleep, an area that remains underexplored in integrative symptom science.
Several limitations should be acknowledged. First, as a secondary analysis, the study was not originally powered to detect differences in sleep outcomes; therefore, all findings should be interpreted as exploratory and hypothesis-generating. Second, the sample size was small, which limited precision and statistical power, particularly for between-group comparisons and mediation models. Third, there were baseline imbalances between groups, including differences in ISI severity category distribution and missing ethnicity data, which may have influenced observed changes and limited comparability between groups. Fourth, although participants were blinded to group assignment between the T-APA and NT-APA interventions, expectancy and nonspecific effects cannot be fully ruled out given the tactile and interactive nature of APA. Fifth, sleep outcomes were self-reported using the ISI and PROMIS-29 rather than objective measures such as actigraphy or polysomnography, which could introduce reporting bias. Sixth, concurrent use of medications and other pain management strategies was not restricted, which may have confounded the observed associations. Lastly, as this study only assessed short-term (4-week) outcomes, the durability of APA's effects on sleep and pain over time remains unknown.
4.3. Future directions
Future studies should use APA protocols that include acupoints specifically recommended to promote sleep regulation. Incorporating auricular points traditionally associated with insomnia, rather than pain-related points, may allow for a more precise evaluation of point-specific effects on sleep outcomes. Larger, prospectively powered randomized controlled trials focused on sleep are needed to confirm these exploratory findings. Objective assessments such as actigraphy or polysomnography should be used alongside self-reported measures to validate physiological effects. The mechanistic discussion presented in this study is speculative, reflecting the possible involvement of multiple interacting systems; however, the actual mechanisms remain to be clarified through dedicated mechanistic research. Therefore, studies integrating biomarkers of autonomic and neuroendocrine function, including cortisol, melatonin, and heart rate variability, are warranted to identify the physiological pathways underlying APA's effects on sleep. Longer intervention periods and follow-up assessments are also needed to determine the durability of effects, while qualitative or mixed-methods approaches could enhance understanding of participant experience, expectancy, and adherence to APA in real-world settings.
5. Conclusion
In conclusion, this secondary analysis provides preliminary evidence suggesting that APA, whether targeted to somatotopic regions associated with low back pain or non-targeted to gastrointestinal points, may improve sleep disturbance and insomnia in older adults with cLBP. Both APA protocols were associated with significant improvements in sleep and pain outcomes, with the non-targeted group demonstrating greater effects on insomnia severity. Importantly, sleep improvements appeared to occur independently of pain reduction, suggesting potential systemic or neurophysiological mechanisms beyond traditional somatotopic targeting. While these findings are promising, they should be interpreted with caution due to the limitations of secondary analysis, including the absence of objective sleep measures, limited statistical power for sleep-specific outcomes, and small sample size. Future prospective studies with larger samples, multimodal sleep assessments, longer follow-up periods, and biomarker assessments are needed to understand APA's mechanisms of action on sleep and its own long-term effects. Nonetheless, APA shows promise as a safe, feasible, and accessible intervention that may enhance nonpharmacologic strategies for managing both chronic pain and insomnia in older adults.
CRediT authorship contribution statement
Jingyu Zhang: Writing – original draft, Visualization, Project administration, Formal analysis, Data curation. Giulia Castelli: Writing – original draft, Visualization. Aomei Shen: Visualization, Formal analysis, Data curation. Junxin Li: Writing – review & editing, Validation. Jennifer Kawi: Writing – review & editing, Validation. Hulin Wu: Writing – review & editing, Validation. Paul Christo: Writing – review & editing. Claudia M. Campbell: Writing – review & editing, Validation. Johannes Thrul: Writing – review & editing. Constance M. Johnson: Writing – review & editing, Validation, Supervision, Funding acquisition. Nada Lukkahatai: Writing – review & editing, Validation, Supervision, Methodology, Investigation, Funding acquisition, Conceptualization.
Data availability statement
The full trial protocol and statistical analysis plan are publicly available on ClinicalTrials.gov (NCT03589703) and have been published in the protocol paper [18] in Trials. De-identified individual participant data (IPD), the data dictionary, and the statistical code used in this secondary analysis are available from the corresponding author upon reasonable request. Access to these materials will be provided in accordance with institutional policies, ethical considerations, and applicable data use agreements.
Ethics statement
The study was approved by the institutional review board of Johns Hopkins Medicine (IRB00175409). All procedures were performed in compliance with relevant laws and institutional guidelines. The written informed consent has been obtained for all study participants prior to participation.
Funding Source(s)
This is a secondary data analysis of a parent study supported by the National Institute of Aging (R01AG056587).
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgement
The authors acknowledge that this study is funded by a grant from the National Institutes of Health;National Institute on Aging, United States (R01AG056587).
It is with deep sadness that we acknowledge the passing of our esteemed Principal Investigator, Professor Dr. Chao Hsing Yeh, whose exceptional mentorship, leadership, and scholarly vision were foundational to the conception and execution of this study. Although she is no longer with us, her legacy lives on in every aspect of this manuscript and in the hearts of all who had the privilege to work with her. This manuscript is dedicated to her memory, as a testament to her lasting impact on our lives and our work. We are profoundly grateful and honored to have been mentored by her and are committed to carrying forward her passion for research and scientific excellence.
We also extend our sincere appreciation to the research staff for their dedication and effort throughout the course of this study. Their contributions were essential to the successful execution of the research. Finally, we express our deepest gratitude to all the patients who participated in this study. Their willingness and involvement to contribute to research has been invaluable in advancing our understanding of auricular point acupressure and its potential clinical benefits.
Glossary
- APA
Auricular Point Acupressure
- T-APA
Targeted Auricular Point Acupressure
- NT-APA
Non-Targeted Auricular Point Acupressure
- cLBP
Chronic Low Back Pain
- RCT
Randomized Controlled Trial
- ISI
Insomnia Severity Index
- PROMIS-29
Patient-Reported Outcomes Measurement Information System-29 items
- TCM
Traditional Chinese Medicine
- SD
Standard Deviation
- CI
Confidence Interval
References
- 1.Organization WH, editor. International classification of diseases. eleventh ed. World Health Organization; 2022. [Google Scholar]
- 2.Morin C.M., Jarrin D.C. Epidemiology of insomnia: prevalence, course, risk factors, and public health burden. Sleep medicine clinics. 2022;17:173–191. doi: 10.1016/j.jsmc.2022.03.003. [DOI] [PubMed] [Google Scholar]
- 3.Haack M., Simpson N., Sethna N., Kaur S., Mullington J. Sleep deficiency and chronic pain: potential underlying mechanisms and clinical implications. Neuropsychopharmacology. 2020;45:205–216. doi: 10.1038/s41386-019-0439-z. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Hu L., Wang E.J.-H. Sleep as a therapeutic target for pain management. Curr Pain Headache Rep. 2023;27:131–141. doi: 10.1007/s11916-023-01115-4. [DOI] [PubMed] [Google Scholar]
- 5.Alessandri-Bonetti A., Sangalli L., Boggero I.A. Relationship between insomnia and pain in patients with chronic orofacial pain. Pain Med. 2024;25:319–326. doi: 10.1093/pm/pnae003. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Aroke E.N., Wiggins A.M., Hobson J.M., Srinivasasainagendra V., Quinn T.L., Kottae P., et al. The pace of biological aging helps explain the association between insomnia and chronic low back pain. Mol Pain. 2023;19 doi: 10.1177/17448069231210648. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Edinger J.D., Arnedt J.T., Bertisch S.M., Carney C.E., Harrington J.J., Lichstein K.L., et al. Behavioral and psychological treatments for chronic insomnia disorder in adults: an American academy of sleep medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med. 2021;17:263–298. doi: 10.5664/jcsm.8988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Furukawa Y., Sakata M., Yamamoto R., Nakajima S., Kikuchi S., Inoue M., et al. Components and delivery formats of cognitive behavioral therapy for chronic insomnia in adults. JAMA Psychiatry. 2024;81:357. doi: 10.1001/jamapsychiatry.2023.5060. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Sateia M.J., Buysse D.J., Krystal A.D., Neubauer D.N., Heald J.L. Clinical practice guideline for the pharmacologic treatment of chronic insomnia in adults: an American academy of sleep medicine clinical practice guideline. J Clin Sleep Med : JCSM : Off Publ Am Acad Sleep Med. 2017;13:307–349. doi: 10.5664/jcsm.6470. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Gordon N.P., Yao J.H., Brickner L.A., Lo J.C. Prevalence of sleep-related problems and risks in a community-dwelling older adult population: a cross-sectional survey-based study. BMC Public Health. 2022;22:2045. doi: 10.1186/s12889-022-14443-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Riemann D., Nissen C., Palagini L., Otte A., Perlis M.L., Spiegelhalder K. The neurobiology, investigation, and treatment of chronic insomnia. Lancet Neurol. 2015;14:547–558. doi: 10.1016/S1474-4422(15)00021-6. [DOI] [PubMed] [Google Scholar]
- 12.Dincer B., İnangil D., İnangil G., Bahçecik N., Ayaz E.Y., Arslanoğlu A., Keskinler M.V., Kabuk A., Özkan G. The effect of acupressure on sleep quality of older people: a systematic review and meta-analysis of randomized controlled trials. Explore. 2022;18:635–645. doi: 10.1016/j.explore.2021.11.010. [DOI] [PubMed] [Google Scholar]
- 13.Huang X.R., Xu M., Xu Y., Wang S.J., Ni F.L. Auricular acupressure for insomnia in women with breast cancer: a systematic review and meta-analysis of randomized controlled trials. Medicine (Baltim) 2025;104 doi: 10.1097/MD.0000000000041498. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Jun L., Xiong L., Wen Y., Yongxiang W. Effectiveness of applying auricular acupressure to treat insomnia: a systematic review and meta-analysis. Front Sleep. 2024;3 [Google Scholar]
- 15.Yeh C.H., Li C., Glick R., Schlenk E.A., Albers K., Suen L.K., et al. A prospective randomized controlled study of auricular point acupressure to manage chronic low back pain in older adults: study protocol. Trials. 2020;21:99. doi: 10.1186/s13063-019-4016-x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Kawi J., Yeh C.H., Lukkahatai N., Wu H., Morone N.E., Glick R., et al. Auricular point acupressure for older adults with chronic low back pain: a randomized controlled trial. Pain Med. 2025;26:515–526. doi: 10.1093/pm/pnaf035. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.He J.K., Jia B.H., Wang Y., Li S.Y., Zhao B., Zhou Z.G., et al. Transcutaneous auricular vagus nerve stimulation modulates the prefrontal cortex in chronic insomnia patients: fMRI study in the first session. Front Neurol. 2022;13 doi: 10.3389/fneur.2022.827749. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Bastien C.H., Vallières A., Morin C.M. Validation of the insomnia severity index as an outcome measure for insomnia research. Sleep Med. 2001;2:297–307. doi: 10.1016/s1389-9457(00)00065-4. [DOI] [PubMed] [Google Scholar]
- 19.Hays R.D., Spritzer K.L., Schalet B.D., Cella D. PROMIS®-29 v2.0 profile physical and mental health summary scores. Qual Life Res: Int J Qual Life Aspect Treat Care Rehabil. 2018;27:1885–1891. doi: 10.1007/s11136-018-1842-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Bahcecioglu Turan G., Ozer Z., Yanmis S., Aksoy A. The effects of self-acupressure on pain, fatigue, and sleep quality in colon and pancreatic cancer patients receiving chemotherapy: a randomized controlled study. Cancer Nurs. 2023;46:457–466. doi: 10.1097/NCC.0000000000001193. [DOI] [PubMed] [Google Scholar]
- 21.Lim Y., Park H. The effects of auricular acupressure on low back pain, neuropathy and sleep in patients with Persistent Spinal Pain Syndrome (PSPS): a single-blind, randomized placebo-controlled trial. Int J Environ Res Publ Health. 2023;20 doi: 10.3390/ijerph20031705. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Yeh C.H., Lukkahatai N., Huang X., Wu H., Wang H., Zhang J., et al. Biological correlates of the effects of auricular point acupressure on pain. Pain Manag Nurs. 2023;24:19–26. doi: 10.1016/j.pmn.2022.11.004. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Lin W.C., Yeh C.H., Chien L.C., Morone N.E., Glick R.M., Albers K.M. The anti-inflammatory actions of auricular point acupressure for chronic low back pain. Evid Based Complement Alternat Med. 2015 doi: 10.1155/2015/103570. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Efverman A. Understanding placebo and nocebo responses based on a randomized sham-controlled study on acupuncture in integrative cancer care. Integr Cancer Ther. 2024;23 doi: 10.1177/15347354241300068. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Vase L. Can insights from placebo and nocebo mechanisms studies improve the randomized controlled trial? Scand J pain. 2020;20:451–467. doi: 10.1515/sjpain-2019-0183. [DOI] [PubMed] [Google Scholar]
- 26.Mueller N.T., Liu T., Debelius J., Zhao N. The gut-brain-sleep connection in older adults: what do we learn from the microbiome? J Gerontol A Biol Sci Med Sci. 2023;78:1933–1934. doi: 10.1093/gerona/glad049. [DOI] [PubMed] [Google Scholar]
- 27.Oleson T. fourth ed. Elsevier; New York: 2014. Auriculotherapy manual: chinese and western systems of ear acupuncture. [Google Scholar]
- 28.Dos Reis L.D., Pereira Generoso L., Pereira G.S., Teixeira Baru J., Candido N.L., Maziero Capello M.G., et al. Effects of multisession prefrontal cortex tDCS or taVNS on stress, perceived stress and sleep quality: a double-blind, randomized controlled study. Front Psychol. 2024;15 doi: 10.3389/fpsyg.2024.1343413. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Wong M.L., Lau K.N.T., Espie C.A., Luik A.I., Kyle S.D., Lau E.Y.Y. Psychometric properties of the sleep condition indicator and insomnia severity index in the evaluation of insomnia disorder. Sleep Med. 2017;33:76–81. doi: 10.1016/j.sleep.2016.05.019. [DOI] [PubMed] [Google Scholar]
- 30.Brossoit R.M., Stark H.P., Crain T.L., Bodner T.E., Hammer L.B., Mohr C.D., et al. Multidimensionality of the PROMIS sleep disturbance 8b short form in working adult populations. Sleep health. 2023;9:925–932. doi: 10.1016/j.sleh.2023.08.001. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31.Du L., Langhough R., Hermann B.P., Jonaitis E., Betthauser T.J., Cody K.A., et al. Associations between self-reported sleep patterns and health, cognition and amyloid measures: results from the Wisconsin registry for Alzheimer's prevention. Brain Commun. 2023;5 doi: 10.1093/braincomms/fcad039. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32.Alsaadi S.M., McAuley J.H., Hush J.M., Bartlett D.J., Henschke N., Grunstein R.R., et al. Detecting insomnia in patients with low back pain: accuracy of four self-report sleep measures. BMC Muscoskelet Disord. 2013;14:196. doi: 10.1186/1471-2474-14-196. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The full trial protocol and statistical analysis plan are publicly available on ClinicalTrials.gov (NCT03589703) and have been published in the protocol paper [18] in Trials. De-identified individual participant data (IPD), the data dictionary, and the statistical code used in this secondary analysis are available from the corresponding author upon reasonable request. Access to these materials will be provided in accordance with institutional policies, ethical considerations, and applicable data use agreements.