RCT of a Weighted Blanket to Reduce Pain in Veterans With Chronic Pain

Chronic pain is a major health concern for returning Veterans15 and is associated with decreases in quality of life16, increased opioid use/misuse and self-injury17,18, and significant emotional toll on the patient and medical provider19. The management of pain is a high priority for the Veterans Administration (VA)20 and VA primary care providers21. In addition, chronic pain is highly comorbid with significant disturbance in sleep22, and sleep fragmentation and poor sleep, in turn, are associated with increases in pain sensitivity and pain interference23,24. Decreasing sleep disturbance among Veterans with chronic pain therefore has the potential to greatly reduce pain22, ultimately improving quality of life.

Sensory interventions may offer effective, low-cost complementary tools for chronic pain and sleep disturbance in Veterans. Deep pressure is pleasant and calming25, and reduces acute pain8 and anxiety25 in healthy adults. Weighted Blankets (WB)- blankets sewn with weighted material inside to provide widespread pressure to the body- are a low-cost wellness product used for anxiety and sleep. WBs have demonstrated large reductions in insomnia in individuals with (Cohen's d = 1.9)11 and without12 psychiatric disorders, as well as significant reductions in anxiety and sympathetic arousal26. Tm nl;phe investigators have demonstrated that 1-week of overnight WB use can also reduce chronic pain (severity/interference)27. However, effects and mechanisms of longer WB use have not been examined in individuals with pain and sleep disturbance. The investigators posit that pressure from a WB reduces pain and anxiety while falling asleep and sleeping, decreasing sleep fragmentation and sleep disturbance overnight and, in turn, decreasing pain and pain catastrophizing. The investigators therefore propose a randomized controlled trial examining the effects of WBs on pain and sleep quality in Veterans.

The two objectives of this CSR\&D Merit Review are to determine whether in Veterans with musculoskeletal chronic pain and sleep disturbance, a heavy WB versus light (control) blanket will reduce pain impact (severity/interference) and sleep disturbance, and whether improvements in sleep mediate such reductions in pain. The investigators will recruit Veterans with chronic pain and sleep disturbance from the VA San Diego Healthcare System (VASDHS) and VA San Francisco Healthcare System (VASFHS) and randomize 160 Veterans to receive either a light (3-lb; N = 80) or heavy (15-lb; N = 80) blanket. The investigators will collect measures of pain (primary), pain catastrophizing, and pain medication use, as well as sleep disturbance (primary) and sleep efficiency and total sleep time over 6 weeks of overnight use of the assigned blanket. The investigators will also explore physiological effects of WBs on sleep quality using actigraphy (exploratory) in VASDHS participants. Ecological momentary assessment (EMA) methods will be deployed via smartphone to capture study adherence. Our central hypothesis is that although both study arms will be associated with positive clinical outcomes, deeper pressure from the WB will be associated with significantly greater reductions in pain impact and sleep disturbance, with improvements in sleep mediating reductions in pain. The investigators will examine the following aims:

Aim1: Compare the efficacy of a WB versus control blanket on pain in Veterans with musculoskeletal chronic pain and sleep disturbance. Hypothesis 1a: Pain impact (severity and interference) measured by the Pain, Enjoyment of Life, and General Activity (PEG) Scale28 (primary outcome) and pain catastrophizing (Pain Catastrophizing Scale; PCS)29 will show significantly greater improvement in a group of Veterans with chronic pain over 6 weeks from nightly use of a 15-lb versus 3-lb blanket. Hypothesis 1b: Veterans with chronic pain using the 15-lb versus 3-lb blanket will show significantly greater reductions in pain medication use. Exploratory Hypothesis 1c: Pain impact of 15 vs 3-lb blanket will remain higher 12-weeks after randomization.

Aim2: Compare the efficacy of a WB versus control blanket on sleep disturbance in Veterans with musculoskeletal chronic pain and sleep disturbance. Hypothesis 2a: Veterans using the 15-lb versus 3-lb blanket will show significantly greater improvement in sleep disturbance (Insomnia Severity Index; ISI30; primary outcome measure) and sleep efficiency and total sleep time (Daily Sleep Diary31,32) over 6 weeks of use of a 15-lb versus 3-lb blanket. Exploratory Hypothesis 2b: Veterans using the 15-lb versus 3-lb blanket will show increased sleep efficiency and total sleep time (measured by actigraphy) after six weeks of use.

Aim3: Examine the mediation effect of sleep on pain. Hypothesis 3a: Decreases in sleep disturbance (Insomnia Severity Index; ISI30) will mediate reductions in pain impact (PEG28) over the 6-week intervention. Exploratory Hypothesis 3b: Improvements in sleep efficiency (actigraphy) will mediate reductions in PEG pain.

Our expected outcomes are to identify the effects of a WB on chronic pain and sleep disturbance, and the relationship between these clinical factors. The proposed research findings will have a positive impact by providing evidence for effects on chronic pain and sleep disturbance for this novel, accessible and fully remote intervention. Study results will inform both future research and treatment of chronic pain.