Treatments for enhancing sleep quality in fibromyalgia: a systematic review and meta-analysis.

This systematic review and meta-analysis investigated the effectiveness of two main categories of interventions for improving sleep quality in people diagnosed with fibromyalgia:

1. **Cognitive Behavioral Therapy (CBT) interventions:**

* **CBT for Insomnia (CBT-I):** A specific type of CBT tailored to address sleep difficulties, typically involving techniques like sleep restriction, stimulus control, cognitive restructuring, and sleep hygiene education.

* **CBT for Pain (CBT-P):** A broader form of CBT aimed at managing chronic pain, which might indirectly affect sleep but is not primarily focused on sleep.

2. **Pharmacological treatments (medications):**

* **Gabapentinoids:** Specifically, pregabalin (often prescribed for neuropathic pain and anxiety).

* **Sodium Oxybate:** A central nervous system depressant used to treat narcolepsy, sometimes explored for fibromyalgia.

* **Antidepressants:** Amitriptyline (a tricyclic antidepressant), milnacipran (a serotonin-norepinephrine reuptake inhibitor, SNRI), and duloxetine (another SNRI). These are often used in fibromyalgia for pain and mood, but their impact on sleep was specifically assessed here.

The primary **comparators** for these interventions were:

**Placebo medication:** For pharmacological studies, an inactive substance designed to look identical to the active drug, administered in the same way.

**Standard care or control groups:** For CBT studies, this could involve usual medical care, waitlist control, or non-specific support.

The **outcome measures** focused on various aspects of sleep quality. While the abstract doesn't list all specific tools, the methodology section indicates a preference for validated self-report tools such as:

**Jenkins Sleep Scale (JSS)**

**Medical Outcomes Study Sleep Scale (MOS-SS)**

**Pittsburgh Sleep Quality Index (PSQI)**

The review also included studies that used objective measures of sleep quality, though specific examples were not provided in the abstract. The goal was to quantify improvements in how well participants slept, how long they slept, and how refreshed they felt.

This systematic review and meta-analysis synthesized data from **47 randomized controlled trials (RCTs)**, involving a substantial total of **11,094 participants**.

The participants were individuals who had received a diagnosis of **fibromyalgia**. The studies included in the review required this diagnosis to be based on established criteria, specifically:

The American College of Rheumatology (ACR) 1990, 2010, or 2016 diagnostic criteria.

The ACTTION-APS Pain Taxonomy (AAPT) diagnostic criteria.

The German Association of the Scientific Medical Societies (AWMF) diagnostic criteria.

Key demographic characteristics of the pooled participant population were:

**Mean age:** 47.28 years (with a standard deviation of 4 years).

**Gender:** A significant majority were female, comprising 95.5% of the total participants. This high proportion of female participants is typical for fibromyalgia research, as the condition is more prevalent in women.

The **setting** for participant recruitment varied across the included studies, with reports from both hospital outpatient clinics and community settings. However, the specific methodology for recruitment was often unclear in the original studies, which is a potential limitation.

The **sample sizes** of the individual RCTs varied widely:

For pharmacological studies: The median sample size was 125 participants, with a range from 19 to 1196 participants.

For CBT studies: The median sample size was 64 participants, with a range from 26 to 148 participants.

This large number of participants across many studies provides a robust foundation for the meta-analysis, increasing the confidence in the pooled results compared to individual smaller studies. However, the predominance of female participants means the findings are most directly applicable to women with fibromyalgia.

The studies included in this systematic review and meta-analysis primarily measured sleep quality using **quantitative self-report measures**. The authors prioritized the use of validated and widely recognized sleep assessment tools to ensure consistency and comparability across different studies. When multiple sleep measurement methods were used within a single study, the reviewers preferentially selected data from these validated tools.

Specific validated self-report instruments mentioned include:

**Jenkins Sleep Scale (JSS):** A brief questionnaire assessing the frequency of sleep problems (e.g., trouble falling asleep, waking up tired) over the past month.

**Medical Outcomes Study Sleep Scale (MOS-SS):** A comprehensive scale that evaluates various dimensions of sleep, including sleep disturbance, sleep adequacy, somnolence, and snoring.

**Pittsburgh Sleep Quality Index (PSQI):** A widely used self-rated questionnaire that assesses sleep quality and disturbances over a one-month period. It comprises seven components: subjective sleep quality, sleep latency (how long it takes to fall asleep), sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Scores range from 0 to 21, with higher scores indicating poorer sleep quality.

The review also included studies that used **objective measures of sleep quality**. While the abstract does not specify which objective measures were used (e.g., polysomnography, actigraphy), their inclusion suggests an attempt to capture physiological aspects of sleep beyond subjective perception. However, the emphasis on validated self-report tools for data extraction implies that these were the most consistently available and comparable measures across the diverse set of included studies.

For the meta-analysis, when studies reported multiple sleep measurement methods, the reviewers aimed to extract the most consistently used methods within a selected study group to improve comparison. This approach helps to standardize the outcome data as much as possible, despite the inherent variability in how sleep is assessed across different research teams.

This study is a **systematic review and meta-analysis** of **randomized controlled trials (RCTs)**. This design sits at the top of the evidence hierarchy, meaning it provides the strongest evidence for cause-and-effect relationships.

**How they ran the study:**

1. **Systematic Search:** The researchers conducted a comprehensive search across five major electronic databases (PubMed, MEDLINE, Embase, Cochrane CENTRAL, and CINAHL) for studies published up to April 2023. They used specific keywords related to pharmacological treatments or CBT in fibromyalgia. This systematic approach aims to minimize publication bias and ensure all relevant studies are identified.

2. **Study Selection:**

* Initial screening involved reviewing titles and abstracts, followed by full-text review of potentially relevant articles.

* Four researchers independently reviewed papers for eligibility, resolving discrepancies through discussion to ensure consistent application of inclusion criteria.

* **Inclusion Criteria:**

* Only **original research from RCTs** were included. This is crucial because RCTs are the gold standard for testing interventions. Non-randomized trials and observational studies were excluded to maintain a high level of evidence.

* Studies had to be published in English or translated.

* Participants needed a confirmed fibromyalgia diagnosis based on established criteria (ACR 1990, 2010, 2016; ACTTION-APS; AWMF). This ensures the findings are relevant to the target population.

* Interventions had to be pharmacological or CBT, with **quantitative self-report or objective measures of sleep quality as an outcome**. Studies not directly measuring sleep were excluded.

* For pharmacological therapies, the control group had to receive a **placebo medication** of identical appearance and dosing. This is essential for blinding and isolating the drug's effect.

* For CBT studies, CBT had to be delivered by trained therapists or via internet-based programs adhering to CBT principles. Studies combining CBT with other interventions (e.g., physiotherapy) were excluded to isolate the effect of CBT itself.

3. **Risk of Bias Assessment:** Three authors independently assessed the risk of bias for each included RCT using the **Cochrane Risk of Bias tool**. This tool evaluates several domains:

* **Random sequence generation:** How participants were randomly assigned to groups (e.g., coin flip, computer generator).

* **Allocation concealment:** Whether researchers knew which group participants would be assigned to before enrollment.

* **Blinding of participants and personnel:** Whether participants and those delivering the intervention knew who was receiving treatment vs. placebo/control.

* **Blinding of outcome assessors:** Whether those measuring the results knew