This pilot-feasibility study of a cluster parallel randomized design comparing CBT-i against usual care (UC) was performed at two primary health care centers in Majorca, Spain. Patients were included if they were 18 to 65 years-old; had diagnoses of chronic insomnia according to the Insomnia Severity Index (ISI more than 8) and had insomnia longer than 3 months; and did or did not use a hypnotic medication. 25 GPs and nurses and 32 patients were randomly allocated to two groups: The outcome of the trial was improving the quality of sleep. Other primary outcomes on feasibility and applicability of the intervention were collected through nominal groups. Description of usual care was described through previous studies. Moreover we assessed recruitment process, compliance with the intervention sessions, and patient's retention.

Objectives

The primary objectives of this pilot-feasibility study were:

1. To design and adapt a brief CBT-i intervention to be provided by PCPs for the treatment of chronic insomnia in individuals who are 18 to 65 years-old.
2. To define usual care (UC) for the treatment of chronic insomnia provided by PCPs as a comparative intervention (control group).
3. To assess the training activities for the CBT-i intervention by determining GPs' and nurses' satisfaction with the content and applicability of the intervention.
4. To determine the acceptability of the intervention by GPs and nurses.
5. To assess PCPs and patient recruitment, follow-up, and adherence to the intervention The secondary objective was to assess the quality of sleep in patients after 3 months of the CBT-i.

Methods Design This pilot-feasibility study of a cluster parallel randomized design comparing CBT-I against usual care (UC) was performed from September 2014 to April 2015 at two primary health care centers of Majorca (Spain) with 56,000 registered inhabitants.

Collection of information and follow up Intervention The CBT-i intervention was developed by two family physicians (IT and CV) and two psychologists (ET and MRP-P). First, a review of the literature on the use of CBT-i was performed, with a focus on interventions applied in primary care. After the literature review, the CBT-i created by Morin [24] was adapted to our setting, in which there were fewer sessions and shorter sessions. The CBT-i included sleep hygiene counseling, stimulus control, cognitive restructuring, relaxation techniques, and benzodiazepine therapy or withdrawal (when needed). To conduct the intervention, guidelines for GPs and nurses and graphic and written materials for patients (sleep diary, registry of behavior habits, and cognitive problems) were developed.

Usual care The usual treatment for persistent insomnia in a primary care setting was previously described in two cross-sectional studies performed by general practitioners and family nurses of the Primary Care Majorca Department during 2011 and 2015

Inclusion criteria:

• 18 to 65 years-old
• Diagnoses of chronic insomnia according to the Insomnia Severity Index (ISI equal or higher than 8) and had insomnia longer than 3 months;
• Did or did not use a hypnotic medication.

Exclusion criteria:

• Clinical diagnosis of secondary insomnia or another sleep disorder, such as restless legs syndrome, parasomnia, or alterations of the circadian rhythm (e.g., due to shift work)
• Use of a medication that could produce sleep alterations
• Severe psychiatric disorder; depression (HADS score ≥ 8) or diagnosis of major depression in the clinical records
• Suicide attempt
• Use of an antidepressant or anti-psychotic medication
• Alcohol or drug abuse during the last year
• Reception of another CBT-i
• Sleep apnea
• Dementia or presence of a cognitive deficit (Mini Mental State Evaluation score lower than 23)
• Neurodegenerative or oncological disease with poor prognosis
• Mental or physical incapacities that impeded participation in interviews
• Acute or chronic pain secondary to a rheumatic disease or another untreated chronic disease
• Pregnancy
• Participation in a previous clinical trial in the participating health centers

Data not shared