Cervicogenic headache is a secondary headache disorder that originates from the cervical spine and often presents with pain radiating from the neck to the head, reduced functional capacity, and impaired quality of life. In modern society, prolonged smartphone use and dependence are increasingly recognized as potential contributors to musculoskeletal problems, poor posture, psychological distress, and sleep disturbances.

This study was designed as a case-control investigation to explore the relationship between smartphone addiction (problematic smartphone use) and clinical characteristics of cervicogenic headache in comparison with healthy individuals. Participants were evaluated in the outpatient clinics of Physical Medicine and Rehabilitation and Neurology at Yozgat Bozok University.

A structured sociodemographic form was administered, and each participant completed a set of validated assessment tools. Smartphone use behavior was assessed with the Smartphone Addiction Scale-Short Form. Headache-related disability was measured with the Headache Impact Test. Cervical function was evaluated with the Neck Disability Index. Psychological status was assessed using the Hospital Anxiety and Depression Scale. Sleep quality was examined with the Jenkins Sleep Scale. Health-related quality of life was measured using the 12-item Short Form Health Survey, and pain intensity was evaluated with the Visual Analog Scale.

The study was conducted in accordance with the Declaration of Helsinki. Approval was obtained from the Clinical Research Ethics Committee, and written informed consent was provided by all participants prior to enrollment.

Cervicogenic headache is a secondary headache that arises from dysfunction or pathology of the cervical spine and associated structures. It is characterized by unilateral head and neck pain, which may radiate to the frontal or temporal regions and is often aggravated by neck movements. Cervicogenic headache is known to cause substantial functional disability, emotional distress, and reduced quality of life.

With the rapid increase in smartphone use worldwide, attention has been drawn to its possible musculoskeletal and psychological consequences. Prolonged forward head posture, repetitive neck movements, and excessive screen time may contribute to cervical dysfunction and exacerbate symptoms of cervicogenic headache. In addition, behavioral dependence on smartphones has been associated with mood disorders, sleep disturbances, and impaired daily functioning. Understanding the potential role of smartphone addiction as a modifiable factor in cervicogenic headache is therefore of clinical importance.

The present study was designed as a case-control observational protocol to investigate the association between smartphone addiction and clinical outcomes in individuals with cervicogenic headache compared with healthy controls. Data were collected in the outpatient clinics of Physical Medicine and Rehabilitation and Neurology at Yozgat Bozok University.

A standardized sociodemographic form was administered, followed by a comprehensive set of validated assessment instruments. These included the Smartphone Addiction Scale-Short Form to evaluate problematic smartphone use, the Headache Impact Test to measure the burden of headaches on daily life, the Neck Disability Index to assess functional limitations related to cervical spine disorders, the Hospital Anxiety and Depression Scale to screen for symptoms of anxiety and depression, the Jenkins Sleep Scale to evaluate sleep quality and disturbances, the 12-item Short Form Health Survey to assess physical and mental aspects of health-related quality of life, and the Visual Analog Scale to record the intensity of pain.

All assessments were performed face-to-face by trained professionals in a clinical setting. The study protocol was approved by the Clinical Research Ethics Committee. Written informed consent was obtained from each participant before enrollment, and all procedures were carried out in accordance with the principles of the Declaration of Helsinki.

Inclusion Criteria:

Adults aged 18-65 years

Literate and cognitively capable of completing questionnaires

Willing to participate and provide written informed consent

For the patient group: Diagnosis of cervicogenic headache based on the International Classification of Headache Disorders, third edition, confirmed by a neurologist

For the control group: Healthy volunteers with no known medical conditions or active complaints, age- and sex-matched with patients

Exclusion Criteria:

Comorbidities that may affect pain perception or mood, including diabetes mellitus, thyroid dysfunction, malignancy, chronic kidney disease, neurological diseases associated with neuropathic pain, rheumatoid arthritis, ankylosing spondylitis, or fibromyalgia

Illiteracy or impaired communication

Current use of medications that may interfere with outcome measures

Withdrawal of consent at any stage

Patients diagnosed with cervicogenic headache according to the International Classification of Headache Disorders, third edition, confirmed by a neurologist, were recruited from the outpatient clinics of the Departments of Physical Medicine and Rehabilitation and Neurology at Yozgat Bozok University. Age- and sex-matched healthy volunteers were recruited from the same community.

De-identified individual participant data collected for this study, including questionnaire scores and demographic variables, will be available upon reasonable request.

The datasets will be available beginning 6 months after publication of the study results and will remain accessible for 5 years thereafter.

Researchers who provide a methodologically sound proposal may request access to the de-identified datasets. Data will be shared after approval of the proposal and signing of a data access agreement. Requests should be directed to the corresponding author via the institutional email address.