This cross-sectional survey was designed to estimate the self-reported prevalence of depression in a convenience sample of airline pilots in Saudi Arabia and identify associated demographic, occupational, and health behavior factors.

In Saudi Arabia, the General Authority of Civil Aviation (GACA) is responsible for establishing and overseeing health surveillance protocols for pilots. Saudi aviation medical examiners conduct thorough evaluations during mandatory occupational health visits. These examinations are typically performed at least annually for medical certification [12].

Participants were recruited from various commercial airlines in Saudi Arabia. The inclusion criterion included active pilots. Pilots were recruited through targeted outreach on social media platforms, with a focus on pilot forums and groups to ensure diverse representations. Referrals within professional networks were encouraged, and no incentives were provided for referrals to maintain voluntary participation. Approximately 500 pilots were estimated to be targeted for recruitment.

To ensure accessibility and convenience, the questionnaire was administered online. A survey link was disseminated through social media platforms, including LinkedIn, Twitter, and Facebook, allowing diverse types of participation. This mode accommodates pilots’ busy schedules, with an estimated completion time of 7 min. The data were collected over 6 weeks, from August 1, 2023, to September 12, 2023.

A structured questionnaire was developed through a literature review and expert consultation. The questionnaire comprises sections on demographic and professional characteristics, occupational information, health habits, and the Patient Health Questionnaire-9 (PHQ-9) questionnaire for depression assessment [13]. Prior to the main study, the questionnaire underwent preliminary testing through a pilot study involving 20 participants to ensure its clarity, relevance, and comprehensiveness.

The questionnaire covered various demographic variables, such as age group (< 30 years, 30–39 years, 40–49 years, ≥ 50 years), sex (male or female), marital status (single, married, divorced), self-reported weight (kg), height (cm), and the presence of chronic disease. Occupational information included position (captain or senior officer), years of experience, total flying hours (< 3,000, 3,000–5,000, 5,000–10,000, > 10,000), flying hours in the past year (< 500, 500–700, > 700), rest time between flights (< 1 h, 1–4 h, 4–24 h, > 24 h), and flight route duration (< 6 h, 6–12 h, > 12 h). The health behavior habit questions included whether the participant engaged in regular exercise, defined as exercising at least 3 times per week, exercise intensity (low, moderate, or high), smoking status (nonsmoker or smoker), and sleep duration (< 5 h, 5–8 h, or > 8 h). The survey questionnaire also included a section about musculoskeletal complaints, which were reported separately.

Depression severity was assessed via the PHQ-9 questionnaire, which categorizes scores into different severity levels. The PHQ-9 scores were categorized into five distinct severity levels: minimal depression (scores ranging from 0 to 4), mild depression (scores between 5 and 9), moderate depression (scores ranging from 10 to 14), moderately severe depression (scores ranging from 15 to 19), and severe depression (scores falling within the range of 20–27). The cutoff point for significant depression on the PHQ-9 questionnaire was defined as a score of 10 or higher, indicating the presence of moderate to severe depressive symptoms requiring clinical attention [13]. The primary outcome was the prevalence of depression among pilots. The secondary outcomes included associations between depression and demographic, occupational, and health behavior factors.

The data were analyzed via IBM SPSS Statistics version 26 (IBM Corp., Armonk, NY, USA). The chi-square test was used for comparisons between variables. Multivariable logistic regression analysis was conducted to identify independent factors associated with depression, with odds ratios (ORs) and 95% confidence intervals (CIs) estimated. All p values were calculated via two-tailed tests with an alpha level of 0.05.

To assess the potential confounding effects of age on the relationships between flying hours, years of experience, and depression, a sensitivity analysis was performed. This analysis included interaction terms between age groups and years of experience to explore whether age influenced these relationships. The results of the sensitivity analysis revealed no significant interactions, indicating that age did not substantially confound the associations between flying hours, years of experience, and depression.

Ethical approval was obtained from the Ethics Committee of King Abdulaziz University. Informed consent was obtained, ensuring voluntary participation and confidentiality. Stringent data privacy and security measures were implemented to uphold ethical standards. The participants were informed that the survey was not a diagnostic tool and encouraged them to consult their healthcare provider if they were concerned about their mental health.