Association of Prophylactic Treatment With Treatment Burden and Psychosocial Variables in Patients With Hemophilia

Treatment burden will be assessed using the Spanish version of the Treatment Burden Questionnaire (TBQ). This self-administered multidimensional instrument consists of 15 items that measure the perceived burden of treatment in dimensions such as time spent, emotional impact, physical effort, medical coordination, and interference with daily life. Each item is scored on a Likert scale from 0 (no burden) to 10 (extreme burden). A total score is obtained, with higher values indicating greater perceived burden. This version has demonstrated good internal reliability in the Spanish chronic population (Cronbach's α = 0.89).

Perceived self-efficacy in health will be measured using the Spanish version of the General Self-Efficacy Scale (GSE). This questionnaire consists of 10 items with a 4-point Likert scale (1 = strongly disagree to 4 = strongly agree). It assesses the individual's general belief in their ability to cope with difficulties and manage their health. The total score ranges from 10 to 40, with higher values indicating greater self-efficacy. The scale has shown good internal consistency (Cronbach's α = 0.87) in the Spanish population.

Adherence to treatment will be assessed using the Torres scale. This structured self-report, specific for patients with hemophilia, includes 25 items, grouped into 5 dimensions: awareness of the disease, knowledge of sequelae, treatment difficulties, doctor-patient relationship, and treatment of bleeding episodes. This scale has proven to be valid and reliable for assessing adherence in these patients, with good internal consistency across all dimensions. The total score ranges from 0 to 100, with higher values indicating poorer adherence.

Sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI) in its validated Spanish version. This self-administered questionnaire assesses sleep quality over the last month through 19 items grouped into seven components (latency, duration, efficiency, disturbances, medication use, daytime dysfunction, and subjective sleep quality). Each component is scored from 0 to 3, generating an overall score from 0 to 21, where a score >5 indicates poor sleep quality. Its test-retest reliability and internal consistency have been adequate (Cronbach's α = 0.81).

Health locus of control will be measured using the Spanish version of the Multidimensional Health Locus of Control Form C (MHLC-C). This scale consists of 18 items that assess the extent to which people attribute control of their health to internal, medical or random factors. It consists of three subscales of 6 items each, scored on a scale from 1 (total disagreement) to 6 (total agreement). Each subscale generates an independent score. Validation in Spanish has shown good internal reliability (Cronbach's α > 0.70 in all three dimensions).

The sociodemographic variable age will be assessed by calculating the age (in months) from the date of birth to the date of assessment.

The clinical variable number of weekly infusions of clotting factor concentrates will be assessed by calculating the age (in months) from the date of birth to the date of assessment.

The sociodemographic variable educational level will be assessed using closed-ended questions (primary education / secondary education / university education / postgraduate education).

The sociodemographic variable 'living arrangements' will be assessed using a qualitative variable with three response options: alone / with family / with partner.

The clinical variable type of hospital where treatment is received will be a dichotomous variable, with two response options: national referral hospital-CESUR / regional referral hospital.