title: Adherence to Prophylaxis in Adolescents and Young Adults with Severe Haemophilia: A Quantitative Study with Patients.
abstract: BACKGROUND
  haemophilia is an inherited bleeding disorder caused by a deficiency in one of the blood coagulation factors. For people affected by severe haemophilia, the deficiency can cause spontaneous internal bleeding. Most young people with severe haemophilia in the UK follow a preventative treatment regimen (prophylaxis) consisting of several intravenous injections of factor concentrate each week. There is good evidence that prophylaxis reduces bleeds whilst also improving quality of life. However, levels of adherence among young people with haemophilia reported in the existing literature vary widely and are predominately based on estimations made by healthcare professionals and parents. Additionally, drivers of (non)adherence among young people specifically have not been evidenced.
  
  
  OBJECTIVE
  to assess self-reported adherence among young people with haemophilia, provide evidence of psychosocial predictors of adherence, and to establish the associations between non-adherence and number of bleeds and hospital visits.
  
  
  METHODS
  91 participants were recruited during outpatient appointments in 13 haemophilia centres across England and Wales, and invited to complete a questionnaire assessing self-reported adherence (VERITAS-Pro), Haemophilia-related pain and impact of pain, Illness Perceptions, Beliefs about Medications, Self-efficacy, Outcome expectations, Positive and Negative Affect, and Social support. Number of hospital visits and bleeds during the previous six months were collected from medical files.
  
  
  RESULTS
  Of 78 participants with complete data, just 18% had scores indicating non-adherence. Psychosocial predictors differed between intentional (skipping) and un-intentional (forgetting) non-adherence. Overall, however, better adherence was reported where participants perceived the need for prophylaxis was greater than their concern over taking it as well as having a positive expectancy of its effectiveness, good social support and a stronger emotional reaction to having haemophilia.
  
  
  CONCLUSIONS
  The findings indicate that adherence is generally good, and that assessing illness and treatment beliefs, social support and outcome expectations may play a valuable role in identifying which individuals are at risk of non-adherence. Interventions aimed at improving adherence should particularly consider improving social support, reducing patients' concerns about prophylaxis, increasing their belief in the necessity of prophylaxis, and increasing positive outcome expectations.
authors.affiliation: Psychology and Sport Sciences Department, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, United Kingdom.
authors.forename: Sandra B
authors.identifier: http://orcid.org/0000-0001-8998-8331
authors.initials: SB
authors.lastname: van Os
authors.affiliation: Psychology and Sport Sciences Department, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, United Kingdom.
authors.forename: Nick A
authors.initials: NA
authors.lastname: Troop
authors.affiliation: Psychology and Sport Sciences Department, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, United Kingdom.
authors.forename: Keith R
authors.initials: KR
authors.lastname: Sullivan
authors.affiliation: The Royal London Hospital Haemophilia Centre, Barts Health NHS Trust, London, United Kingdom.|Barts and The London School of Medicine and Dentistry, QMUL, London, United Kingdom.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Hart
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001294:Attitude to Health; D001779:Blood Coagulation Factors / Q000627:therapeutic use*; D002648:Child; D004739:England; D006467:Hemophilia A / Q000517:prevention & control* / Q000523:psychology; D006801:Humans; D055118:Medication Adherence / Q000523:psychology; D011581:Psychological Tests; D011584:Psychology; D012944:Social Support; D011795:Surveys and Questionnaires; D014852:Wales; D055815:Young Adult; D016903:Drug Monitoring
chemical_list: D001779:Blood Coagulation Factors