title: Adherence to treatment in a Western European paediatric population with haemophilia: reliability and validity of the VERITAS-Pro scale.
abstract: Treatment adherence in haemophilia is strongly associated with quality of life and the cost-benefit of treatment. Therefore, it is important to quantify and monitor it. This study aimed to validate a translation of the VERITAS-Pro cross-culturally and analyse treatment adherence in a Dutch population of paediatric haemophilia patients. Children aged 1-18 years with haemophilia were included from three Haemophilia Treatment Centres, on prophylactic clotting factor replacement therapy for more than 1 year. Parents and adolescents were analysed separately. The adherence scale for prophylactic therapy (VERITAS-Pro) was translated according to international guidelines. This instrument contains a total of six subscales ('Time', 'Dose', 'Plan', 'Remember', 'Skip' and 'Communicate') each with four items. Lower scores reflect higher adherence. Overall response rate was 85%, leading to a study population of 60 children. Mean age was 10 years (SD 4.1). Internal consistency reliability: Mean Cronbach's alphas were adequate (>0.70) for total score and the subscales 'Skip' and 'Communicate'. Item-own subscale correlations were stronger than most item-other subscale correlations. Convergent validity: Total scores were higher for non-adherent participants compared with adherent participants according to patient infusion logs (n = 48; P < 0.05). Test-retest correlations: Significant for all scales except 'Dose' (n = 58; P < 0.01). This study demonstrates applicability of VERITAS-Pro outside the United States, as total score and most subscales effectively quantified treatment adherence in a Dutch paediatric population on prophylactic therapy. Non-adherent respondents' total scores were significantly higher, demonstrating the ability of VERITAS-Pro to identify non-adherent individuals.
authors.affiliation: Department of Paediatric Haematology, Erasmus MC - Sophia Children's Hospital, Rotterdam, Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Lock
authors.forename: H
authors.initials: H
authors.lastname: Raat
authors.forename: N
authors.initials: N
authors.lastname: Duncan
authors.forename: A
authors.initials: A
authors.lastname: Shapiro
authors.forename: M
authors.initials: M
authors.lastname: Beijlevelt
authors.forename: M
authors.initials: M
authors.lastname: Peters
authors.forename: R Y J
authors.initials: RY
authors.lastname: Tamminga
authors.forename: F W G
authors.initials: FW
authors.lastname: Leebeek
authors.forename: H A
authors.initials: HA
authors.lastname: Moll
authors.forename: M H
authors.initials: MH
authors.lastname: Cnossen
mesh_terms: D000293:Adolescent; D001779:Blood Coagulation Factors / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006467:Hemophilia A / Q000188:drug therapy*; D006801:Humans; D007223:Infant; D008297:Male; D009426:Netherlands; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D012646:Self Administration / Q000592:standards*; D011795:Surveys and Questionnaires; D014481:United States; D016903:Drug Monitoring
chemical_list: D001779:Blood Coagulation Factors
keywords: Validated Haemophilia Regimen Treatment Adherence Scale-Prophylaxis (VERITAS-Pro); adherence; children; haemophilia; reliability; validity