Adherence determinants in cystic fibrosis: Cluster analysis of parental psychosocial, religious, and/or spiritual factors

Rationale: Cystic fibrosis is a progressive disease requiring a complex, time-consuming treatment regimen. Nonadherence may contribute to an acceleration of the disease process. Spirituality influences some parental healthcare behaviors and medical decision-making. Objectives: We hypothesized that parents of children with cystic fibrosis, when classified into groups based on adherence rates, would share certain psychosocial and religious and/or spiritual variables distinguishing them from other adherence groups. Methods: We conducted a multisite, prospective, observational study focused on parents of children younger than 13 years old at two cystic fibrosis center sites (Site 1, n = 83; Site 2, n = 59). Religious and/or spiritual constructs, depression, and marital adjustment were measured by using previously validated questionnaires. Determinants of adherence included parental attitude toward treatment, perceived behavioral norms, motivation, and self-efficacy. Adherence patterns were measured with the Daily Phone Diary, a validated instrument used to collect adherence data. Cluster analysis identified discrete adherence patterns, including parents' completion of more treatments than prescribed. Measurements and Main Results: For airway clearance therapy, four adherence groups were identified: median adherence rates of 23%, 52%, 77%, and 120%. These four groups differed significantly for parental depression, sanctification of their child's body, and self-efficacy. Three adherence groups were identified for nebulized medications: median adherence rates of 35%, 82%, and 130%. These three groups differed significantly for sanctification of their child's body and self-efficacy. Conclusions: Our results indicated that parents in each group shared psychosocial and religious and/or spiritual factors that differentiated them. Therefore, conversations about adherence likely should be tailored to baseline adherence patterns. Development of efficacious religious and/or spiritual interventions that promote adherence by caregivers of children with cystic fibrosis may be useful.