Background: Non-medical data, such as the amount of time that patients and caregivers spend managing their condition, may be relevant when assessing therapeutic strategies. For chronic pediatric conditions, the time that patients and caregivers spend in seeking and providing care (which are the indirect costs in an economic evaluation) can be significantly different depending on the treatment arm. To explore methods for collecting information on the care burden for caregivers and patients, we investigated whether a patient diary provided additional information compared to retrospective investigator-led interviews and whether a diary that was completed intermittently produced more or less information than a diary completed continually. The main objective of this study was to identify which type of data collection was most effective for measuring the time spent by caregivers and for estimating indirect treatment costs over 9 months.
Methods: Start-In! is a randomized controlled trial comparing the efficacy of three strategies of real-time continuous glucose monitoring for 12 months in children and adolescents with type 1 diabetes. We designed an ancillary study to assess methods of collecting information on the time spent by patients and caregivers in managing their condition (indirect costs). Data were entered retrospectively in case report forms (CRFs) by investigators during quarterly follow-up visits, which were supplemented with diaries completed prospectively by children or caregivers either continuously or intermittently. Data about absences from school and work as well as the time that caregivers spent on diabetes care were collected and the three collection methods were compared.
Results: At the end of the 9-month study, 42% of the study participants failed to return their diary. For the diaries that were received, less than 10% of expected data were collected versus 82% during investigators'interviews. Based on all the information collected, we calculated that over 9 months, caregivers lost on average 3.9 days of working time (€786) and 4 days of personal time, i.e. the equivalent of €526, and spent around 15 min of time on care per day, i.e. the equivalent of €1700.
Conclusions: The CRFs completed by investigators during quarterly visits cannot be replaced by a diary. Completing the diaries appeared to represent an important additional burden to children and their caregivers, and the diaries provided little additional information compared to investigators' entries in the CRF.
Trial registration: ClinicalTrials.gov, NCT00949221. Registered on 30 July 2009. Registry name: Study of Insulin Therapy Augmented by Real Time Sensor in Type 1 Children and Adolescents (START-IN!).
Keywords: data collection; investigator-led interview; patient diary; time costs.