The Epidemiology of Transition into Adulthood of Rare Diseases Patients: Results from a Population-Based Registry

Abstract

Background: Despite the fact that a considerable number of patients diagnosed with childhood-onset rare diseases (RD) survive into adulthood, limited information is available on the epidemiology of this phenomenon, which has a considerable impact both on patients’ care and on the health services. This study describes the epidemiology of transition in a population of RD patients, using data from the Veneto Region Rare Diseases Registry (VRRDR), a web-based registry monitoring since 2002 a consistent number of RD in a defined area (4.9 million inhabitants). Methods: Longitudinal cohorts of patients born in the years 1988 to 1998 and enrolled in the VRRDR in their paediatric age were identified. Data referred to this group of patients, experiencing transition from paediatric to adult age during the years 2006–2016, are presented. Results: 2153 RD patients (44.1% females and 55.9% males) passed from childhood to adulthood in the study period, corresponding to a 3-fold increase from 2006 to 2016. The majority of these patients was affected by congenital anomalies (32.0%), by hematologic diseases (15.9%), eye disorders (12.1%) and neoplasms (7.9%). RD patients who experienced transition from paediatric age to adulthood represent the 9.2% of adult patients enrolled in the Registry at 31 December 2016. Conclusions: We described a subset of RD young adults experiencing transition into adulthood. The data reported can be considered as minimum values for estimating the size of this increasing population presenting specific transition needs. These figures are valuable for clinicians, patients and health planners. Public policy interventions are needed in order to promote dedicated care transition pathways in the broader framework of health policies devoted to RD.

Reply to E. Vicente et al.

“…In order to provide as robust an estimate as possible, only diseases with prevalence as an epidemiological indicator were selected, and using prevalence values from a wide geographic area were incorporated. While our resulting estimate of 3.5-5.9% does seem high compared to the 0.6% for the Veneto region derived from 331 disorders and groups of disorders from which some prevalent diseases (i.e., cystic fibrosis) are excluded [8], higher figures have been reported in other countries. Walker et al [9] and Chiu et al [10] report prevalences of 2% in Western Australia and 1.5% in Hong Kong respectively, using linked hospital data capture of 467 diseases of the >6000 rare diseases on Orphanet.…”

Regarding the estimations of people affected by rare diseases

“…Therefore, from our point of view, the figure yielded by the authors' comprehensive approach (~3.5-5.9%), not only would not be underestimated (as pointed out in the manuscript) but it seems to be overestimated. It is considerably higher than, e.g., the data provided by the Italian population register of the Veneto region (with >15-year of experience), which estimated that 0.61% of its population suffers from one of the RDs they were monitoring (58% of total included in Orphanet) [10].…”

Long-Term Neurological Outcomes of Adult Patients with Phenylketonuria before and after Newborn Screening in Japan

“…Our results also indicated that the transition to an adult internal medicine department is not easy at this time in Japan. In fact, this issue has been observed in not only Japan but also other countries [ 24 ] and for not only PKU patients but also patients with other rare diseases [ 25 ]. The explanation for this finding is that internal medicine physicians for adults have little knowledge of PKU or are unable to appropriately treat this disease.…”