Participant Disposition

A total of 104 responders were included in the survey; of these, 64 (61.5%) participants were female. The mean age was 24.4 years (95% CI 23.8–25.0), with 53 (51%) participants 18–24 years old and 51 (49%) 25–30 years old. The mean age at the time of T1D diagnosis was 11.9 years (95% CI 10.9–12.9) and the mean time elapsed since diagnosis was 12.5 years (95% CI 11.2–13.8). The mean age at the time of transition was 18.4 years (95% CI 17.8–18.9) with 61 (59%) participants ≤ 18 years and 43 (41%) participants > 18 years of age. The mean time elapsed since transition was 6.0 years (95% CI 5.3–6.8) and the time since transition ranged between 6 months and 5 years in 49 (47%) participants and was more than 5 years in 55 (53%) participants (Table 1).

Table 1 Baseline characteristics

Regarding site for care, 77 (74%) participants were followed in public hospitals before transition. For 58 (56%) participants, the first adult diabetology department was in the same institution. Overall, 65% of participants had consulted a diabetologist after the transition; a general practitioner, dietitian, pharmacist, ophthalmologist, nurse, podiatrist and psychologist/psychiatrist were consulted by smaller proportions of participants.

Transition-Triggering Event

The main event that triggered the transition was a jointly made decision with the paediatrician in 36% of participants; the remaining participants initiated the transition because of reasons such as the decision was made by the paediatrician alone, wish of parents, own wish, relocation, and paediatrician relocation or retirement and miscellaneous. Moreover, the transition started naturally at the age of 18 years in 30% of participants and lasted mostly between 2 and 6 months (33%) or less than 2 months (28%). Overall, for 72% of transitions, the adult diabetologists were consulted within a short period before the final departure from the paediatric department. The participants declared that they had one or more consultations with the adult diabetologist (47%) and/or with the paramedical team (specialized nurse, dietitian, psychologist, etc.) (45%).

Insulin Treatment Regimen Before and After Transition

Among the responders, 49% changed their insulin treatment regimen after the transition. The insulin treatment regimen with use of classic injectable pens decreased with an increase in the use of the latest-generation devices.

Treatment and Glucose Monitoring

Six months after the transition, participants tended to change their insulin administration device from the classic pen (47 to 29%) and to one of the latest-generation devices (6 to 28%) and their glucose monitoring from self-monitoring of blood glucose (48 to 32%) to intermittently scanned continuous glucose monitoring (is-CGM) (14 to 30%). However, from national care insurance coverage of is-CGM in 2017, much more participants in paediatrics had used this monitoring mode prior to transition (9% transition before 2017 vs. 21% transition after 2017). Participants who changed treatment soon after transition were more likely to change their glucose monitoring device as well versus participants who had no change of treatment (78% vs. 34%; P < 0.001).

Participant Insights: Personal Issues Faced During Transition

Almost three quarters of participants declared having experienced personal issues at the time of transition (mean of the number of issues 1.6). Moreover, one out of four participants mentioned the stress was related to school. Overall, female participants experienced slightly more issues than male participants (2.3 vs. 2.0 average mean). For the majority of participants (93%), the transition did not delay or disrupt a life plan, while for the rest of the participants (7%), the main life projects impacted were studies and travels.

Diabetes Monitoring Issues After Transition

Of the 76 participants who experienced personal issues at the time of transition, 74% experienced at least one issue with their diabetes management in the months following the transition. Personal concerns during the transition were significantly associated with new or unexpected issues in the months following the transition (P < 0.001) as presented in Fig. 1.

Fig. 1

Diabetes monitoring difficulties after transition (n = 104)

Overall, 61% of participants experienced new or unexpected issues in monitoring their diabetes after the transition. Twenty percent of all respondents identified two or more issues, which commonly included feeling alone (29%) and loss of motivation (25%) (Fig. 2).

Fig. 2

Diabetes monitoring difficulties after transition in overall population (n = 104)

Among participants who transitioned to a different institution, the feeling of loneliness after the transition was reported more often (43%) than other issues. Also, respondents who had no issues in the months following their transition reported higher mean scores for diabetes team expertise (8.8 vs. 7.6; P < 0.001), diabetes team support (8.1 vs. 7.3; P = 0.001) and relatives’ support (8.7 vs. 7.9; P < 0.001) than respondents who had issues.

Diabetes Imbalance After Transition

Overall, 56 (54%) participants did not experience any unexpected diabetes imbalance after transition. Further analysis revealed that, out of 44% of participants who experienced unusual diabetes imbalance after the transition, 8 (8%) were hospitalised because of unusual hypoglycaemia and 9 (9%) as a result of unusual hyperglycaemia, as shown in Fig. 3.

Fig. 3

Diabetes imbalance after the transition (n = 104)

Amongst participants who had one or more consultations with the diabetologists (n = 35), 17 (49%) did not experience any unexpected diabetes imbalance, while among participants who did not have any consultations with the diabetologists (n = 69), 24 (35%) did not experience any unexpected diabetes imbalance.

Participants who experienced personal issues during the transition were likely to remember having an unusual diabetes imbalance compared to those who did not experience personal issues (54% vs. 20%) in the months following the transition.

Respondents who had an unexpected diabetes imbalance gave a significantly lower score (7.6 vs. 8.5; P < 0.05) to the expertise of the adult diabetes team than those who did not have any diabetes imbalance.

Unmet Needs and Satisfaction

Overall, half of the participants who received information about transition did so from their medical team and half through other means. Overall, 17% of respondents wished they had information about diabetes management at work or school.

On average, participants used mean number of services (1.8) or tools to help them in their transition. The most used were apps (32%) and specialised websites (31%) in diabetes care. In total, 70% of respondents had a smooth transition or had no suggestions how to improve the transition process. The remaining participants (30%) identified support, good listening (8.6%) and communication between the paediatric and adult diabetes teams (5.7%) as the primary causes to improve the transition.

Participants’ Experience, Benefits and Main Concerns with the Transition

A quarter (24%) of respondents expected more autonomy from their transition. Half of the respondents (52%) expected no benefits (Table 2). The risk of less involvement of the medical team was the biggest concern of the participants about transition (ranked in top three by 43% of the respondents). The second most reported concern was having a different organisation and 10% had no apprehension (Fig. 4).

Table 2 Benefits of transition (n = 104)Fig. 4

Participants’ main concerns about transition (n = 104)

Satisfaction with the Transition

Overall, 41% reported that they were very satisfied, although some participants (8%) were rather dissatisfied with the way their transition was prepared. Participants who had a prepared transition (< 2 months or between 2 and 6 months) seemed to be more satisfied with their transition. Importantly, total satisfaction was reported in only 26% of those who reported at least one personal issue.

Key Aspects of the Transition

Meeting the adult diabetology medical team and initiating the transition process by having their diabetes under control were ranked as the two most important aspects for a successful transition by 40% and 38% participants, respectively. The main concern related to the transition was losing the benefit from relatives’ support throughout the process (14.4% of participants) (Fig. 5). Compared to participants who transitioned to another institution (47%), significantly more participants (66%) who transitioned in the same hospital believed that staying in the same hospital through transition was important (P < 0.001).

Fig. 5

Aspects of transition from paediatric to adult diabetes care (n = 104)