Aims/hypothesis Against a background of a near-universally increasing incidence of childhood type 1 diabetes, recent reports from some countries suggest a slowing in this increase. Occasional reports also describe cyclical variations in incidence, with periodicities of between 4 and 6 years. Methods Age/sex-standardised incidence rates for the 0- to 14-year-old age group are reported for 26 European centres (representing 22 countries) that have registered newly diagnosed individuals in geographically defined regions for up to 25 years during the period 1989–2013. Poisson regression was used to estimate rates of increase and test for cyclical patterns. Joinpoint regression software was used to fit segmented log-linear relationships to incidence trends. Results Significant increases in incidence were noted in all but two small centres, with a maximum rate of increase of 6.6% per annum in a Polish centre. Several centres in high-incidence countries showed reducing rates of increase in more recent years. Despite this, a pooled analysis across all centres revealed a 3.4% (95% CI 2.8%, 3.9%) per annum increase in incidence rate, although there was some suggestion of a reduced rate of increase in the 2004–2008 period. Rates of increase were similar in boys and girls in the 0- to 4-year-old age group (3.7% and 3.7% per annum, respectively) and in the 5- to 9-year-old age group (3.4% and 3.7% per annum, respectively), but were higher in boys than girls in the 10- to 14-year-old age group (3.3% and 2.6% per annum, respectively). Significant 4 year periodicity was detected in four centres, with three centres showing that the most recent peak in fitted rates occurred in 2012. Conclusions/interpretation Despite reductions in the rate of increase in some high-risk countries, the pooled estimate across centres continues to show a 3.4% increase per annum in incidence rate, suggesting a doubling in incidence rate within approximately 20 years in Europe. Although four centres showed support for a cyclical pattern of incidence with a 4 year periodicity, no plausible explanation for this can be given.

Aims/hypothesis: Data on type 1 diabetes incidence and prevalence are limited, particularly for adults. This study aims to estimate global numbers of incident and prevalent cases of type 1 diabetes in 2017 for all age groups, by country and areas defined by income and region. Methods: Incidence rates of type 1 diabetes in children (available from 94 countries) from the IDF Atlas were used and extrapolated to countries without data. Age-specific incidence rates in adults (only known across full age range for fewer than ten countries) were obtained by applying scaling ratios for each adult age group relative to the incidence rate in children. Age-specific incidence rates were applied to population estimates to obtain incident case numbers. Duration of diabetes was estimated from available data and adjusted using differences in childhood mortality rate between countries from United Nations demographic data. Prevalent case numbers were derived by modelling the relationship between prevalence, incidence and disease duration. Sensitivity analyses were performed to quantify the impact of alternative assumptions and model inputs. Results: Global numbers of incident and prevalent cases of type 1 diabetes were estimated to be 234,710 and 9,004,610, respectively, in 2017. High-income countries, with 17% of the global population, accounted for 49% of global incident cases and 52% of prevalent cases. Asia, which has the largest proportion of the world’s population (60%), had the largest number of incident (32%) and prevalent (31%) cases of type 1 diabetes. Globally, 6%, 35%, 43% and 16% of prevalent cases were in the age groups 0–14, 15–39, 40–64 and 65+ years, respectively. Based on sensitivity analyses, the estimates could deviate by ±15%. Conclusions/interpretation: Globally, type 1 diabetes represents about 2% of the estimated total cases of diabetes, ranging from less than 1% in certain Pacific countries to more than 15% in Northern European populations in 2017. This study provides information for the development of healthcare and policy approaches to manage type 1 diabetes. The estimates need further validation due to limitations and assumptions related to data availability and estimation methods. Graphical

Physical activity (PA) interventions are generally effective in supporting short-term behaviour change, but increases are not always maintained. This review examined the effectiveness of PA interventions for behaviour change maintenance in young and middle-aged adults, and investigated which Behaviour Change Techniques (BCTs) and other intervention features were associated with maintenance. Six databases (Medline, EMBASE, PsycINFO, Cochrane Database of Systematic Reviews, CINAHL, Web of Science) were systematically searched. Eligibility criteria were controlled trials investigating the effectiveness of PA interventions with adult (mean age 18-64 years) non-clinical populations using validated measures of PA behaviour at baseline and ≥six months' post-baseline. Results were pooled in meta-analyses using standardised mean differences (SMD) at five time intervals (6-9, 9-15, 15-21, 21-24, >24 months). Moderator analyses investigated the influence of sample and intervention characteristics on PA maintenance at 6-9 months. Sixty-two studies were included. PA interventions had a significant effect on behaviour maintenance 6-15 months post-baseline relative to controls. Interventions had a larger effect on maintenance at 6-9 months (SMD = 0.28; 95% CI: 0.20, 0.35; I2 = 73%) compared to 9-15 months (SMD = 0.20; 95% CI: 0.13, 0.26; I2 = 70%). Beyond 15 months, PA measurements were infrequent with little evidence supporting maintenance. Moderator analyses showed some BCTs and intervention settings moderated PA outcomes at 6-9 months. A multivariable meta-regression model showed interventions using the BCTs 'Prompt self-monitoring of behavioural outcome' (b = 1.46, p < 0.01) and 'Use of follow-up prompts' (b = 0.38, p < 0.01) demonstrated greater effectiveness at promoting PA maintenance at 6-9 months. Interventions implemented in primary care (versus community or workplace/university) settings (b = -0.13, p = 0.10) tended to demonstrate less effectiveness. This review provides evidence of some effective BCTs for maintaining behaviour to 15 months. Greater consideration must be given to how future interventions encourage and measure maintenance of changes, and investigate broader psychological, social and environmental influences of PA behaviour. PROSPERO 2015:CRD42015025462.