Aims In developed countries, the incidence of inflammatory bowel disease (IBD) such as Crohn's disease (CD) and ulcerative colitis (UC) is increasing. Therefore, we aimed to investigate the incidence rates and trends over time in the population of children and adolescents in one of the federal states of Germany, in Saxony. Methods Over the 10-year period 2000–2009 all 31 children’s hospitals and pediatric gastroenterologists, respectively in Saxony reported all IBD patients up to 15 years of age to the Saxon Pediatric IBD Registry. The completeness of the registry was estimated as 96.7% by independent surveys in the years 2005–2009. Incidence rates were presented as age-standardized incidence rates (ASR) regarding New European Standard Population 1990 per 100,000 person-years (PY) with 95% confidence intervals [CI]. Joinpoint and linear regression was used for trend analyses. Results 344 patients with confirmed IBD between 2000–2009 were included in the epidemiological evaluation: 212 (61.6%) patients with CD, 122 (35.6%) with UC and 10 (2.9%) with unclassified IBD (IBD-U). The ASR per 100,000 PY over the whole observation period was 7.2 [6.4–7.9] for IBD, 4.4 [3.8–5.0] for CD, 2.6 [2.1–3.0] for UC and 0.2 [0.1–0.3] for IBD-U. For IBD, the ASR per 100,000 PY increased from 4.6 [2.8–6.3] in 2000 to 10.5 [7.5–13.6] in 2009. The incidence trend analysis of ASRs using the joinpoint regression confirmed a significant increase of IBD as well as UC. The mean age at first diagnosis decreased significantly during the observation period from 11.5 (11.0–13.4) in 2000 to 9.6 (5.1–13.5) years in 2009. The median of the diagnostic latency among IBD patients was 3 months. Conclusion The incidence of IBD in children and adolescents in Saxony was slightly higher than the average of other countries in the same time period and followed the trend towards a general increase of IBD. The age at diagnosis was subject to a very unfavorable downward trend.

IntroductionThe incidence and prevalence of chronic inflammatory bowel diseases in childhood and adolescence is increasing and varies internationally. The systematic literature review aims to describe international epidemiological trends of chronic inflammatory bowel diseases in the child and adolescence age. A period from 1970 to 2019 will be taken into account when searching for suitable studies as well as geographical differences in the development of incidences will be presented.Methods and analysisThe literature databases PubMed and Embase will be searched for the period from 01 January 1970 to 31 December 2019 using linked keywords. A manual search in bibliographies of already published and relevant systematic reviews will complete the systematic literature search. The included studies will be combined in a qualitative and quantitative synthesis and statistically evaluated.Ethics and disseminationEthical approval is not required for this study as it is a systematicreview. The results will be submitted to peer-reviewed journals and presented in national andinternational meetings. This research received no specific grant from any funding agency inthe public, commercial or not-for-profit sectors. This systematic review protocol was registeredwith the International Prospective Register of Systematic Reviews (PROSPERO-NR:CRD42020168644).

Aims An increasing number of children and adolescents worldwide suffer from inflammatory bowel disease (IBD) such as Crohn’s disease (CD) and ulcerative colitis (UC). The present work aims to investigate the incidence, prevalence and future trends of IBD in children and adolescents in Saxony, Germany. Methods The Saxon Pediatric IBD Registry collected data on patients up to 15 years of age from all 31 pediatric hospitals and pediatric gastroenterologists in Saxony over a 15-year period (2000–2014). In 2019, an independent survey estimated a registry completeness of 95.7%. Age-standardized incidence rates (ASR) per 100,000 person-years (PY) and prevalence per 100,000 children and adolescents were calculated. Evaluation was also been performed in sex and age subgroups. Joinpoint and Poisson regression were used for trend analyses and projections. Results 532 patients with confirmed IBD during 2000–2014 were included in the epidemiological evaluation. 63.5% (n = 338) patients had CD, 33.1% (n = 176) had UC and 3.4% (n = 18) had unclassified IBD (IBD-U). The 15-year IBD prevalence was 111.8 [95%-CI: 102.3–121.3] per 100,000. The incidence ASR of IBD per 100,000 PY over the whole observation period was 7.5 [6.9–8.1]. ASR for the subtypes were 4.8 [4.3–5.3] for CD, 2.5 [2.1–2.9] for UC and 0.3 [0.1–0.4] for IBD-U. The trend analysis of ASR using the joinpoint regression confirmed a significant increase for incidence of IBD as well as CD. For IBD, the ASR per 100,000 PY increased from 4.6 [2.8–6.3] in 2000 to 8.2 [7.5–13.6] in 2014; projected incidence rates for IBD in Germany are 12.9 [6.5–25.5] in the year 2025 and 14.9 [6.7–32.8] in 2030, respectively. Thus, the number of new IBD diagnoses in Germany would more than triple (325%) in 2030 compared to 2000. The increase is expected to be faster in CD than UC, and be more in males than in females. The expected number of newly diagnosed children with IBD in Germany is projected to rise to about 1,584 [1,512–1,655] in 2025, and to about 1,918 [1,807–2,29] in 2030. Conclusion The incidence of IBD in children and adolescents in Saxony increased at a similar rate as in other developed countries during the observation period. Given this trend, the health care system must provide adequate resources for the care of these young patients in the future.