Dataset Information

Trends in maternal age distribution and the live birth prevalence of Down's syndrome in England and Wales: 1938-2010.

ABSTRACT: There have been concerns about the effects of increases in maternal age since the 1980s on the prevalence of Down's syndrome. This study examined changes in the distribution of maternal age in England and Wales from 1938 to 2010. The live birth prevalence of Down's syndrome in the absence of screening and subsequent termination was estimated using the numbers of babies born in England and Wales according to maternal age and the maternal age-related risk of a birth with Down's syndrome. The proportion of women age 35 years or older at the time of giving birth reached a peak of 20% in 1945, declined to 5.5% in 1977 and rose to 20% in 2007. In the absence of screening and subsequent termination, the estimated live birth prevalence of Down's syndrome would have mirrored these changes (2.3 per 1000 births in 1945, 1.2 per 1000 in 1976 and 2.2 per 1000 in 2007). The observed live birth prevalence (recorded by the National Down Syndrome Cytogenetic Register) was1.0 per 1000 from 1989 to 2010, due to screening and subsequent termination. In conclusion since the 1980s there has been an increase in the mean maternal age and in the expected prevalence of Down's syndrome. When put in a longer historical context the current expected live birth prevalence is similar to that in the 1940s and the observed live birth prevalence is about 54% less than expected, due to screening and subsequent termination, and has remained reasonably constant since 1989 at 1.0 per 1000 births.

SUBMITTER: Wu J

PROVIDER: S-EPMC3746264 | biostudies-other | 2013 Sep

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:BACKGROUND:Hypospadias is a common male birth defect that has shown widespread variation in reported prevalence estimates. Many countries have reported increasing trends over recent decades. OBJECTIVE:To analyze the prevalence and trends of hypospadias for 27 international programs over a 31-yr period. DESIGN, SETTING, AND PARTICIPANTS:The study population included live births, stillbirths, and elective terminations of pregnancy diagnosed with hypospadias during 1980-2010 from 27 surveillance programs around the world. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS:We used joinpoint regression to analyze changes over time in international total prevalence of hypospadias across programs, prevalence for each specific program, and prevalence across different degrees of severity of hypospadias. RESULTS AND LIMITATIONS:The international total prevalence of hypospadias for all years was 20.9 (95% confidence interval: 19.2-22.6) per 10000 births. The prevalence for each program ranged from 2.1 to 39.1 per 10000 births. The international total prevalence increased 1.6 times during the study period, by 0.25 cases per 10000 births per year (p<0.05). When analyzed separately, there were increasing trends for first-, second-, and third-degree hypospadias during the early 1990s to mid-2000s. The majority of programs (61.9%) had a significantly increasing trend during many of the years evaluated. Limitations include known differences in data collection methods across programs. CONCLUSIONS:Although there have been changes in clinical practice and registry ascertainment over time in some countries, the consistency in the observed increasing trends across many programs and by degrees of severity suggests that the total prevalence of hypospadias may be increasing in many countries. This observation is contrary to some previous reports that suggested that the total prevalence of hypospadias was no longer increasing in recent decades. PATIENT SUMMARY:We report on the prevalence and trends of hypospadias among 27 birth defect surveillance systems, which indicate that the prevalence of hypospadias continues to increase internationally.

Project description:Scotland has disproportionately high rates of suicide compared with England. An analysis of trends may help reveal whether rates appear driven more by birth cohort, period or age. A 'birth cohort effect' for England & Wales has been previously reported by Gunnell et al. (B J Psych 182:164-70, 2003). This study replicates this analysis for Scotland, makes comparisons between the countries, and provides information on 'vulnerable' cohorts.Suicide and corresponding general population data were obtained from the National Records of Scotland, 1950 to 2014. Age and gender specific mortality rates were estimated. Age, period and cohort patterns were explored graphically by trend analysis.A pattern was found whereby successive male birth cohorts born after 1940 experienced higher suicide rates, in increasingly younger age groups, echoing findings reported for England & Wales. Young men (aged 20-39) were found to have a marked and statistically significant increase in suicide between those in the 1960 and 1965 birth cohorts. The 1965 cohort peaked in suicide rate aged 35-39, and the subsequent 1970 cohort peaked even younger, aged 25-29; it is possible that these 1965 and 1970 cohorts are at greater mass vulnerability to suicide than earlier cohorts. This was reflected in data for England & Wales, but to a lesser extent. Suicide rates associated with male birth cohorts subsequent to 1975 were less severe, and not statistically significantly different from earlier cohorts, suggestive of an amelioration of any possible influential 'cohort' effect. Scottish female suicide rates for all age groups converged and stabilised over time. Women have not been as affected as men, with less variation in patterns by different birth cohorts and with a much less convincing corresponding pattern suggestive of a 'cohort' effect.Trend analysis is useful in identifying 'vulnerable' cohorts, providing opportunities to develop suicide prevention strategies addressing these cohorts as they age.

Project description:IntroductionDisease registers and electronic health records are valuable resources for disease surveillance and research but can be limited by variation in data quality over time. Quality may be limited in terms of the accuracy of clinical information, of the internal linkage that supports person-based analysis of most administrative datasets, or by errors in linkage between multiple datasets.ObjectivesBy linking the National Down Syndrome Cytogenetic Register (NDSCR) to Hospital Episode Statistics for England (HES), we aimed to assess the quality of each and establish a consistent approach for analysis of trends in prevalence of Down's syndrome among live births in England.MethodsProbabilistic record linkage of NDSCR to HES for the period 1998-2013 was supported by linkage of babies to mothers within HES. Comparison of prevalence estimates in England were made using NDSCR only, HES data only, and linked data. Capture-recapture analysis and quantitative bias analysis were used to account for potential errors, including false positive diagnostic codes, unrecorded diagnoses, and linkage error.ResultsAnalyses of single-source data indicated increasing live birth prevalence of Down's Syndrome, particularly in the analysis of HES. Linked data indicated a contrastingly stable prevalence of 12.3 (plausible range: 11.6-12.7) cases per 10 000 live births.ConclusionCase ascertainment in NDSCR improved slightly over time, creating a picture of slowly increasing prevalence. The emerging epidemic suggested by HES primarily reflects improving linkage within HES (assignment of unique patient identifiers to hospital episodes). Administrative data are valuable but trends should be interpreted with caution, and with assessment of data quality over time. Data linkage with quantitative bias analysis can provide more robust estimation and, in this case, stronger evidence that prevalence is not increasing. Routine linkage of administrative and register data can enhance the value of each.

Dataset Information

Trends in maternal age distribution and the live birth prevalence of Down's syndrome in England and Wales: 1938-2010.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets