Early academic achievement in children with isolated clefts: a population-based study in England.

OBJECTIVES: We used national data to study differences in academic achievement between 5-year-old children with an isolated oral cleft and the general population. We also assessed differences by cleft type. METHODS: Children born in England with an oral cleft were identified in a national cleft registry. Their records were linked to databases of hospital admissions (to identify additional anomalies) and educational outcomes. Z-scores (signed number of SD actual score is above national average) were calculated to make outcome scores comparable across school years and across six assessed areas (personal development, communication and language, maths, knowledge of world, physical development andcreative development). RESULTS: 2802 children without additional anomalies, 5 years old between 2006 and 2012, were included. Academic achievement was significantly below national average for all six assessed areas with z-scores ranging from -0.24 (95% CI -0.32 to -0.16) for knowledge of world to -0.31 (-0.38 to -0.23) for personal development. Differences were small with only a cleft lip but considerably larger with clefts involving the palate. 29.4% of children were documented as having special education needs (national rate 9.7%), which varied according to cleft type from 13.2% with cleft lip to 47.6% with bilateral cleft lip and palate. CONCLUSIONS: Compared with national average, 5-year-old children with an isolated oral cleft, especially those involving the palate, have significantly poorer academic achievement across all areas of learning. These outcomes reflect results of modern surgical techniques and multidisciplinary approach. Children with a cleft may benefit from extra academic support when starting school

Linking consented cohort and routinely collected health data to enhance investigations into childhood obesity, asthma, infections, immunisations, and injuries

Background In longitudinal health research, combining the richness of cohort data to the extensiveness of routine data opens up new possibilities, providing information not available from one data source alone. In this study, we set out to extend information from a longitudinal birth cohort study by linking to the cohort child’s routine primary and secondary health care data. The resulting linked datasets will be used to examine health outcomes and patterns of health service utilisation for a set of common childhood health problems. We describe the experiences and challenges of acquiring and linking electronic health records for participants in a national longitudinal study, the UK Millennium Cohort Study (MCS). Method Written parental consent to link routine health data to survey responses of the MCS cohort member, mother and her partner was obtained for 90.7% of respondents when interviews took place at age seven years in the MCS. Probabilistic and deterministic linkage was used to link MCS cohort members to multiple routinely-collected health data sources in Wales and Scotland. Results Overall linkage rates for the consented population using country-specific health service data sources were 97.6% for Scotland and 99.9% for Wales. Linkage rates between different health data sources ranged from 65.3% to 99.6%. Issues relating to acquisition and linkage of data sources are discussed. Conclusions Linking longitudinal cohort participants with routine data sources is becoming increasingly popular in population data research. Our results suggest that this is a valid method to enhance information held in both sources of data

Using consented health record linkage in a longitudinal cohort study

ABSTRACT Objectives The aim of this project is to address important issues relevant to children’s health This will be done by enhancing information collected in the longitudinal, UK-wide Millennium Cohort Study (MCS) by linking participating children to their routine health records. These issues include: health service implications of early life onset of obesity and overweight; timeliness of immunisations; association of infections with asthma and allergic disorders in childhood; and burden of disease due to childhood injuries. Approach The MCS comprises information on the social, economic and health-related circumstances of children surveyed at ages 9 months, 3, 5, 7, 11 and 14 years. At the age 7 interview, 12517 (89.1%) of the 14043 adults with parental responsibility consented for information from their child’s routine heath records to be released to the MCS (a). Routine health records have been requested for Wales, England and Scotland to be linked to MCS responses within the Secure Anonymised Information Linkage Databank at Swansea University. Data will be analysed using weights for non-response, non-consent and non-linkage and the linkage reported according to the RECORD guidelines (b). Results To date, all 1881 MCS children with valid consent who live or have lived in Wales have been linked by assigning an Anonymous Linking Field (ALF) to each individual which can be mapped across multiple datasets without risk of identification (c). Of these children, 1365 (72.3%) had experienced at least one hospital admission by the age of 14 years. Risk of admission by each of the survey ages for boys and girls separately will be calculated adjusting for non-response at different sweeps. These children have also been linked to their immunisation records (n = 1872), Emergency Department attendances (n = 1276), and available GP records (n = 1151) to enable analyses in fulfilment of the project objectives. Conclusions Routine health records are a potentially valuable enhancement to longitudinal studies, allowing evaluation of questions of relevance to public health and health services, and the completeness and consistency of records from these different sources to be addressed. References a. Shepherd, P. (2013) Consent to linkage to child health data ISBN 978-1-906929-59-6 b. Benchimol, E.I. et al (2015) DOI: 10.1371/journal.pmed.1001885 c. Ford, D.V. et al (2009) DOI: 10.1186/1472-6963-9-15

The pattern of risk of myocardial infarction in patients taking asthma medication:a study with the General Practice Research Database.

Aim: To describe the patterns of risks of acute myocardial infarction (MI) during exposure to long-acting beta2-agonists (LABA). Methods: The study population consisted of patients aged 18+ years prescribed LABA or short-acting beta2-agonists (SABA) in the UK General Practice Research Database (GPRD). The outcomes included acute MI as recorded in GPRD and hospitalization for acute MI as obtained from the national registry of hospital admissions in England. The patterns of the hazard rates over time (i.e. absolute risks) were evaluated. Results: The study population included 507,966 patients, who received a total of 5.5 million inhaled SABA, 4.0 million inhaled corticosteroids (ICS) and 1.3 million LABA prescriptions. In patients who recently started asthma medication, there were substantial changes in the hazard rates of MI over time: hazard rates were increased shortly following the prescription and then decreased. The hazard rates of MI in GPRD and of MI hospitalizations were proportional over time between inhaled SABA, LABA and ICS. Heavy long-term users (13+ Rx of the same asthma drug in the 1 year before) had increased risks of MI both with inhaled SABA and ICS. The relative rate in the heavy long-term users was 1.6 with inhaled SABA, 1.1 with LABA and 1.7 with ICS. The pattern of risk was similar between LABA with and without concomitant ICS use. Conclusion: The patterns of risks of MI were broadly similar between inhaled SABA, LABA and ICS, suggesting that there were no major differences between these drugs

Linking strategies and biases when matching cohorts to the National Pupil Database.

ABSTRACT Objectives To compare sample biases when linking education data to external datasets using opt in and opt out consent models for the Millennium Cohort Study (MCS) – opt in, and the Case Register Interactive Search Child and Adolescent Mental Health sample (CRIS CAMHS) –opt out. Approach We compared demographic factors in the linked and unlinked populations when two cohorts, the MCS, and CRIS CAMHS data were linked to the National Pupil Database. The MCS is a birth cohort collecting prospective data on the social, economic and health-related circumstances of children surveyed at roughly two-yearly intervals from the age of 9 months. At age 7, parents were asked to consent for information from their child’s education records (via the UK Department for Education’s National Pupil Database, NPD) to linked to the MCS. Of the 9000 adults with parental responsibility, 8448 (93.9%) consented. The CRIS CAMHS sample is the UK's largest, anonymised clinical database for children and adolescents referred to South London child and adolescent mental health services, which is collected using opt out consent. All 35, 426 children were eligible for linkage to their educational data. Results For MCS, 7446 (82.7% of the population) eligible children were successfully linked to NPD following opt in consent. After stratification into distinct geographical regions, London children in the most deprived quartile of neighbourhood deprivation were over twice as likely (O.R 2.5, C.I 1.18-5.3) not to have their educational records linked. For the opt out CRIS CAMHS cohort, 30,178 (85.1%) were linked, with no significant differences in linkage rates between children in the highest and lowest quartiles of deprivation (O.R 1.05, C.I 0.93-1.18). Relative to children of White ethnicity, Asian, Black African and Mixed ethnic groups were significantly less likely to be matched in both studies. Black Caribbean ethnicity was significantly associated with non-linkage in the MCS cohort (O.R 3.0, C.I 1.49-6.01), but not in CRIS CAMHS (0.96, C.I 0.83-1.12). Conclusion Record linkages are a valuable enhancement to child-based longitudinal studies and clinical registries, allowing evaluation of questions relevant to public health and social care policy. Opt out consent approaches improve representation of more socially disadvantaged populations. Nevertheless, whether using opt in and opt out consent process, possible biases due to linkage error can be important and need to be addressed when analysing and interpreting results

Combining deterministic and probabilistic matching to reduce data linkage errors in hospital administrative data

ABSTRACT Objectives Data linkage algorithms are used to link together multiple episodes of care belonging to the same patient. For example, the HESID algorithm is used to generate Hospital Episode Statistics (HES) in England. HESID is a deterministic algorithm, requiring identifiers to agree or disagree at each step. Data linkage errors occur when episodes belonging to two patients are incorrectly linked (a false match) or when episodes belonging to the same patient are not linked (a missed match). This typically occurs because patient identifiers (e.g. NHS number, postcode) contain errors or have missing data. We previously showed that HESID has a low false match rate (0.2%) but a high missed match rate (4.1%) when applied to paediatric intensive care data. This biased the true readmission rate, particularly for some patient groups including ethnic minorities. The aim of our study was to evaluate whether an additional step involving probabilistic matching would lower the missed match rate in HES without increasing the false matched rate. Approach We simulated three datasets having the same characteristics as HES, for three age groups expected to have different levels of postcode stability (at age 0/1, 5/6 and 18/19). We compared the deterministic algorithm to a probabilistic algorithm, and then to a deterministic algorithm with an additional probabilistic step. In sensitivity analyses, we evaluated the algorithms under different data quality scenarios. Results Results show that deterministic followed by probabilistic matching is the best solution for reducing missed matches, particularly in scenarios where errors in patient identifiers are more common. Conclusion Data linkage algorithms need to be evaluated against good quality reference standard data sets. For hospital data in England, the Personal Demographics Service (PDS) could be used to evaluate our approach, because it contains many of the same patient identifiers used in HES. Reducing data linkage error will improve monitoring of hospital activity in England

Idun (Årg. 2, N:r 15)

AIM: To describe the patterns of risks of acute myocardial infarction (MI) during exposure to long-acting beta2-agonists (LABA). METHODS: The study population consisted of patients aged 18+ years prescribed LABA or short-acting beta2-agonists (SABA) in the UK General Practice Research Database (GPRD). The outcomes included acute MI as recorded in GPRD and hospitalization for acute MI as obtained from the national registry of hospital admissions in England. The patterns of the hazard rates over time (i.e. absolute risks) were evaluated. RESULTS: The study population included 507,966 patients, who received a total of 5.5 million inhaled SABA, 4.0 million inhaled corticosteroids (ICS) and 1.3 million LABA prescriptions. In patients who recently started asthma medication, there were substantial changes in the hazard rates of MI over time: hazard rates were increased shortly following the prescription and then decreased. The hazard rates of MI in GPRD and of MI hospitalizations were proportional over time between inhaled SABA, LABA and ICS. Heavy long-term users (13+ Rx of the same asthma drug in the 1 year before) had increased risks of MI both with inhaled SABA and ICS. The relative rate in the heavy long-term users was 1.6 with inhaled SABA, 1.1 with LABA and 1.7 with ICS. The pattern of risk was similar between LABA with and without concomitant ICS use. CONCLUSION: The patterns of risks of MI were broadly similar between inhaled SABA, LABA and ICS, suggesting that there were no major differences between these drugs