Social class differences in health until the age of seven years among the Finnish 1987 birth cohort

Studies on social class differences in childhood health are controversial partly because of different data collection methods, limited sample sizes and the use of limited numbers of health indicators. The increasing collection of health register data enables the use of such data in social class studies. Our purpose was to investigate social class differences in mortality and morbidity among all children born in Finland in 1987 (N=59,865 liveborns) until the age of seven by using several national health registers, and to study whether perinatal health explains these differences. The follow-up was based on data linkage with six national health registers, with 18 regional registers of mentally disabled children, covering the whole country, and with 38 educational registers of the largest county. Morbidity was measured in terms of a cumulative disease index, the cumulative incidence of asthma, diabetes, epilepsy and intellectual disability, hospitalisations, disease-related welfare benefits and special education. Social class, divided in four groups (I–III, Others) was defined by using the mother's occupation at the time the child was seven years old. Our study showed that register-based data collection is a feasible method for studying social class differences in health. In the unadjusted analysis, social class differences were found for all indicators except mortality after the age of one year and for the cumulative incidence of asthma and diabetes. After adjusting for confounders, the children in the lowest social class had the highest risk for poor health outcome both in the perinatal period and in childhood, and had the most intellectual disabilities, the highest mean of hospitalisation days, and received the most special education. The differences were not explained by perinatal health. The health of the children in the lowest social class was poorer, especially regarding mental indicators.     

Health registers as a feasible means of measuring health status in childhood – a 7-year follow-up of the 1987 Finnish birth cohort

Follow-up studies on health have usually been based on ad hoc cohort studies in which detailed information is collected specifically for research purposes on a certain group of people. The increasing collection of routine health data provides an alternative method of gathering follow-up data. In this study, the feasibility of using routinely collected health-register data and data linkages to follow up children's health was investigated. Five nationwide registers, 18 regional registers of intellectually disabled children and school administration data in one county were found to be of use for our follow-up and were combined with the 1987 Finnish Medical Birth Register ( n  = 60 254 births). In the follow-up, 62 children were untraced (0.1%), 327 were stillborn (0.5%), 440 died after birth (0.7%) and 287 emigrated (0.5%) before the age of 7 years. The cumulative incidences for all diseases (8.9% of all children living in Finland at the age of 7 years), for diabetes (3.0/1000), for epilepsy (6.8/1000) and for asthma (34.2/1000) correspond to the estim-ates of other studies, but our estimate for intellectual disabilities (18.0/1000, of whom 18% were reported to have an IQ of 70 or less) seems to be an underestimate. Our data collection did not provide reliable information on institutionalised children or children taken into care. Data collec-tion conducted by using health registers is a feasible method, and it saves both time and financial resources compared with cohort studies. Poten-tial problems with data linkage studies are variation in the content of data and in data quality of different registers and data protection issues.     

Regional equity in childhood health--register-based follow-up of the Finnish 1987 birth cohort

Our objective was to investigate regional health differences among Finnish children using a population-based longitudinal register data. All live births born in 1987 were included in the study (N=59,546) and followed-up until the age of seven years. Statistically significant regional variation was found for all health indicators but diabetes. Background variables, such as maternal age and social class, explained only the difference in mortality. Various indicators gave different geographical patterns. Regional equity in childhood health has not been achieved in Finland. Existing health registers were feasible in studying regional variation in health, but a set of comprehensive morbidity indicators - preferably derived from different data sources - should be developed to monitor equity in health.     

Validation of the new Swedish vaccination register – Accuracy and completeness of register data

ObjectiveThe aims of this study are to validate infant vaccination data in the Swedish Vaccination Register (SVR) to the Swedish administrative coverage reports, and to assess differences in register-based vaccination coverage estimates between providers using different data reporting methods.MethodsThe study population included all infants born in Sweden with a Swedish Personal Identity Number during 2014 and 2015 (n = 230,220). Data on all National Immunisation Programme vaccinations administered before 24 months of age were collected from the SVR and from administrative coverage reports. Information regarding data registration methods in the SVR were collected from national and regional authorities. Coverage from health care providers using single registration methods, where vaccination data were transferred automatically from the electronic health care record to the SVR, was compared to that from providers using double registration methods where data had to be added into the SVR in a separate process.ResultsFor 98,4% of the study population at least one vaccination was recorded in the SVR. The coverage of 3-dose DTP-containing (87,1%) and 1 dose MMR (91,1%) in the register did not reach administrative data coverage (97,4% for 3-dose DTP-containing and 97,0% for MMR). Single registration procedures yielded significantly higher coverage than double registration procedures (92,24% vs 87,10%, p < 0,0001). A regional switch from double to single registration increased coverage from 80,0 to 95,2%.ConclusionsThe SVR is a valuable data source for vaccination coverage monitoring. For research purposes, the SVR provides valuable data, since every health care provider is obliged to register all vaccine doses given within the national immunisation program. The SVR shows a high completeness validated by comparison to a very well-functioning administrative data system. Single-registration procedures give more complete data and should be supported by health systems while creating health care registers.     

Regional equity in childhood health — register-based follow-up of the Finnish 1987 birth cohort

Our objective was to investigate regional health differences among Finnish children using a population-based longitudinal register data. All live births born in 1987 were included in the study (N=59,546) and followed-up until the age of seven years. Statistically significant regional variation was found for all health indicators but diabetes. Background variables, such as maternal age and social class, explained only the difference in mortality. Various indicators gave different geographical patterns. Regional equity in childhood health has not been achieved in Finland. Existing health registers were feasible in studying regional variation in health, but a set of comprehensive morbidity indicators — preferably derived from different data sources — should be developed to monitor equity in health.     

Linking ‘data silos’ to investigate anaemia among Aboriginal and Torres Strait Islander mothers and children in Far North Queensland

Objective : Data collection ‘silos’ can be linked for health research. Anaemia in early childhood is a long‐recognised health issue in remote Aboriginal communities of the Northern Territory and Western Australia, but information is lacking for Queensland. The objective of this work was to compile existing information from health and education data collections to investigate anaemia among Aboriginal and Torres Strait Islander mothers and their children in Far North Queensland. Methods : Data mapping identified four health data collections and one education data collection holding relevant information. Data Custodians’ approval was secured for release of linked de‐identified information. Results : Approval processes and preparation of the dataset for release took 23 months. Birth information was obtained for 2,205 mother–child pairs where the Aboriginal and/or Torres Strait Islander child was born in Far North Queensland between 2006 and 2010. Pathology information from before/during pregnancy was obtained for 2,126 mothers (96.4%), growth and haemoglobin information for 982 children (44.5%), and childhood development indicators at school entry for 963 children (43.7%). Conclusion : Linking existing information ‘silos’ enables research into key public health issues. Implications for public health : Information linkage is particularly valuable in respect of vulnerable populations including rural and remote Aboriginal and Torres Strait Islander peoples.     

Asthma during pregnancy – a population based study

To study delivery outcome in women with asthma, using Swedish health registers. Women with asthma were identified in two ways: by information in interviews performed by midwives at the pregnant woman's first visit to antenatal care, and by linkage between a medical birth register and a hospital discharge register, identifying women who had been hospitalized for asthma and also had a delivery. Births between 1984 and 1995 were studied. An increased risk for preterm birth and low birth weight was seen, possibly co-varying with disease severity. Also a significant increase in pregnancies of more than 41 weeks duration was noticed. An increase in infant death but not in congenital malformations rate was observed. An association with preeclampsia, gestational diabetes, and infant hypoglycemia was verified. Maternal asthma appears to be a risk factor for preterm and postterm births and increases the risk for some pregnancy complications.     

Linking survey data with administrative health information: characteristics associated with consent from a neonatal intensive care unit follow-up study

BACKGROUND: Health services and population health research often depends on the ready availability of administrative health data. However, the linkage of survey-based data to administrative data for health research purposes has raised concerns about privacy. Our aim was to compare consent rates to data linkage in two samples of caregivers and describe characteristics associated with consenters. METHODS: Subjects included caregivers of children admitted at birth to neonatal intensive care units (NICU) in British Columbia and caregivers of a sample of healthy children. Caregivers were asked to sign a consent form enabling researchers to link the survey information with theirs and their child's provincially collected health records. Bivariate analysis identified sample characteristics associated with consent. These were entered into logistic regression models. RESULTS: The sample included 1,140 of 2,221 NICU children and 393 of 718 healthy children. The overall response rate was 55% and the response rate for located families was 67.1%. Consent to data linkage with the child data was given by 71.6% of respondents and with caregiver data by 67% of respondents. Families of healthy children were as likely to provide consent as families of NICU children. Higher rates of consent were associated with being a biological parent, not requiring survey reminders, involvement in a parent support group, not working full-time, having less healthy children, multiple births and higher income. CONCLUSION: The level of consent achieved suggests that when given a choice, most people are willing to permit researcher access to their personal health information for research purposes. There is scope for educating the public about the nature and importance of research that combines survey and administrative data to address important health questions.     

A qualitative study, using focused interviews, of the information needs of families whose children's names are on a cerebral palsy register

BACKGROUND: We were concerned that information held on a register of children with cerebral palsy was not being made available to contributing families, and that the existence and purpose of the register was not sufficiently understood. METHODS: Focused interviews with 13 families selected by purposive sampling. RESULTS: Many parents would like more information about the data on registers which include their child. They would also like to be more involved in the design of the register and its reports, but there are practical difficulties in making time available for such activity. Although parents were surprised that they had not already been given more information about the existence and purpose of the register, none were resentful that their child's name was on the register once they were reassured about confidentiality and database security. Parents also had general concerns unrelated to the register which were about their need to be treated as equals by professionals, to have more information about equipment and to have earlier and clearer diagnoses. CONCLUSIONS: Registers of children with uncommon conditions have well-established roles in epidemiology, planning and research. By fully involving parents in ways suggested by this study, registers can also empower parents. The study should also provide reassurance to those who hold such registers without explicit consent that the requirement to now obtain consent should not create resentment or jeopardize completeness.     

The role of national quality registers in the Swedish health service

This article reports on a quality movement in Sweden that has gone largely unnoticed, namely the national quality control registers. These registers represent a potentially important primary data source for comparative studies and can play an important role in a national strategy for control and improvement of health care quality. First, we review the recent health care quality initiatives in Sweden and the background of national quality control registers. Secondly, we discuss our findings from a study on the purpose, content, value and problems associated with the registers. Our findings are based on (a) interviews with physician managers of the registers, (b) questionnaires to selected hospital departments participating in the registers and (c) questionnaires to elected officials and administrators representing the local health care providers. Finally, we discuss several crucial issues related to the registers. Although some have existed for several years, the registers are still defining their roles. Traditionally, this activity has been managed by the medical profession. However, interest in register information is increasing among health care policy makers and administrators at all levels in the system. Two key issues concern register ownership and finance, but the most sensitive issue concerns the right of policy makers and the public to access register information. The registers and the information they contain illustrate the ongoing conflict between openness and consumer sovereignty in health care on the one hand and professional autonomy on the other.     

Rheumatic diseases in a health interview survey and in in-patient care. A record linkage study on two registers

A record linkage was performed between the in-patient register of Stockholm County and the Stockholm County sample of a national health interview survey. The purpose was to describe and compare characteristics of the two registers, particularly as regards rheumatic diseases. All persons included in the health interview survey of 1977-78 were sought in the in-patient register for the same period. 37% of the population had reported long-term illness in the health interview survey and 22% had been hospitalized, according to the in-patient register. 11% reported a rheumatic disease in the health interview survey, but only 2% were hospitalized with a rheumatic diagnosis. Persons who reported a rheumatic disease in the health interview survey were compared with persons hospitalized with a rheumatic diagnosis by using items in the health interview survey on perceived health, physical mobility and work capacity. The most important difference between the groups was a much higher proportion of disabled persons in the hospitalized group. Perceived health was reported very similarly in the two groups. The reports on hospital episodes in the health interview survey were validated against the in-patient register. An under-reporting of 13% and several inaccuracies in the timing of the hospital episodes were found.     

The Copenhagen County child cohort: design of a longitudinal study of child mental health

BACKGROUND: Epidemiological studies of psychopathology in the first years of life are few, and the association between mental health problems in infancy and psychiatric disturbances later in life has not been systematically investigated. The aim of the present project was to study mental health problems and possibilities of intervention from infancy and onward. METHODS: The basic study population consists of a birth cohort of 6,090 children born in the year 2000 in the County of Copenhagen, the Copenhagen County Child Cohort, CCCC 2000. At stage one CCCC 2000 was established on data from the Civil Registration System, Danish national registers, and standardized, longitudinal data from the first year of living obtained by public health nurses. At stage two a subsample was assessed at 1(1/2) years of age concerning child psychiatric illness and associated factors in a case-control study nested in the cohort, including a random sample. Participation rate at stage one was 92%. PERSPECTIVES: Ongoing studies of CCCC 2000 include studies of failure to thrive, register studies, and studies of the predictive validity of public health screening. A follow-up study concerning the prevalence of psychopathology at age 5 is planned. SUMMARY: The Copenhagen County Child Cohort CCCC 2000 is a longitudinal study of mental health from infancy investigating psychopathology in early childhood. Results from this study will add to the knowledge of risk factors and course of mental health problems in childhood and contribute to the validation of the mental health screening made by public health nurses.     

A POPULATION-BASED DIABETES REGISTER — DEVELOPMENT & APPLICATIONS

Population-based registers for chronic disorders are invaluable for better understanding the epidemiology, aetiology and natural history of a particular disorder. Insulin-dependent diabetes mellitus is one example where registers have been used. The disorder often develops at a relatively young age continuing throughout life with adverse influences on health, frequently causing premature mortality. It is well suited to systematised data collection and register development. In this paper, the rationale for registers is considered and methods used in development of a diabetes register in the Canterbury region of New Zealand (pop. one-third of a million) are described. A preliminary analysis of data using prevalence date of 1 January 1984, has shown that there are 1,148 (M = 574, F = 574) insulin-treated diabetic persons on the register. Ages range from two to 93 years (median = 52 years). Only 11.1 per cent of the diabetic population were aged under 20 years whereas 27 per cent were 65 or more years of age. Duration of diabetes was one to 58 years (median = 12 years). Only 28 per cent of cases had presented with diabetes at age under 20 years, most being diagnosed in adult life. The overall prevalence of insulin-treated diabetes was 3.3 per 1,000 population and peak prevalence was observed in those aged 60–69 years (7.5 per 1,000). Ongoing research with this register will document the natural history of the disorder, its morbidity and mortality, and will measure the use of secondary health care resources, particularly in-patient services.     

A survey of handicap registers for pre-school children in England and Wales

Summary This survey conducted by the Office of Population, Censuses and Surveys revealed 142 registers in England and Wales for pre-school children with impairments, disabilities and handicaps. Many registers were set up immediately after the re-organisation in 1974. In 1981 there were 18 computerized registers and of the manual registers 54 (44 per cent) had both an alphabetical and diagnostic index. It is estimated that 158 District Health Authorities would have good coverage by existing registers, though 96 registers (60 per cent) were operating at the former Area tier. The registers in general covered both congenital malformations and acquired impairments from birth to 5 years. A broad evaluation demonstrated that the registers were not meeting their stated objectives, and the survey highlighted wide variations in both the incidence and prevalence of selected conditions. Standardized systems need to be developed to obtain both useful and reliable information in this field, and the development of a register derived from the child health information system should be given consideration in the immediate future.     

Relative age for grade and adolescent risky health behavior

This paper uses Danish register data to examine the effect of relative age for grade on women’s risky health behavior. I exploit an administrative rule that creates a discontinuous jump in relative age for grade for children born around January 1. Being young-for-grade leads to a higher probability of an abortion and alcohol poisoning in adolescence and earlier births, cohabitation and contraceptive use. The results show how relative age for grade is a determinant of adolescent women’s risky sex and heavy drinking. For men, being young-for-grade have no effect on alcohol poisonings, fatherhood and cohabitation.     

Contingent Valuation Scenarios for Chronic Illnesses: The Case of Childhood Asthma

ObjectivesWe use a contingent valuation (CV) study of childhood asthma to discuss a central issue in designing CV studies of chronic illness—the need for a detailed, realistic scenario that minimizes confounding factors—and show how to address this issue. We apply our methodology to estimate households' willingness to pay (WTP) for reductions in asthma morbidity.MethodsBy using a combination of focus groups, revealed preference surveys, and epidemiological surveys, we gathered information on health status, attitudes, and beliefs regarding asthma, risk-averting behaviors, perceptions of these behaviors, and household socioeconomic characteristics. We used this information to design a CV survey that we extensively tested for validity. In the survey, we elicited participants' WTP for a hypothetical device that would reduce symptom-days by improving asthma management; these data enabled us to estimate household WTP by using a variety of econometric models.ResultsOur analysis of households with children with asthma yielded the following conclusions: the scenario should address both physical asthma symptoms and the psychosocial stress of managing a chronic illness; the survey should measure household perceptions of the burden of asthma in addition to objective measures such as symptom-days; and the scenario should not involve substantial behavioral changes or a new medication, to avoid confounding household preferences with unrelated attributes of the scenario. Our primary models estimated mean household WTP for a 50% reduction in symptom-days (and accompanying reductions in psychosocial stress) at $56.48 to $64.84 per month.ConclusionsOur methodology can be used to inform CV studies of chronic illness. Our WTP estimates can help regulatory agencies assess a wide range of policies that affect the incidence or severity of asthma.     

Health, place and childhood asthma in southwest Alaska

Social science theories of health and place posit that individuals perceive a relationship between characteristics of the geographic location in which they reside and their health, well-being, and self-identity. A number of ethnographies of health and place have studied how urban and suburban populations impacted by industrial pollution or waste have come to perceive a link between rates of cancer and their unhealthy environment. There has been little study of the applicability of the health and place framework to community perceptions of long-term chronic illness. This paper examines the asthma perceptions of Yup'ik parents of asthmatic children using data from semi-structured ethnographic interviews conducted in five villages and one town of the Yukon-Kuskokwim delta of southwest Alaska. Informants cited local climatic features, large-scale changes of the last 30 years to the village built landscape, and ongoing conditions of substandard housing and sanitation as etiological factors associated with childhood asthma. Our study suggests the need for further research concerning lay perceptions of one aspect of the epidemilogic transition-the association between chronic illness and place, especially in rural communities undergoing dramatic developmental change.