Birth weight in a large series of triplets

Background: Triplets are often born premature and with a low birth weight. Because the incidence of triplet births is rare, there are relatively few studies describing triplet birth weight characteristics. Earlier studies are often characterized by small sample sizes and lack information on important background variables such as zygosity. The objective of this study is to examine factors associated with birth weight in a large, population-based sample of triplets registered with the Netherlands Twin Register (NTR).Methods: In a sample of 1230 triplets from 410 families, the effects of assisted reproductive techniques, zygosity, birth order, gestational age, sex, maternal smoking and alcohol consumption during pregnancy on birth weight were assessed. The resemblance among triplets for birth weight was estimated as a function of zygosity. Birth weight discordance within families was studied by the pair-wise difference between triplets, expressed as a percentage of the birth weight of the heaviest child. We compare data from triplets registered with the NTR with data from population records, which include live births, stillbirths and children that have deceased within days after birth.Results: There was no effect of assisted reproductive techniques on triplet birth weight. At gestational age 24 to 40 weeks triplets gained on average 130 grams per week; boys weighed 110 grams more than girls and triplets of smoking mothers weighted 104 grams less than children of non-smoking mothers. Monozygotic triplets had lower birth weights than di- and trizygotic triplets and birth weight discordance was smaller in monozygotic triplets than in di- and trizygotic triplets. The correlation in birth weight among monozygotic and dizygotic triplets was 0.42 and 0.32, respectively. In nearly two-thirds of the families, the heaviest and the lightest triplet had a birth weight discordance over 15%. The NTR sample is representative for the Dutch triplet population that is still alive 28 days after birth.Conclusion: Birth weight is an important determinant of childhood development. Triplet status, gestational age, sex, zygosity and maternal smoking affect birth weight. The combined effects amount to a difference of 364 grams between monozygotic girl triplets of smoking mothers compared to dizygotic boy triplets of non-smoking mothers of the same gestational age. Birth weight in triplets is also influenced by genetic factors, as indicated by a larger correlation in monozygotic than in di- and trizygotic triplets

Canadian Valuation of EQ-5D Health States: Preliminary Value Set and Considerations for Future Valuation Studies

Background The EQ-5D is a preference based instrument which provides a description of a respondent's health status, and an empirically derived value for that health state often from a representative sample of the general population. It is commonly used to derive Quality Adjusted Life Year calculations (QALY) in economic evaluations. However, values for health states have been found to differ between countries. The objective of this study was to develop a set of values for the EQ-5D health states for use in Canada. Methods Values for 48 different EQ-5D health states were elicited using the Time Trade Off (TTO) via a web survey in English. A random effect model was fitted to the data to estimate values for all 243 health states of the EQ-5D. Various model specifications were explored. Comparisons with EQ-5D values from the UK and US were made. Sensitivity analysis explored different transformations of values worse than dead, and exclusion criteria of subjects. Results The final model was estimated from the values of 1145 subjects with socio-demographics broadly representative of Canadian general population with the exception of Quebec. This yielded a good fit with observed TTO values, with an overall R2 of 0.403 and a mean absolute error of 0.044. Conclusion A preference-weight algorithm for Canadian studies that include the EQ-5D is developed. The primary limitations regarded the representativeness of the final sample, given the language used (English only), the method of recruitment, and the difficulty in the task. Insights into potential issues for conducting valuation studies in countries as large and diverse as Canada are gained

Heritability estimates of body size in fetal life and early childhood

Background: The objective was to estimate the heritability for height and weight during fetal life and early childhood in two independent studies, one i

Economische evaluatie van preventie. Modelleringstudies naar de kosteneffectiviteit van accijnsverhogingen op alcohol en van depressiepreventie

Accijnsverhogingen op alcohol en een vroegtijdige opsporing van depressies leveren veel gezondheidswinst op tegen relatief lage kosten. De opsporing van dit stadium van een depressie door de huisarts, gevolgd door minimale contact psychotherapie (MCP) levert naar verwachting 13.000 gezonde levensjaren op en kost op termijn gemiddeld euro 6.800,- per gewonnen gezond levensjaar. De geplande accijnsverhoging voor 2009 levert naar verwachting 13.000 gezonde levensjaren op en kost op termijn gemiddeld euro 5.100,- per gewonnen gezond levensjaar. Beide maatregelen zijn daarmee kosteneffectieve interventies. Uit eerder onderzoek bleek dat beide interventies effectief zijn in het voorkomen van ziekte, alleen was nog weinig bekend over de kosteneffectiviteit. Daarom is in dit rapport met behulp van modelberekeningen de mogelijke kosteneffectiviteit in de Nederlandse context onderzocht. Hierbij is uitgegaan van grootschalige implementatie van de maatregelen. De gezondheidseffecten zijn uitgedrukt in voor kwaliteit gecorrigeerde gewonnen levensjaren (QALYs, oftewel gewonnen gezonde levensjaren) en alleen kosten binnen het gezondheidszorgperspectief zijn meegenomen. Andere kosten- en effectencategorieen zoals ziekteverzuim hebben ook een grote invloed op de kosteneffectiviteit van de interventies. Onderzoek naar de bredere kosten en effecten van preventieve interventies is daarom gewenst.Increasing alcohol taxes and case finding of sub-threshold depression and subsequent treatment thereof are both preventive interventions that yield high benefits at low costs. Case finding of sub-threshold depression in the setting of the Dutch general practitioner is estimated to result in health gains of approximately 13,000 QALYs at a cost of euro 6.800,- per QALY gained. The planned Dutch alcohol tax increase for 2009 results in on average 13,000 QALYs at a cost of euro 5.100,- per QALY gained. This report describes research on the cost-effectiveness of increases in alcohol taxes and case finding of sub-threshold depression and subsequent treatment thereof with Minimal Contact Psychotherapy (MCP). Both interventions have been proven effective in previous research. However, not much is known on the cost-effectiveness of these interventions. Therefore, using simulation models, the cost effectiveness of these interventions has been investigated for the Netherlands in this report. To do this, a health care perspective was taken implying that only health care costs were taken into account and that effects were expressed in Quality Adjusted Life Years (QALYs). Especially for the tax increase, taking the health care perspective effectively illustrated the advantages compared to interventions whose intervention costs traditionally fall inside the health sector like treatment of alcohol addiction or curative treatments in a hospital setting. For depression, which also has a high impact on health care costs, our modelling exercise revealed that even within this narrow perspective ignoring several important costs outside the health care setting, prevention of major depression appears to be cost-effective. However, it deserves recommendation to carry out further research into these interventions focusing on costs and consequences outside the health care sector.VWS-P

Economic evaluation of prevention. Modelling the cost-effectiveness of increasing alcohol taxes and of prevention of major depression

Accijnsverhogingen op alcohol en een vroegtijdige opsporing van depressies leveren veel gezondheidswinst op tegen relatief lage kosten. De opsporing van dit stadium van een depressie door de huisarts, gevolgd door minimale contact psychotherapie (MCP) levert naar verwachting 13.000 gezonde levensjaren op en kost op termijn gemiddeld euro 6.800,- per gewonnen gezond levensjaar. De geplande accijnsverhoging voor 2009 levert naar verwachting 13.000 gezonde levensjaren op en kost op termijn gemiddeld euro 5.100,- per gewonnen gezond levensjaar. Beide maatregelen zijn daarmee kosteneffectieve interventies. Uit eerder onderzoek bleek dat beide interventies effectief zijn in het voorkomen van ziekte, alleen was nog weinig bekend over de kosteneffectiviteit. Daarom is in dit rapport met behulp van modelberekeningen de mogelijke kosteneffectiviteit in de Nederlandse context onderzocht. Hierbij is uitgegaan van grootschalige implementatie van de maatregelen. De gezondheidseffecten zijn uitgedrukt in voor kwaliteit gecorrigeerde gewonnen levensjaren (QALYs, oftewel gewonnen gezonde levensjaren) en alleen kosten binnen het gezondheidszorgperspectief zijn meegenomen. Andere kosten- en effectencategorieen zoals ziekteverzuim hebben ook een grote invloed op de kosteneffectiviteit van de interventies. Onderzoek naar de bredere kosten en effecten van preventieve interventies is daarom gewenst