Evaluating the immediate and longer term impact of a refusal conversion strategy in a large scale longitudinal study

Refusal conversion is one of the fieldwork strategies commonly used to minimise non-response in surveys. There is, however, relatively little evidence about the effectiveness of this strategy, particularly for face-to-face longitudinal surveys. Moreover, much of the existing evidence is based on observational studies. This paper evaluates the effectiveness of a fieldwork strategy – intensive re-issuing - to convert refusals using evidence from an intervention on a random sub-sample of refusals implemented in wave four of a large scale longitudinal study in the UK: the Millennium Cohort Study. We show that intensive re-issuing is an effective way of reducing the refusal rate. We also show that refusal conversion led to a modest reduction in non-response bias in the survey estimates for several key variables. The longer term impact of refusal conversion is also a key concern in longitudinal surveys. We demonstrate that, although the majority of converted refusals go on to participate in the subsequent wave of the study, there is no overall effect of intensive re-issuing on sample size at this wave

Adjusting for Measurement Error in Retrospectively Reported Work Histories: An Analysis Using Swedish Register Data

We use work histories retrospectively reported and matched to register data from the Swedish unemployment office to assess: 1) the prevalence of measurement error in reported spells of unemployment; 2) the impact of using such spells as the response variable of an exponential model; and 3) strategies for the adjustment of the measurement error. Due to the omission or misclassification of spells in work histories we cannot carry out typical adjustments for memory failures based on multiplicative models. Instead we suggest an adjustment method based on a mixture Bayesian model capable of differentiating between misdated spells and those for which the observed and true durations are unrelated. This adjustment is applied in two manners, one assuming access to a validation subsample and another relying on a strong prior for the mixture mechanism. Both solutions demonstrate a substantial reduction in the vast biases observed in the regression coefficients of the exponential model when survey data is used

Higher IL-10 levels are associated with less effective clearance of Plasmodium falciparum parasites

The implications of high levels of the immune regulatory cytokine IL-10 in Plasmodium falciparum malaria are unclear. IL-10 may down-regulate pro-inflammatory responses and also exacerbate disease by inhibiting anti-parasitic immune functions. To study possible inhibiting effects on parasite clearance, IL-10 plasma levels were determined in 104 Tanzanian children, 1 to 4 years old, with acute uncomplicated P. falciparum malaria, and analysed for association with parasite densities during 3 days of anti-malarial treatment. Higher baseline IL-10 plasma levels were associated with statistically significantly higher parasite densities after 24, 48 and 72 h of treatment. These associations could not be explained by differences in initial parasitaemia, temperature, age, sex or type of treatment. Induction of high IL-10 production might be a direct or indirect mechanism whereby the parasite evades the immune response

Teenage social behaviour and emotional well‐being : the role of gender and socio‐economic factors

his article draws on the Millennium Cohort Study (MCS) to examine parent ratings of social, emotional and behavioural difficulties and prosocial behaviour in pre‐ and mid‐adolescents. A series of mixed‐design ANOVAs yielded interesting results. Parent ratings of emotional difficulties in girls increased as they moved from pre‐ to mid‐adolescence whereas for boys the reverse was found. Peer problems were found to be on the rise, whereas prosocial skills decreased for 14‐year‐olds. Most importantly, significant associations were found between socio‐economic measures (that is, family income and parent education) and ratings across the domains of the Strengths and Difficulties Questionnaire, highlighting the socio‐economic specificity of behaviour and well‐being in adolescents. These findings have significant implications for understanding trends in young people's social behaviour and emotional well‐being from pre‐ to mid‐adolescence within their socio‐economic context

Mobile Families and Other Challenges in the Design of the Millennium Cohort Study

The Millennium Cohort Study continues the tradition of Britain?s national longitudinal birth cohort surveys, but it has broken the design mould of being based on all births in a week. The specification that it should cover a year?s births provided the opportunity for some innovative design. This paper describes the disproportionately stratified design, based on a sample of electoral wards and the practicalities of implementing it. The need to sample offered the possibility of over representing populations of particular interest: children living in economically deprived areas, in areas where minority ethnic groups are concentrated, and in the smaller countries of the UK. Eligible families in sampled wards are selected from records held by the Department for Work and Pensions, who also subsequently administer an opt-out to families in sampled areas. Although the final analysis of the sampling process (and the substantive results) will not be ready until 2003, it will be possible to present an interim report on the experience of drawing the sample in this way, focusing particularly on England and Wales, where the survey started earlier. The number of children identified through the administrative records will be compared with those recorded in Birth Registration records, as far as ward boundary changes allow. The cases withdrawn before a sample can be issued to field are analysed by type of ward and type of claimant. A preliminary assessment of the coverage of the Child Benefit Register is offered in a comparison with data from vital registration. This exercise has so far only covered those wards in England where there have been no boundary changes between those used to define the sample in 1998 and those applying in 2000-2001 when the children were actually born. The extent of mobility in and out of target areas by families with children aged 6-9 months is also to be discussed. The strengths of using the Child Benefit register as a sampling frame have been confirmed. The difficulties have in some ways been less than anticipated, and the requirement of a geographically defined sample would have formed a challenge whatever method of sampling had been adopted

Psychological wellbeing of fathers with and without a child with intellectual disability : a population-based study

Background Few studies have explored the well‐being of fathers of children with intellectual disability (ID), despite the significant role that they play in their children's lives. The current study compared fathers of children with and without a child with ID on measures of psychological well‐being (life satisfaction, work–family balance and general health) and dimensions of parenting (parenting self‐efficacy and parent–child closeness) and then examined whether the presence of a child with ID in the family was a significant predictor of paternal well‐being when controlling for a number of father (age, education, employment and residency), child (ID status, gender, behavioural and emotional problems) and family (income poverty and number of children in the household) variables. Methods Data were drawn from the third wave of the Millennium Cohort Study, a UK population‐representative and cohort study, where the cohort child was 5 years of age; 256 fathers were identified as having a child with ID, with data available for 10 187 fathers without a child with ID. Fathers were compared on the four well‐being and parenting outcomes and then multiple regression models were conducted to explore associations between these outcomes and variables identified as potential correlates of well‐being. Results Initial group comparisons showed that there were differences in the well‐being of fathers, with fathers of children with ID reporting poorer life satisfaction and general health. However, these differences were small. Regression analyses showed that child behavioural and emotional problems, living in income poverty and paternal employment were more important than disability status in predicting fathers' well‐being. Conclusions These works add to the limited amount of research on fathers using population‐representative data. The current findings are consistent with rejecting a general simplistic and negative narrative that raising a child with ID puts fathers at risk of poorer outcomes. However, some fathers, such as those with children with behavioural problems and living in poverty, may require greater support. Future longitudinal research that explores the impact of paternal well‐being on the long‐term outcomes of children with and without ID is warranted

Prevalence of maternal smoking and environmental tobacco smoke exposure during pregnancy and impact on birth weight: retrospective study using Millennium Cohort

<p>Abstract</p> <p>Background</p> <p>Meta-analyses of studies investigating the impact of maternal environmental tobacco smoke (ETS) on birth weight have not produced robust findings. Although, ante natal ETS exposure probably reduces infant's birth weights, the scale of this exposure remains unknown. We conducted a large, cohort study to assess the impact of ETS exposure on birth weight whilst adjusting for the many factors known to influence this.</p> <p>Method</p> <p>Retrospective study using interview data from parents of 18,297 children born in 2000/2001 and living in the UK 9 months afterwards (the Millennium Cohort Survey). Comparison of birth weight, sex and gestational age specific (SGA) z score, birth before 37 weeks and birth weight < 2.5 Kg (LBW) in infants born to women exposed to: i) no tobacco smoke, ii) ETS only and iii) maternal smoking whilst pregnant.</p> <p>Results</p> <p>13% of UK infants were exposed to ETS and 36% to maternal smoking ante natally. Compared to no ante natal tobacco smoke exposure, domestic ETS lowered infants' adjusted mean birth weights by 36 g (95% CI, 5 g to 67 g) and this effect showed a dose-response relationship. ETS exposure also caused non-significant increases in the adjusted risks of Low Birth Weight (<2.5 Kg) [OR 1.23 (95% CI, 0.96 to 1.58) and premature birth [OR 1.21 (95% CI, 0.96 to 1.51)], whilst the impacts of maternal smoking were greater and statistically significant.</p> <p>Conclusion</p> <p>UK prevalences of domestic ETS exposure and maternal smoking in pregnancy remain high and ETS exposure lowers infants' birth weights.</p