Ethnic disparities in infectious disease hospitalisations in the first year of life in New Zealand

AIM

Infectious disease (ID) hospitalisation rates are increasing in New Zealand (NZ), especially in pre-school children, and Māori and Pacific people. We aimed to identify risk factors for ID hospitalisation in infancy within a birth cohort of NZ children, and to identify differences in risk factors between ethnic groups.

METHODS

We investigated an established cohort of 6846 NZ children, born in 2009-2010, with linkage to a national data set of hospitalisations. We used multivariable logistic regression to obtain odds ratios (OR) for factors associated with ID hospitalisation in the first year of life, firstly for all children, and then separately for Māori or Pacific children.

RESULTS

In the whole cohort, factors associated with ID hospitalisation were Māori (OR: 1.49, 95% CI: 1.17-1.89) or Pacific (2.51; 2.00-3.15) versus European maternal ethnicity, male gender (1.32; 1.13-1.55), low birthweight (1.94, 1.39-2.66), exclusive breastfeeding for <4 months (1.22, 1.04-1.43), maternal experience of health-care racism (1.60, 1.19-2.12), household deprivation (most vs. least deprived quintile of households (1.50, 1.12-2.02)), day-care attendance (1.43, 1.12-1.81) and maternal smoking (1.55, 1.26-1.91). Factors associated with ID hospitalisation for Māori infants were high household deprivation (2.16, 1.06-5.02) and maternal smoking (1.48, 1.02-2.14); and for Pacific infants were delayed immunisation (1.72, 1.23-2.38), maternal experience of health-care racism (2.20, 1.29-3.70) and maternal smoking (1.59, 1.10-2.29).

CONCLUSIONS

Māori and Pacific children in NZ experience a high burden of ID hospitalisation. Some risk factors, for example maternal smoking, are shared, while others are ethnic-specific. Interventions aimed at preventing ID hospitalisations should address both shared and ethnic-specific factors.

Internal living environment and respiratory disease in children: findings from the Growing Up in New Zealand longitudinal child cohort study

BACKGROUND

The incidence of early childhood acute respiratory infections (ARIs) has been associated with aspects of the indoor environment. In recent years, public awareness about some of these environmental issues has increased, including new laws and subsequent changes in occupant behaviours. This New Zealand study investigated current exposures to specific risk factors in the home during the first five years of life and provided updated evidence on the links between the home environment and childhood ARI hospitalisation.

METHODS

Pregnant women (n = 6822) were recruited in 2009 and 2010, and their 6853 children created a child cohort that was representative of New Zealand births from 2007-10. Longitudinal data were collected through face-to-face interviews and linkage to routinely collected national datasets. Incidence rates with Poisson distribution confidence intervals were computed and Cox regression modelling for repeated events was performed.

RESULTS

Living in a rented dwelling (48%), household crowding (22%) or dampness (20%); and, in the child's room, heavy condensation (20%) or mould or mildew on walls or ceilings (13%) were prevalent. In 14% of the households, the mother smoked cigarettes and in 30%, other household members smoked. Electric heaters were commonly used, followed by wood, flued gas and unflued portable gas heaters. The incidence of ARI hospitalisation before age five years was 33/1000 person-years. The risk of ARI hospitalisation was higher for children living in households where there was a gas heater in the child's bedroom: hazard ratio for flued gas heater 1.69 (95% CI: 1.21-2.36); and for unflued gas heater 1.68 (95% CI: 1.12-2.53); and where a gas heater was the sole type of household heating (hazard ratio: 1.64 (95% CI: 1.29-2.09)). The risk was reduced in households that used electric heaters (Hazard ratio: 0.74 (95% CI: 0.61-0.89)) or wood burners (hazard ratio: 0.79 (95% CI: 0.66-0.93)) as a form of household heating. The associations with other risk factors were not significant.

CONCLUSIONS

The risk of early childhood ARI hospitalisation is increased by gas heater usage, specifically in the child's bedroom. Use of non-gas forms of heating may reduce the risk of early childhood ARI hospitalisation.

The association between maternal and partner experienced racial discrimination and prenatal perceived stress, prenatal and postnatal depression: findings from the growing up in New Zealand cohort study

BACKGROUND

A growing number of studies document the association between maternal experiences of racial discrimination and adverse children's outcomes, but our understanding of how experiences of racial discrimination are associated with pre- and post-natal maternal mental health, is limited. In addition, existent literature rarely takes into consideration racial discrimination experienced by the partner.

METHODS

We analysed data from the Growing Up in New Zealand study to examine the burden of lifetime and past year experiences of racial discrimination on prenatal and postnatal mental health among Māori, Pacific, and Asian women in New Zealand (NZ), and to study the individual and joint contribution of mother's and partner's experiences of lifetime and past year racial discrimination to women's prenatal and postnatal mental health.

RESULTS

Our findings show strong associations between lifetime and past year experiences of ethnically-motivated interpersonal attacks and unfair treatment on mother's mental health. Māori, Pacific, and Asian women who had experienced unfair treatment by a health professional in their lifetime were 66 % more likely to suffer from postnatal depression, compared to women who did not report these experiences. We found a cumulative effect of lifetime experiences of ethnically-motivated personal attacks on poor maternal mental health if both the mother and the partner had experienced a racist attack.

CONCLUSIONS

Experiences of racial discrimination have severe direct consequences for the mother's mental health. Given the importance of mother's mental health for the basic human needs of a healthy child, racism and racial discrimination should be addressed.

A review of intrauterine contraception in the Asia-Pacific region

BACKGROUND

Across the Asia-Pacific region, approximately 38% of pregnancies are unintended. Long-acting reversible contraception, such as intrauterine contraception (IUC), is effective in reducing unintended pregnancy.

OBJECTIVE

This study aims to review access to, uptake of and influencing factors on IUC use in the Asia-Pacific region.

METHODS

We searched PubMed and MEDLINE for articles published between 1990 and 2015. We identified and reviewed primary studies that examined the following points and were relevant to the Asia-Pacific region: available types and utilization rates of IUC and factors that influence these. We also obtained the opinions of local experts to gain a better understanding of the situation in specific countries.

RESULTS

Types of IUC used and utilization rates vary widely across the region. Factors influencing rates of utilization relate to healthcare systems, such as government policy on and subsidization of IUC, types of healthcare providers authorized to place IUC and local guidelines on preinsertion screening. Healthcare provider factors include concerns around pelvic inflammatory disease and the suitability of IUC in certain groups of women, whereas end-user factors include lack of awareness of IUC, concerns about safety, cultural or religious attitudes, access to IUC and costs.

CONCLUSIONS

Across the Asia-Pacific region, clear data gaps and unmet needs exist in terms of access to and uptake of IUC. We believe that several recommendations are necessary to update future practice and policy for enhanced IUC utilization so that women across this region have better access to IUC.

Dietary Patterns in Pregnancy in New Zealand-Influence of Maternal Socio-Demographic, Health and Lifestyle Factors

Exploration of dietary pattern associations within a multi-ethnic society context has been limited. We aimed to describe dietary patterns of 5664 pregnant women from the Growing Up in New Zealand study, and investigate associations between these patterns and maternal socio-demographic, place of birth, health and lifestyle factors. Participants completed a food frequency questionnaire prior to the birth of their child. Principal components analysis was used to extract dietary patterns and multivariable analyses used to determine associations. Four dietary components were extracted. Higher scores on, ‘Junk’ and ‘Traditional/White bread’, were associated with decreasing age, lower educational levels, being of Pacific or Māori ethnicity and smoking. Higher scores on, ‘Health conscious’ and ‘Fusion/Protein’, were associated with increasing age, better self-rated health, lower pre-pregnancy body mass index (BMI) and not smoking. Higher scores on ‘Junk’ and ‘Health conscious’ were associated with being born in New Zealand (NZ), whereas higher scores on ‘Fusion/Protein’ was associated with being born outside NZ and being of non-European ethnicity, particularly Asian. High scores on the ‘Health conscious’ dietary pattern showed the highest odds of adherence to the pregnancy dietary guidelines. In this cohort of pregnant women different dietary patterns were associated with migration, ethnicity, socio-demographic characteristics, health behaviors and adherence to dietary guidelines.

Longitudinal Intergenerational Birth Cohort Designs: A Systematic Review of Australian and New Zealand Studies

BACKGROUND

The longitudinal birth cohort design has yielded a substantial contribution to knowledge of child health and development. The last full review in New Zealand and Australia in 2004 identified 13 studies. Since then, birth cohort designs continue to be an important tool in understanding how intrauterine, infant and childhood development affect long-term health and well-being. This updated review in a defined geographical area was conducted to better understand the factors associated with successful quality and productivity, and greater scientific and policy contribution and scope.

METHODS

We adopted the preferred reporting items for systematic reviews and meta-analyses (PRISMA) approach, searching PubMed, Scopus, Cinahl, Medline, Science Direct and ProQuest between 1963 and 2013. Experts were consulted regarding further studies. Five inclusion criteria were used: (1) have longitudinally tracked a birth cohort, (2) have collected data on the child and at least one parent or caregiver (3) be based in Australia or New Zealand, (4) be empirical in design, and (5) have been published in English.

RESULTS

10665 records were initially retrieved from which 23 birth cohort studies met the selection criteria. Together these studies recruited 91,196 participants, with 38,600 mothers, 14,206 fathers and 38,390 live births. Seventeen studies were located in Australia and six in New Zealand. Research questions initially focused on the perinatal period, but as studies matured, longer-term effects and outcomes were examined.

CONCLUSIONS

This review demonstrates the significant yield from this effort both in terms of scientific discovery and social policy impact. Further opportunities have been recognised with cross-study collaboration and pooling of data between established and newer studies and international studies to investigate global health determinants.

Antenatal immunisation intentions of expectant parents: Relationship to immunisation timeliness during infancy

BACKGROUND

Most women decide about infant immunisation during pregnancy. However, we have limited knowledge of the immunisation intentions of their partners. We aimed to describe what pregnant women and their partners intended for their future child's immunisations, and to identify associations between parental intentions and the subsequent timeliness of infant immunisation.

METHODS

We recruited a cohort of pregnant New Zealand (NZ) women expecting to deliver between April 2009 and March 2010. The cohort included 11% of births in NZ during the recruitment period and was generalisable to the national birth cohort. We completed antenatal interviews independently with mothers and partners. We determined immunisation receipt from the National Immunisation Register and defined timely immunisation as receiving all vaccines (scheduled at 6-weeks, 3- and 5-months) within 30 days of their due date. We described independent associations of immunisation intentions with timeliness using adjusted odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Of 6172 women, 5014 (81%) intended full immunisation, 245 (4%) partial immunisation, 140 (2%) no immunisation and 773 (13%) were undecided. Of 4152 partners, 2942 (71%) intended full immunisation, 208 (5%) partial immunisation, 83 (2%) no immunisation and 921 (22%) were undecided. Agreement between mothers and partners was moderate (Kappa=0.42). Timely immunisation occurred in 70% of infants. Independent of their partner's intentions, infants of pregnant women who decided upon full immunisation were more likely to be immunised on time (OR=7.65, 95% CI: 4.87-12.18). Independent of the future mother's intentions, infants of partners who had decided upon full immunisations were more likely to be immunised on time (OR=3.33, 95% CI: 2.29-4.84).

CONCLUSIONS

During pregnancy, most future parents intend to fully immunise their child; however, more partners than mothers remain undecided about immunisation. Both future mothers' and future fathers' intentions are independently associated with the timeliness of their infant's immunisations.

Depression symptoms during pregnancy: Evidence from Growing Up in New Zealand

BACKGROUND

Depression during pregnancy has significant implications for pregnancy outcomes and maternal and child health. There is a need to identify which family, physical and mental health factors are associated with depression during pregnancy.

METHODS

An ethnically and socioeconomically diverse sample of 5664 pregnant women living in New Zealand completed a face-to-face interview during the third trimester. Antenatal depression (AD) symptoms were assessed using the Edinburgh Postnatal Depression Scale (EPDS). Maternal demographic, physical and mental health, and family and relationship characteristics were measured. The association between symptoms of AD and maternal characteristics was determined using multiple logistic regression.

RESULTS

11.9% of the participating women had EPDS scores (13+) that indicated probable AD. When considering sociodemographic predictors of AD symptoms, we found that women from non-European ethnicities, specifically Pacific Islander, Asian and other, were more likely to suffer from AD symptoms. Greater perceived stress during pregnancy and a diagnosis of anxiety both before and during pregnancy were also associated with greater odds of having AD according to the EPDS.

LIMITATIONS

The women were in their third trimester of pregnancy at the interview. Therefore, we cannot discount the possibility of recall bias for questions relating to pre-pregnancy status or early-pregnancy behaviours.

CONCLUSIONS

AD is prevalent amongst New Zealand women. Ethnicity, perceived stress and anxiety are particularly associated with a greater likelihood of depression during pregnancy. Further attention to supporting maternal mental health status in the antenatal period is required.

Provider engagement and choice in the Lead Maternity Carer System: Evidence from Growing Up in New Zealand

BACKGROUND

New Zealand (NZ) has a unique choice-based model of maternity care.

AIMS

To examine how engagement in antenatal care and choice of Lead Maternity Care provider (LMC) vary with maternal demographics.

MATERIALS AND METHODS

Our sample consisted of 6822 women enrolled during 2009 and 2010 into a longitudinal cohort study Growing Up in New Zealand. We asked if women had engaged a LMC, the type of LMC and whether they had a choice of LMC. Associations with maternal ethnicity, age, parity and education and household deprivation were determined.

RESULTS

Ninety-eight per cent of women had engaged a LMC provider. Twelve per cent reported not experiencing choice and 11% not receiving their first choice of LMC provider. The reported LMC provider type was independent midwife (66%), hospital midwife (15%), private obstetrician (8%), shared midwife and general practitioner (GP) (5%) and GP-only care (<1%). LMC provider type and choice varied with maternal demographics. Women not engaging a LMC were more likely to be non-European, <20 years or >40 years old, with poorer educational attainment, or living in more deprived households. Women not experiencing choice of provider were more likely to be non-European, <20 years old, or living in more deprived households.

CONCLUSIONS

The current unequal distribution of provider engagement and choice in NZ has relevance for a number of specific maternity policies, including policies seeking to improve engagement in antenatal care. The study findings have international relevance as an example of the impact of choice policies on equity.

Early engagement with a Lead Maternity Carer: results from Growing Up in New Zealand

BACKGROUND

Timely engagement in antenatal care improves maternal and child health outcomes and is an important element of healthcare performance measurement.

AIMS

To describe the timeliness of lead maternity carer (LMC) engagement and identify the factors associated with timely engagement.

MATERIALS AND METHODS

The Growing Up in New Zealand longitudinal study enrolled a diverse sample of pregnant women during 2009 and 2010. Timely engagement was defined as before ten weeks gestation. Independent associations of LMC type; maternal ethnicity, age, parity and education, and household deprivation with timely engagement were described using odds ratios (OR) and 95% confidence intervals (CIs).

RESULTS

Of the 6822 women enrolled, 6661 (98%) stated they had a LMC. Of these 6661, 6012 (90%) reported the time taken to engage a LMC. Eighty-six to 92% of women engaged a LMC in a timely manner depending upon the estimate of gestational time used. Factors independently associated with delayed engagement were Māori (odds ratio (OR) = 0.59, 95% CI 0.44-0.80), Pacific (0.63, 0.46-0.86) or Asian (0.51, 0.39-0.67) ethnicity; first pregnancy (0.71, 0.58-0.88); age <20 years (0.62, 0.41-0.94); socio-economic deprivation (0.69, 0.52-0.92); and LMC type being a hospital midwife (0.47, 0.38-0.60), or a combination of care providers (0.60, 0.42-0.90).

CONCLUSIONS

Timeliness of LMC engagement in NZ is poorer for non-European women, younger women, women in their first pregnancy, and women living in more socioeconomically deprived areas. Improving the timeliness of LMC engagement for these groups of women has the potential to reduce inequalities in maternal and child health outcomes.

Professionally designed information materials and telephone reminders improved consent response rates: evidence from an RCT nested within a cohort study

Objectives

To investigate whether different study-to-participant communication methods increase response, increase response from hard-to-engage individuals, and influence participants' consent decisions.

Study Design and Setting

A randomized controlled trial within the Avon Longitudinal Study of Parents and Children. Cohort members were invited to re-enroll at age 18 and consent to linkage to their health and administrative records. Participants were randomized to receive one of eight combinations of three interventions: a prior-notification postcard or no contact, a standard or professionally designed consent pack, and a phone or postal reminder. The primary outcome was return of the consent form (“response”), with consent decision being the secondary outcome.

Results

Of 1,950 participants, 806 (41%) responded. Response rates were 2.7% higher (95% confidence interval: −0.06, 5.5%; P = 0.06) among those receiving designed packs than among those receiving standard packs and 6.4% higher (2.3, 10.6%; P = 0.002) among those receiving phone reminders (compared with postal reminders). The prior-notification postcard did not influence response rates [difference = 0% (−2.8, 2.8%; P = 1.0)], and we found no evidence that the communication method influenced consent decision.

Conclusion

This trial provides evidence that communication material design can influence response rates and that phone reminders have superior cost/benefit returns over designed materials. Experimental evaluation of communications strategies and dissemination of findings may benefit cohort studies.

Demographic and psychological predictors of panel attrition: evidence from the New Zealand attitudes and values study

This study examines attrition rates over the first four years of the New Zealand Attitudes and Values Study, a longitudinal national panel sample of New Zealand adults. We report the base rate and covariates for the following four distinct classes of respondents: explicit withdrawals, lost respondents, intermittent respondents and constant respondents. A multinomial logistic regression examined an extensive range of demographic and socio-psychological covariates (among them the Big-Six personality traits) associated with membership in these classes (N = 5,814). Results indicated that men, Māori and Asian peoples were less likely to be constant respondents. Conscientiousness and Honesty-Humility were also positively associated with membership in the constant respondent class. Notably, the effect sizes for the socio-psychological covariates of panel attrition tended to match or exceed those of standard demographic covariates. This investigation broadens the focus of research on panel attrition beyond demographics by including a comprehensive set of socio-psychological covariates. Our findings show that core psychological covariates convey important information about panel attrition, and are practically important to the management of longitudinal panel samples like the New Zealand Attitudes and Values Study.

The interaction between epigenetics, nutrition and the development of cancer

Unlike the genome, the epigenome can be modified and hence some epigenetic risk markers have the potential to be reversed. Such modifications take place by means of drugs, diet or environmental exposures. It is widely accepted that epigenetic modifications take place during early embryonic and primordial cell development, but it is also important that we gain an understanding of the potential for such changes later in life. These “later life” epigenetic modifications in response to dietary intervention are the focus of this paper. The epigenetic modifications investigated include DNA methylation, histone modifications and the influence of microRNAs. The epigenotype could be used not only to predict susceptibility to certain cancers but also to assess the effectiveness of dietary modifications to reduce such risk. The influence of diet or dietary components on epigenetic modifications and the impact on cancer initiation or progression has been assessed herein.

Adherence to nutritional guidelines in pregnancy: evidence from the Growing Up in New Zealand birth cohort study

OBJECTIVE

To determine adherence to nutritional guidelines by pregnant women in New Zealand and maternal characteristics associated with adherence.

DESIGN

A cohort of the pregnant women enrolled into New Zealand's new birth cohort study, Growing Up in New Zealand.

SETTING

Women residing within a North Island region of New Zealand, where one-third of the national population lives.

SUBJECTS

Pregnant women (n 5664) were interviewed during 2009-2010. An FFQ was administered during the face-to-face interview.

RESULTS

The recommended daily number of servings of vegetables and fruit (≥6) were met by 25 % of the women; of breads and cereals (≥6) by 26 %; of milk and milk products (≥3) by 58 %; and of lean meat, meat alternatives and eggs (≥2) by 21 %. One in four women did not meet the recommendations for any food group. Only 3 % met all four food group recommendations. Although adherence to recommendation for the vegetables/fruit group did not vary by ethnicity (P=0·38), it did vary for the breads/cereals, milk/milk products and meat/eggs groups (all P<0·001). Adherence to recommendations for the vegetables/fruit group was higher among older women (P=0·001); for the breads/cereals group was higher for women with previous children (P<0·001) and from lower-income households (P<0·001); and for the meat/eggs group was higher for women with previous children (P=0·003) and from lower-income households (P=0·004).

CONCLUSIONS

Most pregnant women in New Zealand do not adhere to nutritional guidelines in pregnancy, with only 3 % meeting the recommendations for all four food groups. Adherence varies more so with ethnicity than with other sociodemographic characteristics.