Interventions to improve vaccine coverage of pregnant women in Aotearoa New Zealand.

Introduction Maternal vaccination against influenza and pertussis protects mothers and babies from severe disease and is recommended and funded in Aotearoa New Zealand. Despite this, maternal vaccination uptake is low, varies by region and is inequitable, with Maori and Pacific mama (mothers) less likely to receive vaccination. Aim To determine what interventions currently exist to support and encourage maternal vaccination against influenza and pertussis and what changes and interventions could be implemented to improve coverage, with a focus on Maori and Pacific hapu mama (pregnant mothers). Methods Interviews with six participants with diverse roles in the vaccination workforce were conducted. Participants were involved in education, certification and supporting vaccinators, high-level strategising, and vaccination. Interviews aimed to determine what interventions currently exist for hapu mama, what changes need to be made to improve coverage and how Maori and Pacific people have been specifically engaged. Qualitative data analysis was used to determine themes. Results Participants identified that interventions must focus on prioritising and emphasising the importance of maternal vaccination, promoting collaboration and innovation, making interventions accessible, and empowering Maori- and Pacific-driven avenues to vaccination. To create positive foundations, participants identified the importance of building and maintaining trust and affording mothers' time and autonomy in vaccination. Discussion Healthcare professionals need to proactively engage hapu mama about vaccination and collaborate in service delivery. Interventions must be suitably accessible and allow for the autonomy of hapu mama over vaccination decisions. Equity should be considered at the foundation of vaccine interventions to improve the accessibility of vaccines to all communities.

A retrospective cohort study investigating the comparative effectiveness of pneumococcal vaccines against hospitalisation with otitis media and pneumonia in New Zealand.

BACKGROUND: Since 2008 New Zealand has used three different formulations of pneumococcal vaccines on the national infant schedule, PCV7, PCV10 and PCV13, switching between PCV10 and PCV13 twice in 10 years. We have used New Zealand's linkable, administrative health data to examine the comparative risk of otitis media (OM) and pneumonia hospitalisations among children receiving three different pneumococcal conjugate vaccines (PCV). METHODS: This was a retrospective cohort study using linked administrative data. Outcomes were otitis media, all cause pneumonia and bacterial pneumonia related hospitalisation for children in three cohorts representing periods where PCVs transitioned between PCV7, PCV10, PCV13 and back to PCV10 between 2011 and 2017. Cox's proportional hazard regression was used to provide hazard ratio estimates to compare outcomes for children vaccinated with different vaccine formulations and to adjust for different sub population characteristics. RESULTS: Each observation period, where different vaccine formulations coincided, and therefore comparable with respect to age and the environment, included over fifty-thousand infants and children. PCV10 was associated with a reduced risk for OM compared with PCV7 (Adjusted HR 0.89, 95 %CI 0.82-0.97). There were no significant differences between PCV10 and PCV13 in risk of hospitalisation with either otitis media or all-cause pneumonia amongst the transition 2 cohort. In the 18 -month follow-up, after transition 3, PCV13 was associated with a marginally higher risk of all-cause pneumonia and otitis media compared to PCV10. CONCLUSION: These results should offer reassurance about the equivalence of these pneumococcal vaccines against the broader pneumococcal disease outcomes OM and pneumonia.

Multi-decade national cohort identifies adverse pregnancy and birth outcomes associated with acute respiratory illness hospitalisations during the influenza season.

BACKGROUND: Despite the World Health Organization (WHO) recommendation that pregnant women be prioritised for seasonal influenza vaccination, coverage in the Western Pacific Region remains low. Our goal was to provide additional data for the Western Pacific Region about the value of maternal influenza vaccination to pregnant women and their families. METHODS: We conducted a 16-year retrospective cohort to evaluate risks associated with influenza-associated maternal acute respiratory infection (ARI) in New Zealand. ARI hospitalisations during the May to September influenza season were identified using select ICD-10-AM primary and secondary discharge codes from chapter J00-J99 (diseases of the respiratory system). Cox proportional hazards models were used to calculate crude and adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). RESULTS: We identified 822,391 pregnancies among New Zealand residents between 2003 and 2018; 5095 (0.6%) had ≥1 associated ARI hospitalisation during the influenza season; these pregnancies were at greater risk of preterm birth (aHR 1.50, 95% CI 1.39-1.61) and low birthweight (aHR 1.64, 95% CI 1.51-1.79) than pregnancies without such hospitalisations. We did not find an association between maternal ARI hospitalisation and fetal death (aHR 0.96, 95% CI 0.69-1.34) during the influenza season. Maternal influenza vaccination was associated with reduced risk of preterm birth (aHR 0.79, 95% CI 0.77-0.82), low birthweight (aHR 0.87, 95% CI 0.83-0.90) and fetal death (aHR 0.50%, 95% CI 0.44-0.57). CONCLUSION: In this population-based cohort, being hospitalised for an ARI during the influenza season while pregnant was a risk factor for delivering a preterm or a low birthweight infant and vaccination reduced this risk.

Evidence of suboptimal maternal vaccination coverage in pregnant New Zealand women and increasing inequity over time: A nationwide retrospective cohort study.

BACKGROUND: Adequate maternal vaccination coverage is critical for the prevention and control of infectious disease outbreaks such as pertussis, influenza, and more recently COVID-19. To guide efforts to increase vaccination coverage this study examined the extent of vaccination coverage in pregnant New Zealand women over time by area-level deprivation and ethnicity. METHODS: A retrospective cohort study was used consisting of all pregnant women who delivered between 01 January 2013 and 31 December 2018, using administrative health datasets. Outcomes were defined as receipt of influenza or pertussis vaccination in any one of the relevant data sources (National Immunisation Register, Proclaims, or Pharmaceutical collection) during their eligible pregnancy. Ethnicity was prioritised as Maori (NZ indigenous), Pacific, Asian, and Other or NZ European and deprivation was defined using New Zealand Index of Multiple Deprivation (IMD). RESULTS: Between 2013 and 2018, Asian women had the highest maternal vaccination coverage (36%) for pertussis, while Maori and Pacific women had the lowest, 13% and 15% respectively. Coverage of pertussis vaccination during pregnancy in low deprivation Maori women was 24% and 28% in Pacific women. This is in comparison to 30% and 25% in high deprivation Asian and European/Other women, respectively. Similar trends were seen for influenza. CONCLUSION: Between 2013 and 2018 maternal vaccination coverage increased for pertussis and influenza. Despite this coverage remains suboptimal, and existing ethnic and deprivation inequities increased. There is an urgent need to focus on equity, to engage and support ethic communities by creating genuinely accessible, culturally appropriate health services.

Increasing Uptake of Maternal Pertussis Vaccinations through Funded Administration in Community Pharmacies.

Although maternal pertussis vaccination is recommended, uptake is suboptimal in New Zealand (NZ), despite full funding in general practice and hospitals. We determined whether funding maternal pertussis vaccination in community pharmacy increases its uptake. Pertussis vaccination during pregnancy was compared between non-contiguous, demographically similar regions of NZ. The pertussis vaccine was funded at pharmacies from Nov 2016 in one NZ region (Waikato), but not in comparator regions (Northland, Hawkes Bay). Vaccinations during pregnancy were determined from the National Immunisation Register, general practice and pharmacy claims data, and a maternity database. Comparisons were made using adjusted odds ratios (OR) and 95% confidence intervals (CI) for Nov 2015 to Oct 2016 versus Nov 2016 to Oct 2019. The odds of pregnancy pertussis vaccination increased in the post-intervention versus pre-intervention period with this increase being larger (p = 0.0014) in the intervention (35% versus 21%, OR = 2.07, 95% CI 1.89-2.27) versus the control regions (38% versus 26%, OR = 1.67, 95% CI 1.52-1.84). Coverage was lower for Maori versus non-Maori, but increased more for Maori in the intervention versus control regions (117% versus 38% increase). It was found that funding maternal pertussis vaccination in pharmacy increases uptake, particularly for Maori women. Measures to increase coverage should include reducing barriers to vaccines being offered by non-traditional providers, including pharmacies.

Does the National Immunisation Register stack up? Quantifying accuracy when compared to parent-held health record books.

AIM: The National Immunisation Register (NIR), which is derived from general practice management systems, is an important tool for the provision of clinical services, national immunisation programme evaluation and immunisation research in New Zealand. However, the accuracy of the NIR data has not yet been quantified. This study aimed to examine, describe and quantify the extent of discrepancy in the NIR compared to Well Child Tamariki Ora parent-held health record books (Health Books). METHOD: Immunisation data for vaccinations given between birth and four years old for children born between 2006 and 2019 were compared between the Health Books and the NIR. Health Book records were used as the reference standard to calculate performance measures: sensitivity, specificity, positive and negative predictive values for the NIR. RESULTS: Overall, NIR performance was high: sensitivity ranged from 90% to 93%, specificity from 78% to 85%, the positive predictive value from 91% to 94% and the negative predictive value from 77% to 84%. NIR performance was higher for National Immunisation Schedule (NIS) vaccines compared with non-NIS vaccines. CONCLUSION: This study indicates the NIR data accuracy generally performs well compared with international equivalents, especially for NIS vaccine records. Further work is required to ascertain why discrepancies between the Health Books and NIR continue to occur, with particular attention to important subgroups and translating records across from migrant populations. Also, future work is required to understand the accuracy of vaccination records for groups who experience lower-quality healthcare and a higher burden of infectious diseases.

The new dynamics of residential aged care in Australia: continuity and change.

ObjectiveThis paper tests the hypothesis that increases in recorded dependency levels of permanent residential aged care clients are associated with reduced length of stay and higher turnover. A secondary objective is to compare the Aged Care Funding Instrument with its predecessor, the Resident Classification Scale, on a common schema.MethodsAdministrative data for all Commonwealth-subsidised residential aged care services in Australia from 2008-09 to 2018-19 were obtained from the National Aged Care Data Clearinghouse. More than 750000 episodes of permanent residential aged care were analysed. The categories from the two rating systems were mapped to a six-level schema, primarily based on the dollar value of the categories at the time of transition.ResultsThere was a strong trend towards higher dependency ratings across admissions, residents, and separations. However, contrary to expectation, measures of system activity showed a slowing of the system: length of stay increased and turnover decreased.ConclusionsThe mapping of dependency rating schemes to a common rating enables the analysis of long-term trends in residential care dynamics. There is no evidence that the marked increases in reported dependency ratings led to accelerated system activity, consistent with an earlier study. This analysis forms a solid base for ongoing analysis of care appraisals in the context of a possible new rating scheme. It highlights the interplay between policy changes and provider behaviour, and the need for robust data to monitor care appraisals and system dynamics.What is known about the topic?Residential aged care subsidies are determined by care needs in relation to assessed dependency levels, using the Aged Care Funding Instrument since 2008, and before that, the Resident Classification Scale. Between 2008-09 and 2018-19, there was considerable growth in residents classified at more dependent levels, and this would be expected to result in greater turnover in the system.What does this paper add?This paper maps the rating schemes to a simplified, common rating that enables the analysis of long-term trends in residential care dynamics. It shows that the system is slowing, contrary to the trends expected if residents were more frail as the reported ratings imply. The paper examines possible explanations of these trends, and addresses policy implications.What are the implications for practitioners?In the context of a potential new client-dependency classification, this study shows the importance of robust measures of the dynamics of the system-and the underlying data-vis-à-vis the means by which client dependency is assessed.

How strong is the housing assets pillar of funding for residential aged care?

OBJECTIVE: To explore reasons for the gap between the perception that high home ownership provides a strong pillar of funding for aged care accommodation and the actuality of half of those in residential care having this cost met by the Accommodation Supplement. METHODS: Review of data from Australian Bureau of Statistics and administrative sources, and recent research studies. RESULTS: Trends in payment methods show continuing reliance on the Accommodation Supplement. Reasons are found in patterns of home ownership at older ages, changes in tenure and living arrangements over the age range, and increasing use of the exchange value of housing assets. Policy tensions arise between protecting access for low means residents and requiring those who are able to pay to do so. CONCLUSIONS: The housing assets pillar at advanced ages is not as strong as early in retirement and makes it increasingly unreliable as a source of funding.

Pertussis and influenza immunisation coverage of pregnant women in New Zealand.

BACKGROUND: Immunisation is an important public health policy and measuring coverage is imperative to identify gaps and monitor trends. New Zealand (NZ), like many countries, does not routinely publish coverage of immunisations given during pregnancy. Therefore, this study examined pregnancy immunisation coverage of all pregnant NZ women between 2013 and 2018, and what factors affected uptake. METHODS: A retrospective cohort study of pregnant women who delivered between 2013 and 2018 was undertaken using administrative datasets. Maternity and immunisation data were linked to determine coverage of pertussis and influenza vaccinations in pregnancy. Generalised estimating equations were used to estimate the odds of receiving a vaccination during pregnancy. RESULTS: From 2013 to 2018 data were available for 323,622 pregnant women, of whom 21.7% received maternal influenza immunisations and 25.7% maternal pertussis immunisations. Coverage for both vaccines increased over time, pertussis increased from 10.2% to 43.6% and influenza from 11.2% to 30.8%. The odds of being vaccinated, with either vaccine, during pregnancy increased with increasing age and decreasing deprivation. Compared to NZ European or Other women, Maori and Pacific women had lower odds of receiving a maternal pertussis (OR:0.55, 95% CI: 0.54, 0.57; OR:0.60, 95% CI: 0.58, 0.62, respectively) and influenza (OR: 0.69, 95% CI: 0.67, 0.71; OR:0.90, 95% CI: 0.87, 0.94, respectively) immunisations during pregnancy. Women were also more likely to be vaccinated against pertussis if they received antenatal care from a General Practitioner or Obstetrician compared to a Midwife. A similar pattern was seen for influenza vaccination. CONCLUSION: Gaps in maternal coverage for pertussis and influenza exist and work is needed to reduce immunisation inequities.

Social jetlag is associated with cardiorespiratory fitness in male but not female adolescents.

INTRODUCTION: Cardiorespiratory fitness (CRF) is a vital sign that can improve risk classification for adverse health outcomes. While lifestyle-related factors are associated with CRF, few have examined the influence of sleep characteristics, especially in youths. Social jetlag, a mismatch between one's biological clock and sleep schedule, is prevalent in adolescents and associated with increased adiposity, though its relationship with CRF is unclear. OBJECTIVE: To quantify the relationship between social jetlag and CRF, independent of other sleep characteristics. METHODS: This cross-sectional sample includes 276 New Zealand adolescents (14-18 years, 52.5% female). CRF (VO2max) was estimated from a 20-m multi-stage shuttle run. Average sleep duration, sleep disturbances, social jetlag, physical activity, and the number of bedroom screens were estimated from validated self-report surveys. Social jetlag is the difference in hours between the midpoint of sleep during weekdays (school) and weekend days (free). Combined and sex-stratified linear regression assessed the association between sleep outcomes and CRF, controlling for relevant covariates. RESULTS: Males slept 17.6 min less, had less sleep disturbances, and a 25.1-min greater social jetlag than their female peers (all p < 0.05). A 1-h increase in social jetlag was associated with a 0.72 ml/kg/min decrease in VO2max (95% CI: -1.31, -0.14), independent of other sleep variables, which were not associated with CRF. Sex-specific models indicated an association in males (B -0.93, 95% CI: -1.76, -0.09), but not females (B -0.32, 95% CI: -1.18, 0.55). CONCLUSIONS: Social jetlag is negatively associated with CRF in adolescent males and may be a simple, measurable target for public health interventions.

Impact of rotavirus vaccine on paediatric rotavirus hospitalisation and intussusception in New Zealand: A retrospective cohort study.

BACKGROUND: Rotavirus results in a significant burden of hospitalisations and deaths globally. Rotavirus vaccine has been used in New Zealand since July 2014. The aim of this study was to assess the safety and effectiveness of RotaTeq® vaccine in New Zealand between 2006 and 2016. METHODS: A national cohort study of 723,695 children aged less than 6 years was carried out using linked administrative datasets. Study outcomes were hospitalisation for intussusception, rotavirus, and all-cause gastroenteritis. Intussusception hospitalisation rates were calculated from 2006 to 2016, and rotavirus and all-cause gastroenteritis hospitalisation rates from 2011 to 2016. We examined the effect of RotaTeq® vaccination on rotavirus and all-cause gastroenteritis hospitalisation rates using Poisson regression. Adjusted incidence rate ratios controlled for sex, year of birth, ethnicity, socioeconomic deprivation, and district health board area. RESULTS: Significant reductions in the incidence of rotavirus hospitalisation were seen in all age groups, ethnicities, and deprivation following the introduction of RotaTeq®. There was a 92.6% reduction in hospitalisation incidence in the vaccinated cohort (p < 0.0001). There was also a 48% reduction in all-cause gastroenteritis hospitalisation incidence in the vaccinated cohort (p < 0.0001). The average annual intussusception rate in children aged less than 3 years was 26.2 per 100,000, with no significant change over time (p = 0.847). CONCLUSIONS: In New Zealand the introduction of RotaTeq® resulted in a significant reduction in rotavirus hospitalisation, and a halving in all-cause gastroenteritis hospitalisation. There has been no change in the overall incidence of intussusception or clear change in patterns of cases, although intussusception cases did occur within risk period immediately post vaccine.

Comparative effectiveness of metformin versus insulin for gestational diabetes in New Zealand.

PURPOSE: To measure the comparative effectiveness of metformin versus insulin for initial pharmacological management of gestational diabetes mellitus (GDM). METHODS: We conducted a population-based retrospective cohort study using administrative claims, maternity care, and laboratory result data from New Zealand. We followed pregnant women aged 15 to 45 from GDM diagnosis through delivery and assessed outcomes using maternity care and hospitalization data. We adjusted for covariates using inverse probability of treatment weights and multiple imputation for missing covariate information. We estimated unadjusted and adjusted risk ratios (RRs), risk differences (RDs) per 100, and 95% confidence intervals (CIs). Linear regression was used to estimate the association of treatment with birthweight. We stratified analyses by ethnicity and infant sex in prespecified sensitivity analyses. RESULTS: We compared 3818 metformin-treated pregnancies with 3450 insulin-treated pregnancies. We observed differences in treatment initiation by ethnicity, socioeconomic status, region, and calendar year. Treatment groups were similar in age, body mass index (BMI), and timing of diagnosis/treatment initiation. After adjustment, metformin was associated with reduced absolute risk of planned elective c-section (RD = -2.3, 95% CI, -4.3 to -0.3), large for gestational age (RD = -3.7, 95% CI, -5.5 to -1.8), and neonatal hypoglycemia (RD = -5.0, 95% CI, -6.9 to -3.2) compared with insulin. There were no clinically meaningful differences in average birthweight between metformin- and insulin-treated pregnancies. We observed variation in estimates by ethnicity and infant sex for some neonatal outcomes. CONCLUSION: Metformin appears to be an effective treatment for women with GDM and may reduce risk of some adverse neonatal outcomes when compared with insulin.

A Retrospective Cohort Study of Safety Outcomes in New Zealand Infants Exposed to Tdap Vaccine in Utero.

We aimed to evaluate the safety of maternal Tdap; thus, we assessed health events by examining the difference in birth and hospital-related outcomes of infants with and without fetal exposure to Tdap. This was a retrospective cohort study using linked administrative datasets. The study population were all live-born infants in New Zealand (NZ) weighing at least 400 g at delivery and born to women who were eligible for the government funded, national-level vaccination program in 2013. Infants were followed from birth up to one year of age. There were a total of 69,389 eligible infants in the cohort. Of these, 8299 infants were born to 8178 mothers exposed to Tdap (12%), primarily between 28 and 38 weeks gestation as per the national schedule. Among the outcomes, we found a reduced risk for moderate to late preterm birth, low birth weight, small for gestational age, large for gestational age, respiratory distress syndrome, transient tachypnea of newborn, tachycardia or bradycardia, haemolytic diseases, other neonatal jaundice, anaemia, syndrome of infant of mother with gestational diabetes, and hypoglycemia in infants born to vaccinated mothers. There was no association between maternal Tdap, infant Apgar score at 5 min after birth, asphyxia, sepsis or infection, or hypoxic ischemic encephalopathy. Infant exposure to Tdap during pregnancy was associated with a higher mean birthweight (not clinically significant) and higher odds for ankyloglossia and neonatal erythema toxicum diagnoses. There were insufficient observations to allow examination of the effect of Tdap on extreme preterm and very preterm birth, and stillbirth, infant death, or microcephaly. Overall, we found no outcomes of concern associated with the administration of Tdap during pregnancy. NZ Health and Disability Ethics Committee Approval #14/N.T.A/169/AM05.

Pertussis Vaccination Failure in the New Zealand Pediatric Population: Study Protocol.

Pertussis vaccines have been effective at reducing pertussis-associated morbidity and mortality. However, they have a complex array of limitations, particularly associated with the duration of protection against clinical disease and imperfect immunity (carriage and transmission). Little is known about risk factors for pertussis vaccination failure. Understanding pertussis vaccination failure risk is most important in the paediatric population. This study aims to investigate risk factors for pertussis vaccination failure in (1) infants between birth and six weeks of age born to mothers who received pertussis booster vaccinations during pregnancy and (2) infants after the completion of the primary series (approximately five months old) to four years old. This will be achieved in a two-step process for each study group. Pertussis vaccination failure cases will first be described using a case series study design, relevant case characteristics will be sourced from six national administrative datasets. The case series study results will help select candidate risk factors (hypothesis generating step) to be tested in the retrospective cohort study (hypothesis testing step. Pattern analysis will be used to investigate risk factor patterns in the cohort study. The identification of higher risk groups enables targeting strategies, such as additional doses, to better prevent pertussis disease.

Research reported in the AJA: Who does it and where do they do it?

OBJECTIVE: To review research published in the AJA in terms of authors' positions and disciplinary backgrounds, and the settings in which research was done. METHODS: Eighty two papers by 373 authors, in Vol. 35 No 1, March 2016, to Vol 37 No 2, June 2018, were reviewed. RESULTS: Different clusters of authorship were found for research using surveys or database analyses, research in hospitals and aged care settings. Two out of three authors held academic positions, and professional practitioners in hospitals were much more likely to have academic affiliations than in aged care settings. Differing research cultures are seen to contribute to these outcomes. CONCLUSIONS: Editorial policies have been central to maintaining publication standards. The Journal's publication partners could take a number of actions to advance recognition of professionals in different roles as authors and to expand the range of research published, especially nursing and social science research.

Suboptimal performance of rotavirus testing in a vaccinated community population should prompt laboratories to review their rotavirus testing algorithms in response to changes in disease prevalence.

Rotavirus vaccine has reduced disease prevalence in many countries. Consequently, we aimed to assess the reliability of a rotavirus immunoassay in the community population of Auckland and Northland, New Zealand. Between 22 October 2015 and 31 December 2016, 2873 fecal samples were tested by enzyme immunoassay (EIA, Rotascreen II, Microgen, UK) from 2748 patients (median age 8 years, range 0-101 years). Eighty-nine (3.1%) samples were reactive; 86 samples were tested by a second method. Rotavirus was confirmed in 49/86 (57%). Positive rotavirus EIAs were more likely to be confirmed in samples from cases ≥1 year of age (positive predictive value [PPV] 61%, 95% confidence interval [CI] 50-72%, P = 0.049) and in spring/summer (PPV 67%, 95% CI 55-78%, P = 0.003). Reactive rotavirus tests required confirmatory testing regardless of demographic, vaccine, or seasonal factors; a review of rotavirus testing algorithms may be necessary in other vaccinated community populations.

Pneumococcal Conjugate Vaccines Turning the Tide on Inequity: A Retrospective Cohort Study of New Zealand Children Born 2006-2015.

BACKGROUND: Hospitalization rates for infectious diseases in New Zealand (NZ) children have increased since 1989. The highest burden is among Maori and Pacific children, and the most socioeconomically deprived. New Zealand introduced pneumococcal conjugate vaccine (PCV)7 in June 2008, PCV10 in 2011, and PCV13 in 2014. METHODS: A retrospective cohort study of NZ children aged <6 years between 2006 and 2015 was performed using administrative databases. Demographics and hospitalizations were linked to evaluate the impact of the PCV vaccination program on cases of invasive pneumococcal disease (IPD), all-cause pneumonia (ACP), and otitis media (OM), defined by ICD-10-AM codes, and to explore the effect by ethnicity and deprivation. RESULTS: Between 2006 and 2015, there were 640 children hospitalized with IPD, 26589 for ACP, and 44545 for OM. IPD hospitalizations declined by 73% between 2005 and 2015 for children <6 years of age, whereas ACP and OM declined by 8% and 25%, respectively. The highest rates for all diseases were among Maori and Pacific children and those from high deprivation. However, the declines were highest among Maori and Pacific children and those from socioeconomically deprived areas. IPD hospitalizations declined by 79% and 67% for Maori and Pacific children, respectively, between 2006 and 2015. ACP declined by 12% in Maori and 21% in Pacific children. OM declined by 51% in Maori children. CONCLUSION: In contrast to the increasing trend of hospitalization rates for infectious disease in New Zealand, the use of PCV appears associated with reductions in ethnic and socioeconomic disparities in hospitalization for IPD, ACP, and OM.

Association of Long-term Child Growth and Developmental Outcomes With Metformin vs Insulin Treatment for Gestational Diabetes.

Importance: Metformin is an emerging option for treating gestational diabetes (GDM). However, because metformin crosses the placenta, patients and clinicians are concerned with its long-term effect on child health. Objective: To estimate the association of treating GDM with metformin vs insulin with child growth and development. Design, Setting, and Participants: Population-based cohort study of New Zealand women treated with metformin or insulin for GDM from 2005 to 2012 and their children. This study linked national health care data to create a cohort of mothers and their children, including data from maternity care, pharmaceutical dispensing, hospitalizations, demographic records, and the B4 School Check (B4SC) preschool health assessment. Women treated pharmacologically with metformin or insulin during pregnancy were included. We excluded pregnancies with evidence of diabetes and deliveries prior to 2013. Liveborn infants were linked to their B4SC results. Data were analyzed between January 2017 and May 2018. Exposures: Pharmacologic treatment for GDM with metformin or insulin, measured using pharmaceutical claims data. Main Outcomes and Measures: Child growth (weight and height) and Strengths and Difficulties Questionnaire (SDQ) scores for behavioral development. All outcomes were derived from the B4SC screening program. Linear and log-binomial regression with inverse probability of treatment weighting was used to estimate the association of child growth and psychosocial outcomes with metformin vs insulin treatment for GDM. Results: In both treatment groups, the mean (SD) maternal age was 32 (5) years. A large proportion of mothers who were treated with insulin identified as New Zealand European (867 [44.9%]) while 576 mothers who were treated with metformin (28.9%) identified as New Zealand European. Approximately one-third of mothers who were treated with metformin (n = 639) identified as Asian. We identified 3928 pregnancies treated with metformin (n = 1996) or insulin (n = 1932). After adjustment, we observed no meaningful difference in weight for height z scores between children exposed to metformin compared with insulin (mean difference, -0.10; 95% CI, -0.20 to 0.01). Risk of being 85th percentile or greater for weight for height was similar between treatment groups (adjusted risk ratio, 0.92; 95% CI, 0.83-1.02). Mean SDQ scores were not meaningfully different between the treatment groups, Children of metformin-treated mothers were not significantly more likely to have parent-reported SDQ scores of 14 or more (adjusted risk ratio, 1.13; 95% CI, 0.88-1.46) than those of insulin-treated mothers. Conclusions and Relevance: Our study compares long-term outcomes among school-aged children following maternal use of metformin vs insulin treatment for GDM. Children of metformin-treated mothers were indistinguishable on growth and developmental assessments from those of insulin-treated mothers. These results will help inform future GDM treatment guidelines.

Pertussis Immunisation in Pregnancy Safety (PIPS) Study: A retrospective cohort study of safety outcomes in pregnant women vaccinated with Tdap vaccine.

BACKGROUND: New Zealand has funded the administration of tetanus, diphtheria and acellular pertussis (Tdap) vaccine during pregnancy to prevent infant pertussis since 2013. The aim of this study was to assess the safety of Tdap vaccine administered to pregnant women as part of a national maternal immunisation programme. METHODS: We conducted a national retrospective observational study using linked administrative New Zealand datasets. The study population consisted of pregnant women eligible to receive funded Tdap vaccination from 28 to 38 weeks gestation in 2013. Primary study outcomes were based on prioritised adverse events for the assessment of vaccine safety in pregnant women, as defined by WHO and Brighton Collaboration taskforces. We examined the effect of Tdap vaccination on prioritised maternal outcomes using Cox proportional hazard models. Adjusted hazard ratios controlled for key confounding variables. RESULTS: In the cohort of 68,550 women eligible to receive funded antenatal Tdap vaccination during 2013, 8178 (11.9%) were vaccinated and 60,372 (88.1%) were unvaccinated. The use of Tdap in pregnancy was not associated with an increase in the rate of primary outcomes, including preterm labour; pre-eclampsia; pre-eclampsia with severe features; eclampsia; gestational hypertension; fetal growth restriction; or post-partum haemorrhage. Tdap also did not increase secondary outcomes, including gestational diabetes mellitus; antenatal bleeding; placental abruption; premature rupture of membranes; preterm delivery; fetal distress; chorioamnionitis; or, maternal fever during or after labour. Lactation disorders was the only secondary maternal outcome with a significantly increased hazard ratio. Tdap vaccine had a protective effect on pre-eclampsia with severe features, preterm labour, preterm delivery, and antenatal bleeding. CONCLUSION: We did not detect any biologically plausible adverse maternal outcomes following Tdap vaccination during pregnancy. This study provides further assurance that Tdap administration during pregnancy is not associated with unexpected safety risks.