How can we make international comparisons of infant mortality in high income countries based on aggregate data more relevant to policy?

Comparison of stillbirth trends over two decades in Wales, United Kingdom and Western Australia: An international retrospective cohort study

BACKGROUND

Stillbirth is a critical public health issue worldwide. While the rates in high-income countries are relatively low, there are persistent between-country disparities.

OBJECTIVES

To compare stillbirth rates and trends in Wales and the State of Western Australia (WA), Australia, and provide insights into any differences.

METHODS

In this international retrospective cohort study, we pooled population-based data collections of all births ≥24 weeks' gestation (excluding terminations for congenital anomalies) between 1993 and 2015, divided into six time periods. The stillbirth rate per 1000 births was estimated for each cohort in each time period. Multivariable Poisson regression analyses, adjusted for appropriateness of growth, socio-economic status, maternal age, and multiple birth, were performed to evaluate the interaction between cohort and time period. Relative risk (RR) and 95% confidence interval (CI) for each time period and cohort were calculated.

RESULTS

There were 767 731 births (3725 stillbirths) in Wales and 648 373 (2431 stillbirths) in WA. The overall stillbirth rate declined by 15.9% over the study period in Wales (from 5.3 in 1993-96 to 4.5 per 1000 births in 2013-15; P_trend  < .01) but by 40.4% in WA (from 4.9 to 2.9 per 1000 births in WA; P_trend  < .01). Using 1993-96 in WA as the reference group, the adjusted RRs for stillbirths at 37-38 weeks' gestation in the most recent study period (2013-15) were 0.85 (95% CI 0.64, 1.13) in Wales and 0.51 (95% CI 0.36, 0.73) in WA.

CONCLUSIONS

The stillbirth rates between Wales and WA have widened in the last two decades (especially among late-term births), although the absolute rates for both are distinctly higher than the best-performing nations. While the differences may be partly explained by timing of birth and maternal life style behaviours such as smoking, it is important to identify and ameliorate the associated risk factors to support a reduction in preventable stillbirths.

The match between need and use of health services among healthy under-fives in Denmark: A register-based national cohort study

OBJECTIVES

To study a potential positive association (referred to as 'a match') between the need for health service (expressed by a mortality risk score) and observed health service utilisation among healthy Danish under-fives. Further, municipal differences in the match were examined to motivate focused comparisons between the organisation of regional health services.

DESIGN

Register-based national cohort study.

PARTICIPANTS

The population of 1,246,599 Danish children born 1997-2016 who survived until date of first discharge to the home after birth without a diagnosis of severe chronic disease.

MAIN OUTCOME MEASURES

Hazard ratios (HR) for a doubling of the mortality rate were calculated for the following health services: total contacts, inpatient contacts (admission > 1 day), outpatient contacts, general practitioner contacts, specialist contacts, medication use, and vaccinations.

RESULTS

The use of total contacts, inpatient contacts (> 1 day) and general practitioner contacts as well as medication matched with the mortality risk score, HRs between 1.027 (1.026 to 1.028) and 1.111 (1.108 to 1.113), whereas outpatient and specialist contacts as well as vaccinations did not, HRs between 0.913 (0.912 to 0.915) and 0.991 (0.991 to 0.991). There were some remarkable differences among the 98 Danish municipalities.

CONCLUSIONS

We found some match between need and use for total contacts, inpatient contacts (> 1 day), contacts with general practitioner, and medication use although the associations were relatively weak. For outpatient and specialist contacts, the mismatch may be related to services not addressing potentially fatal disease whereas for vaccination there was a small mismatch. Our results indicate local discrepancies in diagnosis, and a low adjusted utilisation of hospital admissions in Aarhus compared to the other three major cities in Denmark suggests that a comparison of the organisation of services could be useful.

Risk factors of post-discharge under-five mortality among Danish children 1997-2016: A register-based study

Objectives

Estimating associations between somatic and socioeconomic risk factors and post-discharge under-five mortality.

Design

Register-based national cohort study using multiple Cox regression.

Participants

The population of 1,263,795 Danish children live-born 1997–2016 who survived until date of first discharge to the home after birth was followed from that date until death, emigration, 5 years of age or 31 December 2016.

Main outcome measures

(A) Mortality hazard ratios (HRs) among all children, (B) mortality HRs among children without severe chronic disease, and (C) mortality HRs among children without severe chronic disease or asthma.

Main results

In the total population (1,947 deaths) severe chronic disease was associated with mortality HR = 15.28 (95% CI: 13.77–16.95). In children without severe chronic-disease (719 deaths) other somatic risk factors were immature birth HR = 3.40 (1.92–6.02), maternal smoking HR = 1.84 (1.55–2.18) and low birth weight HR = 1.74 (1.21–2.51). Socioeconomic risk factors for mortality included: maternal age < 25 years HR = 1.91 (1.38–2.64) compared to > 35 years (similar for 30–35 years and 25–29 years), lowest vs. highest family income tertile HR = 1.76 (1.23–2.51), not living with both parents HR = 1.63 (1.25–2.13), maternal unemployment HR = 1.54 (1.12–2.12), presence of siblings HR = 1.44 (1.20–1.71) and secondary vs. tertiary parental education HR = 1.33 (1.07–1.65) for fathers and HR = 1.23 (1.01–1.52) for mothers. Factors not found to be associated with child mortality in this population included presence of asthma HR = 1.29 (0.83–1.98) and non-Danish ethnicity HR = 0.98 (0.70–1.37).

Conclusions

Childhood death after discharge to the home after birth and before 5 years of age is a very rare event in Denmark. This ‘post-discharge’ mortality was heavily associated with severe chronic disease. In children without severe chronic disease, immature birth, maternal smoking and certain socioeconomic characteristics were noticeable risk factors. Mortality may possibly be decreased by focusing on vulnerable groups.

Impact of preventive primary care on children's unplanned hospital admissions: a population-based birth cohort study of UK children 2000-2013

BACKGROUND

Universal health coverage (UHC) aims to improve child health through preventive primary care and vaccine coverage. Yet, in many developed countries with UHC, unplanned and ambulatory care sensitive (ACS) hospital admissions in childhood continue to rise. We investigated the relation between preventive primary care and risk of unplanned and ACS admission in children in a high-income country with UHC.

METHODS

We followed 319,780 children registered from birth with 363 English practices in Clinical Practice Research Datalink linked to Hospital Episodes Statistics, born between January 2000 and March 2013. We used Cox regression estimating adjusted hazard ratios (HR) to examine subsequent risk of unplanned and ACS hospital admissions in children who received preventive primary care (development checks and vaccinations), compared with those who did not.

RESULTS

Overall, 98% of children had complete vaccinations and 87% had development checks. Unplanned admission rates were 259, 105 and 42 per 1000 child-years in infants (aged < 1 year), preschool (1-4 years) and primary school (5-9 years) children, respectively. Lack of preventive care was associated with more unplanned admissions. Infants with incomplete vaccination had increased risk for all unplanned admissions (HR 1.89, 1.79-2.00) and vaccine-preventable admissions (HR 4.41, 2.59-7.49). Infants lacking development checks had higher risk for unplanned admission (HR 4.63, 4.55-4.71). These associations persisted across childhood. Children who had higher consulting rates with primary care providers also had higher risk of unplanned admission (preschool children: HR 1.17, 1.17-1.17). One third of all unplanned admissions (62,154/183,530) were for ACS infectious illness. Children with chronic ACS conditions, asthma, diabetes or epilepsy had increased risk of unplanned admission (HR 1.90, 1.77-2.04, HR 11.43, 8.48-15.39, and HR 4.82, 3.93-5.91, respectively). These associations were modified in children who consulted more in primary care.

CONCLUSIONS

A high uptake of preventive primary care from birth is associated with fewer unplanned and ACS admissions in children. However, the clustering of poor health, a lack of preventive care uptake, and social deprivation puts some children with comorbid conditions at very high risk of admission. Strengthening immunisation coverage and preventive primary care in countries with poor UHC could potentially significantly reduce the health burden from hospital admission in children.