10th November 2017, Volume 130 Number 1465

Fiona Catherine Langridge, Sione Vaioleti Hufanga, Malakai Mahunui ‘Ofanoa, Toakase Fakakovikaetau, Teuila Mary Percival, Cameron Charles Grant

The Millennium Development Goals have provided a focus for the global reporting of child health in recent decades1 by describing child population health using under-five year, neonatal and infant mortality rates.2 The more recently adopted Sustainable Development Goals continue the focus on mortality measures in the under-five age group with the stated goal “By 2030, end preventable deaths of newborns and children under five years of age, with all countries aiming to reduce neonatal mortality to at least as low as 12 per 1,000 live births and under-five mortality to at least as low as 25 per 1,000 live births”.3 While this preschool-age focus has been necessary, a consequence of it has been relative ignorance of the health of children beyond five years of age.4

Eighty-four percent of deaths globally in children <5 years old are due to seven causes: neonatal problems, pneumonia, diarrhoea, malaria, measles, human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS), and injuries.2 A range of initiatives have resulted in improvement nutrition, immunisation, newborn health and case management of diseases such as pneumonia and diarrhoea.5 As a result, more children are now surviving beyond five years of age.

For primary school aged children in resource-limited countries, both cause of death and burden of disease have been investigated less comprehensively than in the under five-year age group. The data that are available suggest that allergic disease and bronchiectasis are becoming more prevalent in primary school aged children in developing countries.6,7 Gastrointestinal conditions, including acute, chronic, persistent diarrhoea and constipation, are also common.8,9 The global burden of disease study reports that globally unintentional injuries are the cause of 10–20% of deaths in children aged 5–14 years.10 Dental caries is a common chronic disease in childhood,11 estimated to affect 60–90% of school aged children,12 despite being largely preventable.13

Health issues that are prevalent in primary school aged children predict future public health priorities, and social and economic development.14 Currently, global research in the developing world context in this age group is limited to studies that have focused on specific health issues such as nutrition,15 ear and hearing health,16 respiratory health,17 parasitic disease,18 communicable disease,19–21 vision,22 anaemia,23 disability,24 behaviour25 and oral health.26 To date there does not appear to be any study that has quantified disease burden at a population level in this age group in the developing world setting.

In addition to being limited in scope, studies of health in school-aged children in resource-limited countries has been restricted to the African and Asian regions.1 In the Pacific region, the 5–12 year-old age group has received minimal attention and the available information is largely anecdotal.27 Research on the strategies to improve health in this primary school age group is just as scant, although there is growing evidence for school-based interventions.28–30

This lack of data is of specific relevance to New Zealand, where 11.3% of the population identify with a Pacific ethnicity and over a third (35.7%) of Pacific peoples were aged under 15 years in the 2013 Census compared to one-fifth (20.4%) of the total population.31 Contemporary data on women of child bearing age in New Zealand shows that approximately half of those of Pacific ethnicity were born in the Pacific. Hence, their health during childhood in the Pacific is likely to impact upon their adult health in New Zealand and the health of their children.32

In order to identify priority areas for promoting health in primary school aged children in the Pacific, an understanding of the predominant health issues affecting them is required. Our aim in this study was to describe patterns of hospital utilisation for primary school aged children living in Tonga to help begin to understand the epidemiology of primary school aged health in the Pacific region.

Methods

Study setting

We completed our study in Tonga, a South Pacific nation of 170 islands (36 inhabited), with the majority of the population living on the main island of Tongatapu. The total estimated population of Tonga (2011) is 103,25233 with 38% in the 0–14 age year group.34

We completed an audit of published literature on child health research in Tonga. This audit identified a small literature generally focused on single health issues or diseases, for example immunisation,35–37 nutrition,38–40 rheumatic heart disease,41–43 respiratory disease44,45 and oral health.46

The Tongan healthcare system

In Tonga, health services are free and services are accessible except for those living in the outer islands.34 Primary health care in Tonga is delivered through 14 health centres. There is one central referral hospital (Vaiola Hospital), and three community hospitals located on three of the smaller groups of islands.

Ethics

Ethical approval was granted by the University of Auckland Participants Ethics Committee and the Tonga National Health Ethics and Research Committee.

Study sample

We collected data on all admissions to Vaiola Hospital from January 2009 to December 2013 of children aged 5–11 (inclusive) years. Vaiola is a 200-bed hospital with a dedicated 34-bed paediatric inpatient facility. There is one paediatric consultant, two junior paediatric registrars and two paediatric interns.

The hospital uses a data system called the Tonga Hospital Information System, developed by iSOFT in 2009. The system has admission, discharge and transfer data capabilities together with a disease classification component. Hospital admission and discharge data is collected and coded using ICD10 and ICD10AM disease classification. For each admission, data were extracted that described child gender and age, diagnosis, facility admitted to and length of hospital stay.

Inclusion and exclusion criteria

All inpatient admissions to Vaiola Hospital for children aged 5–11 (inclusive) years from January 2009 to December 2013 were included in this study. We included all admissions and thus potentially included multiple admissions for the same child. Emergency department-only events were excluded.

Data analysis

Discharge diagnosis data were grouped into 27 diagnostic categories based on the most frequent reasons for hospital admission in children aged 0–14 years (neonates excluded) in New Zealand from 2006 to 2010.47 These 27 diagnostic categories were then organised into the following diagnostic groups: respiratory conditions; injury and poisoning; abdominal and surgical conditions; non-respiratory infectious diseases; chronic conditions; other conditions; dental conditions; cardiac conditions; and neoplasms (Table 1). Note that gastroenteritis is included in abdominal and surgical conditions rather than in non-respiratory infectious diseases. For a further breakdown of diagnoses and groupings, see Appendix 1. The data did not include external cause codes, so for the injury and poisoning category it was not possible to differentiate between intentional and unintentional injury. For this study, open wounds were included in the injury and poisoning group as it was assumed that otherwise the ICD10 code for skin infection would have been used.

Table 1: Groupings and subgroupings of diagnoses for children aged 5–12 admitted to Vaiola Hospital in Tonga 2009–2013.

c

Seasons were separated into ‘wet and warm’ (November to April) and ‘dry and cool’ (May to October). Admissions were grouped into two age groups: 5–7 and 8–11 years. In Tonga, children attend primary school from age 5 to 11 years (inclusive). To allow for a comparison of younger with older primary school aged children we then divided the sample into two age groups: 5–7 years and 8–11 years.

Sample distribution was described using proportions and means with standard deviations (SD) or medians with interquartile ranges (IQR) depending upon the normality of data distribution. Proportions were compared using the chi square test and means and medians using the t-test and the Wilcoxon rank sum test respectively.

For rate calculations, the population and projected population of 5–11 year-olds as defined at the 2006 and 2011 national census were used as the denominator. Of note, the national census in 2011 had a slightly lower actual count than the projected population growth from 2006. There was no explanation for this from the 2011 census report. Hospital admission rates by season, age, gender, diagnostic group and admission facility were described. Rates were compared using rate ratios (RRs) and 95% confidence intervals (CI). Statistical analysis was completed using SAS version 9.3 (SAS Institute, Cary, NC, US) and StatsDirect version 2.7.9 (Altrincham, Cheshire, UK) software.

Results

Over the study interval there were 1,816 admissions of children aged 5–11 years to Vaiola Hospital, giving an average annual admission rate of 20.2/1,000 (95% CI 19.3–21.1). In comparison with 2009, the admission rate was greater in 2012 (RR=1.37) and 2013 (RR=1.39). Admission rates were higher in younger than older children (5–7 versus 8–11 years, RR=1.28) and in boys compared with girls (RR=1.52), and varied by season (dry and cool vs wet and warm, RR=0.96) (Table 2).

Table 2: Hospital admission rates for children aged 5–11 years (inclusive) admitted to hospital in Tonga from 2009 to 2013 by season, age and gender.

Variable

n (%, 95% confidence interval)

Population

Rate per 1,000

(95% CI)

Rate ratio

(95% CI)

Year of admission

2009

305 (17, 15–19)

18,036

16.9 (15.1–18.9)

1.00

2010

328 (18, 16–20)

18,125

18.1 (16.2–20.1)

1.07 (0.91–1.25)

2011

346 (19, 17–21)

17,813

19.4 (17.4–21.6)

1.15 (0.98–1.34)

2012

415 (23, 21–25)

17,915

23.2 (21.0–25.4)

1.37 (1.18–1.59)

2013

422 (23, 21–25)

17,990

23.5 (21.3–25.8)

1.39 (1.19–1.61)

Season

Wet and warm (November to April)

924 (51, 49–54)

89,879

10.3 (9.6–11.0)

1.00

Dry and cool

(May to October)

892 (49, 47–51)

89,879

9.9 (9.3–10.6)

0.96 (0.88–0.97)

Age in years

5

375 (21, 19–23)

13,178

28.5 (25.7–31.4)

1.00

6

308 (17, 15–19)

13,125

23.5 (20.9–26.2)

0.82 (0.71–0.96)

7

226 (12, 11–14)

13,030

17.3 (15.2–19.7)

0.61 (0.51–0.72)

8

218 (12, 11–14)

12,899

16.9 (14.7–19.3)

0.59 (0.50–0.70)

9

227 (13, 11–14)

12,736

17.8 (15.6–20.2)

0.63 (0.53–0.74)

10

228 (13, 11–14)

12,549

18.2 (15.9–20.7)

0.64 (0.54–0.75)

11

234 (13, 11–14)

12,362

18.9 (16.6–21.5)

0.67 (0.56–0.79)

Age group in years

5–7

909 (50, 48–52)

39,333

23.1 (21.6–24.6)

1.00

8–11

907 (50, 48–52)

50,546

17.9 (16.8–19.1)

0.78 (0.71–0.85)

Gender

Female

681 (37, 35–40)

42,910

15.9 (14.7–17.1)

1.00

Male

1,135 (63, 60–65)

46,969

24.1 (22.8–25.6)

1.52 (1.38–1.68)

Based upon 2006 and 2011 census.

Of the 1,816 admissions, 1,474 (85%) were due to diagnoses that placed them in one of five diagnostic groups: injury and poisoning (28%), non-respiratory infectious diseases (19%), respiratory conditions (16%), abdominal, gastrointestinal and surgical conditions (13%) and dental conditions (9%). The median length of stay was three days (IQR 2–6) (Table 3).

Table 3: Diagnostic groups and length of stay for children aged 5–11 years admitted to hospital in Tonga from 2009–2013.

Diagnostic group

n (% of all admissions, 95% CI)

Rate per 1,000 (95% CI)

Injury and poisoning

485 (28, 27–30)

5.6 (5.2–6.2)

Injury/poisoning

377 (22)

4.4 (4.0–4.9)

Open wound (unknown cause)

108 (6)

1.3 (1.0–1.5)

Non-respiratory infectious diseases

328 (19, 17–21)

3.8 (3.4–4.3)

Other infection/infectious disease

209 (12)

2.4 (2.1–2.8)

Skin infection

97 (6)

1.1 (0.9–1.4)

Fever of unknown origin

18 (1)

0.2 (0.1–0.3)

Parasitic infection

4 (0)

0.05 (0.01–0.1)

Respiratory conditions

282 (16, 14–18)

3.3 (2.9–3.7)

Pneumonia

126 (7)

1.5 (1.2–1.7)

Asthma

56 (3)

0.7 (0.5–0.8)

Other respiratory

47 (3)

0.5 (0.4–0.7)

Throat pain/infection

25 (1)

0.3 (0.2–0.4)

Ear infection

22 (1)

0.3 (0.2–0.4)

Other acute upper respiratory

6 (0)

0.07 (0.02–0.1)

Abdominal and surgical conditions

228 (13, 11–15)

2.7 (2.3–3.0)

General or orthopaedic surgery

98 (6)

1.1 (0.9–1.3)

Other abdominal and pelvic conditions

61 (3)

0.7 (0.5–0.9)

Appendicitis

43 (2)

0.5 (0.2–0.3)

Gastroenteritis

23 (1)

0.3 (0.1–0.4)

Liver or renal disease

3 (0)

0.03 (0.007–0.09)

Dental conditions

151 (9, 7–10)

1.7 (1.4–2.0)

Other conditions

142 (8, 7–9)

1.6 (1.3–1.9)

Unspecified

60 (3)

0.7 (0.5–0.9)

Neurology

43 (2)

0.5 (0.3–0.6)

Pain

26 (1)

0.3 (0.2–0.4)

Haematology

12 (1)

0.1 (0.07–0.2)

Sexual abuse

1 (0)

0.01 (0.003–0.06)

Neoplasms

51 (3, 2–4)

0.7 (0.5–0.9)

Cardiac conditions

49 (3, 2–4)

0.5 (0.4–0.7)

Chronic conditions

33 (2, 1–3)

0.3 (0.2–0.5)

Disability/chronic disease

26 (1)

0.3 (0.2–0.4)

Allergy

7 (0)

0.07 (0.03–0.2)

 

median (IQR)

 

Length of stay in days

3 (2–6)

 

CI confidence interval.
Assuming a total population of 85,915 based on 2011 Census data. 

Between 2009 and 2013, year-to-year variability was evident in the frequency of several of the diagnostic groups: respiratory conditions (P=0.005); abdominal and surgical conditions (P<0.001); other infectious diseases (P=0.02); other conditions (P=0.004); dental conditions (P<0.001) and neoplasms (P=0.001). Directional trends were present for respiratory conditions (P=0.001), injury and poisoning (P=0.047), other infectious disease (P=0.02), dental conditions (P<0.001) and neoplasms (P<0.001) (Figure 1). The proportion of hospital admissions per year due to respiratory conditions (P=0.001), other infectious diseases (P=0.02) and neoplasms decreased (P<0.001). The proportion of hospital admissions per year for injury and poisoning (P=0.047), and dental conditions increased (P<0.001).

Figure 1: Admissions to Vaiola Hospital from 2009–2013 for children aged 5–11 years.

c 

The number of admissions by diagnostic group varied by age (Figure 2). A larger proportion of younger (5–7 years) versus older (8–12 years) children were admitted for treatment of dental (16% vs 1%, P<0.001) or respiratory conditions (18% vs 14%, P=0.02). A larger proportion of older children were admitted for abdominal and surgical conditions (15% vs 11%, P=0.008), other infectious diseases (21% vs 17%, P=0.04), other conditions (10% vs 6%, P<0.001) and cardiac conditions (2% vs 1%, P<0.001).

Figure 2: Admissions to Vaiola Hospital from 2009–2013 for children by diagnostic group versus age, gender and season of admission. 

c 

The number of admissions by diagnostic group varied with gender (Figure 2). A larger proportion of boys than girls had a hospital admission for injury or poisoning (31% vs 22%, P<0.001) or neoplasm (4% vs 1%, P<0.001). A larger proportion of girls than boys had a hospital admission for a dental (15% vs 5%, P<0.001) or a cardiac condition (5% vs 2%, P<0.001).

Admissions by diagnostic group varied by season (Figure 2). A larger proportion of the hospital admissions in the dry/cool season were for respiratory (18% vs 14%, P=0.013) or dental conditions (5% vs 3%, P<0.001). A larger proportion of the hospital admissions in the wet/warm season were due to injury and poisoning (30% vs 26%, P=0.04) or for abdominal and surgical conditions (15% vs 11%, P=0.006).

There were six in-hospital deaths over the five-year study period in the age group 5–11 (inclusive) years, three due to neoplasms and one each due to encephalopathy, sepsis and hepatic failure.

Discussion

Our study of hospital admissions from 2009–2013 of children in Tonga aged 5–11 years showed an average annual hospitalisation rate of 20.2/1,000, with injury and poisoning, infectious diseases, respiratory conditions, abdominal, gastrointestinal and surgical conditions and dental conditions accounting for 85% of hospital admissions. Hospitalisation rates decreased with increasing age. A larger proportion of hospital admissions among younger children (5–7 years old) were for dental or respiratory conditions and a larger proportion of hospital admissions among older children (8–11 years old) were for abdominal and surgical conditions, other infectious diseases and cardiac conditions.

This is the first study that has quantified population disease burden in this age group in the Pacific. The primary school age group is important because it is an age when diseases such as asthma, rheumatic heart disease and obesity, which cause long-term morbidity, can first manifest clinically.14 This age group is also one for whom health care is facilitated by the potential ease of access created by school-based delivery of healthcare.

Our intention in this first study was simply to describe the prevalent causes of disease burden and how these varied by demographic characteristics. As such, our study has a number of limitations. As we restricted our analysis to hospital admission data we were unable to describe health status or to consider the many important health issues that are infrequent causes of hospital admission. Thus our study provides no information, for example, about nutritional status, vision and hearing; nor any understanding of emotional, psychological, social, cognitive or behavioural wellbeing. Nor do our data allow for any consideration of the status of the child’s environment, including family, culture, economics, school and home environment. It does however provide baseline information and point of focus to inform future investigations and policy development.

It is important to acknowledge that due to external cause coding not being available, it was not possible to identify if an injury was intentional or unintentional. A number of child advocates in Tonga have highlighted the need for more work to be done on preventing child maltreatment, as well as improving the processes in place for managing and recording it. A recent study on violence against women in Tonga placed the nation among the highest in the world for levels of physical violence against women by non-partners.48,49 Another study comparing three Pacific Island countries reported that Tongan children expressed the highest levels of violence against them, including in the criminal justice system, schools and home.50

In low-resource countries such as Tonga, many children do not access hospital care regardless of the severity of their disease. This is certainly the case for acute lower respiratory infection in developing countries where most deaths take place outside hospitals.51 Hospital admission data is consequently likely to underestimate the burden of disease. In global burden of disease studies, hospital discharge data is only one of nine different data sources used to show burden of disease and years lived with disability. These studies also use systematic reviews for disease sequelae, reports to governments, population-based disease registries, antenatal clinics, outpatient data, household surveys, re-analysis of cohort studies and indirect prevalence studies.52 The hospital data presented therefore needs to be interpreted with some caution, however this should not be a deterrent to presenting this part of the picture, particularly in countries where there is such a lack of baseline information.

The Tongan Hospital Information System enabled us to use electronic data to describe relationships between demographics and hospital utilisation. The use of ICD discharge codes and the creation of a smaller number of diagnostic groupings enabled comparisons over time and between population subgroups in this study, which can also be used with subsequent comparisons to different time intervals and other Pacific nations.

The temporal trends over the relatively short time interval of this study need to be interpreted with caution. The reduction in proportion of hospital admissions per year due to respiratory conditions and infectious diseases could be due to improved management of these conditions in the community and/or better preventative measures to combat such diseases. The increase in accident and injury admissions potentially indicates an area where more focused preventive strategies may be needed. The dramatic increase in dental admissions between 2010 and 2011 may be contributed by changes in documentation methods within the dental department. The larger number of younger children admitted to the dental department does indicate though the fragility of the primary dentition in this age group. The finding that younger children were at increased risk of admission with respiratory issues and that boys were at increased risk of admission with injury and poisoning is consistent with the global literature.53,54

Our findings appear consistent with the small number of reports from other countries of the prevalent health issues in this age group. Lozano et al10 studied age-specific mortality across 21 global regions (Tonga and other Pacific countries were included as Oceania) between 1980 and 2010 and found that in the 5–14 year old age group, infectious diseases, HIV/tuberculosis, injuries and some cancers prevailed, with mortality rates low in this age group. In a study investigating health expenditure due to multiple chronic diseases in the 0–17 year age group in the US, Zhong et al55 found the most prevalent chronic conditions were asthma/chronic obstructive pulmonary disease, allergic rhinitis and behavioural problems. In Australia, a study of children’s wellbeing in their middle years (8–14 years) found a significant proportion of children had low wellbeing, and particularly those considered to be marginalised.4 This marginalised group included those defined as “culturally and linguistically diverse”, which would include migrants from Pacific Islands.

The data presented here are the first to describe child health in the primary school age group in Tonga. Our findings complement data reported in 2010 about 12–15 year-old children from 24 high schools in Tonga, which participated in a global school-based health survey. In this older age group, 59% were overweight and 21% obese. Among students that had ever used drugs, approximately two-thirds (68%) were using drugs before the age of 14 years. More than one-third (36%) of students had attempted suicide one or more times in the past 12 months. Bullying was a concern for 66% of students. Only 27% reported parents and guardians understanding their problems. Violence was significant with 49% reporting physical fights, 51% being attacked and 63% seriously injured in the past 12 months.56 These prevalent concerning health issues highlight the need to determine earlier childhood predictors of adolescent health.57

This description of disease in primary school aged children requiring inpatient hospital care makes an important contribution to child health research in Tonga and the rest of the Pacific. These data and analyses provide a contemporary description that can be used to inform priority areas for healthcare spending and to enable comparisons over time and between different countries in the Pacific region. From these data the key areas to target for health prevention strategies are injury and poisoning, infectious diseases, respiratory conditions, abdominal and surgical and dental conditions. While this study cannot determine the best way to target these particular issues, it does establish a baseline description of disease burden against which the effectiveness of interventions can be measured.

This report of morbidity and mortality data represents the first phase of a more comprehensive description of the health status of children in Tonga. Our findings have helped to inform other projects in progress, which will allow a broader and more detailed description of the contemporary health status and challenges to health faced by children growing up in Tonga.

The global state of primary school children’s health in resource-limited countries and the conditions which affect this age group remain relatively undefined. Although under five-year mortality rates do show the condition of overall society due to the vulnerability of this age group, they do not encompass the whole of child wellbeing. The current lack of global focus on the Pacific region and on the primary school age group in particular provides a challenge worth rectifying.

Appendix 

Appendix 1:The nine diagnostic groups and the diagnostic categories within each of these groups.c

 c

 c

Summary

New Zealand is situated close to the Pacific Islands geographically and has a high Pacific population. Unfortunately, children living in these small but important Pacific nations have not received much attention in regards to their health status. In this paper, 85% of admissions to hospital in Tonga for primary school children were for injury and poisoning, non-respiratory infectious disease, respiratory conditions, abdominal/surgical conditions and dental disease. This information is helpful to inform healthcare priorities for Tonga and other similar countries.

Abstract

Aim

To describe inpatient utilisation patterns for primary school aged children in Tonga.

Method

We described admissions for children aged 5–11 years to the main hospital in Tonga from January 2009 to December 2013. Rates with 95% confidence intervals (CI) were compared using rate ratios (RR).

Results

There were 1,816 admissions. The average annual admission rate was 20.2/1,000 (95% CI 19.3–21.1). Hospital admission rates were higher in younger than older children (5–7 versus 8–11 years, RR=1.28, 95% CI 1.18–1.41) and in boys than girls (RR=1.52, 95% CI 1.38–1.68). Injury and poisoning (28%), non-respiratory infectious diseases (19%), respiratory conditions (16%), abdominal/surgical conditions (13%) and dental (9%) were the most frequent admission reasons. A larger proportion of younger versus older children were hospitalised for dental (16% vs 1%, P<0.001) or respiratory conditions (18% vs 14%, P=0.02). A larger proportion of older children were hospitalised for abdominal/surgical conditions (15% vs 11%, P=0.008), other infectious diseases (21% vs 17%, P=0.04), other conditions (10% vs 6%, P<0.001) and cardiac conditions (2% vs 1%, P<0.001).

Conclusion

In children 5–11 years in Tonga, 85% of admissions were for five groups of conditions. These data inform priority areas for healthcare spending and enable comparisons over time and between different Pacific countries.

Author Information

Fiona Catherine Langridge, PhD Candidate, Departments of Pacific Health, Paediatrics: Child and Youth Health, The University of Auckland, Auckland; Sione Vaioleti Hufanga, Biostatistician, Biostatistics Department, Chief Information Officer, Ministry of Health, Tonga;
Malakai Mahunui ‘Ofanoa, Senior Lecturer, Departments of Pacific Health;
Toakase Fakakovikaetau, Paediatrician, Paediatrics Department, Vaiola Hospital, Nuku’alofa, Tonga; Teuila Mary Percival, Paediatrician and Senior Lecturer, Departments of Pacific Health;
Cameron Charles Grant, Paediatrician and Professor, Paediatrics: Child and Youth Health, The University of Auckland, Auckland, Starship Children’s Hospital, Auckland.

Acknowledgements

The authors would like to thank the Ministry of Health in Tonga. We acknowledge NZAID, The Oticon Foundation, NZOVRF and the Ranchhod Foundation for funding support. FL is supported by The University of Auckland Doctoral Scholarship. The authors have no competing interests to declare.

Correspondence

Fiona Langridge, Department of Pacific Health, Faculty of Medicine and Health Sciences, University of Auckland, Private Bag 92019, Auckland.

Correspondence Email

f.langridge@auckland.ac.nz

Competing Interests

Mrs Langridge reports grants from University of Auckland during the conduct of the study; grants from New Zealand Optometric Vision Research Foundation, grants from The Oticon Foundation, non-financial support from The Ranchhod Foundation, outside the submitted work. MO is part of the supervision team for this PhD candidate (main author).

References

  1. Duke T, Kado JH, Auto J, et al. Closing the gaps in child health in the Pacific: An achievable goal in the next 20 years. J Paediatr Child Health. 2015; 51:54–60. 
  2. Denno D. Global child health. Pediatr Rev. 2011; 32:e25–e38.
  3. United Nations. The sustainable development goal report 2016; New York: United Nations 2016. Available from: http://unstats.un.org/sdgs/report/2016/The%20Sustainable%20Development%20Goals%20Report%202016.pdf accessed 10 August 2017.
  4. Redmond G, Skattebol J, Saunders P, et al. Are the kids alright? Young Australians in their middle years: Final report of the Australian Child Wellbeing Project, Flinders University, University of New South Wales and Australian Council for Educational Research. Flinders University, University of New South Wales and Australian Council for Educational Research, 2016. Available from: http://australianchildwellbeing.com.au/sites/default/files/uploads/ACWP_Final_Report_2016_Full.pdf accessed 10 August 2017.
  5. Bryce J, Terreri N, Victora CG, et al. Countdown to 2015: tracking intervention coverage for child survival. Lancet. 2006; 368:1067–1076.
  6. Karadag B, Karakoc F, Ersu R, et al. Non-cystic-fibrosis bronchiectasis in children: a persisting problem in developing countries. Respiration. 2005; 72:233–238.
  7. Prescott SL, Pawankar R, Allen KJ, et al. A global survey of changing patterns of food allergy burden in children. World Allergy Organ J. 2013; 6:21.
  8. Thapar N, Sanderson IR. Diarrhoea in children: an interface between developing and developed countries. Lancet. 2004; 363:641–653.
  9. Wald A, Sigurdsson L. Quality of life in children and adults with constipation. Best Pract Res Clin Gastroenterol. 2011; 25:19–27.
  10. Lozano R, Naghavi M, Foreman K, et al. Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet. 2013; 380:2095–2128.
  11. Jackson SL, Vann Jr WF, Kotch JB, et al. Impact of poor oral health on children’s school attendance and performance. Am J Public Health. 2011; 101:1900–1906.
  12. Petersen PE, Bourgeois D, Ogawa H, et al. The global burden of oral diseases and risks to oral health. Bull World Health Organ. 2005; 83:661–669.
  13. Parker EJ, Jamieson LM, Broughton J, et al. The oral health of Indigenous children: A review of four nations. J Paediatr Child Health. 2010; 46:483–486.
  14. Gore FM, Bloem PJ, Patton GC, et al. Global burden of disease in young people aged 10–24 years: a systematic analysis. Lancet. 2011; 377:2093–2102.
  15. Asiegbu UV, Asiegbu OG, Onyire BN, et al. Assessment of gross malnutrition among primary school children using body mass index as an assessment tool in abakaliki metropolis of Ebonyi State, South-East Nigeria. Niger J Clin Pract. 2017; 20:693–699.
  16. Ukaegbe OC, Umedum NG, Chime EN, Orji FT. Assessment of common otolaryngological diseases among children in rural primary schools in south eastern Nigeria. Int J Pediatr Otorhinolaryngol. 2016; 89:169–172.
  17. Gharaibeh NS. Effects of indoor air pollution on lung function of primary school children in Jordan. Ann Trop Paediatr. 1996; 16:97–102.
  18. Odinaka KK, Nwolisa EC, Mbanefo F, et al. Prevalence and Pattern of Soil-Transmitted Helminthic Infection among Primary School Children in a Rural Community in Imo State, Nigeria. J Trop Med. 2015; 2015:349–439.
  19. Kombich JJ, Muchai PC, Tukei P, Borus PK. Rubella seroprevalence among primary and pre- primary school pupils at Moi’s Bridge location, Uasin Gishu District, Kenya. BMC Public Health 2009; 9:269.
  20. Klepp KI, Ndeki SS, Seha AM, et al. AIDS education for primary school children in Tanzania: an evaluation study. AIDS. 1994; 8:1157–1162.
  21. Gajanana A, Thenmozhi V, Samuel PP, Reuben R. A community-based study of subclinical flavivirus infections in children in an area of Tamil Nadu, India, where Japanese encephalitis is endemic. Bull World Health Organ. 1995; 73:237–244.
  22. Ayanniyi AA, Mahmoud AO, Olatunji FO. Causes and prevalence of ocular morbidity among primary school children in Ilorin, Nigeria. Niger J Clin Pract. 2010; 13:248–253.
  23. Sarvamangala K, Koujalgi MB, Manjunath TP. Prevalence of anemia, morbidity and school absenteeism among lower primary school children of Davangere city. Indian J Public Health Res Dev. 2014; 5:220–225.
  24. Thapa KB, Okalidou A, Anastasiadou S. Teachers’ screening estimations of speech-language impairments in primary school children in Nepal. Int J Lang Commun Disord. 2016; 51:310–327.
  25. Rabbani MG, Hossain MM. Behaviour disorders in urban primary school children in Dhaka, Bangladesh. Public Health. 1999; 113:233–236.
  26. Narwaria YS, Saksena DN. Prevalence of dental fluorosis among primary school children in rural areas of Karera Block, Madhya Pradesh. Indian J Pediatr. 2013; 80:718–720.
  27. Percival T, Langridge F, Stowers L. Keeping promises, measuring results: implications for maternal and child health in the pacific. Health information Services Knowledge Hub working paper series. Queensland: School of Population Health, University of Queensland, AusAID. 2013 (26). Available from: http://www.researchgate.net/profile/Teuila_Percival/publication/237084244_Keeping_promises_measuring_results_the_Pacific_Maternal_and_Child_Health_Indicators_Project/links/00b4953c84c336c6da000000/Keeping-promises-measuring-results-the-Pacific-Maternal-and-Child-Health-Indicators-Project.pdf accessed 10 August 2017.
  28. Gray S, Lennon D, Anderson P, et al. Nurse-led school-based clinics for skin infections and rheumatic fever prevention: results from a pilot study in South Auckland. N Z Med J. 2013 Apr 19; 126:53–61.
  29. Lennon D, Stewart J, Farrell E, et al. School-based prevention of acute rheumatic fever: a group randomized trial in New Zealand. Pediatr Infect Dis J. 2009; 28:787–794.
  30. Anderson P, King J, Moss M, et al. Nurse-led school-based clinics for rheumatic fever prevention and skin infection management: evaluation of Mana Kidz programme in Counties Manukau. NZ Med J. 2016; 129:36–45.
  31. New Zealand Ministry of Health. Tagata Pasifika in New Zealand. 2014; Available at: http://www.health.govt.nz/our-work/populations/pacific-health/tagata-pasifika-new-zealand accessed 02/10, 2017.
  32. Morton SM, Atatoa Carr PE, Grant CC, et al. Cohort profile: growing up in New Zealand. Int J Epidemiol. 2013; 42(1):65–75.
  33. Tonga Department of Statistics. Census Statistics 2011. 2016; Available at: http://tonga.prism.spc.int/#population-statistics-including-administrative-information-and-statistical-tabulation-of-the-2011 accessed 5 November 2016.
  34. World Health Organisation. Tonga: A Country Profile. 2011. Available from: http://www.wpro.who.int/countries/ton/33TONpro2011_finaldraft.pdf accessed 10 August 2017.
  35. Russell FM, Fakakovi T, Paasi S, et al. Reduction of meningitis and impact on under-5 pneumonia after introducing the Hib vaccine in the Kingdom of Tonga. Ann Trop Paediatr. 2009; 29:111–117.
  36. Danielsson N, Fakakovikaetau T, Szegedi E. Improved immunization practices reduce childhood hepatitis B infection in Tonga. Vaccine. 2009; 27:4462–4467.
  37. Lutui F, Grant CC, Best E, et al. Invasive Pneumococcal Disease in Children in Tonga. Pediatr Infect Dis J. 2017; 36:239–240.
  38. Schultz J, Utter J, Mathews L, et al. The Pacific OPIC project (Obesity Prevention in Communities): action plans and interventions. Pac Health Dialog. 2007; 14:147–153.
  39. Swinburn B, Pryor J, McCabe M, et al. The Pacific OPIC project (Obesity Prevention in Communities)-objectives and designs. Pac Health Dialog. 2007; 14:139–146.
  40. Fotu K, Moodie M, Mavoa H, et al. Process evaluation of a community-based adolescent obesity prevention project in Tonga. BMC Public Health. 2011; 11:284.
  41. Finau SA, Taylor L. Rheumatic heart disease and school screening: Initiatives at an isolated hospital in Tonga. Med J Aust. 1988; 148:563–567.
  42. Carapetis JR, Hardy M, Fakakovikaetau T, Taib R, et al. Evaluation of a screening protocol using auscultation and portable echocardiography to detect asymptomatic rheumatic heart disease in Tongan schoolchildren. Nat Clin Pract Cardiovasc Med. 2008; 5:411–417.
  43. Poole-Wilson PA, Seth S. Rheumatic fever: The potential advantages of technology. Nat Clin Pract Cardiovasc Med. 2008; 5:426–427.
  44. Foliaki S, Annesi-Maesano I, Daniel R, et al. Prevalence of symptoms of childhood asthma, allergic rhinoconjunctivitis and eczema in the Pacific: The International Study of Asthma and Allergies in Childhood (ISAAC). Allergy Eur J Allergy Clin Immunol. 2007; 62:259–264.
  45. Foliaki S, Fakakovikaetau T, D’Souza W, et al. Reduction in asthma morbidity following a community-based asthma self-management programme in Tonga. Int J Tuberc Lung Dis. 2009; 13:142–147.
  46. Hoffman MP, Cutress TW, Tomiki S. Prevalence of developmental defects of enamel in children in the Kingdom of Tonga. N Z Dent J. 1988; 84:7–10.
  47. Craig L, Adams J, Oben G, et al. The Health Status of Children and Young People in New Zealand. Dunedin: New Zealand Child and Youth Epidemiology Service, University of Otago; 2013. Available from: http://www.otago.ac.nz/nzcyes/otago086007.pdf accessed on 10 August 2017. 
  48. Jansen H, Johansson-Fua S, Hafoka-Blake B, ‘Ilolahia GR. National Study on Domestic Violence against Women in Tonga Nofo ‘a kainga. Kingdom of Tonga: Ma`a Fafine mo e Famili Inc. 2012. Available from: http://www.pacificwomen.org/wp-content/uploads/tonga-vaw-report-final-20121.pdf accessed 10 August 2017 
  49. McLean A. Corporal Punishment of Children in Tonga–A Violation of Constitutional Rights. Asia-Pacific Journal on Human Rights and the Law. 2014; 15:73–118.
  50. Smith BJ, Phongsavan P, Bampton D, et al. Intentional injury reported by young people in the Federated States of Micronesia, Kingdom of Tonga and Vanuatu. BMC Public Health. 2008; 8:145.
  51. Nair H, Simões EA, Rudan I, et al. Global and regional burden of hospital admissions for severe acute lower respiratory infections in young children in 2010: a systematic analysis. Lancet. 2013; 381:1380–1390.
  52. Vos T, Flaxman AD, Naghavi M, et al. Years lived with disability (YLDs) for 1,160 sequelae of 289 diseases and injuries 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet. 2013; 380:2163–2196.
  53. Morrongiello BA, Rennie H. Why do boys engage in more risk taking than girls? The role of attributions, beliefs, and risk appraisals. J Pediatr Psychol. 1998; 23:33–43.
  54. Walker CLF, Rudan I, Liu L, et al. Global burden of childhood pneumonia and diarrhoea. Lancet. 2013; 381:1405–1416.
  55. Zhong W, Finnie DM, Shah ND, et al. Effect of multiple chronic diseases on health care expenditures in childhood. J Prim Care Community Health. 2015 Jan;6:2–9.
  56. World Health Organisation. Tonga - 2010 Global School-based Student Health Survey. Kingdom of Tonga: World Health Organisation. 2012. Available from: http://www.who.int/chp/gshs/GSHS_Tonga_2010_Report.pdf?ua=1 accessed 10 August 2017.
  57. Kessler RC, Berglund P, Demler O, et al. Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication. Arch Gen Psychiatry. 2005; 62:593–602.