1. Reduction in sociodemographic disparities for otitis media hospitalisation rates in young children following introduction of pneumococcal conjugate vaccine in NZ
Anna Howe, Helen Petousis-Harris, Janine Paynter, Emma Best, Donna Watson, Nikki Turner

2. Disclosure
This study has received financial support from GlaxoSmithKline (GSK).
GSK has not had input into the design, analyses or
interpretation of this study.

3. NZ Situation Otitis Media in NZ Primary Care
Cohort study NZ GP children <5 years
Raw incidence of AOM 273 per 1,000 children
27.3%; 95% CI 216–330
4% developed recurrent AOM
Incidence declined with age
No difference between ethnicities in primary care
Otitis Media in NZ Hospitals
Pacific and Maori children 0-4y more likely to admitted for AOM (1 ½ times higher)
Admission rates for grommets in under 4’s higher for European, lower for Pacific
Admission rates for grommets in over 5’s higher in Pacific, lower in European
Gribben et al. Journal of primary Health Care. 2012;4(3):
McCallum et al. The New Zealand Medical Journal. 2014;128(1416):10-20.

4. Method – retrospective cohort
Data sources Investigators
NHI encrypted
NHI database
NIR
NMDS
EpiSurv
First hospitalisations for all children born between 2006 and 2015

5. Results
Otitis Media hospitalisations

6. PCV vaccination in NZ 2008 - 2015 NZ PCV primary schedule:
6 weeks, 3 months,
5 months, 15 months
n = 483,683
Dose 1
Dose 2
Dose 3
Dose 4
PCV7
47.2
44.4
41.0
29.6
PCV10
37.1
36.2
35.6
33.6
PCV13
14.8
13.8
13.4
12.4
Overseas
0.8
0.5
0.4
0.1
Unable to determine
0.2
Missing -
5.0
9.5
24.2
Excluding not recorded in NIR, records of more than four PCV doses, recorded as having PCV dose 1 before four weeks of age

7. Timeliness of dose by ethnicity and deprivation
NZ PCV primary schedule:
6 weeks, 3 months,
5 months, 15 months
Overall 85%
Overall 76%
Overall 67%
Overall 51%
In total only 42% are vaccinated on-time for all 4 doses, 64% for the first three
Figure 1. Proportion of NZ children receiving PCV dose on time by socioeconomic deprivation and ethnicity, between 2006 and 2015 (inclusive)
least
most

8. Otitis Media Hospitalisations (2006 – 2015)
(%)
Total number 1
34,959
(78.5) 2
6,964
(15.6) 3
1,774
(4.0) 4
529
(1.2) 5
190
(0.4)
6-12
129
(0.3)
Hospitalisation
44,087
Surgical
29,099
NZ case definition
ICD-10-AM
Non-supportive Otitis Media
H650, H651, H652, H653, H654, H659
Suppurative and unspecified Otitis Media
H660, H661, H662, H663, H664, H669
Otitis Media in disease classified elsewhere
H700, H701, H708, H709
Other disorders of middle ear and mastoid
H740, H741, H743, H744, H748, H749
Other disorders of middle ear and mastoid in disease classified elsewhere
H750
Otalgia and effusion of ear
H920, H921, H922
Myringotomy with tube insertion ,

9. Otitis Media Hospitalisations by Age
Mean age 2.2 (SD 1.6) years
Figure 2. Rates of hospitalised Otitis Media by age group, for children under 6 years of age between 2006 and 2015 (inclusive)

10. Otitis Media Hospitalisations by Ethnicity
(%)
Asian
1,930
(4.3)
Maori
13,523
(30.4)
NZ European
23,754
(53.3)
Other
506
(1.1)
Pacific
4,703
(10.6)
Missing
129
(0.29)
Figure 3. Rates of hospitalised Otitis Media by ethnicity, for children under 6 years of age between 2006 and 2015 (inclusive)

11. Otitis Media Hospitalisations by Deprivation
(%)
1-2 (least)
6,326
(14.2)
3-4
6,626
(14.9)
5-6
7,895
(17.7)
7-8
9,864
(22.1)
9-10 (most)
13,660
(30.7)
Missing
174
(0.39)
Figure 4. Rates of hospitalised Otitis Media by quintile of NZ deprivation index, for children under 6 years of age between 2006 and 2015 (inclusive)
least
deprived
most
deprived

12. Otitis Media Hospitalisations by Deprivation
Categorisation of NZDep13 Index
Low = 1, 2 & 3
Medium = 4, 5, 6 & 7
High = 8, 9 & 10
Figure 5. Linear regression of rates of hospitalised Otitis Media by NZ deprivation, for children under 6 years of age between 2006 and 2015 (inclusive)

13. Conclusions
Between 2006 and 2015, 44,545 children less than 6 years of age were hospitalised for Otitis Media related conditions
Rates have fallen significantly during the study period, particular among the under two year olds
The greatest overall declines occurred among Maori and Pacific and the discrepancy between the most and least deprived
NZ’s PCV programme has made in roads to reducing inequality, more work is required

14. Thank you Grateful appreciation to: GSK for funding
Ministry of Health for data provision and NHI encryption
KPS for my Fellowship

15. Estimated VE Time period^ n Person-years
Crude incidence rate ratio (95% CI)
Adjusted incidence rate ratio (95% CI)*
Pre-vaccine
01 Jan 2006 – 30 May 2008
32,772
147,992
1.00
(PCV7)
01 Jun 2008 – 15 Oct 2011
19,887
197,554
0.45 (0.45,0.46)
0.45 (0.44, 0.46)
(PCV10)
26 Feb 2012 – 27 Sep 2014
12,056
156,658
0.35 (0.34, 0.35)
0.34 (0.33, 0.35)
(PCV13)
18 Jan 2015 – 31 Dec 2015
3,904
58,178
0.30 (0.29, 0.31)
0.29 (0.28, 0.30)
Not a examining VE directly, but a mixture of direct and indirect effects of PCV at a population level
VE of between 55 and 71
Incorporated a washout period
Other potential confounders include other demographics (deprivation), circulating pathogens at various time points
When stratified by age, stronger results with an adjusted VE of between 65 and 78 for under 2 year olds, 3-5 years olds of between 27 and 52
^ Vaccine usage defined by calendar time period
* Adjusted for age at the time of hospitalisation and ethnicity

16. Demographics n (%) Sex Male 26,339 (59.1) Female 18,206 (40.9) Region
Northern
15,308
(34.4)
Midland
11,212
(25.2)
Central
7,199
(16.2)
South Island
10,654
(23.9)
Overseas
171
(0.38)
Missing 1
(<0.1)