Approaching the immunisation target: Insights into ‘Partially immunised’ and ‘Declined’
Sarah Radke Research Fellow - Epidemiologist Lynn Taylor National Manager Research &
InnovationUniversity of Auckland
IMAC Conference 2015, Hamilton
Introduction
93% fully immunised at 8 months of age Approx.. 3.5% are ‘not fully immunised’ Approx.. 3.5% are coded as ‘decline’
Extension of “Translating best practice research to reduce equity gaps in mmunisation” Part 1: Analysis of NIR data – partial immunisation Part 2: Practice interviews – decline Part 3: GeoMapping exercise (not presented
today)Funded by Health Research Council of NZ
Objectives – part 1rtial immunisatione data from the National Immunisation Register (NIR) to ntify and compare children with records indicating:
• Selective immunisation by opting out of specific vaccines
• Incomplete immunisation by not completing all doses
tterns of decline e data from the National Immunisation Register (NIR) to antify children with vaccination status=‘declined’se this information to enable development of better understanding of
Objectives – part 2cus on decline immunisationserview selected practices to gain an understanding of what ds to a child being coded as ‘decline’ in the electronic PMS:
• The challenges of the local population
• The common systematic approaches taken at the general practices
se this information to enable development of better vaccination strategies
CHARACTERISING PARTIAL MMUNISATION IN NEW
ZEALAND
arah Radke
Methods
udy population– all children who were less than two years old
between 01 January 2010 and 31 December 2013; and
– were enrolled on the NIR
Exclusions• children whose parents ever elected to have their
information opted off the NIR• children who died prior to their second birthday • children with a record of any vaccine given overseas• children with inexplicable or erroneous information
Methods
ta sources– NIR records through 31 December 2013
• If status field=“completed” we considered corresponding vaccine injection to be received
• Otherwise we considered corresponding vaccine injection not to be received
– If status field=“declined” we considered vaccine injection actively declined versus simply not being received
– National Health Index (NHI) database
I numbers were encrypted and used to link the two data t th i di id l l l
MethodsNational Immunisation Schedule
Infanrix‐hexaPCV
Infanrix‐hexaPCV
Infanrix‐hexaPCV
MMRHibPCV
6 doses by 5 months of age
MethodsPartially immunised
Received some but not all age‐appropriate
doses
UnimmunisedReceived no doses
Fully immunisedReceived all age‐appropriate doses
DeclinedAt least one record
with status of ‘declined’
No records of immunisation
Selectively immunisedeceived no doses for at least one vaccine but received at
least one dose for the remaining vaccines
completely immunisedeived at least one dose for ach vaccine but did not mplete all vaccine series
Methods
alysis– We compared demographic characteristics between
groups• Pearson’s chi-square test for categorical variables • Wilcoxon two-sample test for continuous variables. • All tests for assessing statistical significance were two-sided with
α=0.05.
– We identified independent predictors• multivariable log-linear binomial regression• backwards elimination, removing covariables from the model in order
of p-value magnitude• final predictive model based on a p-value of less than 0.05.
– 3 age cut-offs
Results
Immunisation status (%) 2010 2011 2012 2013
Total (N) 62,610 61,892 60,059 60,053
Unimmunised 4.78 4.20 3.76 3.21Partially immunised 11.77 10.61 9.34 6.30Fully immunised 83.45 85.19 86.89 90.49
mmunisation status by year of 8 completed months of age
Results
Immunisation status, 2013
not receive…fanrix‐hexa (n=28)CV (n=224)
Resultsdependent predictors of incomplete immunisationeristic (%)
Selectively immunised
Incompletely immunised
RR (95% CI) P‐value
ypean 76.19 31.24 1.00 <0.001ri 15.87 41.65 1.13 (1.10, 1.16)ic 2.78 14.86 1.13 (1.11, 1.17)n 3.97 10.53 1.13 (1.10, 1.16)er 1.19 1.61 1.11 (1.05, 1.17)of residencehern 28.17 45.98and 29.76 25.69ral 18.25 13.87hern 23.81 14.09rivation Index
17.93 9.07 1.00 0.01123.51 11.59 1.05 (1.01, 1.08)
Results
‘decline’ records 2010 2011 2012 2013
Total 2,993 2,601 2,261 1,926
None 51.75 47.37 41.97 27.731‐8 doses 26.56 28.10 30.08 36.609 doses 16.61 16.57 19.55 22.90>9 records 5.08 7.96 8.40 12.77
‘Decline’ records among unimmunized children, by year of eight completed months of age
Conclusion
Down to small numbers each vaccine dose delivered requires more resources compared to when coverage was lower
To continue making progress towards and above 95% argets, more information is needed about those not ully immunised
That information should be timely – 2013 info too old to be useful now MoH should incorporate breakdowns nto their quarterly coverage reports – Additional data could be incorporated (e.g. eligibility for
outreach services, immigration data, etc.)
That information should be used to inform strategy
THE CHALLENGES AND NSIGHTS INTO “DECLINE”
ynn Taylor
MethodsNIR reports
(12 month reporting to 30 Nov 2014)Exclude if < 10 eligible children
Rank top 40 HIGH decline rate (2 x national average) for milestone ages of 6m, 8, 12m
24m)
Exclude those in known ‘anti‐immunisation’ areasFinal list approved by Ministry of Health
HIGH decline practices invited to participateLOW decline practices ‘matched’ by DHB and PHO
f d i i
NTIFY
VITE
LECT
ANK
Recruitment
HIGH(Target 20)
30 invited
21 Interviewed5 Declined 5 No response
LOW(Target 20)
20 invited
14 Interviewed5 Declined 1 No response
No LOW comparator for 7 practices
HIGH decline ratePractice ID code
LOW decline rateReason no comparator practice was matched
7 and 8 No comparator practices identified with LOW decline rates
17 Two potential comparator practices identified ‐ Declined to participate
18 and 20 One potential comparator practice identified – No response to follow up
19 and 21 One potential comparator practice identified – Declined to participate
Findings – Local population
efs• Natural lifestyles• Religious persuasion• Lobbyists• Misinformation and own ‘research’
xiety• Fear • Influence of family / friends
ctical challenges• Earthquake• Living remotely• Transient life
Findings – Influencers
ommunity:• Midwives
• Early learning centres, childcare centres
• Coffee groups
ocial media:• Facebook
• You Tube
Findings – Doctors and Nurses
erience• In many “LOW” decline practices, Doctors been in practice many
years• Nurses were mothers themselves• Relationship important• Sharing knowledge about diseases
dical contra-indications• Not common in any practice (LOW or HIGH)• Generally only delay if fever > 37.5C
Findings – Practice systems & processes
ecline policy of practice:• Use of decline form• Process for informed discussion• Open door• Use of OIS• Process for coding decline in PMS
rly enrolment All “accept” nomination if family knownf not known would “reject” or leave in inbox
Would not code as “Decline”
Conclusions
Some people are very firm in their decision to ‘Decline’ due to firmly entrenched beliefs
Some people are influenced by peers in their community and their own “research”
Practice staff “relationship” with the parent is important
Practice systems and processes are
Overall summary & recommendations
NZ has a wealth of data – let’s use it!
nvesting our time and resources wiselyCreate public awareness before new vaccines are launchedUse social media as that is where the parents are looking for their info!
Questions?AcknowledgementsNikki Turner Director (IMAC, UoA)Lynn Taylor National Manager – Research & Innovation (UoA)Sarah Radke Research Fellow – Epidemiologist (UoA)Angela Chong Project Manager (UoA)Barbara Horrell Contract researcherNadia Charania Lecturer Dept Public Health (AUT)Dr Janine Paynter Data Manager (UoA)Dudley Gentles Data Manager (UoA)Dr Dan Exeter Senior Lecturer in Epidemiology (UoA)Jinfeng Zhao Research Fellow in Geographic Information Science (UoA)Joanna Stewart Senior Research Fellow in Epidemiology & BioStatistics (UoA)Suryaprakash Mishra Senior Advisor - Epidemiology, National Immunisation ProgrammeDr Pat Tuohy Chief Advisor - Child & Youth Health (MoH)Rachel Webber Senior Advisor Immunisation - Infant Immunisation (MoH)Interview participants General practices