  |
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Journal of the New Zealand Medical Association,
06-May-2005, Vol 118 No 1214
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Knowledge and attitudes about influenza vaccination amongst
general practitioners, practice nurses, and people aged 65 and over
Cheryl Brunton, Rob Weir, Lance Jennings; for the National
Influenza and Pneumococcal Immunisation Attitudes Study (NIPIAS) Group
Influenza remains a disease of public health importance in
New Zealand. The national general practice-based sentinel surveillance programme
estimated that an annual average of 2.7% of the population attended their
general practitioner because of an influenza-like illness between 1990 and
1999.1 Additionally, during the same time
period, there were 278 hospital admissions and 34 fatalities per year directly
attributed to influenza. This is also likely to be a significant underestimate
since influenza modelling carried out by the Ministry of Health for
1980–1992 suggested that for each death attributed to influenza, a further
7.7 were also attributable to influenza but not diagnosed as
such.2
Older people are more likely to experience severe
consequences of influenza. They have higher hospitalisation rates (33.7 per
100,000 in those persons aged ≥65 years compared with 7.5 per 100,000 in
the overall population) and higher mortality rates (10.5 per 100,000 in the 65
and over group compared with 0.9 per 100,000 in the overall
population).1 This higher risk of complications
from influenza is the rationale for recommending influenza vaccination in the 65
and over age group, as influenza vaccination is effective in preventing
morbidity and mortality from influenza in older
people.3
In New Zealand, influenza
vaccination became available free of charge to people aged 65 years and over in
1997. Since then, vaccination coverage has increased in this age group - from
39% in 1997 to 59% in 2000.1 However, there is
still wide variation by region (see Table 1) and the Ministry of Health’s
national coverage target (75% in those aged 65 and over) has not yet been
met.
Table 1. Influenza vaccination coverage in people aged
65 years and over during 2000.
Studies in several countries have shown that patient
attitudes and beliefs influence influenza vaccine uptake. Many older people
believe that the vaccine is unnecessary, because they are not at risk if they
are generally healthy.4–6 However,
elderly people without existing comorbidity7
also benefit from vaccination. Concern about side effects following
vaccination is frequently given as a reason for not being
vaccinated4,5,8,9, however, minor reactions are
uncommon and serious side effects are rare.10
Some patients also think influenza can be acquired from
vaccination,11 although this is not the case.
Patient beliefs that vaccination does not prevent serious disease or reduce
their risk of developing complications from influenza are also associated with
lower vaccine uptake.5,8,9
Other patient-related reasons for lower vaccine uptake
include difficulties with access to a doctor,9
fewer visits to the doctor,5 and a reduction in
other preventive health activities12. The
influence of demographic factors is less clear. An Australian study found that
the ‘older old’ were less likely to receive influenza
vaccination,13 although a US study noted that
older subjects were more likely to be
vaccinated.5 Existing illness is also
associated with higher levels of vaccine
uptake7,14.
Identifying factors associated with influenza vaccine uptake
is important to enable public health campaigns to tailor their advice to
eligible patients more effectively. For example, a recommendation from a
patient’s doctor has been shown to have a major influence on the
patient’s decision to be
vaccinated,4,5,8,9 even when they did not
initially want vaccination.11 A nurse’s
recommendation is also a positive predictor of vaccine
uptake.4,15 Performance of other preventive
activities by doctors is also associated with higher levels of
vaccination.12
Strategies to increase influenza vaccination uptake can be
categorised as client oriented (such as mail reminders and phone reminders),
provider oriented (such as chart reminders), and system oriented (such as
standing orders). All categories of strategy have been shown to increase vaccine
uptake, although system-oriented strategies seem to be most
effective.16 However, the proportion of
healthcare providers in New Zealand who believe in and have implemented such
strategies is unclear.
This study aimed to identify the knowledge, attitudes, and
beliefs that influence influenza immunisation coverage in people aged 65 years
and over in New Zealand. In particular, we sought to determine the factors that
influence general practitioners and practice nurses to recommend immunisation,
and that influence immunisation uptake by people aged 65 and over.
MethodsStudy regionsGeneral
practitioners, practice nurses, and people aged 65 and over from four regions
throughout New Zealand were included in our study which was carried out between
November 2001 and February 2002. The study regions were selected on the basis of
year-2000 influenza immunisation coverage, and two high (Waikato and
Christchurch) and two low (Northland and Bay of Plenty) coverage regions were
included. The regional selection also took into account the need to have a
reasonably representative mix of urban/rural, Maori and non-Maori, and
North/South Island population distributions.
Selection and contact of study participantsGeneral
practitioners and practice nurses—Within each region, a postal
survey of a random sample of 150 general practitioners (except in Northland
where all general practitioners were included as there are fewer than 150) and
up to 150 practice nurses was undertaken. Covering letters; study information; a
self-complete questionnaire; and a stamped, addressed, return envelope were
mailed to general practitioners. They were asked to pass on an enclosed letter
of invitation, study information, questionnaire, and return envelope to the
practice nurse who would usually administer influenza immunisations to their
patients.
If two general practitioners within a practice
nominated the same nurse, they were then asked to pass on the second
questionnaire to another nurse from that practice. The assistance of Independent
Practitioner Associations (IPAs) within each region was also sought to help
inform general practices about the study. Two weeks after the initial mail-out,
a further mail-out of a study package was made to each practice if one or both
of the general practitioner or practice nurse questionnaires had not yet been
returned.
People aged 65 and
over—A stratified sample of 1000 people aged 65 and over in each of
the four regions was randomly drawn from the corresponding electoral rolls (both
general and Maori rolls). To approximate the distributions found in data from
the most recent census, the regional samples were stratified according to age
group (65–69, 70–74, 75–79, 80–84, and 85 and over),
gender, and ethnicity. The sampled individuals’ name and address details
were cross-checked with the Telecom Internet White Pages to identify contact
telephone numbers. Those persons without a telephone number (n=339) were not
approached to take part in the study. A letter containing information about the
study, and an invitation to take part, was sent to the randomly selected people
who had a telephone (2 weeks before any telephone contact was made with them).
In that letter, potential participants were advised
that they could decline further contact by the study team (either by returning a
reply-paid response to that effect, telephoning a designated phone number in the
study region, or declining to take part when telephoned). They were also given
information about the study’s exclusion criteria (recently bereaved, too
unwell to be interviewed, and cognitive or hearing impairment that would prevent
being interviewed by telephone). Those persons who had not previously declined
further contact were telephoned by a study interviewer within the next 2 weeks,
and interviewed if they gave consent.
Study questionnairesThe study questionnaires were
based on those used by John Litt in his Australian study of the knowledge and
attitudes of general practitioners and their patients about influenza
immunisation.13 A New Zealand version of both
questionnaires was pilot tested with small groups of general practitioners and
people aged 65 and over before use in the main study. The general practitioner
and practice nurse questionnaires were virtually identical, and required
respondents to indicate agreement/disagreement with a series of statements about
influenza and influenza immunisation using a Likert scale. The provider
questionnaires also asked about the respondent’s own vaccination status,
and asked them to rank a list of possible strategies to improve vaccination
coverage. The questionnaire for the people aged 65 and over also contained the
same basic knowledge and attitude items and asked about vaccination status.
Instead of a section about strategies to increase coverage, this questionnaire
contained a final section about potential barriers to access to influenza
vaccination.
Data entryThree databases (one for each
group of participants) were created for study data entry using EpiInfo version
6.04.17 An experienced data entry operator
entered all the questionnaire data and the study databases were cross-checked
and cleaned by another member of the study team.
Data analysisData analysis was carried out
using STATA version 7.18 Simple frequencies
were calculated for questionnaire response categories for each group of
respondents. The responses of the three
groups were compared for similar items. Chi-squared testing was used for
comparisons of categorical data provided the expected values in all cells was at
least five (Fisher’s exact test was used if this criterion was not met).
Regional breakdowns of data from all three respondent groups were also carried
out. Analysis by vaccination status was also conducted in the 65 and over
group.
Ethical approval for the study was granted by the
Canterbury, Bay of Plenty, Waikato, and Northland Ethics Committees.
ResultsResponse ratesProviders—319
(58%) of the 552 invited general practitioners completed a questionnaire. The
response rate among practice nurses is less straightforward as an unknown number
of index general practitioners either did not have a practice nurse or shared
the services of a practice nurse within a group practice. Without taking these
factors into account, the response rate among practice nurses was 271 out of 549
(49%).
People aged 65 and
over—1558 (39%) of the 4000 people aged 65 and over (selected from
the electoral roll) completed a study interview. Of the remainder, 1659 declined
to participate, 413 met the study’s exclusion criteria (hearing impairment
165, cognitive impairment 77, currently too ill to be interviewed 171), 339 had
no telephone, and 5 had moved and were not contactable. Although this
non-response rate is comparatively high, the age and sex distributions of the
respondent sample did not differ significantly from aggregate census data for
the study regions. The overall proportion of Maori respondents (4%) was slightly
lower than would have been expected from regional census data (7%).
Provider knowledge about influenza and influenza vaccinationAlmost all (>99%) of the general
practitioners and practice nurses agreed that
influenza can be serious in older
people and healthy people can get
influenza. Moreover, 97% of general practitioner and practice nurse
respondents believed the influenza injection would reduce the risk of patients
becoming seriously ill from influenza and its complications.
However, while 92% of general practitioners disagreed with
the statement people can get influenza from
the influenza injection, 4% were unsure and 4% agreed with the statement.
Levels of disagreement were slightly lower among practice nurses (89%), although
8% were unsure and 3% agreed. A higher proportion of Northland general
practitioners agreed with this statement (12%) than in each of the other three
regions (Bay of Plenty 1%, Waikato 5%, and Christchurch 3% [p=0.02]).
Northland had the lowest influenza vaccination coverage in
people aged 65 and over in 2000. The comparative regional figures were slightly
different for practice nurses (Northland 15%, Bay of Plenty 15%, Waikato 13%,
Christchurch 3% [p=0.05]).
Among both general practitioners and practice nurses,
Christchurch had both the highest vaccination coverage in 2000 and the lowest
levels of agreement with the statement.
Only 88% of general
practitioners disagreed with the statement
healthy older people
do not need the influenza injection as they rarely get
sick (7% were unsure and 5% agreed). This
contrasts with practice nurses—93% disagreed with the statement, 3% were
unsure, and 4% agreed. There were no statistically significant regional
differences in answers to this question.
Influenza vaccination coverage among providersThe majority of providers had been
immunised against influenza at some time; however, a lower proportion of both
general practitioners (68%) and practice nurses (64%) had been immunised in 2001
compared to 2000 (see Figure 1)—although this difference was not
statistically significant.
Respondents who had been vaccinated in 2001 were asked to
rank three factors (from a range of six options) as the main reasons for their
decision to have an influenza injection in 2001. Concern about getting influenza
and reducing the chance of being off work were the highest ranked for both
provider groups, however, there were some differences in rankings of other
reasons between the groups (see Table 2). The main reasons given by providers
for not being vaccinated were that they rarely get sick or didn’t get
around to it (see Table 2).
Figure 1. Proportion of general practitioners (GPs) and
practice nurses (PNs) who had been vaccinated against influenza
 Table 2. Proportion of general practitioners (GPs) and
practice nurses (PNs) ranking stipulated reasons for choosing to be/or not to be
vaccinated against influenza in 2001
Strategies to improve or maintain vaccination coverageRespondents were asked to rank
(essential=1, would help a lot=2, would help a
little=3, no help at all=4, or make things worse=5) strategies that would
improve or maintain their patient vaccination coverage. The questionnaire listed
18 possible strategies, and provided space for respondents to add others. Fifty
percent of general practitioners ranked
increasing the subsidy for influenza
vaccination as essential. Better use of
a recall system was ranked second most important (with 30% of general
practitioners considering this strategy essential).
By contrast, practice nurses ranked
increasing the subsidy for influenza
vaccination a close second in importance (with 42% considering this
essential). Increased emphasis on wider
community education about recommended vaccination was ranked as essential
by 43% of practice nurses (this strategy was ranked as third-most important by
GPs, with 27% considering it essential).
People 65 and over - knowledge about influenza and influenza vaccinationThe vast majority (93%) of
respondents from the sample of people aged 65 and over agreed that
influenza can be a serious disease in older
people and 78% agreed that an influenza
injection will reduce your risk of becoming seriously ill from influenza and
from the complications of influenza. While not as high as the proportions
of providers agreeing with similar statements (99% and 97% respectively), these
are still high rates of agreement with correct information about influenza.
However, only just over half (52%) of the respondents aged 65 and over agreed
that healthy older people are at just as much
risk of getting influenza as older people with chronic illness.
Just under a third (30%) of respondents agreed that
people can get influenza from the influenza
injection. There was some regional variation in response to this
question, and agreement was less frequent in higher coverage areas (24 and 25%
in Waikato and Canterbury vs 37 and 32% in Northland and Bay of Plenty). Thirty
percent of participants agreed that people can
get sick from the influenza injection compared to only 4% of GPs and 3%
of practice nurses. Twenty-two percent of respondents agreed that
I don’t need an influenza injection as I
rarely get sick. Regional responses to this question showed no consistent
association with regional coverage levels.
Influenza vaccination coverage among sample aged 65 and overOverall, 76% of respondents
reported having had an influenza vaccination in 2001. Self-reported vaccination
status varied with age, and was highest in the 75–79 age group (see Figure
2).
Figure 2. Self-reported influenza immunisation status
by age
 Among those respondents who were immunised against influenza
in 2001, the three commonest reasons for having had the injection were:
believe influenza vaccine prevents me from
getting influenza (68%), concerned
about getting influenza or its complications (61%),
believe influenza injection prevents serious
disease (49%). There were no significant regional differences, except
that a higher proportion of respondents in high coverage regions chose to be
vaccinated because of a belief that influenza vaccine prevents influenza (72% vs
64%, p=0.005).
Among respondents who were
not immunised in 2001, the three commonest reasons for choosing not to be
vaccinated were:
didn’t need it
as I rarely get sick (67%),
I was unlikely to get
influenza this year (39%), and
concerned about side
effects or having a bad reaction (35%).
There were no significant regional differences in reasons for not being
vaccinated in 2001.
Role of provider recommendationSixty-seven
percent of the respondents recalled receiving a recommendation from their GP or
practice nurse to have the influenza vaccination in 2001. Eighty-three percent
of these respondents were vaccinated, in contrast to 63% of those who did not
receive such a recommendation (p<0.001).
Knowledge and immunisation status in people aged 65 and overWhile
high proportions of both vaccinated and unvaccinated respondents agreed that
influenza can be a serious disease in older people, there were some differences
in the knowledge and beliefs of those who had chosen not to be vaccinated
against influenza in 2002 (see Table 3).
Table 3 Knowledge about influenza and influenza
vaccination and self-reported vaccination status—people aged 65 and
over
Timing and preferred venue for influenza vaccinationMost respondents had been
vaccinated against influenza during either a special visit to their practice
nurse for immunisation (49%) or during a routine visit to their GP for another
reason (27%). The remainder had been vaccinated during a special visit to their
GP for immunisation (9%), a routine visit to practice nurse for another reason
(9%), a visit to a special immunisation clinic (3%), or a visit organised by
their GP or practice nurse. The vast majority of respondents (95%) preferred to
have their vaccination at their GP’s surgery or medical centre, and most
(94%) said they had experienced no difficulty in getting access to their
provider for vaccination.
DiscussionThis study has found that general
practitioners, practice nurses, and people aged 65 and over are generally very
well-informed about the importance of influenza and its complications as well as
the effectiveness of influenza immunisation. As other
studies4–6,11 have found, some
misinformation still exists among people aged 65 and over, such as the belief
that people can get influenza from the influenza injection and that healthy
older people do not need to be vaccinated against influenza.
This study provides evidence that these beliefs discourage
at least some older people from being immunised. The respondents aged 65 and
over strongly preferred general practice as the venue for influenza vaccination,
and only a very small proportion had experienced difficulty in gaining access to
vaccination. While general practitioners and practice nurses differed somewhat
in the relative importance they ascribed to particular strategies to improve
vaccine coverage, there was a high level of support overall for increasing the
vaccination subsidy, providing wider public education about influenza
vaccination, and improving the use of recall systems. The latter two strategies
are already part of current influenza immunisation campaigns.
There were limitations to this study. The response rate was
low, particularly in the 65 and over sample. This may have meant that those who
did respond tended to be more supportive of influenza vaccination and more
likely to be vaccinated. Indeed, vaccination coverage in the study sample was
higher than that estimated from vaccine claims data in 2000 (see Table 1),
although the accuracy of claims data is uncertain. However, vaccination coverage
in the current study was similar to that estimated amongst a cohort of
Canterbury rest home residents.19
It is also likely that this study overestimated knowledge
about influenza vaccination in this target group. The study sample was selected
from two high-coverage regions and two low-coverage regions (based on influenza
vaccine claims data from year 2000). It is unclear how representative knowledge
and attitudes of GPs, practice nurses, and people aged 65 and over in these
regions are of those in New Zealand as a whole. Information bias is also likely
to exist, particularly in the 65 and over age group component of the study.
Influenza vaccination status was based on self-reported data, and all data in
this component were collected by telephone interview. As a result, the study may
have overestimated positive attitudes towards vaccination if respondents tended
to give the interviewers ‘desirable’ responses.
While the levels of awareness about influenza and the role
of vaccination in its control are very encouraging, this study suggests some
potential issues that could be addressed to further increase vaccination
coverage towards the Ministry of Health’s targets. The younger age groups
of people in the 65 and over sample had lower self-reported vaccination status.
For instance, just under half of the 65 and over sample were either unsure or
disagreed that healthy older people are at risk of influenza or its
complications. Thus information strategies (providing evidence about the
benefits of vaccination in healthy older adults) may be needed that are
specifically targeted to this age
group.20
Provider recommendation was also associated with increased
influenza vaccination coverage in people aged 65 years and over. As far as
providers themselves are concerned, although the study general practitioners and
practice nurses reported far higher rates of personal uptake of influenza
vaccination than previously found in studies involving NZ hospital
personnel,21 their levels of protection could
still be improved.
This study supports the contention that GPs and practice
nurses, as well as people aged 65 and over, all have important roles in the
uptake of influenza vaccination in the 65 and over age group. Therefore, to
achieve further increases in influenza vaccination coverage in New Zealand, the
National Influenza Immunisation Strategy Group should continue to target both
providers and groups recommended annual influenza vaccination.
Author information:
Cheryl Brunton, Senior Lecturer, Department of Public Health and General
Practice; Rob Weir, Senior Research Fellow, NZ Health Technology Assessment
Centre, Christchurch School of Medicine and Health Sciences, University of
Otago, Christchurch; Lance Jennings, Virologist, Canterbury Health
Laboratories Ltd, Christchurch—all on behalf of the National Influenza and
Pneumococcal Immunisation Attitudes Study (NIPIAS) Group. NIPIAS group members
include Cheryl Brunton, Rob Weir, Lance Jennings, John Litt, Graham
McGeoch, Andrew Manning, and Lyn Smith.
Acknowledgements:
This study was funded by a grant from the Ministry of Health and supported by
the National Influenza Immunisation Strategy Group. The support of independent
practitioner associations in all the study regions is gratefully
acknowledged.
We are also grateful for the assistance of the fieldworkers
in the four study regions (Northland, Waikato, Bay of Plenty, and Christchurch)
without whom this study could not have happened.
Correspondence: Dr
Cheryl Brunton, Department of Public Health & General Practice, Christchurch
School of Medicine and Health Sciences, PO Box 4345, Christchurch. Fax: (03) 364
3614; email: cheryl.brunton@chmeds.ac.nz
References:
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| | Current
issue | Search journal |
Archived issues | Classifieds
| Hotline (free ads) Subscribe | Contribute | Advertise | Contact Us | Copyright | Other Journals |
|