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| Journal of the New Zealand Medical Association,
21-November-2003, Vol 116 No 1186
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Randomised trials in general practice – a New Zealand
experience in recruitment
Ann Pearl, Susan Wright, Greg Gamble, Robert Doughty and
Norman Sharpe
There is a well-recognised need to carry out trials in the
primary care setting.1–4 Results of
randomised trials from secondary and tertiary healthcare environments may not
have relevance in the primary sector where the majority of patient contacts
occur.3,4 Increasingly, trials that examine
tests and interventions may be conducted in primary care in order to develop
evidence-based healthcare in this setting. However, it has been well
acknowledged that conducting trials in primary care is
difficult,2–6 and not all trials are
successful.1,3
Gaining access to primary care
settings,7 and achieving good levels of patient
recruitment,2,3,5,6 are key components in an
effective randomised trial and are invariably dependent on general practitioner
(GP) participation. It has been shown, however, that GPs may not have a great
interest in research.8 Strategies that
facilitate GP and patient involvement in clinical trials are therefore
essential. Overseas studies have suggested that the following factors are
important in determining GP participation: clinically relevant
study,2,6 personal approach by study
investigators,2,4,7 perceived benefit for GPs
and patients,4,6 no interference in the
doctor–patient relationship,6 simple and
quick study documentation,2,6 effective
communication and support from study
personnel,2,4,6 and appropriate financial
reimbursement.4,6,9
There have been few reports of the experience of conducting
randomised clinical trials in primary care in New Zealand. This paper examines
GP and patient recruitment issues in a clinical trial based in
Auckland.
MethodsA randomised controlled trial,
the Natriuretic Peptides in the Community
Study,10 was developed to investigate the
usefulness of brain natriuretic peptide (BNP) measurement in the diagnosis of
heart failure in the community setting. Briefly, patients aged 45 years or more
who presented to their GP with symptoms of shortness of breath and/or oedema
were eligible for the study. At this initial consultation the GP made a clinical
diagnosis of whether or not heart failure was present. The GP initiated
treatment as necessary. Patients were then referred by GPs to the hospital study
centre where they had a full cardiological evaluation including clinical
assessment, electrocardiogram (ECG), chest X-ray, echocardiography and
measurement of BNP. Patients were randomly allocated as to whether or not their
GP received the BNP result. Each patient then returned to his/her GP for a final
review where the GP revised the diagnosis with or without the BNP result. For
study purposes the decision as to whether or not heart failure was present was
made by a panel of three cardiologists and one general physician who were
blinded to the BNP result. The primary study end point was to compare the
accuracy of the final diagnosis between the two groups of GPs. The overall study
result was that diagnostic accuracy improved 21% in the BNP group compared with
only 8% in the control group,10 demonstrating
that BNP measurement can significantly improve the accuracy of the diagnosis of
heart failure by GPs.
The trial required patients presenting with shortness
of breath and/or oedema to be recruited from primary care. A multi-faceted
approach was used to recruit patients. First, a small number of local GPs were
consulted to estimate the number of patients with these symptoms presenting to a
GP and to discuss aspects of the proposed study. A comprehensive list of
Auckland GPs (excluding those based in accident and medical clinics) was
compiled using a commercial database supplemented by the local phone directory
and phone calls to practices. GPs were then approached on a suburb-by-suburb
basis. Each GP was initially sent a letter. The letter outlined the study aims
and requirements for participating GPs and patients, described patients who
might be eligible for the study, and discussed benefits of participation for GPs
and patients. One of the study investigators phoned each GP approximately one
week after the letter had been sent to determine if the GP was eligible to
participate (working more than four tenths) and interested in taking part. Each
eligible, interested GP was visited by one of the study investigators. At this
visit the study and the involvement of the GP and patients were explained in
more detail. The GP was given a study pack that included study documentation,
patient information sheets, the Heart Foundation heart failure guidelines, and
information regarding BNP.
Each participating GP was asked to identify patients
suitable for the study at normal consultations. Suitable patients were those
aged 45 years or more who presented with shortness of breath and/or oedema, and
who had not been admitted to hospital for heart failure or had a cardiological
assessment in the previous year. The GP gave each eligible patient a brief
explanation of the study and provided a patient information sheet. The GP
completed a simple study documentation sheet that was faxed to the study centre.
Each eligible patient was then seen at Auckland Hospital for independent
cardiological evaluation. The GP had no further involvement in the study until
approximately two weeks later when the GP reviewed the patient with or without a
BNP result. At this time, final study documentation was completed.
Once the final review for each patient was completed
the GP received a full cardiological report including echocardiography, ECG,
chest X-ray, and clinical assessment. GPs received a payment (NZ$150.00) for
each patient they enrolled in the study. This payment was reimbursement for time
spent on study matters and the cost of the final consultation as this was to be
free to the patient. Participating GPs (with their consent) were acknowledged as
co-investigators. The study was also approved by the Royal New Zealand College
of General Practitioners so that GPs could receive MOPS (Maintenance of
Professional Standards) points for their involvement in the study. Participating
GPs also received bimonthly, one-page newsletters to update them on study
progress and inform them of new, relevant developments in heart failure
management.
Following completion of the study all GPs who had
agreed to participate were sent an evaluation questionnaire to complete. There
were different questionnaires for those GPs who had referred and those who had
not referred patients. Both questionnaires consisted of rating scales to
determine GP attitudes to aspects of the study and research in general, with
some items common to both questionnaires.
The study took place in Auckland and the Auckland
Ethics Committee approved the study. GP recruitment began in November 1999 and
continued until April 2001. Patient recruitment began in November 1999 and final
patient data collection was completed in November 2001.
Statistical
analysis Comparison of the characteristics of recruiters and
non-recruiters was made using Wilcoxon unpaired test for continuous variables
and Fisher’s exact test for categorical variables. The questionnaire was
designed to facilitate multivariate analysis with a trunk statement –
‘Overall this has been a good study to be involved in’ – and
branches addressing study communication, study organisation, patient
involvement, and GP participation. Within each branch a number of specific
points were tested by presenting a statement and then asking the respondent to
answer with a rating from 1 to 5 (1 = strongly disagree, 5 = strongly agree). A
second questionnaire was developed for GPs who agreed to participate but who
were unable to refer any patients. Both questionnaires were analysed using a
variety of iterative (stepwise, forward and backward selection), multivariate
regression procedures; consistency and parsimony were sought from amongst the
models. A probability of 0.15 was considered sufficient for inclusion in the
model; however, the threshold for statistical significance was set at 5%. All
analyses were performed using SAS (SAS Institute Inc).
ResultsThe introductory letter was sent to
327 GPs from 135 practices. All these GPs were contacted by phone; 294 were
eligible to take part in the study and 186 GPs (63% of eligible GPs) from 92
practices agreed to participate. From these participating GPs, 92 (31% of
eligible GPs) from 62 practices referred a total of 307 patients to the study
(Figure 1).
Figure 1. General practitioner participation in the
Natriuretic Peptides in the Community Study
 The GPs who agreed to participate and those who actually
referred were very similar to the total group of GPs approached for the
variables measured. Of the GPs approached, 59% (193/327) were male and 9%
(29/327) were in solo practice. In the group of GPs that agreed to participate
61% (113/186) were male and 9% (17/186) were in solo practice. Similarly, in the
group of GPs that actually referred, 58% (53/92) were male and 7% (6/92) were in
solo practice (Table 1). There was no significant difference between the two
groups – GPs approached and referring GPs – with respect to median
years since graduation (p = 0.77) (Table 1).
Table 1. Sociodemographic characteristics of GPs
involved in Natriuretic Peptides in the Community Study
IQR = inter-quartile range
Of the GPs who agreed to participate, 51% (94/186) did not
refer any patients to the study (Table 2). The remaining 92 GPs referred 307
patients with a median of one patient per GP (range 1–14). A maximum of 10
patients per GP had been set but five GPs exceeded this number before they could
be advised that the limit had been reached. Two female practitioners referred
the largest number of participants, 14 each, but overall male GPs referred more
patients to the study. Participating GPs began their involvement in the study at
different times as a result of the rolling recruitment process. The
participating GPs were involved in the study for a median of 332 days
(inter-quartile range 161,452).
Table 2. Number of patients referred by GPs who agreed
to participate
Evaluation
questionnaire The response rate for the questionnaire sent to the
referring GPs was 64% (59/92) and 27% (25/94) for the questionnaire sent to GPs
who agreed to participate but did not refer. Of the referring GPs, 97% (57/59)
agreed or strongly agreed that GPs should participate in research and 93%
(55/59) agreed or strongly agreed that the Department of General Practice (in
this study at University of Auckland) should be involved in research based in
general practice (Table 3). Eighty five per cent (50/59) of referring GPs agreed
or strongly agreed that GPs should be reimbursed for involvement in trials and
46% (27/59) agreed or strongly agreed that they could not participate without
reimbursement (Table 3).
Table 3. Items from process evaluation questionnaire
for referring GPs (n = 59)
The provision of MOPS points was not an important factor for
referring GPs when deciding to participate in the study, while the bimonthly
newsletter was helpful for 80% (47/59) of referring GPs (Table 3). Of the
referring GPs, 97% (57/59) found it a good study to be involved in (Table 3),
with multivariate analysis showing that overall satisfaction was independently
related to the involvement of the Department of General Practice (partial
r2 = 25%) and patient benefit (partial
r2 = 17%).
Although the response rate for non-referring GPs was low
(27%) similar responses were seen as those for the referring group: 92% (23/25)
agreed that it was important that GPs participated in research; 76% (19/25)
agreed that GPs should be paid for involvement in trials; and 36% (9/25) stated
that they could not participate without reimbursement. The main reason for not
referring was having no patients who met the study criteria.
DiscussionThis study, a randomised controlled
effectiveness study demonstrating the positive effect of BNP measurement on the
accurate diagnosis of heart failure in primary care, showed that randomised
trials can be successfully conducted in the primary care setting by working
collaboratively with GPs and paying consideration to their needs. It was
essential that this study was executed in the primary care sector where heart
failure can be very difficult to diagnose and access to investigations can be
limited. Ninety two GPs from 62 practices successfully recruited 307 patients
for the study. This, however, represents the involvement of approximately one
third of all eligible GPs approached and half of those GPs who agreed to
participate. These figures support findings from overseas studies that have
shown that many GPs who agree to participate in trials do not subsequently
recruit patients. Peto et al, in their trial involving patients with
menorrhagia, found that 41% of GPs who agreed to participate actually referred
patients.5 Other researchers have reported
recruitment rates ranging from 8% of GPs who agreed to participate to
66%.1,6
Our finding that a common reason for GPs not referring was
that they had no patients who met the study criteria is also echoed in other
studies.2,5 Other reported reasons for
non-recruitment include forgetfulness5,6 and
time pressures.4–6 These factors did not
appear to be so important for GPs involved in this study. One weakness of our
study is that although patients were referred prospectively we do not know how
many eligible patients actually presented to their GPs but were not referred.
However, Peto et al found in a notes review of some of the practices involved in
their study that only 20% of eligible patients had actually been
referred.5
Our decision to reimburse GPs financially was initially
questioned by the external study reviewers. However, this strategy clearly had
significant support from the GPs, with 85% of referring GPs agreeing with the
principle that GPs should be reimbursed for participation in trials. Silagy and
Carson reported in 1989 that Australian GPs gave financial reward a low rating
as a reason for participating in research.8
However, they acknowledged that financial reward may be important in the context
of a busy GP’s life. The need for appropriate financial reward is
increasingly acknowledged and accepted.2,6,9,11
Arguably, the acceptance of financial reimbursement in the New Zealand setting
should be no different.
This trial attempted to maximise patient recruitment by
using techniques and strategies that had been recommended by other researchers,
and provided an opportunity to evaluate the effectiveness of these strategies
with a post-study questionnaire. The use of these strategies, which included
early consultation with GPs at the time of study design, a relevant study with
good benefits for participating GPs and patients, and effective communication,
resulted in successful recruitment. However, the study also demonstrated that
many GPs who agree to participate will not recruit patients. Researchers
carrying out trials in primary care may need to identify and work more closely
with this group early in the course of the trial.
Primary care in New Zealand will in all likelihood continue
to develop as an important research environment. The success of trials in this
sector will depend on careful and sensitive planning with cooperation and
collaboration between primary healthcare professionals and research
teams.
Author information:
Ann Pearl, Research Fellow, Department of General Practice and Primary Health
Care; Susan Wright, HRC Trainee Fellow; Greg Gamble, Biostatistician; Norman
Sharpe, Emeritus Professor of Medicine; Robert Doughty, Senior Lecturer in
Cardiology, Department of Medicine, University of Auckland.
Acknowledgements:
This trial was supported by grants from the Health Research Council of New
Zealand and the New Zealand National Heart Foundation.
We acknowledge the participation of Auckland general
practitioners who were co-investigators in this study (the NPC Study GP
Collaborative Group):
Dr Abeysekera, Dr TR Akroyd, Dr SP Barclay, Dr RMD Batt, Dr
JB Buckley, Dr HA Budelmann, Dr CM Built, Dr S Calthrop-Owen, Dr JG Carter, Dr R
Chan, Dr SA Chand, Dr S Chunilal, Dr JD Clark, Dr PJ Clemo, Dr G Collinson, Dr
PA Cotton-Barker, Dr SC Crerar, Dr SD Cutmore, Dr D Dalziel, Dr DM De Lacey, Dr
GJ Desborough, Dr MI Eade, Dr TN Farquharson, Dr JC Fetherston, Dr J Frater, Dr
G Ganesh, Dr J Gardner, Dr HM Gardyne, Dr DI Gibson, Dr DJ Gillanders, Dr DM
Good, Dr RK Haydon, Dr NJH Hefford, Dr C Hong, Dr G Houng-Lee, Dr HI Jenkins, Dr
L Johnson, Dr N Kerse, Dr W Khoo, Dr H King, Dr K Large, Dr RW Leitch, Dr A
Leong, Dr R Levenberg, Dr C Lodder, Dr MV Long, Dr DBH Loos, Dr M Loten, Dr SA
Newman, Dr PF Nola, Dr HM MacDonald, Dr BE McKinney, Dr IA Maclean, Dr RAP Mok,
Dr S Moller, Dr JJ O'Sullivan, Dr N Patel, Dr R Potts, Dr N Rasalingam, Dr GW
Robertson, Dr TA Robinson, Dr JJ Rosby, Dr BW Roy, Dr C Sanders, Dr A Sharma, Dr
V Sharma, Dr KL Settle, Dr R Sood, Dr JRG Stewart, Dr RN Stirling, Dr MK Stone,
Dr AG Svensen, Dr JCO Tseung, Dr SJ Turner, Dr AN Twhigg, Dr B Tye, Dr MD Wah,
Dr RH Wallace, Dr G Wardrope, Dr HPV Waterfall, Dr RK Watt, Dr S Weeramuni, Dr
AP Williams, Dr P Woolford, Dr L Young, Dr L Zhuang
Correspondence: Dr
Ann Pearl, Department of General Practice and Primary Health Care, University of
Auckland, Private Bag 92019, Auckland. Fax: (09) 373 7006; email: a.pearl@auckland.ac.nz
References:
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