8th July 2011, Volume 124 Number 1337

Gillian M Abel, Lee Thompson

Colorectal cancer (CRC) is second only to lung cancer in being the most common cause of cancer registration and deaths in New Zealand and with an ageing population, the absolute number of people with CRC in New Zealand is expected to increase.1

CRC fits most of the World Health Organization criteria for a population screening programme.2 In 1997, the New Zealand National Health Committee convened a working party to look at population screening and at that time recommended that such a programme not be considered because of inadequate resources within New Zealand, as well as the fact that they considered that the benefit would only be a modest one and that there was potential for harm.3 Instead, New Zealand opted for surveillance guidelines4 which would identify those at increased risk of CRC who could then be referred for surveillance colonoscopy.

People identified for surveillance colonoscopy have, however, experienced long waiting periods before being tested because the current health services cannot meet the existing need5. Despite this current pressure on public health services, the Ministry of Health’s Bowel Cancer Team have continued to discuss the issue of CRC screening with health providers and the Government is now committed to introducing a 4-year bowel screening pilot in 2011 to determine whether a bowel screening programme should be rolled out nationally.6

The proposed screening test is the immunochemical faecal occult blood test (FOBT) with those testing positive going on to colonoscopy.

The aim of this paper is to explore the views of GPs and specialists on CRC screening. To date, no other New Zealand study has questioned health professionals in-depth on their attitudes and perceptions towards surveillance and screening for CRC. This highlights the importance of this research as their buy-in would have an impact on implementation and uptake of such interventions in New Zealand.

Research done in Australia suggests that medical practitioners are supportive of CRC screening programmes, particularly if provided through general practice.7 Studies have shown that GP involvement has an impact on uptake of screening,8,9 although Federici et al8 qualify this claim by pointing out that whether GPs are effective in improving compliance depends upon whether they are willing to be involved.

Beliefs about the effectiveness of the different screening tests for CRC also play a role, with a US study finding that there are significant concerns regarding the accuracy of the FOBT,10 although in the Australian context, several studies indicate increasing sympathy with FOBT over time.11,12

As well as concerns regarding the role of GPs and the accuracy of the FOBT, there have also been concerns expressed by medical professionals about the increased demand on already over-stretched public health services.7

Methods

The data analysed in this paper were obtained from in-depth, semi-structured interviews with 15 GPs and 11 specialists, who included general surgeons, gastroenterologists and medical oncologists. Participants were from the three largest cities in New Zealand: Auckland, Wellington and Christchurch, and were selected purposively for inclusion in the study to reflect the diversity of socioeconomic patient lists.
All participants received a $50 book voucher in appreciation of their time. Ethical Approval for the study was granted by the New Zealand Health and Disability Multi-region Ethics Committee.
The in-depth interviews were carried out by three experienced interviewers and were digitally recorded and transcribed. Participants were asked questions about their thoughts on a population-based screening programme, the surveillance guidelines for CRC, screening, advice to patients at different levels of risk for CRC and referrals for colonoscopic investigation.
Each of the three interviewers had the same semi-structured interview guide to ensure that that they all covered the same topic areas. Questioning on the topic of FOBT was conducted in a general way and participants were not pointed towards any particular type of test to make comment on. This allowed for the potential for participants to raise differences in test types.
A thematic analysis was undertaken which is a method used extensively in qualitative research to identify, analyse and report patterns in data.13,14 Meaning is sought in the accounts and/or actions of participants, taking into account how the broader social and political context impinge on these meanings.14,15 The transcripts were all read prior to the start of coding.
The data collected were sorted into datasets, which are extracts from all the data divided into topics of particular analytical interest. The data in each dataset were read and re-read and coded for features of specific interest. The coded segments of the transcripts were sorted into overarching themes and sub-themes and then refined.

Results

The majority of specialists and GPs thought that in theory a population-based CRC screening programme was a good idea, yet they saw this as being idealistic. They perceived such a programme to be unrealistic primarily due to lack of resources and they also had concerns about what they perceived to be the low sensitivity and specificity of the FOBT. Another concern held by the GPs in relation to both the above mentioned themes was the possibility of engendering anxiety in their patients.

Resourcing a screening programme—Lack of resources include a concern by both groups about the shortage of colonoscopists in the public system to cope with a population screening programme, and a concern by the GPs regarding the lack of financial compensation when they are likely to have to bear the responsibility of promoting and monitoring the screening programme.

If a population-based screening programme was to be introduced, specialists perceived that it was the GP’s job, as the ambulance at the bottom of the cliff, to communicate risk of CRC to patients and recommend screening. Specialists saw themselves as just there to deal to people at the bottom of the cliff:

GPs actually, I think, are where all screening programmes— the hub of all screening programmes in reality, effective screening programmes— are managed. That’s what they do. It’s their job. I’m the ambulance at the bottom of the cliff. GPs basically are to stop them falling over the cliff, and that’s what screening’s about. So it has to be run through GP programmes. GPs will run the databases, their electronic data systems should talk to the government systems, patients should be sent out reminders that they have their thing, just like you do with breast cancer, cervical cancer screening. All those things, the tools are there. They’re already using them. (Sp4)

The GPs agreed that they were the best source to deliver information on screening to their patients; however, they were concerned about the lack of resources to carry out this role as there were not the financial resources to do so:

For anything to be rolled out effectively, General Practice has to be involved, but for General Practice to be involved, there has to be financial recognition of that. It will not work if it’s rolled out just through public health. (GP4)
I don’t know how that would work. Because, no, unless the screening’s done away from General Practice, you know, if we would be asked to coordinate it and invite patients for it and to look at the results that come back and make decisions on who needs what, then obviously that’s an expense to us that we wouldn’t do unless someone is paying us. (GP7)

But notwithstanding financial issues, GPs were concerned about bringing up the topic of screening for other reasons, including a reluctance to increase patient anxiety:

I have to sit down and talk to people about the risks of not having the screening as opposed to screening and their anxiety. (GP1)
On the whole, women come out of there, we’ve scared them shitless, we’ve subjected them to all this, our agenda of screening, we’ve frightened them, then they come back there and told that they’re all right, and they feel so grateful. They feel so relieved that they forget that it was us bloody doctors who’ve put them through it all in the first place. (GP5)

Screening was also a difficult concept for some GPs to explain to patients especially when they were not convinced of the benefits of screening:

So you’ve got to be very clear that if you’re going to make somebody worried or going to concern them about something, you are doing it with the best interests at heart and that they are going to get some benefit from this. And if you’re just going to worry them, well we’ve got a whole worried population in all sorts of ways. (GP1)

Both groups argued that there would be insufficient resources to deal with the many anticipated follow-up colonoscopies:

Oh great idea, great idea (screening programme), but a lot of work for someone, who has to tease through what’s the best screening to offer, and I would, I would be hugely concerned if it was offered before we could deliver the next step. That would worry me a lot. So it’s a lot of gear and it needs to be rolled out very slowly.... well it, you can’t throw money at it, that’s out at the moment, and it, if for example, if you did fund a screening policy that identified those people with faecal occult bloods who are positive, you’d then want to offer them a colonoscopy. We need more colonoscopists. (Sp11)

Both GPs and specialists identified the increasingly long waiting list in the public system for people requiring colonoscopies at present, which would be compounded after the introduction of a screening programme:

Well considering they can’t, can’t get timely colonoscopy done for symptomatic patients, surely the whole idea of it really just makes me feel absolutely awful. The idea of having this raised expectation that this is all going to be set up for them, and there’s going to be a huge focus on this. Either it won’t fly because they just haven’t got the resources to put it in, or they’re going to take resources away from somewhere else. That’s a huge concern, and I can’t see that happening. And so if you have a situation where you can’t actually do anything about the positive faecal occult bloods or have to wait for months... (GP6)

In response to their concerns about resourcing, specialists and GPs argued that it would be more beneficial to have a targeted screening programme aimed only at those at increased risk or rather than a recall system, provide a one-off colonoscopy to people at the age of 50:

In fact that could be a strategy for the country obviously, having a one-off screen at 50. I know people get bowel cancer at 25 and so on and so on, but on a population base it’s unlikely, or very rare. (Sp3)
So it’s probably better addressed in the first instance to the at-risk group, just because of the logistics of trying to redress the system. (Sp10)

Colonoscopy was seen as the gold-standard test of choice for CRC screening, especially by specialists:

Well faecal occult bloods are positive ... So that’s not accurate, um and there are false negatives, um which means if they come back negative, that person will decide he doesn’t need screening by the gold standard, which is colonoscopy. So you’ve missed a whole chance and you’ve lost... (Sp5)

This specialist argued that colonoscopy was a preferred choice of screening tool to the FOBT because of the greater specificity it provided.

Test sensitivity and specificity—As mentioned previously, the screening test proposed in New Zealand is the immunochemical FOBT with individuals testing positive going on for colonoscopic investigation. The immunochemical FOBT has a higher sensitivity and specificity than the guaiac FOBT.

Participants were asked about FOBT screening in general, not specifically on their thoughts on guaiac and immunochemical FOBTs. Most GPs did not differentiate between the two and talked about FOBT tests in general having a low specificity and sensitivity:

I don’t generally do faecal occult bloods. It’s a waste of time. If they’re negative, you’re still going to have to investigate them cause of the 50% false negative rate. So there’s little point in stuffing around doing that if they’ve just got to have a colonoscopy. (GP6)

Few specialists, too, differentiated between the different types of FOBT:

(FOBT) generates some, generates more colonoscopies than truly needed, so it’s, you know, it’s not specific. (SP6)

One specialist acknowledged that there were different types of FOBT but was unsure about which one would be used in the proposed screening programme, implying that neither was optimal:

So I suspect that faecal occult blood testing in one form or another, be it guaiac or be it immuno-histo-chemistry, the issue’s unresolved there. I think that’s probably the way we’re going to go, but I suspect that with a bit of luck in 10, 20 years time we’ll actually do testing for mutagens within the stool and we’ll be able to detect it better that way. (SP4)

Similar to the discussion on screening with patients, GPs were concerned about the heightened anxiety false positives would engender in their patients which reinforced in their minds the lack of merit in doing an FOBT:

I mean inevitably you get a lot of false positive screening tests that subsequently turn out to be negative on colonoscopy, so yes, it can create a lot of anxiety. (GP7)

Some GPs argued that FOBTs did not feature in their decision-making about referral for screening but “if the person has got risk factors, they need the screening whether or not the faecal occult blood’s positive or not” (GP11). Many GPs instead indicated that they would currently refer patients for CT colonography as a first step instead of FOBT as they perceived the sensitivity and specificity of that test to be superior to FOBT:

CT colonogram, yeah, I’ve certainly made a lot of use of that test since it became available. And as a screening tool, well it’s supposed to be, it’s supposed to have a high, you know, a very high sensitivity and specificity for diagnosing bowel cancer. And it’s quite good at picking up polyps as well. Of course if you pick up a polyp, those people have got to then go on and have a colonoscopy. (GP7)

There was a lot of support by GPs for CT colonography whether or not their patients were drawn from low or high socioeconomic areas. It was seen as less invasive and risky than colonoscopy with no likelihood of perforation, more reliable in picking up abnormalities than FOBT and, in addition, would pick up other abnormalities which both FOBT and colonoscopy would miss.

The specialists, on the other hand, did not see this as an advantage and as well as being concerned about the risk of radiation, argued that the increased cost to the screening programme through picking up other abnormalities was not warranted.

CT colonography obviously offers a possibility, but the issues with that, I think, is the CT, is the radiological dose, if you’re giving to a huge, you know, whole population, and one of the things that could end up making a screening programme really expensive is the picking up of other things that you didn’t expect that you then feel obliged to follow, so like adrenal tumours or the like. I mean some people could see that as a good trade off, they’re picking up things that you might not otherwise, but it adds quite a cost to your screening programme. (SP1)

The holistic nature of general practice and the relationship of trust between patient and GP meant that the concerns of GPs regarding the merits of particular tests were not echoed by those of the specialists. This may have implications in the implementation of a CRC screening programme in New Zealand.

Discussion

The study findings generally support those international studies which indicate that GPs are supportive of screening7; have concerns about the accuracy of FOBT,10 may not be convinced that capacity exists to introduce the programme7 and have concerns about screening engendering worry for patients which is a concern also supported in the literature in relation to mammographic screening.18 But, significant effort is likely to be required to ‘sell’ a screening programme to New Zealand GPs and specialists that has as its point of entry the FOBT.

GPs, especially, perceived the sensitivity and specificity of FOBT to be low but it is most likely that these perceptions were based on the guaiac FOBT which until recently has been the standard test used in New Zealand. The proposed screening programme in New Zealand would make use of the newer immunochemical FOBT which has a higher sensitivity and specificity for detecting left-sided CRC and also does not require the dietary restrictions called for by older tests.16

The fact that participants were not questioned directly on the different types of FOBT is a potential limitation of the study, but their responses do also highlight the need for up-to-date information on contemporary forms of FOBT. It may also be the case, as has been found elsewhere, that GPs become more confident about the use of FOBT over time11,12

The GP advocates for and acts in the best interests of their patients.17 Family GPs, because of the ongoing relationship with their patients and their families, develop a relationship of trust and it is more likely that their advice on risk and need for screening would hold more weight than information from an unknown other.

In order for GPs to have some confidence in advocating screening to patients, they obviously need to be convinced that the process is worthwhile. The issue of the role of GPs in the implementation of a screening programme for CRC and the potential increase in their workload and responsibilities as a result, needs to be addressed.

The concerns of both GPs and specialists surrounding resourcing in relation to the physical availability of colonoscopic services also need to be addressed. This is particularly important in the case of the GPs as it became clear from the other participants (members of the public) in the wider research project of which this is a part, that they still very much respect the advice of their family doctor. In giving this advice, GPs are cognisant of not wanting to unnecessarily engender patient anxiety and because of their ongoing relationship, are concerned to do the best for their patients.

If GPs are to have confidence in promoting the programme, then they need to be convinced that it will work for their patients.

Summary

GPs and specialists, whilst supportive of screening, are not convinced that there is the capacity in New Zealand to introduce a colorectal screening programme. A shortage of colonoscopists in New Zealand means that there is already a long waiting-list for people accessing colonoscopies in the public service. GPs are often in the position of advocating screening to patients and they are unconvinced about the value of the test which is likely to be used for screening (faecal occult blood test) feeling that there will be a number of false positives These will then require colonoscopic follow-up which will mean unnecessary anxiety will be engendered amongst their patients.

Abstract

Aim

To explore the views of GPs and specialists on colorectal cancer (CRC) screening.

Method

Qualitative study using semi-structured interviews of 15 GPs and 11 specialists investigating views on the proposed introduction of CRC screening in New Zealand.

Results

Both GPs and specialists in this study, whilst agreeing on the overall merit of a population screening programme for CRC in New Zealand, argued that there were not sufficient resources to warrant the implementation of such a programme. There was also little support, especially by the GPs, for the faecal occult blood test, which is likely to be the screening test if implemented.

Conclusion

The concerns of GPs and specialists need to be addressed if a screening programme for CRC is introduced in New Zealand. GPs undoubtedly would have to be the advocates of this programme to their patients and therefore they will have to be convinced of the value of this exercise.

Author Information

Gillian Abel, Senior Lecturer; Lee Thompson, Senior Lecturer; Department of Public Health and General Practice, University of Otago, Christchurch

Correspondence

Gillian Abel, Department of Public Health and General Practice, University of Otago – Christchurch, PO Box 4345, Christchurch, New Zealand. Fax: +64 (0)3 3643614

Correspondence Email

gillian.abel@otago.ac.nz

Competing Interests

None.

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