Podcast: Screening for impaired vision: clinical practice guideline
Transcript
Diane Kelsall: Impaired vision is an important health burden, especially among older adults. The proportion of adults with vision impairment is expected to double in Canada by 2032 as the population ages. Impaired vision can have a negative impact on quality of life, and may also be indicative of eye disease or other health problems. But is it beneficial to screen actively for vision impairments in community dwelling older adults in primary care? I'm Dr. Diane Kelsall, interim editor-in-chief for the Canadian Medical Association Journal. And today I'm speaking with one of the authors of a new Canadian Task Force guideline on screening for impaired vision in primary care settings, published in CMAJ. Dr. Brenda Wilson is a professor of Community Health and Humanities at Memorial University in Newfoundland, and a member of the Canadian Task Force on Preventive Health Care. I've reached Dr. Wilson in St. John's, Newfoundland. Welcome, Brenda.
Brenda Wilson: Hi, nice to meet you.
Diane Kelsall: We're looking at this new guideline that you published and my first question is, what are the consequences of impaired vision in seniors, especially those with undiagnosed or untreated impaired vision?
Brenda Wilson: Impaired vision in seniors can be one of those quiet impairments that leads to disability that people don't realize. What the evidence seems to suggest is that this can lead to injuries of various kinds, usually from accidents, particularly falls. And also problems just with activities of daily living or shopping, housework, the ability to work, and certainly the ability to drive safely. But what the evidence also suggests is that it can lead people to get depressed, or to have decreased participation in social activities, to cut down on hobbies, and to have difficulties in family relationships. So, these are the kind of concerns which liked the task force to look at this topic.
Diane Kelsall: So in seniors, this kind of thing, the vision impairment, can lead, it sounds like, to social isolation.
Brenda Wilson: That's right. And I think that's one of the things that may be hardest for people to think about. Because we're used to thinking about vision and glasses and eye disorders. But I think it's the effect on quality of life, and on the ability just to live the kind of life that people want to live. Which is quite important and which can be affected by impaired vision.
Diane Kelsall: So given this serious problem, I know the Canadian Task Force went ahead and wrote this guideline, can you tell us a bit about what the scope of the guideline is?
Brenda Wilson: Yes. So this guideline applies to people aged 65 and older who are living independently in the community. So it's not for people who are living in institutional settings, or people who have dementia or need a lot of support already. It also doesn't apply to people who are already known to have serious eye conditions, or who are known to be at high risk disease, for example, because they have diabetes. And really, it probably doesn't also apply in the situation where a primary care practitioner already suspects that there may be a problem such as, a history of repeated falls or increasing social isolation. So it's really people who have no other reason to think that they have a problem, who are living and supporting themselves in the community independently.
Diane Kelsall: So really, what it's focused on is, as you said, it's a senior that comes into a primary care practice, no suspicion that they're at high risk or have any problems connected. It's whether we should, as family physicians and other primary care practitioners, take the time to screen their vision.
Brenda Wilson: That's right.
Diane Kelsall: So we've mentioned that this is a big problem. But why did the task force decide that this was the right time to write this guideline?
Brenda Wilson: Well, there are so many guidelines that we could write. There is actually a task force process for deciding on the topics to take on for any given year. So this one came up through the standard task force process for identifying and selecting topics for guidelines. Where these topics come from, we draw them in from a range of inputs. Particularly suggestions from stakeholder and professional groups, also members of the public. And we're looking around to guidelines being produced by other bodies, and there was a US task force guideline on this topic, which came through as well. So, just to talk about the process generally, we start off with a very long list of potential topics and go through that and review it initially against criteria, like the potential for health benefits, evidence that there might be variation in the practice, or where we think there may be new evidence that we could build on. And then from that we have a short list and the science team at the Public Health Agency pulls together more information on each of these topics and the task force has a consensus method to select the three. I would say probably this one came through because of the US task force guideline. And also because we felt that the potential for health benefits and an important section of the population in older people, probably would make this a useful guideline.
Diane Kelsall: So, what is the guideline actually recommending then, in terms of screening in primary care for impaired vision in older adults?
Brenda Wilson: So this guideline recommends against routinely screening this population for impaired vision in primary care settings, and it's a weak recommendation. So this means that screening shouldn't be done by default. The default should be to not screen. But the practitioner should actually take into account any individual patient's preferences and make their own judgments. So then talk a bit more about this. The task force does make a distinction between vision screening and vision testing. So our recommendation does not mean that people should not see their optometrist for eye checks, as recommended for their age, I think we would probably call that vision testing. And we would always encourage everyone to have their eyes checked as recommended for their age and their personal situation. So what we were talking about the vision screening was, we're talking about using some kind of a test in a primary care setting to check whether someone might have a visual problem. So the screening test could be eye charts, but it could also be something like a short questionnaire or targeted questions that the professional asks. This is a diagnostic approach, it's root at the very preliminary assessment. And the idea would be for someone, picked up in this way with a suspicion of a visual impairment, to then be referred on to an optometrist or perhaps even an ophthalmologist for a more definitive assessment and further management. But just to reiterate, the guideline recommended against doing this routinely for people aged 65 and over living independently in the community, in primary care settings.
Diane Kelsall: So what what is the rationale behind this recommendation? What does the literature say?
Brenda Wilson: So we identified 15 randomized control trials from around the world, which examined vision screening in primary care in some form. And we were particularly interested in outcomes that we considered important, which were to do with health and functioning and quality of life. So outcomes such as risk of dying, social functioning, quality of life, fractures. So those were the outcomes we looked at. Overall, we found the quality of the evidence to be low, or very low. But it was quite consistent in suggesting no evidence that your screening made a difference to any of these outcomes that we were interested in. Now, there were issues to do with this evidence base, to do with the overall rigor of the trials, which I think we can see with low quality evidence assessment. Many trials were done that didn't measure the outcomes that were of interest to us. And for some, it was the context. So how far could our particular approach to vision screening developed in one country be applied to the primary care context in Canada? I'd like to go back to this as a weak recommendation. So as I said, this does mean that a practitioner should use her judgment and her assessment of patient preferences, because some patients may want their vision screened. With a weak recommendation, we can go either way. We can have weak recommendations for or against. In this case, we really judged there was likely no great harm from screening, even if it is ineffective. But we did consider the opportunity cost that comes with supporting an activity, which would consume significant practitioner time and healthcare resources, with no evidence of benefit. So then we reflect on the time it would take to do a test, to discuss what it means, offer advice, and maybe for some, make a referral and follow-up. This resource used in tiniest really mounts up. And with the graying of the population, the number of patients on a practitioners roster, or with this guideline would apply, would continue to grow. So this could turn into a substantial commitment, with no evidence of benefit. And that's why it was a weak recommendation. But against screening.
Diane Kelsall 9:58 Well, that's what's so interesting actually. Because we're finding out more and more how little evidence supports the things that we traditionally have done. And I know it will probably seem strange for some physicians who've been doing this routinely, to stop. But as you said, it does give time to maybe tackle some other activities that might have more evidence behind them.Brenda Wilson: Well, that's right. And I think sometimes we forget about that time taken to do one thing is not time available for another. And really, with the health system we have in Canada and the demands of primary care, we really should be making sure that all the energy efforts and time are being directed towards things that we know really work.
Diane Kelsall: You mentioned a couple of times now the US guidelines, their task force guidelines on this, how does the recommendation from your group compare to the US recommendation?
Brenda Wilson: The US guideline concluded there was insufficient evidence to make a recommendation either way.
Diane Kelsall: Okay. Now, I wanted to talk a little bit about government funding in Canada for coverage of vision checks. You mentioned already that obviously, this guideline doesn't say, and you're encouraging, seniors to go get their eyes checked by optometrists. Now, most Canadian provinces cover vision screening by optometrists only for children and seniors. In your opinion, is this the best approach?
Brenda Wilson: Well, this is an important question. So I'll start off by saying that the task force's mandate is for primary care based prevention activities. Considering these broader questions are without their mandate. However, I'll offer some of my own thoughts on this. So you're right that most provinces cover eye tests by optometrists for seniors, but not all of them do. For example, where I am here in Newfoundland, Labrador, it's not covered. I think many people are likely covered by benefit plans of one kind or another. And so it's really hard to know how far some people are falling through the net and not getting their eyes tested. And it's quite hard to find this data. Now, we did look at this as a task force, and the best we could find was a paper out of the University of Toronto. But the actual data we based it on are now more than 10 years old. But for what it's worth, that analysis seemed to suggest that in any given year, about 40% of people reported having an eye test, and that about 85% of people over 65 had had an eye test in the previous two years. This is data from the Canadian Community Health Survey. So about 85% of people in our age group appear to be getting eye tests. The reasons that people gave for not having eye tests were often things like, they just didn't get around to it, or they didn't think it was necessary. Cost was not one of the important things that was mentioned and only 4% of people over 65 years actually mentioned this as an issue. Now, my own interpretation is that we don't know whether increasing coverage of eye tests would actually make a difference to health outcomes generally, or would be the best use of healthcare dollars. There are a lot of other things that motivate people to get their eyes tested. Are they on a course such as applying for a driver's license? So, in response to your question about covering eye tests, I think, particularly from the point of view of access for some people, particular socioeconomic groups, that might provide a safety net. But it does suggest that most of the population, most of the time, is paying for eye tests themselves or having them covered by benefit plans. Now, we do know that there are conditions which predispose to vision loss, like diabetes and glaucoma. So the question about whether extending health coverage to these eye tests include eye tests for everyone is a way to reduce vision loss or whether we need to target it. I can't really answer these questions. But I think this is a more complex issue than it might seem on the surface.
Diane Kelsall: So what would you say then, sort of going back to the beginning of our conversation, the patient, the senior, who comes in to see a primary care physician, for example and is otherwise healthy, no red flags? That one of the things that, maybe we can do is suggest that if they haven't had their eyes tested recently, that they should consider going to an optometrist.
Brenda Wilson: Yeah, I would agree with that. I think that's a simple instruction, a simple piece of advice to give and certainly we are encouraging people to make use of eye tests when they're available. What I think we're interested in seeing is that the family physician, or the nurse practitioner, shouldn't feel that they need to go ahead and start screening themselves.
Diane Kelsall: Sounds good. So, any final thoughts at all? Anything that we haven't covered that you'd like to share with our listeners?
Brenda Wilson: Well, the way that I have thought of this guideline myself is within the context of how we think about promoting health and maintaining function and independence in older age. That's always been an important issue and I think we're probably more conscious of this with the demographic shifts and the so called demographic time bomb. So, making a recommendation against this specific screening strategy doesn't undermine the importance of, nevertheless, paying attention to strategies to promote health and independence and quality of life. Primary care practitioners are probably the best place of anybody to pay attention and pick up on the cues that might point to preventable causes of disability in older people. So, maintaining awareness and case finding, following up on red flags, that's always important. And I do believe that's something that primary care practitioners have always done and it's just how they practice good medicine. So I think it's carry on, and do that.
Diane Kelsall: That's excellent advice. Thank you so much, Brenda, for joining me.
Brenda Wilson: You're welcome.
Diane Kelsall: I've been speaking with Dr. Brenda Wilson, a professor of Community Health and Humanities at Memorial University of Newfoundland, and a member of the Canadian Task Force on Preventive Health Care. To read the Canadian Task Force guideline article published in CMAJ, visit cmaj.ca. If you've enjoyed listening to this podcast, we encourage you to subscribe to CMAJ Podcasts in Apple Podcasts, or your favorite podcast app. While you're there, we invite you to listen to our many past episodes. I'm Dr. Diane Kelsall, interim editor-in-chief for CMAJ. Thank you for listening.