A two-year structured survey of 8,000 people in randomly selected North Carolina households revealed that chiropractors are treating a much higher percentage of back pain patients than previous thought.
The research, part of on-going studies funded by the Agency for Health Care Policy and Research (AHCPR) under the Department of Health and Human Services, was headed by Timothy Carey, MD, MPH. Dr. Carey is an associate professor of medicine at the University of North Carolina in Chapel Hill. Though the research won't be published for another few months, Dr. Carey was kind enough to give us this exclusive interview.
DC: The recent issue of Spine Letter reported that you've just finished conducting a two-year structured survey. Could you tell us a little bit about that survey?
Dr. Carey: This was part of a series of studies funded by the Agency for Health Care Policy and Research (AHCPR). We looked at both the prevalence of back pain - that is, how often low back pain occurred in our population in North Carolina - and examined which providers low back pain patients chose to see, if anyone. The second component of our study was an examination of the clinical course of patients and the health care utilization of patients after they were seen by a number of different types of providers.
DC: Could you share the results of your findings of which providers people were choosing for back pain?
Dr. Carey: Our early studies looked at how often back pain occurred and the types of providers seen. Back pain is very common, which is not too surprising. We tried to use a very standardized definition of back pain, and we asked people in a structured telephone interview whether they had back pain that was bad enough that they could not do their usual activities for greater than one day. So we were interested in functionally disabling back pain and also back pain that lasted more than a few hours. We found that slightly over 11 percent of the population had back pain that bad over the course of a year. About two-thirds of those people had acute back pain and one-third had chronic back pain. We found that 60 percent of individuals with acute back pain don't see anyone for their pain.
Of those who seek care, most see an MD. About 39 percent of those with back pain sought care, 24 percent sought care initially from an allopathic physician, 13 percent from a chiropractor, and two percent from other providers. So of those who sought care, 62 percent sought care from an allopathic physician, and 33 percent from a chiropractor. People who had prolonged or severe pain, or who had sciatica were more likely to seek care.
DC: With 80-90 percent of the population sometime experiencing back pain, could we extrapolate from your survey and project what percentage of the population would seek a provider in their lifetimes?
Dr. Carey: I'd be a little reluctant to extrapolate from my data to lifetime prevalence. Some of the problems with all of the studies of prevalence are that if you define low back pain as any twinge or pain in your back (and clearly that's too broad) you can get the prevalence up to nearly 100 percent. I can't extrapolate to lifetime prevalence since many people will have recurrent episodes of pain year after year. While it's going to be substantially greater than 12 percent, functionally disabling back pain is certainly over 50 percent, but that's not a direct extrapolation from this data.
DC: Do you have any figures on the prevalence of use based on data between chiropractors and osteopaths?
Dr. Carey: North Carolina is an unusual state in that there are licensure restrictions for osteopaths that are fairly unusual in United States medical licensure, so there are fewer than 60 osteopaths in the entire state. I really can't comment on osteopathic use because there are so few in the state.
DC: Why was North Carolina chosen for the survey?
Dr. Carey: We chose to focus on North Carolina because it's a large state, it has a substantial urban/rural balance, about half of the state is urban and half is rural; there are about 600 practicing chiropractors; and there is a substantial minority population.
DC: Can we generalize your findings to the entire U.S. population?
Dr. Carey: I think we can probably generalize the findings to states which have substantial numbers of chiropractors. Obviously, if a state has very few chiropractors then the state is going to look somewhat different. I think if chiropractic is available, this type of proportion will hold pretty solid in other states. Dr. Eisenberg's work in the New England Journal of Medicine in January 1993 came up with a fairly similar number for chiropractic utilization. He found that 19 percent of individuals with back problems used a nonstandard therapist, with chiropractors as the major providers of care. We found that 13 percent of individuals with acute low back pain sought care from a chiropractor. He did include massage and other therapists as nonstandard, but the majority of back pain care by non-MDs in his study was by far through doctors of chiropractic.
DC: Yes, but as you said earlier, a third of those who sought care from a provider went to chiropractors.
Dr. Carey: Yes, if you exclude those who did not seek car. The best way to think about it is that 61 percent of adults with acute low back pain did not seek any care, 24 percent sought care from a physician, and 13 percent from a chiropractor. That keeps it more clear.
DC: Did your research review any patterns regarding how payment was made?
Dr. Carey: Not in this study. In our subsequent studies, we will be examining the effects of workers' compensation, but we don't have those results out yet.
DC: In general, you've been involved in a number of studies with the AHCPR. Do you believe that the results of health care research in general are being effectively used to help fashion our national health care policy?
Dr. Carey: All of us would like to see our research used more. I think policy is only partially shaped from research similar to what I do and what Drs. Richard Deyo and Eisenberg do. Other factors help to shape policy, and some anecdotes can shape policy just as much as health services research. I think it is occasionally frustrating for the researcher, but we live in a democracy. Policy is sometimes shaped more by anecdote and opinion than by research. I hope that in the future we will use research more. The responsibility on the research community is to make findings more timely and more immediately accessible, not just in terms of publication, but in the interpretation of the research to policy-makers. Researchers can't have it both ways. We can't say we need more funding and how important our research is, and then at the same time take years and years to do research and then present it in ways that are not interpretable by either policy-makers or the general public.
DC: In 1992, then-Secretary of U.S. Public Health Services Dr. James Mason made an interesting statement. He said, "No other health problem affects working-age Americans as much as low back dysfunction. It reduces quality of life, cuts a persons productivity, and costs society billions of dollars every year." In your opinion, would the results of your research be of benefit to the decisions that are taking place right now in health care reform, and would they ultimately benefit the way that reform occurs and ultimately benefit the American public?
Dr. Carey: I certainly agree that low back pain is one of the biggest functional problems in all Western societies. The research that we recently completed on the prevalence of low back pain helps to frame the size of the problem and provide a benchmark for the type of resources that we need to marshal to figure out how to do a better job. Overall, I don't think that our society has done a very good job with low back pain. Costs of low back pain have gone up enormously in the last 20 years, yet the disability rates appear to be about the same. The only conclusion I can draw is that we are not spending our money very wisely with low back pain. I'm hopeful that over the next year, we will have some results coming out of our cohort study that will be able to point better where perhaps resources might be better spent.
DC: In the Spine Letter you state: "People were definitely more satisfied with the back pain treatment delivered by DCs. They simply felt that DCs did a better job." Can you elaborate on that thought?
Dr. Carey: This was based on the patient's recall about their care. In our cohort study, we're going to have satisfaction data much closer to the time of care. This basically replicated some of the work Cherkin had done on the West Coast, which showed that patient satisfaction was somewhat greater with chiropractic care. When we asked patients, "How satisfied were you with the care,?" the proportion of those very satisfied was greater in the group that had seen chiropractors. Also, when we asked patients, "Who would you go see the next time you get back pain," patients who started with a chiropractor were more likely to stick with one. I think a very interesting question is: "What's causing that satisfaction?" Is it that the patients are getting better faster? Is it that they have more of a hands-on and positive approach from the chiropractors? Or is it that they simply may have more visits from the chiropractors? The improved satisfaction may be due to factors other than improved functional status, because satisfaction is a complex issue and functional status is only one of the components of patient satisfaction.
DC: Where do you see chiropractors in the billions of dollars every year that society spends on back care?
Dr. Carey: Chiropractors are clearly mainstream participants in back pain care. The optimal role of chiropractic and spinal manipulation is still evolving. We need to continue current research programs to determine optimal types of spinal manipulation. The role of adjunctive therapies in back pain is very unclear and this relates to chiropractic and physical therapies. The adjunctive therapies had substantial overlap between those two groups. Many of those therapies have not been well-tested.
A very significant topic that the back pain guidelines group has been dealing with is: What is the appropriate number of visits and manipulations to be recommended for either acute or chronic back pain? Each of those issues is going to be a topic that needs a lot of attention in the next few years as cost containment and cost constraints are integrated more in the health care system.
DC: Do you have other projects that would impact chiropractors or back pain?
Dr. Carey: We're currently analyzing data from our cohort study, looking at rates of improvement among patients who initiate therapy with a chiropractor, compared with several other groups. We're examining urban and rural chiropractors, urban and rural primary-care physicians, orthopedic surgeons, and a staff-model HMO. We're looking at time to improvement, satisfaction and overall health care costs in each of those groups. We may also examine utilization of manual therapy maneuvers, including spinal manipulation by non-chiropractors. Manual therapy is often identified solely with chiropractors, but clearly there are other types of manual therapy being utilized in the United States.
DC: Is there anything you'd like to add about this particular project or anything else you are working on?
Dr. Carey: I think back pain is an interesting problem. I became interested in back pain some years ago as a result of my frustration over the large amount of work disability that I was seeing related to back pain. I looked at the medical literature and found that not very much seemed to be known about it, and there was an enormous amount of cynicism around back pain and a lot of avoidance behavior by practitioners. It seemed that even if I could make a little bit of a contribution, it would be a contribution to an area that we don't know too much about. Whether we're going to make much of a contribution with our field of studies remains to be seen.
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