How to utilize nutritional research in your clinical practice
By David Barnes, PhD, and Kelly Kwiatkowski, MA

What is the best way to determine the nutritional supplementation products that will benefit your patients?

If you practice evidence-based healthcare, you must be able to utilize the best and most current evidence and integrate your individual clinical expertise into the practice, while considering each patient's individual needs (Table 1), because scientific evidence alone is not sufficient to make a clinical decision.

Clinicians have routinely found value in many nutritional products independent of strong scientific evidence.

Treating patients also requires consideration of the benefits and risks to the patient, the patient's values, the level of convenience, and the costs associated with the treatment.¹

Consider this example: You are interested in prescribing glucosamine/chondroitin supplements for patients presenting with osteoarthritis. Where do you begin?

1. Define the problem. A common problem-solving tool used in evidence-based healthcare is a PICO (Patient/Problem, Intervention, Comparison, Outcomes) worksheet.² This worksheet can guide you through the information-seeking process.

In our example, the PICO would look like this:

P (patient/problem): In patients presenting with osteoarthritis how well does
I (intervention/exposure): glucosamin/chondroitin
O (outcome): improve symptoms?

In this case, there isn't a (C) comparison (For example: How well does glucosamine/chondroitin improve symptoms compared to NSAIDs?), but there could be, if that is the information you are seeking.

2. Review the literature. Now that you have identified your problem you can begin a literature search.

Locating useful information can be a daunting process since evidence is abundant and is being published daily. Searching through evidence-based, systematic reviews is the most efficient way to conduct a literature search in evidence-based practice and there are a variety of online resources that provide this information (Table 2).

3. Consider the evidence. Another important consideration is an understanding of the strength of the evidence that is presented in these reviews in order to critically appraise them (Table 3).

The gold standard in research is the randomized control trial (RCT). These experiments randomly assign human subjects to two or more treatment groups and outcomes of these groups are compared. Findings from RCTs provide the strongest evidence for understanding how interventions affect subjects at the population level.

RCTs do not, however, provide strong information about how an intervention will affect an individual, which is why it is important to consider each patient individually at the point of care.

Observational studies measure health outcomes in a certain patient population and provide weaker empirical evidence than the RCT, because unlike RCTs, observational studies are not controlled, thereby making them subject to confounding factors and bias.

Clinical observations provide the weakest evidence for understanding effects on a population, but in clinical practice, they can provide a lot of value in treating individual cases.

With reference to the example introduced earlier, a review of the literature reveals that the evidence on glucosamine as an intervention for osteoarthritis is mixed: High quality studies demonstrated that glucosamine improves pain more than placebo using one type of pain scale, but not using a different scale.³

Meta-analyses of clinical trials on chondroitin for osteoarthritis⁴ and glucosamine and chondroitin for knee osteoarthritis⁵ found that chondroitin improved pain and function compared to placebo.⁶

The Glucosamine/chondroitin Arthritis Intervention Trial (GAIT) provides the most current evidence on the effects of a combined glucosamine/chondroitin supplement on knee osteoarthritis. Findings demonstrated that 79 percent of subjects with moderate to severe pain had a 20 percent or greater reduction in pain when taking the supplement, compared to those taking the placebo; however, for those subjects with mild pain, no statistically significant effects were observed.⁷

4. Apply your findings. Now that you have the findings, how can they be applied in the clinical setting?

As indicated earlier, it is important to make use of your clinical expertise and consider individual patient needs when determining whether or not you will prescribe a given intervention.

For example: If the patient presents with knee osteoarthritis, has recently experienced moderate to severe pain, cannot tolerate NSAID treatment due to gastrointestinal side-effects, is seeking an alternative to taking NSAIDS for pain, and you have treated a similar case with successful results, perhaps this is the right clinical presentation for prescribing the glucosamine/chondroitin supplement (along with other successful, evidence-based interventions such as exercise or weight control measures).

5. Discuss the treatment plan. Your next challenge is to discuss the treatment plan and its underlying foundations with your patient. You need to translate the research so that the patient will understand it.

In evidence-based practice, communicating research findings to patients can be an effective way of developing cooperative partnerships with your patients so that together you can make sound clinical decisions. Communicating this evidence, however, is not always easy, considering there is great variation among patients in terms of their ability to understand information and make informed healthcare decisions.

Research suggests, though, that informed and involved patients are more likely to participate in their care, which leads to better health outcomes.^{8, 9, 10}

Using our example, one way to communicate the scientific evidence on glucosamine/chondroitin might be the following:

"Much research has been conducted separately on the use of glucosamine and chondroitin for osteoarthritis. The results are unclear for glucosamine; however, the results show that chondroitin can be effective in treating pain and improving function for knee osteoarthritis.

"Studies on the combined supplement are few; however, a large-scale clinical trial measured the effects of a combined glucosamine/ chondroitin supplement on patients with knee osteoarthritis and found that a majority of patients with moderate to severe pain saw improvements in their pain when taking the supplement compared to patients that did not."

In addition to this information, you would discuss these findings in light of the specific needs and clinical presentation of the patient.

The evidence-based practice framework provides a solid approach in informing your clinical practice and involving your patients in their own healthcare decisions. Large scientific databases and online evidence-based health resources have made it easier for clinicians to effectively navigate the scientific literature.

In addition to these factors, the availability of high-quality reviews on nutritional supplements makes this a good time to integrate nutritional research into your practice.

Kelly Kwiatkowski, MA, has worked as a communications professional and project manager in the academic and corporate healthcare research sectors for the last seven years. She is currently a scientific writer at Standard Process Inc. David Barnes, PhD, is director of research at Standard Process Inc.

David Barnes, PhD, is director of research at Standard Process Inc. He has been a research fellow at the National Institute of Environmental Health Sciences and has held faculty positions at the University of Arkansas and the University of Wisconsin-Madison. His most recent research has emphasized the multi-drug resistance proteins involved in the detoxification mechanisms of the gut and the mechanism of action of dietary phenolic compounds on cholesterol metabolism. Kwiatkowski and Barnes can be contacted through Standard Process, www.standardprocess.com, or at 800-848-5061.

References
1 Haynes, R.B., et al., Transferring evidence from research into practice: 1. The role of clinical care research evidence in clinical decisions. ACP J Club, 1996. 125(3): p. A14-6.
2 Miller, S., PICO Worksheet and Search Strategy. National Center for Dental Hygiene Research, 2001.
3 Towheed, T., et al., Glucosamine therapy for treating osteoarthritis. Cochrane Database of Systematic Reviews, 2005(Issue 4).
4 Leeb, B.F., et al., A metaanalysis of chondroitin sulfate in the treatment of osteoarthritis. J Rheumatol, 2000. 27(1): p. 205-11.
5 Richy, F., et al., Structural and symptomatic efficacy of glucosamine and chondroitin in knee osteoarthritis: a comprehensive meta-analysis. Arch Intern Med, 2003. 163(13): p. 1514-22.
6 Singh, J., T. Wilt, and R. Mcdonald, Chondroitin for osteoarthritis. Cochrane Database of Systematic Reviews, 2006(Issue 1).
7 Clegg, D.O., et al., Glucosamine, Chondroitin Sulfate, and the Two in Combination for Painful Knee Osteoarthritis. N Engl J Med, 2006. 354(8): p. 795-808.
8 Stewart, M., et al., Evidence on patient-doctor communication. Cancer Prev Control, 1999. 3(1): p. 25-30.
9 Stewart, M.A., Effective physician-patient communication and health outcomes: a review. Cmaj, 1995. 152(9): p. 1423-33.
10 Di Blasi, Z., et al., Influence of context effects on health outcomes: a systematic review. Lancet, 2001. 357(9258): p. 757-62.