Posted in Ella's blog posts

A placebo effect without deception

Author: Ella Ward, date published: 28/10/13

The problem of using placebo’s in sport arises when a coach’s desire to improve performance involves deception and compromises the coach-athlete relationship. A solution would be to demonstrate a placebos efficacy without deception (Benedetti et al., 2011). Recently, a study by Friedlander et al. (2010) supported the solution, concluding open-label placebos improved the symptoms in patients with Irritable Bowel Syndrome (IBS). Conversely, a study by Fitzpatrick et al. (2007) reported a decline in force production after disclosing the nature of the placebo intervention. Contrary to these two studies, the solution is sparsely investigated in the literature. Thus, a research proposal will be constructed to investigate a placebo intervention without deception. This will also provide coaches and sports scientists with a framework to optimise a placebo effect without deception.

The purpose of the proposed study is to determine whether Kinesio-tape improves circulation in the gastrocnemius muscle during cycling. The study design will be within-group. This is an improvement to Friedlander’s between-group design, where participants assigned no treatment may have been disappointed. This may have negatively influenced the results (Kaptchuk et al., 2011). Furthermore, the study will be unblinded. This is integral to its validity because it needs to reflect the circumstances where both the coach and athlete are agreeable to the placebo. However, unblinded studies have associated risks of bias (Chen et al., 2011; Kaptchuk et al., 2011).

For example, participants may change their behaviour during experimental research. This change is known as the Hawthorne Effect (Campbell et al., 2009; Rowland, 1994). Despite being difficult to overcome in a laboratory environment, measures will be taken to prevent this. For example, the cycle ergometer wattage and revolutions per minute would be maintained at constant values throughout the testing to prevent participants exercising at a higher work rate.

Another limitation is response bias, which occurs through self-reporting methods (Kaptchuk et al., 2011). An example of this occurs when participant’s who are overweight tend to over-estimate duration and intensity of exercise to “please” the experimenters (Acra et al., 1999). This bias was a limitation of Friedlander’s study because only subjective measures were collected. This inhibited researchers from discriminating between response bias or the placebo physiologically improving the condition (Kaptchuk et al., 2010). Therefore, this study will collect objective measures (Kaptchuk et al., 2011). For example, circulation will be measured by exercise physiologists using a non-invasive Laser Doppler. This method has been used in previous studies investigating KT and circulation (Docherty et al., 2012; Hashimoto & Kase, 1998). Differences between responders and non-responders will be investigated by sports psychologists. This would consist of a pre-participation questionnaire, examining the individual’s expectations, beliefs and personality traits such as Five Factor Model (McCrae & John, 1992). Each participants subjective results would be compared to their objective results.

Lastly, an unblinded study may heighten a placebo effect through the expectancy effect (Kaptchuk et al., 2011). Expectancy plays an important role in the efficacy of placebos (Benedetti et al., 2005). Friedlander’s study contained this bias due to its persuasive debriefing, which inadvertently communicated to the participants the expected results (Campbell et al., 2009; Kaptchuk et al., 2010). It is important to note that discussion of the pros and cons of treatment and shared decision making is an integral component in the coach-athlete relationship (Miller et al., 2012). Therefore, the debriefing rationale will not induce expectation, but will present multiple findings from clinical studies. For example: “one study concluded KT did not affect circulation, however another study concluded KT improved circulation when combined with low-strength exercises” (Docherty et al., 2012; Hashimoto & Kase, 1998).

The results from this study would further advance the knowledge in this field. It would also have the potential to improve performance and provide an alternate route for coaches to pursue which does not compromise the coach-athlete relationship. However overall, there is no empirical evidence supporting the efficacy of placebo’s without deception (Fitzpatrick et al., 2007). Thus, the solution would require large amounts of clinical research to match the literature that has been previously published on placebos, which may be unrealistic. The solution may also have implications to previous research, which may become invalid and meaningless when compared to overt placebo trials. The question still exists that if the research yields significant findings, will sports scientists and coaches use the results? Or will the traditional method of deception still be used due to its simplistic nature?

 

Reference list:

Acra, S. A., Buchowski, M. S., Chen, K. Y., Sun, M., & Townsend, K. M. (1999). Energy expenditure determined by self-reported physical activity is related to body fatness. Obes Res, 7(1), 23-33.

Benedetti, F., Carlino, E., & Pollo, A. (2011). Placebo mechanisms across different conditions: from the clinical setting to physical performance. Philosophical Transactions of the Royal Society B: Biological Sciences, 366(1572), 1790-1798.

Benedetti, F., Mayberg, H. S., Wager, T. D., Stohler, C. S., & Zubieta, J.-K. (2005). Neurobiological mechanisms of the placebo effect. The Journal of Neuroscience, 25(45), 10390-10402.

Campbell, Cumming, Gerrig, Wilkes, & Zimbardo. (2009). Psychology and Life (Australian ed.). Australia: Pearson Education Australia.

Chen, M. H., Horsley, T., Moher, D., Morissette, K., & Tricco, A. C. (2011). Blinded versus unblinded assessments of risk of bias in studies included in a systematic review. Cochrane Database Systemic Review, 7(9).

Docherty, C. L., Kroskie, R. M., & Stedge, H. L. (2012). Kinesio Taping and the circulation and endurance ratio of the gastrocnemius muscle. Journal of Athletic Training, 47(6), 635-642.

Fitzpatrick, J., Kalasountas, V., & Reed, J. (2007). The effect of placebo-induced changes in expectancies on maximal force production in college students. Journal of Applied Sport Psychology, 19(1), 116-124.

Hashimoto, T., & Kase, K. (1998). Changes in the volume of the peripheral blood flow by using Kinesio Taping®. Available at www.kinesiotaping.com.

Kaptchuk, T. J., Friedlander, E., Kelley, J. M., & Kirsch, I. (2010). Placebos without deception: a randomized controlled trial in irritable bowel syndrome. PLoS One, 5(12), e15591.

Kaptchuk, T. J., Hrobjartsson, A., & Miller, F. G. (2011). Placebo effect studies are susceptible to response bias and to other types of biases. Journal of Clinical Epidemiology, 64(11), 1223-1229.

McCrae, R. R., & John, O. P. (1992). An introduction to the five-factor model and its applications. Journal of personality, 60(2), 175-215.

Miller, F. G., Brody, H., & Colloca, L. (2012). The placebo phenomenon: implications for the ethics of shared decision-making. Journal of General Internal Medicine(6), 739-742.

Rowland, T. W. (1994). On exercise physiology and the psyche. Pediatric Exercise Science, 6(2), 111-113.

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Author:

This blog was started for a Uni subject, and has since evolved into a place where I can voice my thoughts, typically about coaching and sport. I grew up in Sydney, then moved to Canberra for some further study in 2011 and when I finished in 2014 I moved up to Brisbane. I have played, coached and generally been involved with volleyball since 2013. As of 2017 I am now the QAS Volleyball Assistant Coach.

3 thoughts on “A placebo effect without deception

  1. Hey Ella,

    Glad to see that you’re on the right track. It would be good to be clearer about the study itself. Give a full description of the methods. “I will obtain a volunteer sample of elite cycling participants” “they will be told THIS about KT tape” ” there will be a control group who…” “THIS will be measured, using THIS” “THIS is what will be compared to show…) (but elaborated). Is your control group going to be the same participants a different time (in which case you may have to account for order), or different participants (in which case you need to create some way of matching).

    Genuine question though, if you are measuring blood circulation objectively, does bias come into it? Or is the very crux of a placebo effect the strength of the bias? Does that make sense? It may be an idea to measure both circulation AND strength.

    Here’s an idea to help you out for a research design if you fancy it. 3 groups of different but equal ability participants in 3 different rooms (or instances). One group does strength test, one group uses KT but isn’t told anything about it, and one group uses KT and is told it will improve their performance. Measure their performance in some way, and also circulation. If performance increases due to KT but circulation doesn’t then…? If both increase then…? If neither increase then…? AND/OR compare between groups (ie- the difference (or lack of) in performance between groups). Could even talk about how these two ways of measuring could fit into each other and what it would mean if they did/did not.

    Critical analysis point, KT tape is now kind of famous. You could hide it from the control group, but the middle group (and even the last) could be effected by their previous experience with it.

    Hope this helps,

    Adam

    1. Hey Adam!

      I do like your idea of having different groups, however I don’t agree with outwardly telling the participants it will “improve performance” because that is the traditional idea of placebo’s that I wanted to steer away from. Possibly a better design would be to have two groups; where one group is briefed with the pros and cons of KT and the other group is told nothing.

      Very valid point regarding how KT may already have expectation attached to it. I guess the reality is that in sport many of the ergogenic/therapeutic aids have no proven efficacy, such as compression garments, but we still have the expectancy they will work from the way they are marketed. In hindsight it probably would’ve been better to choose a placebo that is not well-known, or just use a placebo pill (which I could have obtained from this website http://www.placebo.com.au/).

      Thank you for your feedback!

      Ella

      1. Ella,

        So basically you want to see if KT tape would work without deception, and if it does then it’s not a placebo, it’s an aid? I think that could work, but you’d have to be very clear as to what exactly you’re measuring and how that would show what you want, and also acknowledge that it would be easier to research placebos using deception, but then highlight the reasons you are not (Richard loves a bit of ethical insight – you’ll see that if you read one of his papers).

        Regarding the second point, it is ok to use KT tape. What you have just commented there is shows that you are aware of an issue in your research, so use that in your essay (high marks), how valid your research (and all others using KT tape) is as a result (higher marks), and then discuss if it is unavoidable or not (top marks). At the end of the day, how realistic is it that you are going to get participants who can give you valid data? <- these are all questions you have just raised.
        Further to that, with these flaws is your research even worth doing? Discuss that and its a much greater use of words than "there might be biases…". You clearly understand what I'm going on about so demonstrate that.

        Adam

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